FIELD OF THE INVENTION
[0001] This invention relates generally to the field of antennas. More specifically, a multiple-band
antenna is provided that is particularly well-suited for use in wireless mobile communication
devices, generally referred to herein as "mobile devices", such as Personal Digital
Assistants, cellular telephones, and wireless two-way email communication devices.
BACKGROUND OF THE INVENTION
[0002] Mobile devices having structures that support multi-band communications are known.
Many such mobile devices utilize helix, "inverted F" or retractable structures. Helix
and retractable antennas are typically installed outside of a mobile device, and inverted
F antennas are typically embedded inside of a case or housing of a device. Generally,
embedded antennas are preferred over external antennas for mobile communication devices
for mechanical and ergonomic reasons. Embedded antennas are protected by the mobile
device case or housing and therefore tend to be more durable than external antennas.
Although external antennas may physically interfere with the surroundings of a mobile
device and make a mobile device difficult to use, particularly in limited-space environments,
embedded antennas present fewer such challenges.
[0003] In some types of mobile device, however, known embedded structures and design techniques
provide relatively poor communication signal radiation and reception, at least in
certain operating positions of the mobile devices. One of the biggest challenges for
mobile device antenna design is to ensure that the antenna operates effectively in
different positions, since antenna position changes as a mobile device is moved. Typical
operating positions of a mobile device include, for example, a data input position,
in which the mobile device is held in one or both hands such as when a user is entering
a telephone number or email message, a voice communication position, in which the
mobile device may be held next to a user's head and a speaker and microphone are used
to carry on a conversation, and a "set down" position, in which the mobile device
is not in use by the user, and is set down on a surface, placed in a holder, or stored
in or on some other storage apparatus. In these positions, the user's head, hands
and body, the surface, the holder, and the storage apparatus can all block the antenna
and degrade its performance. Although the mobile device is not actively being used
by the user when in the set down position, the antenna should still operate in this
position to at least receive communication signals. Known embedded antennas tend to
perform relatively poorly, particularly when a mobile device is in a voice communication
position.
SUMMARY
[0004] According to an aspect of the invention, a multiple-band antenna having first and
second operating frequency bands comprises a first patch structure associated primarily
with the first operating frequency band, a second patch structure electrically coupled
to the first patch structure and associated primarily with the second operating frequency
band, a first slot structure disposed between a first portion of the first patch structure
and the second patch structure and associated primarily with the first operating frequency
band, and a second slot structure disposed between a second portion of the first patch
structure and the second patch structure and associated primarily with the second
operating frequency band.
[0005] A multiple-band antenna system according to another aspect of the invention comprises
a multiple-band antenna and a mounting structure. The multiple-band antenna system
has first and second operating frequency bands and comprises a first patch structure,
a second patch structure electrically coupled to the first patch structure, a first
slot structure disposed between a first portion of the first patch structure and the
second patch structure, a second slot structure disposed between a second portion
of the first patch structure and the second patch structure, a feeding point electrically
coupled to the first patch structure, and a ground point electrically coupled to the
second patch structure, wherein the first patch structure and the first slot structure
form major radiating and receiving structures for the first operating frequency band,
and the second patch structure and the second slot structure form major radiating
and receiving structures for the second operating frequency band. The mounting structure
comprises a first surface and a second surface opposite to and overlapping the first
surface. The first and second patch structures are mounted to the first surface, and
the feeding point and ground point are mounted to the second surface.
[0006] A wireless mobile communication device incorporating a multiple-band antenna is also
provided. The wireless mobile communication device comprises a first transceiver adapted
to transmit and receive communication signals in a first frequency band, a second
transceiver adapted to transmit and receive communication signals in a second frequency
band, and a multiple-band antenna connected to the first transceiver and the second
transceiver. The multiple-band antenna comprises a first patch structure associated
primarily with the first frequency band, a second patch structure electrically coupled
to the first patch structure and associated primarily with the second frequency band,
a first slot structure disposed between a first portion of the first patch structure
and the second patch structure and associated primarily with the first frequency band,
and a second slot structure disposed between a second portion of the first patch structure
and the second patch structure and associated primarily with the second frequency
band.
[0007] Further features and aspects of the invention will be described or will become apparent
in the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008]
Fig. 1 is a top view of a multiple-band antenna according to an embodiment of the
invention;
Fig. 2 is a bottom isometric view of the multiple-band antenna of Fig. 1;
Fig. 3 is a bottom isometric view of the multiple-band antenna of Fig. 1 and an antenna
mounting structure;
Fig. 4 is a top isometric view of the antenna and mounting structure of Fig. 3 in
an assembled position;
Fig. 5 is a cross-sectional view of the antenna and mounting structure along line
5-5 of Fig. 4;
Fig. 6 is a rear view of a mobile device incorporating the multiple-band antenna and
mounting structure of Fig. 4; and
Fig. 7 is a block diagram of an example mobile device.
DETAILED DESCRIPTION
[0009] Structures in the multiple-band antenna described herein are sized and shaped to
tune the multiple-band antenna for operation in multiple frequency bands. In an embodiment
of the invention described in detail below, the multiple-band antenna includes structures
which are primarily associated with one of a first operating frequency band and a
second operating frequency band, thus enabling the multiple-band antenna to function
as the antenna in a multi-band mobile device. For example, a multiple-band antenna
may be adapted for operation at the Global System for Mobile communications (GSM)
900MHz frequency band and the Personal Communication System (PCS) frequency band.
Those skilled in the art will appreciate that the GSM-900 band includes a transmit
sub-band of 880-915MHz and a receive sub-band 925-960MHz, and the PCS frequency band
similarly includes a transmit sub-band of 1850-1910MHz and a receive sub-band of 1930-1990MHz.
It will also be appreciated by those skilled in the art that these frequency bands
are for illustrative purposes only. Such an antenna may instead be designed to operate
in other pairs of operating frequency bands.
[0010] Fig. 1 is a top view of a multiple-band antenna according to an embodiment of the
invention. The multiple-band antenna 10 includes the structures 12, 14, 16, 18, 20,
22, and 24, as well as mounting bores 26, 28, 30, 32, 34, and 36. The mounting bores
26, 28, 30, 32, 34, and 36 are used to mount the antenna to a mounting structure,
as will be described in further detail below in conjunction with Fig. 4.
[0011] The multiple-band antenna 10 includes patch structures 12 and 14, slot structures
16 and 18, and tuning structures 20, 22, and 24. Patch antennas are popular for their
low profile and virtually unlimited possible shapes and sizes, and inherent flexibility
which allows them to be made to conform to most surface profiles. Patch antenna polarizations
can be linear or elliptical, with a main polarization component parallel to the surface
of the patch. Slot antennas are used to enhance the field strength in required directions
by changing their orientations. Operating characteristics of patch and slot antennas
are established by antenna shape and dimensions. Principles of operation of patch
and slot antennas are well-known to those skilled in the art to which the present
application pertains.
[0012] In the multiple-band antenna 10, the patch structure 12 is a first structure associated
primarily with a first frequency band in which the multiple-band antenna 10 operates.
The patch structure 12 is generally C-shaped, including two end portions, at the left-
and right-hand sides of the multiple-band antenna 10 in the view shown in Fig. 1,
and an adjoining portion, along the top of the multiple-band antenna 10. The size
and shape of the patch structure 12 have a most pronounced effect on antenna operating
characteristics in the first frequency band, such as the actual frequency of the first
frequency band, as well as antenna gain in the first frequency band. Of course, in
any multiple-band antenna such as 10, changes in a part of the antenna associated
with one frequency band may also affect other operating frequency bands of the antenna,
although in the multiple-band antenna 10, the effects of the right-hand end portion
of the structure 12 on the second operating frequency band are not as significant,
as will be described in further detail below.
[0013] The patch structure 14 is a second structure associated primarily with a second operating
frequency band of the multiple-band antenna 10. As described above for the patch structure
12, operating characteristics of the multiple-band antenna 10 in the second size and
shape of the second structure 14.
[0014] The slot structures 16 and 18 are similarly adapted such that each has a dominant
effect on one or the other of the first and second frequency bands. The slot structure
18 is positioned in the multiple-band antenna 10 and dimensioned to affect antenna
operation in the first frequency band, whereas the slot structure 16 is positioned
and dimensioned to primarily affect antenna operation in the second frequency band.
The length and the width of each slot structure 16 and 18 not only sets the respective
frequency bands of the slot structures 16 and 18, but also affects the gain and match
of the antenna 10 at these frequency bands. For example, changing the width and length
of the slot structures 16 and 18 may improve antenna match, but sacrifice gain.
[0015] The patch structures 12 and 14 are shorted along the line 39 in Fig. 1. The multiple-band
antenna 10 is operable with different shorting lengths between the patch structures
12 and 14 along the line 39. This provides flexibility in the design of the multiple-band
antenna 10 in that the positions and dimensions of either or both of the slot structures
16 and 18 may be changed without significantly degrading performance of the multiple-band
antenna 10.
[0016] Tuning structures 20, 22, and 24 are used for fine-tuning the multiple-band antenna
10. Although connected to the first patch structure 12, the tuning structure 20 forms
a tuning tab for the second frequency band. As described in further detail below,
the left-hand end portion of the first patch structure 12 is a shared portion which
is used when the multiple-band antenna 10 is operating in either the first frequency
band or the second frequency band. However, the dimensions of the tuning structure
20 have a dominant effect on the second frequency band. Thus, fine tuning of the second
frequency band is accomplished by setting the dimensions of the fine tuning tab 20.
[0017] The tuning structure 22 is also for fine tuning of the second frequency band. By
changing the length of the tuning structure 22, the match and gain of the second frequency
band can be tuned as required.
[0018] Fine tuning of the multiple-band antenna 10 in the first frequency band is provided
by the tuning structure 24. The tuning tabs in the tuning structure 24 affect the
overall electrical length, and thus the operating frequency band, of the first structure
12. Even though the dimensions of the tabs in the tuning structure 24 also affect
the dimensions of the slot in the tuning structure 22, fine tuning for both operating
bands of the antenna 10 is normally performed at the same time, so that effects of
fine tuning of one band are compensated by adjusting one or more tuning structures
for the other band.
[0019] Referring now to Fig. 2, operation of the multiple-band antenna 10 will be described
in further detail. Fig. 2 is a bottom isometric view of the multiple-band antenna
of Fig. 1. A feeding point 38 and ground point 40, with respective mounting bores
42 and 44, are shown in Fig. 2. The feeding point 38 and the ground point 40 form
a single feeding port for the multiple-band antenna 10. When installed in a mobile
device, the ground point 40 is connected to signal ground to form a ground plane for
the multiple-band antenna 10, and the feeding point 38 is coupled to one or more transceivers
operable to send and/or receive signals in the first and second frequency bands.
[0020] Signals in the first and second frequency bands, established as described above,
are received and radiated by the multiple-band antenna 10. An electromagnetic signal
in the first or second frequency band is received by the multiple-band antenna 10
and converted into an electrical signal for a corresponding receiver or transceiver
coupled to the feeding point 38 and ground point 40. Similarly, an electrical signal
in the first frequency band which is input to the multiple-band antenna 10 via the
feeding point 38 and ground point 40 by a transmitter or transceiver is radiated from
the multiple-band antenna 10. When operating in the first frequency band, the structures
12 and 18 of the multiple-band antenna 10 radiate and receive signals polarized in
directions both parallel and perpendicular to the patch structure 12 in a co-operative
manner to enhance the gain.
[0021] In the second frequency band, operation of the multiple-band antenna 10 is substantially
similar. In this case, however, the structures 14 and 16 are the major radiating and
receiving components.
[0022] Therefore, the multiple-band antenna 10 offers improved signal transmission and reception
relative to known antenna designs, since it uses a combined structure of a patch and
slot antenna which work co-operatively and basically radiates and receives signals
polarized in most popular directions. In this manner, the performance of the multiple-band
antenna 10 is less affected by orientation of a mobile device, such as in the data
input position, the voice communication position, and the set down position described
above.
[0023] Performance of the multiple-band antenna 10 is further enhanced when the antenna
is mounted on a mounting structure as shown in Figs. 3-5. Fig. 3 is a bottom isometric
view of the multiple-band antenna of Fig. 1 and an antenna mounting structure, Fig.
4 is a top isometric view of the antenna and mounting structure of Fig. 3 in an assembled
position, and Fig. 5 is a cross-sectional view of the antenna and mounting structure
along line 5-5 of Fig. 4.
[0024] In Fig. 3, the multiple-band antenna 10 is shown substantially as in Fig. 2, and
has been described above. The mounting structure 50 is preferably made of plastic
or other dielectric material, and includes mounting pins 52 and 54 on a support structure
53, and a preferably smooth non-planar mounting surface 60. The mounting structure
50 also includes a fastener structure 62, an alignment pin 64, and other structural
components 66 and 68 which cooperate with housing sections or other parts of a mobile
device in which the antenna is installed. For example, the alignment pin 64, serves
to align the mounting structure relative to a part of a mobile device which includes
a cooperating alignment hole. The fastener structure 62 is configured to receive a
screw, rivet or other fastener to attach the mounting structure to another part of
the mobile device once the mounting structure 50 is properly aligned. The multiple-band
antenna 10 is preferably mounted to the mounting structure 50 before the mounting
structure is attached to other parts of such a mobile device. The multiple-band antenna
10 and mounting structure 60 comprise an antenna system generally designated 70 in
Fig. 3.
[0025] The mounting pins 52 and 54 are positioned on the support structure 53 so as to be
received in the mounting bores 42 and 44, respectively, when the multiple-band antenna
10 is positioned for mounting as indicated by the dashed lines 56 and 58. The mounting
pins 52 and 54 are then preferably deformed to mount the feeding point 38 and the
ground point 40 to the support structure 53 on the mounting structure 50. The mounting
pins 52 and 54 may, for example, be heat stakes which are melted to overlay a portion
of the feeding point 38 and the ground point 40 surrounding the mounting bores 42
and 44 and thereby retain the feeding point 38 and the ground point 40 in a mounted
position.
[0026] The top side of the antenna system 70 is shown in Fig. 4, in which the multiple-band
antenna 10 is in a mounted position on the mounting structure 50. As shown, the mounting
bores 26, 28, 30, 32, 34, and 36 receive the mounting pins 27, 29, 31, 33, 35, and
37, which are then preferably deformed as described above to retain the multiple-band
antenna 10 in the mounted position. The multiple-band antenna 10 lies substantially
against the smooth surface 60 when mounted on the mounting structure 50. The surface
60 in Figs. 3-5 is an arced surface, although other surface profiles may instead be
used.
[0027] The mounting bores 26, 28, 30, 32, and 34 are surrounded by beveled surfaces, as
shown in Figs. 1-4. These beveled surfaces serve to offset or displace the mounting
bores from the surface the multiple-band antenna 10, such that the cooperating mounting
pins are located below the surface of the multiple-band antenna 10 when the pins are
deformed to retain the multiple-band antenna 10 in its mounted position. Depending
upon the physical limitations imposed by the mobile device in which the antenna system
70 is to be implemented, a smooth finished profile for the antenna system 70 or particular
parts thereof might not be crucial, such that mounting bores need not be displaced
from the surface of the multiple-band antenna 10. The mounting bores 36, 42 and 44
are such flush mounting bores. As will be apparent from Figs. 4 and 5, the mounting
structure 50 is smooth, but not flat. In particular, the portion of the mounting structure
50 which includes the mounting pin 37 tapers away from the remainder of the surface
60, such that the mounting pin 37 lies below the other mounting pins 27, 29, 31, 33,
and 35. This is evident from Fig. 5, for example, in which only the mounting pins
29, 31, 33, and 35 are shown. Similarly, the feeding point 38 and ground point 40
are disposed below a surface of the multiple-band antenna 10, where a smooth finished
profile might not be important. Thus, a multiple-band antenna may include offset mounting
bores such as 26, 28, 30, 32, and 34, flush mounting bores such as 36, 42, and 44,
or both.
[0028] The multiple-band antenna 10 may, for example, be fabricated from a substantially
flat conductive sheet of a conductor such as copper, aluminum, silver, or gold, using
stamping or other cutting techniques, to form antenna blanks. Mounting bores may be
cut or stamped as the blanks are formed, or drilled into the flat antenna blanks.
Antenna blanks are then deformed into the shape shown in Figs. 2 and 3 to conform
to the mounting structure 50. Alternatively, deformation of an antenna blank could
be performed while an antenna is being mounted to the mounting structure 50. The feeding
point 38 and ground point 40 are bent at 46 and 48 to position the feeding point 38
and ground point 40 relative to the structures 12 and 14, as described in further
detail below.
[0029] As shown in Figs. 3-5, the multiple-band antenna 10 includes bent portions 46 and
48 which respectively couple the feeding point 38 and the ground point 40 to the first
structure 12 and second structure 14. The first structure 12 and the second structure
14 comprise a first surface of the structure, which conforms to a first surface, the
surface 60, of the mounting structure 50 when the multiple-band antenna 10 is in its
mounted position. The bent portions 46 and 48 position the feeding point 38 and ground
point 40 on a second surface of the mounting structure 50 opposite to and overlapping
the first surface of the mounting structure 50. The feeding point 38 and ground point
40 thus overlap or oppose the first and second structures 12 and 14.
[0030] As those skilled in the art will appreciate, the bent portions 46 and 48 add electrical
length to the first and second structures 12 and 14, providing a further means to
control antenna gain and frequency for the first and second frequency bands. Also,
as shown most clearly in Fig. 5, the bent portion 48 orients the ground point 40 opposite
the second antenna element 14, which introduces a capacitance between parts of the
multiple-band antenna 10. The distance between the ground point 40, which forms the
ground plane of the multiple-band antenna 10, and the second structure 14 affects
the capacitance between the ground plane and the multiple-band antenna 10, which in
turn affects antenna gain and match. Antenna gain and match can thereby be enhanced
by selecting the distance between the ground plane and the multiple-band structure
10, and establishing dimensions of the support structure 53 accordingly.
[0031] Fig. 6 is a rear view of a mobile device incorporating the multiple-band antenna
and mounting structure of Fig. 4. As will be apparent to those skilled in the art,
the mobile device 100 is normally substantially enclosed within a housing having front,
rear, top, bottom, and side surfaces. Data input and output devices such as a display
and a keypad or keyboard are normally mounted within the front surface of a mobile
device. A speaker and microphone for voice input and output are typically disposed
in the front surface, or alternatively in the top or bottom surface, of the mobile
device. Such mobile devices often incorporate a shield which reduces electromagnetic
energy radiated outward from the front of the device, toward a user.
[0032] In Fig. 6, the mobile device 100 is shown with a rear housing section removed. Internal
components of the mobile device 100 are dependent upon the particular type of mobile
device. However, the mobile device 100 is enabled for voice communications and therefore
includes at least a microphone and speaker, respectively mounted at or near a lower
surface 80 and an upper surface 90 of the mobile device 100. When in use for voice
communications, a user holds the mobile device 100 such that the speaker is near the
user's ear and the microphone is near the user's mouth. The shield 95 extends around
the mobile device, and in particular between the antenna 10 and the front of the mobile
device 100.
[0033] Generally, a user holds a lower portion of a mobile device such as 100 with one hand
when engaged in a conversation. As such, the top rear portion of the mobile device
100, and thus the multiple-band antenna 10, is relatively unobstructed when the mobile
device 100 is in the voice communication position, thereby providing enhanced performance
compared to known antennas and mobile devices.
[0034] In a similar manner, the location of the multiple-band antenna shown in Fig. 6 remains
unobstructed in other positions of the mobile device 100. For example, since data
input devices such as keyboards and keypads are typically located below a display
on a mobile device, the display tends to be positioned near the top of a mobile device.
On such a mobile device, a user enters data using the input device, positioned on
a lower section of the mobile device, and thus supports or holds the lower section
of the mobile device, such that the top rear section of the mobile device remains
unobstructed. Many mobile device holders and storage systems engage only the lower
portion of a mobile device, and thus create no further barrier to the multiple-band
antenna 10 in the mobile device 100. In other types of holders or set down positions,
the multiple-band antenna 10 may be somewhat obstructed, but not to any greater degree
than known embedded antennas.
[0035] Thus, the multiple-band antenna 10, mounted in a mobile device as shown in Fig. 6,
not only radiates and receives in plurality of planes of polarization as described
above, but is also located in the mobile device so as to be substantially unobstructed
in typical use positions of the mobile device.
[0036] Multiple-element antennas according to aspects of the invention are applicable to
different types of mobile device, including, for example, data communication devices,
a voice communication devices, a dual-mode communication devices such as mobile telephones
having data communications functionality, a personal digital assistants (PDAs) enabled
for wireless communications, wireless email communication devices, or laptop or desktop
computer systems with wireless modems. Fig. 7 is a block diagram of an example mobile
device.
[0037] The mobile device 700 is a dual-mode and dual-band mobile device and includes a transceiver
module 711, a microprocessor 738, a display 722, a non-volatile memory 724, a random
access memory (RAM) 726, one or more auxiliary input/output (I/O) devices 728, a serial
port 730, a keyboard 732, a speaker 734, a microphone 736, a short-range wireless
communications sub-system 740, and other device sub-systems 742.
[0038] The transceiver module 711 includes a multiple-band antenna 10, a first transceiver
716, the second transceiver 714, one or more local oscillators 713, and a digital
signal processor (DSP) 720.
[0039] Within the non-volatile memory 724, the device 700 preferably includes a plurality
of software modules 724A-724N that can be executed by the microprocessor 738 (and/or
the DSP 720), including a voice communication module 724A, a data communication module
724B, and a plurality of other operational modules 724N for carrying out a plurality
of other functions.
[0040] The mobile device 700 is preferably a two-way communication device having voice and
data communication capabilities. Thus, for example, the mobile device 700 may communicate
over a voice network, such as any of the analog or digital cellular networks, and
may also communicate over a data network. The voice and data networks are depicted
in Fig. 7 by the communication tower 719. These voice and data networks may be separate
communication networks using separate infrastructure, such as base stations, network
controllers, etc., or they may be integrated into a single wireless network. Each
transceiver 716 and 714 will normally be configured to communicate with different
networks 719.
[0041] The transceiver module 711 is used to communicate with the networks 719, and includes
the first transceiver 116, the second transceiver 114, the one or more local oscillators
713 and may also include the DSP 720. The DSP 720 is used to send and receive signals
to and from the transceivers 714 and 716, and may also provide control information
to the transceivers 714 and 716. If the voice and data communications occur at a single
frequency, or closely-spaced sets of frequencies, then a single local oscillator 713
may be used in conjunction with the transceivers 714 and 716. Alternatively, if different
frequencies are utilized for voice communications versus data communications for example,
then a plurality of local oscillators 713 can be used to generate a plurality of frequencies
corresponding to the voice and data networks 719. Information, which includes both
voice and data information, is communicated to and from the transceiver module 711
via a link between the DSP 720 and the microprocessor 738.
[0042] The detailed design of the transceiver module 711, such as frequency bands, component
selection, power level, etc., will be dependent upon the communication networks 719
in which the mobile device 700 is intended to operate. For example, the transceiver
module 711 may include transceivers 714 and 716 designed to operate with any of a
variety of communication networks, such as the Mobitex™ or DataTAC™ mobile data communication
networks, AMPS, TDMA, CDMA, PCS, and GSM. Other types of data and voice networks,
both separate and integrated, may also be utilized where the mobile device 700 includes
a corresponding transceiver.
[0043] Depending upon the type of network 719, the access requirements for the mobile device
700 may also vary. For example, in the Mobitex and DataTAC data networks, mobile devices
are registered on the network using a unique identification number associated with
each mobile device. In GPRS data networks, however, network access is associated with
a subscriber or user of a mobile device. A GPRS device typically requires a subscriber
identity module ("SIM"), which is required in order to operate a mobile device on
a GPRS network. Local or non-network communication functions (if any) may be operable,
without the SIM device, but a mobile device will be unable to carry out any functions
involving communications over the data network 719, other than any legally required
operations, such as '911' emergency calling.
[0044] After any required network registration or activation procedures have been completed,
the mobile device 700 may the send and receive communication signals, including both
voice and data signals, over the networks 719. Signals received by the antenna 10
from the communication network 719 are routed to one of the transceivers 714 and 716,
which provides for signal amplification, frequency down conversion, filtering, channel
selection, etc., and may also provide analog to digital conversion. Analog to digital
conversion of the received signal allows more complex communication functions, such
as digital demodulation and decoding to be performed using the DSP 720. In a similar
manner, signals to be transmitted to the network 719 are processed, including modulation
and encoding, for example, by the DSP 720 and are then provided to one of the transceivers
714 and 716 for digital to analog conversion, frequency up conversion, filtering,
amplification and transmission to the communication network 719 via the antenna 10.
[0045] In addition to processing the communication signals, the DSP 720 also provides for
transceiver control. For example, the gain levels applied to communication signals
in the transceivers 714 and 716 may be adaptively controlled through automatic gain
control algorithms implemented in the DSP 720. Other transceiver control algorithms
could also be implemented in the DSP 720 in order to provide more sophisticated control
of the transceiver module 711.
[0046] The microprocessor 738 preferably manages and controls the overall operation of the
dual-mode mobile device 700. Many types of microprocessors or microcontrollers could
be used here, or, alternatively, a single DSP 720 could be used to carry out the functions
of the microprocessor 738. Low-level communication functions, including at least data
and voice communications, are performed through the DSP 720 in the transceiver module
711. Other, high-level communication applications, such as a voice communication application
724A, and a data communication application 724B may be stored in the non-volatile
memory 724 for execution by the microprocessor 738. For example, the voice communication
module 724A may provide a high-level user interface operable to transmit and receive
voice calls between the mobile device 700 and a plurality of other voice or dual-mode
devices via the network 719. Similarly, the data communication module 724B may provide
a high-level user interface operable for sending and receiving data, such as e-mail
messages, files, organizer information, short text messages, etc., between the mobile
device 700 and a plurality of other data devices via the networks 719. The microprocessor
738 also interacts with other device subsystems, such as the display 722, the non-volatile
memory 724, the RAM 726, the auxiliary input/output (I/O) subsystems 728, the serial
port 730, the keyboard 732, the speaker 734, the microphone 736, the short-range communications
subsystem 740, and any other device subsystems generally designated as 742.
[0047] Some of the subsystems shown in Fig. 7 perform communication-related functions, whereas
other subsystems may provide "resident" or on-device functions. Notably, some subsystems,
such as keyboard 732 and display 722 may be used for both communication-related functions,
such as entering a text message for transmission over a data communication network,
and device-resident functions such as a calculator or task list or other PDA type
functions.
[0048] Operating system software used by the microprocessor 738 is preferably stored in
a persistent store such as non-volatile memory 724. In addition to the operation system,
which controls all of the low-level functions of the mobile device 700, the non-volatile
memory 724 may include a plurality of high-level software application programs, or
modules, such as a voice communication module 724A, a data communication module 724B,
an organizer module (not shown), or any other type of software module 724N. The non-volatile
memory 724 also may include a file system for storing data. These modules are executed
by the microprocessor 738 and provide a high-level interface between a user and the
mobile device 700. This interface typically includes a graphical component provided
through the display 722, and an input/output component provided through the auxiliary
I/O 728, the keyboard 732, the speaker 734, and the microphone 736. The operating
system, specific device applications or modules, or parts thereof, may be temporarily
loaded into a volatile store, such as RAM 726 for faster operation. Moreover, received
communication signals may also be temporarily stored to RAM 726, before permanently
writing them to a file system located in a persistent store such as the non-volatile
memory 724. The non-volatile memory 724 may be implemented, for example, as a Flash
memory component, or a battery backed-up RAM.
[0049] An exemplary application module 724N that may be loaded onto the mobile device 700
is a personal information manager (PIM) application providing PDA functionality, such
as calendar events, appointments, and task items. This module 724N may also interact
with the voice communication module 724A for managing phone calls, voice mails, etc.,
and may also interact with the data communication module for managing e-mail communications
and other data transmissions. Alternatively, all of the functionality of the voice
communication module 724A and the data communication module 724B may be integrated
into the PIM module.
[0050] The non-volatile memory 724 preferably provides a file system to facilitate storage
of PIM data items on the device. The PIM application preferably includes the ability
to send and receive data items, either by itself, or in conjunction with the voice
and data communication modules 724A, 724B, via the wireless networks 719. The PIM
data items are preferably seamlessly integrated, synchronized and updated, via the
wireless networks 719, with a corresponding set of data items stored or associated
with a host computer system, thereby creating a mirrored system for data items associated
with a particular user.
[0051] The mobile device 700 may also be manually synchronized with a host system by placing
the device 700 in an interface cradle, which couples the serial port 730 of the mobile
device 700 to the serial port of the host system. The serial port 730 may also be
used to enable a user to set preferences through an external device or software application,
or to download other application modules 724N for installation. This wired download
path may be used to load an encryption key onto the device, which is a more secure
method than exchanging encryption information via the wireless network 719. Interfaces
for other wired download paths may be provided in the mobile device 700, in addition
to or instead of the serial port 730. For example, a USB port would provide an interface
to a similarly equipped personal computer.
[0052] Additional application modules 724N may be loaded onto the mobile device 700 through
the networks 719, through an auxiliary I/O subsystem 728, through the serial port
730, through the short-range communications subsystem 740, or through any other suitable
subsystem 742, and installed by a user in the non-volatile memory 724 or RAM 726.
Such flexibility in application installation increases the functionality of the mobile
device 700 and may provide enhanced on-device functions, communication-related functions,
or both. For example, secure communication applications may enable electronic commerce
functions and other such financial transactions to be performed using the mobile device
700.
[0053] When the mobile device 700 is operating in a data communication mode, a received
signal, such as a text message or a web page download, will be processed by the transceiver
module 711 and provided to the microprocessor 738, which will preferably further process
the received signal for output to the display 722, or, alternatively, to an auxiliary
I/O device 728. A user of mobile device 700 may also compose data items, such as email
messages, using the keyboard 732, which is preferably a complete alphanumeric keyboard
laid out in the QWERTY style, although other styles of complete alphanumeric keyboards
such as the known DVORAK style may also be used. User input to the mobile device 700
is further enhanced with a plurality of auxiliary I/O devices 728, which may include
a thumbwheel input device, a touchpad, a variety of switches, a rocker input switch,
etc. The composed data items input by the user may then be transmitted over the communication
networks 719 via the transceiver module 711.
[0054] When the mobile device 700 is operating in a voice communication mode, the overall
operation of the mobile device is substantially similar to the data mode, except that
received signals are preferably be output to the speaker 734 and voice signals for
transmission are generated by a microphone 736. Alternative voice or audio I/O subsystems,
such as a voice message recording subsystem, may also be implemented on the mobile
device 700. Although voice or audio signal output is preferably accomplished primarily
through the speaker 734, the display 722 may also be used to provide an indication
of the identity of a calling party, the duration of a voice call, or other voice call
related information. For example, the microprocessor 738, in conjunction with the
voice communication module and the operating system software, may detect the caller
identification information of an incoming voice call and display it on the display
722.
[0055] A short-range communications subsystem 740 is also included in the mobile device
700. For example, the subsystem 740 may include an infrared device and associated
circuits and components, or a short-range RF communication module such as a Bluetooth™
module or an 802.11 module to provide for communication with similarly-enabled systems
and devices. Those skilled in the art will appreciate that "Bluetooth" and "802.11"
refer to sets of specifications, available from the Institute of Electrical and Electronics
Engineers, relating to wireless personal area networks and wireless local area networks,
respectively.
[0056] This written description uses examples to disclose the invention, including the best
mode, and also to enable any person skilled in the art to make and use the invention.
The invention may include other examples that occur to those skilled in the art.
[0057] For example, although described above primarily in the context of a dual-band antenna,
a multiple-element antenna may also include further antenna elements to provide for
operation in more than two frequency bands.
[0058] The mounting structure 50 is also shown for illustrative purposes only, and may be
shaped differently and include different, further, or fewer cooperating structures
than those shown in the drawings and described above, depending on the particular
mobile device in which the multiple-band antenna is implemented. It should also be
appreciated that the mounting structure could be integral with a mobile device housing
or other component of the mobile device instead of a separate component.
[0059] Layout of the multiple-band antenna is similarly intended to be illustrative and
not restrictive. For example, a multiple-band antenna according to the present invention
may include slot structures of a different shape than shown in the drawings, and need
not necessarily incorporate fine-tuning structures. Similarly, as is typical in antenna
design, the dimensions and positions of antenna structures can be adjusted as necessary
to compensate for effects of other mobile device components, including a shield or
display, for example, on antenna characteristics.
[0060] Although the multiple-band antenna 10 is mounted on the mounting structure 50 using
mounting pins, other types of fasteners, including screws, rivets, and adhesives,
for example, will be apparent to those skilled in the art.
[0061] In addition, fabrication of the multiple-band antenna 10 from a planar conductive
sheet as described above simplifies manufacture of the multiple-band antenna 10, but
the invention is in no way restricted to this particular, or any other, fabrication
technique. Printing or depositing a conductive film on a substrate an etching previously
deposited conductor from a substrate are two possible alternative techniques.
[0062] In further aspects there is provided a multiple-band antenna having first and second
operating frequency bands, comprising a first patch structure associated primarily
with the first operating frequency band; a second patch structure electrically coupled
to the first patch structure and associated primarily with the second operating frequency
band; a fist slot structure disposed between a first portion of the first patch structure
and the second patch structure and associated primarily with the first operating frequency
band; and a second slot structure disposed between a second portion of the first patch
structure and the second patch structure and associated primarily with the second
operating frequency band. The dimensions of the first patch structure and the first
slot structure may primarily determine the first operating frequency band, gain of
the multiple-band antenna in the first operating frequency band, and impedance of
the multiple-band antenna in the first operating frequency band. The dimensions of
the second patch structure and the second slot structure may primarily determine the
second operating frequency band, gain of the multiple-band antenna in the second operating
frequency band, and impedance of the multiple-band antenna in the second operating
frequency band. The multiple band antenna may further comprise a feeding port, the
feeding port comprising: a feeding point electrically coupled to the first patch structure
and positioned to overlap the first patch structure; and a ground point electrically
couple to the second patch structure and positioned to overlap the second patch structure.
The first patch structure may be a substantially C-shaped structure comprising a first
end portion, a second end portion, and an adjoining portion coupling the first end
portion and the second end portion, wherein the second patch structure is electrically
coupled to the adjoining portion, wherein the first slot structure is disposed between
the first end portion and the second patch structure, and wherein the second slot
structure is disposed between the second end portion and the second patch structure.
The multiple band antenna may further comprise a feeding point electrically coupled
to the second end portion and positioned to overlap the second end portion; and a
ground point electrically coupled to the second patch structure and positioned to
overlap the second patch structure, wherein the feeding point and the ground point
comprise a single feeding port of the multiple-band antenna. The first patch structure
may further comprise a bent portion electrically coupling the feeding point to the
second end portion, and the second patch structure may comprise a bent portion electrically
coupling the ground point to the second patch structure. The bent portion of the first
patch structure and the bent portion of the second patch structure may respectively
position the feeding point and the ground point at a predetermined distance from the
first patch structure and the second patch structure. The first operating frequency
band may be a Global System for Mobile communications (GSM) frequency band, and the
second operating frequency band may be a Personal Communication System (PCS) frequency
band. The GSM frequency band may be GSM-900, comprising a transit sub-band of 880-915MHz
and a receive sub-band of 925-960MHz. The PCS frequency band may comprise a transmit
sub-band of 1850-1910MHz and a receive sub-band of 1930-1990MHz. The multiple band
antenna may further comprise a plurality of tuning structures. The plurality of tuning
structures may comprise: a first tuning structure connected to the second portion
of the first patch structure and comprising a fine tuning tab for tuning the second
operating frequency band; a second tuning structure connected to the first portion
of the first patch structure and comprising fine tuning tabs for tuning the first
operating frequency band; and a third tuning structure disposed in the first portion
of the first patch structure, comprising a tuning slot for tuning the second operating
frequency band. The first patch structure and the second patch structure may comprise
electrically conductive material selected from the group consisting of: copper, aluminium,
silver, and gold. The multiple band antenna may be implanted in a wireless mobile
communication device selected from the group consisting of: data communication devices,
voice communication devices, dual-mode devices enabled for both data and voice communications,
cellular telephones, wireless email communication devices, mobile telephones having
data communications functionality, personal digital assistants (PDA's) enabled for
wireless communications, wireless email communication devices, and wireless modems.
[0063] In yet further aspects there is provided a multiple-band antenna system comprising:
a multiple-band antenna having first and second operating frequency bands, comprising:
a fist patch structure; a second patch structure electrically coupled to the first
patch structure; a first slot structure disposed between a first portion of the first
patch structure and the second patch structure; a second slot structure disposed between
a second portion of the first patch structure and the second patch structure; a feeding
point electrically coupled to the first patch structure; and a ground point electrically
coupled to the second patch structure, wherein the first patch structure and the first
slot structure form major radiating and receiving structures for the first operating
frequency band, and the second patch structure and the second slot structure form
major radiating and receiving structures for the second operating frequency band;
and a mounting structure comprising: a first surface structure; and a second surface
structure opposite to and overlapping the first surface, wherein the first and second
patch structures are mounted to the first surface, and wherein the feeding point and
ground point are mounted to the second surface. The multiple-band antenna may further
comprise mounting bores in the first patch structure, the second patch structure,
the feeding point, and the ground point for receiving fasteners to mount the multiple-band
antenna to the mounting structure. The mounting bores may comprise offset mounting
bores in the first patch structure offset from a surface of the first patch structure.
The fasteners may comprise mounting pins disposed on the first surface and the second
surface of the mounting structure and positioned to be received by the mounting bores.
The mounting pins may comprise heat stakes that are melted to retain the multiple-band
antenna on the mounting structure. The multiple-band antenna system may be installed
at a top rear portion of a wireless mobile communication device.
[0064] In yet further aspects there is provided a wireless mobile communication device comprising:
a first transceiver adapted to transmit and receive communication signals in a first
frequency band; a second transceiver adapted to transmit and receive communication
signals in a second frequency band; and a multiple-band antenna connected to the first
transceiver and the second transceiver and comprising: a first patch structure associated
primarily with the first frequency band; a second patch structure electrically coupled
to the first patch structure and associated primarily with the second frequency band;
a first slot structure disposed between a first portion of the first patch structure
and the second patch structure and associated primarily with the first frequency band;
and a second slot structure disposed between a second portion of the first patch structure
and the second patch structure and associated primarily with the second frequency
band. The wireless mobile communication device may further comprise: a housing substantially
enclosing the wireless mobile communication device and having front, rear, top, bottom,
and side surfaces, wherein the multiple-band antenna is mounted in the wireless mobile
communication device adjacent the top and rear surfaces. The wireless mobile communication
device may further comprise a keyboard, a display, a speaker, and a microphone mounted
within the front surface. The first frequency band may be a Global System for Mobile
communications (GSM) frequency band, and the second frequency band may be a Personal
Communication System (PCS) frequency band. The wireless mobile communication device
may further comprise: a fine tuning tab connected to the second portion of the first
patch structure for tuning the second frequency band; a pair of fine tuning tabs connected
to the first portion of the first patch structure for tuning the first frequency band;
and a tuning slot disposed between the pair of fine tuning tabs in the first portion
of the first patch structure for tuning the second frequency band. The wireless communication
device may be selected from the group consisting of: data communication devices, voice
communication devices, dual-mode devices enabled for both data and voice communications,
cellular telephones, wireless email communication devices, mobile telephones having
data communications functionality, personal digital assistants (PDAs) enabled for
wireless communications, wireless email communication devices, and wireless modems.
1. A multiple-band antenna comprising:
a first patch structure comprising spaced apart first and second end portions;
a second patch structure electrically coupled to said first patch structure between
said first and second end portions thereof;
a first triangularly-shaped slot structure between said first end portion of said
first patch structure and said second patch structure;
a second triangularly-shaped slot structure between said second end portion of said
first patch structure and said second patch structure; and
a third slot structure having a length tuning at least one operating characteristic
of the multiple-band antenna.
2. The multiple-band antenna of claim 1, wherein said first and second patch structures
have a non-planar shape.
3. The multiple-band antenna of claim 1, wherein each of said first and second triangularly-shaped
slot structures has a respective apex portion opening outwardly from said first and
second patch structures and a respective base portion opposite the respective apex
portion.
4. The multiple-band antenna of claim 1, wherein dimensions of said first patch structure
and said first triangularly-shaped slot structure primarily determine a first operating
frequency band, gain of the multiple-band antenna in said first operating frequency
band, and impedance of the multiple-band antenna in said first operating frequency
band; and wherein dimensions of said second patch structure and said second triangularly-shaped
slot structure primarily determine said second operating frequency band, gain of the
multiple-band antenna in said second operating frequency band, and impedance of the
multiple-band antenna in said second operating frequency band.
5. The multiple-band antenna of claim 4, wherein said first operating frequency band
comprises a transmit sub-band of 880-915 MHz and a receive sub-band of 925-960 MHz;
and wherein said second frequency band comprises a transmit sub-band of 1850-1910
MHz and a receive sub-band of 1930-1990 MHz.
6. The multiple-band antenna of claim 1, wherein said first patch structure further comprises
an adjoining portion coupling said first and second end portions to define a substantially
C-shaped structure; and wherein said second patch structure is electrically coupled
to the adjoining portion.
7. The multiple-band antenna of claim 1, wherein said multiple-band antenna further comprises:
a feeding point electrically coupled to said second end portion and positioned to
overlap said second end portion; and
a ground point electrically coupled to said second patch structure and positioned
to overlap said second patch structure.
8. The multiple-band antenna of claim 7, wherein said first patch structure further comprises
a bent portion electrically coupling the feeding point to said second end portion;
and wherein said second patch structure comprises a bent portion electrically coupling
the ground point to said second patch structure.
9. The multiple-band antenna of claim 1, further comprising:
a fine tuning tab connected to said second portion of said first patch structure;
and
a pair of fine tuning tabs connected to the first portion of the first patch structure.
10. A method for making a multiple-band antenna comprising:
forming a first patch structure comprising spaced apart first and second end portions;
forming a second patch structure electrically coupled to the first patch structure
between the first and second end portions thereof;
forming a first triangularly-shaped slot structure between the first end portion of
the first patch structure and the second patch structure;
forming a second triangularly-shaped slot structure between the second end portion
of the first patch structure and the second patch structure; and
forming a third slot structure having a length tuning at least one operating characteristic
of the multiple-band antenna.
11. The method of claim 10, wherein forming the first and second patch structures comprises
forming the first and second patch structures to have a non-planar shape.
12. The method of claim 10, wherein forming each of the first and second triangularly-shaped
slot structures comprises forming each of the first and second triangularly-shaped
slot structures to have a respective apex portion opening outwardly from the first
and second patch structures and a respective base portion opposite the respective
apex portion.
13. The method of claim 10, wherein dimensions of the first patch structure and the first
triangularly-shaped slot structure primarily determine a first operating frequency
band, gain of the multiple-band antenna in the first operating frequency band, and
impedance of the multiple-band antenna in the first operating frequency band; and
wherein dimensions of the second patch structure and the second triangularly-shaped
slot structure primarily determine the second operating frequency band, gain of the
multiple-band antenna in the second operating frequency band, and impedance of the
multiple-band antenna in the second operating frequency band.
14. The method of claim 13, wherein the first operating frequency band comprises a transmit
sub-band of 880-915 MHz and a receive sub-band of 925-960 MHz; and wherein the second
frequency band comprises a transmit sub-band of 1850-1910 MHz and a receive sub-band
of 1930-1990 MHz.
15. The method of claim 10, wherein forming the first patch structure further comprises
forming an adjoining portion coupling the first and second end portions to define
a substantially C-shaped structure; and wherein the second patch structure is electrically
coupled to the adjoining portion.