Introduction
[0001] This invention relates to a phased array comprising a plurality of phase shifters.
[0002] An antenna is comprised of one or more radiators which, in conjunction with one another,
emit a radiation pattern which typically is comprised of a main beam and a plurality
of side lobes. In most antenna arrangements, the main beam and associated side lobes
are emitted in duplicate from either side of an antenna. The vast majority of the
power of the transmission signal is contained in the main beams and therefore it is
of high importance that these main beams are directed towards the coverage area designated
for that antenna.
[0003] Variable tilt antennas are useful for deployment in areas which have undulating terrain
comprised of valleys, hillsides and/or natural or man-made obstacles for example.
The main beam emitted from the antenna can be tilted so that appropriate coverage
can be provided down into the valley, up over the hillside and/or around the obstacle.
Thus, the effects of the surrounding terrain can be overcome using a variable tilt
antenna. The main beam in the radiation patterns can also be tilted away from certain
geographical areas so as to avoid causing cross-interference with other radiation
patterns emitted from nearby antennas, for example in adjacent cells of a cellular
network.
[0004] This process of tilting the main beam of an antenna is known as adjusting the vertical
radiation pattern (VRP). There are a number of known methods which are currently employed
to tilt the radiation pattern of an antenna.
[0005] Antennas may be physically tilted in order to adjust the direction of the main beam
into a desired region. However, such manually tiltable antennas are expensive to construct
as additional framework components and moving mechanical parts are required in order
to permit the radiators which form the antenna to be tilted and moved into the correct
positions so as to tilt the radiation pattern emitted from the antenna. The associated
maintenance costs are relatively high as the framework comprises moving parts which
need to be machined to accurate tolerances and are more complicated to maintain and
replace than static component parts.
[0006] Furthermore, the tilting of the manually tiltable antenna may require on site presence
of an engineer which is costly to provide. The actual tilting of the manually operable
antenna is time consuming, and, even if the manually tiltable antenna only needs to
be adjusted during an initial set up stage, it will still be time consuming as various
measurements of the radiation pattern emitted from the tilted antenna will need to
be taken to ensure that the antenna has been manually tilted to the optimum angle.
[0007] A further disadvantage with manually tilted antennas is whilst that the direction
of the main beam emitted from one side of the antenna will be correctly tilted towards
the appropriate area, the main beam emitted from the opposing side of the antenna
will be tilted in an opposite manner which may be an inefficient use of antenna power.
For example, if the antenna is located on a hilltop, one of the main beams emitted
from the antenna will be directed downward from the hilltop to cover the appropriate
area beneath the hill. However, the main beam can only be directed downward on one
side of the hilltop and the main beam emitted on the opposite side of the antenna
will be angled skyward which is a waste of transmission power. Moreover, it is possible
that the main beam whose direction of emission is not controlled and actively adjusted
may cause unwanted cross-interference with signals in neighbouring cells of a cellular
network.
[0008] It is also known from the prior art to "electronically" tilt radiation patterns which
are emitted from antennas by phase shifting each of a plurality of component signals
that are respectively transmitted to the one or more radiators so as to form the radiation
pattern emitted from the antenna. The phase shifts are applied to one or more of the
component signals by delaying the components signals relative to one another and thus
causing a phase shift to be imposed on one or more of the component signals. Delaying
of the component signals relative to one another is achieved by varying the length
of conducting path that each component signal must flow along relative to each other
component signal, before reaching an associated, corresponding radiator in the antenna.
[0009] The conductive paths which the component signals flow along are typically formed
by overlapping separate moveable printed conductive tracks so as to create a conductive
path of variable length. The printed tracks are usually on printed circuit boards
(PCBs). The conductive paths are extended or shortened by the movement of one track
relative to the other track, which is to say the movement of one PCB relative to another
PCB. The overlapping tracks remain in electrical communication throughout; however,
the amount of overlap between the tracks is varied in order to vary the overall operative
length of the conductive path.
[0010] Up to now, it has been known to use a sliding trombone type arrangement as disclosed
in U.S. Patent Publication Number
US2005/0184827 (PALLONE et al.) which describes an input and output transmission line which are printed on PCBs
and are not radioelectrically coupled to one another. A mobile radioelectric coupling
means comprising a first and second arm formed in a substantially U-shaped coupling
circuit connects the input and output transmission lines to form an electric path.
The electric path has a variation range between a first position defining a minimal
electric path and a second position defining a maximal electric path. The U-shaped
coupling circuit moves in a trombone like fashion to extend or decrease the overall
path length from the input transmission line to the output transmission line on the
PCBs.
[0011] There are numerous problems with the phase shifters which are used in the variable
tilt antenna currently available.
[0012] These types of sliding trombone arrangements for "electrically" tiltable phase shifters
are subject to relatively high levels of insertion loss, or attenuation due to the
physical layout of the tracks in the arrangement, which result in the use of more
track length, and thus an increase in attenuation for a similar phase shift. It is
possible to lower the attenuation by reducing the track length of the mobile radioelectric
coupling means, however, small movements will result in larger phase shifts and this
makes the accuracy of the imposed phase shift harder to control and apply.
[0013] A further disadvantage with the sliding trombone arrangement is that a relatively
large amount of circuit board space is required to implement the arrangement. As the
tracks on the PCBs are slid towards and away from each other, typically the primary
PCB, which comprises the unconnected tracks, remains static whilst the secondary PCB,
which comprises the coupling track, is moved in a translational motion. As the secondary
PCB needs to move back and forth relative to the primary PCB, an area on the primary
PCB must be left free to allow the secondary PCB to slid into and away from this space,
thus accommodating the sliding movement of the PCBs relative to one another. In modern
printed circuit boards, space is at a premium, and in order to be as cost effective
as possible, the PCBs should be as compact as possible. The sliding trombone arrangement
is expensive to implement as a result of the need for larger PCBs to be used.
[0014] The provision of translational movement to articulate the coupling circuit relative
to the unconnected input and output transmission lines is relatively complicated and
requires a mechanism to translate the rotational movement of a motor into a translational
directed motion by means of an actuator. This adds to the complexity of the phase
shifter and to the cost of constructing the phase shifter. Document
WO03/036759A1 discloses a phased array with rotational phase shifters.
[0015] The present invention aims at providing an alternative phased array.
Summary of the Invention
[0016] The present invention is directed a phased array according to claim 1. Further more
specific embodiments are defined in the dependent claims.
Detailed Description of Embodiments
[0017] The invention will be more clearly understood from the following description of some
examples and embodiments thereof, given by way of example only with reference to the
accompanying drawings, in which:
Fig. 1 is a detailed exploded perspective view of a variable phase shifter in accordance
with the present invention showing hidden parts in phantom lining;
Fig. 2 is a detailed perspective view of a primary printed circuit board (PCB) of
the variable phase shifter of Fig. 1;
Fig. 3 is a detailed perspective view of a rotating secondary PCB of the variable
phase shifter of Fig. 1;
Fig. 4(a) is an exploded perspective view of a phase shifter employed as a nine-element
phase shifter array;
Fig. 4(b) is an enlarged view of a portion of the nine-element phase shifter array
of Fig. 4(a);
Fig. 5(a) is a plan view of the nine-element phase shifter array of Fig. 4(a);
Fig. 5(b) is a partial plan view of the nine-element phase shifter array of Fig. 5(a);
Fig. 6(a) is a partial plan view of the 9-element phase shifter array of Fig. 5(a)
with a pair of the phase shifters in a neutral position;
Fig. 6(b) is a partial plan view of the 9-element phase shifter array of Fig. 5(a)
with the pair of the phase shifters in a rotated position;
Fig. 7(a) is a is a partial plan view of a further embodiment of a 9-element phase
shifter with the pair of the phase shifters in a neutral position;
Fig. 7(b) is a is a partial plan view of the further embodiment of the 9-element phase
shifter array of Fig. 7(a) with the pair of the phase shifters in a rotated position;
Fig. 8 is a detailed exploded perspective view of a differential phase shifter in
accordance with a further embodiment of the present invention showing hidden parts
in phantom lining;
Fig. 9 is a detailed perspective view of a primary PCB of the differential phase shifter
of Fig. 8; and,
Fig. 10 is a detailed perspective view of a rotating secondary PCB of the differential
phase shifter of Fig. 8.
[0018] Referring to Figs. 1 to 3 initially, there is provided a variable phase shifter indicated
generally by the reference numeral 100. The variable phase shifter 100 comprises a
primary printed circuit board (PCB) 102 and a secondary PCB 104. The secondary PCB
104 is rotatably mounted on the primary PCB 102, as indicated by construction line
103, and is held in position by a central pivot pin 126. The central pivot pin 126
extends through a central hole 110 on the primary PCB 102 and a central hole 120 on
the secondary PCB 104 respectively. A central pivot pin cap 127 is connected atop
the central pivot pin 126 and the central pivot pin cap 127 ensures that a sufficient
amount of pressure is maintained between the primary PCB 102 and the secondary PCB
104.
[0019] The primary PCB 102 comprises a pair of arcuate co-centric unconnected double tracks
106, 108 printed on a topside of the primary PCB 102.
[0020] The secondary PCB 104 comprises a pair of arcuate co-centric double tracks 116, 118
printed on the underside of the secondary PCB 104. Each arcuate co-centric double
track 116, 118 comprises an outer arcuate track 105 and an inner arcuate track 107
connected by a radially extending link track 109 between neighbouring ends of the
arcuate inner and outer tracks 105, 107.
[0021] The secondary PCB 104 further comprises guide slots 122, 124. Lug stops 128, 130
extend through holes 112, 114 in the primary PCB 102 and protrude through the guide
slots 122, 124 respectively. The lug stops 128, 130 restrict the rotation of the secondary
PCB 104 about the central pivot pin 126 relative to the primary PCB 102. Lug caps
129, 131 are connected atop the lug stops 128, 130. Similarly to the central pivot
pin cap 127, the lug caps 129, 131 ensure that a sufficient amount of pressure is
maintained between the primary PCB 102 and the secondary PCB 104. A consistent and
constant conductive coupling between the tracks 106, 108, 116, 118 on the primary
PCB 102 and the secondary PCB 104 may be thus achieved.
[0022] The primary PCB 102 is formed on a substrate 200 that is substantially flat. In the
example shown in Figs. 1 to 3, the secondary PCB 104 is substantially circular in
form however, it will be appreciated that the secondary PCB 104 does not need to be
circular in order for the present invention to be carried out.
[0023] When the secondary PCB 104 overlays the primary PCB 102, the arcuate co-centric unconnected
double tracks 106, 108 on the primary PCB 102 overlap with the arcuate co-centric
tracks 116, 118 on the secondary PCB 104 respectively to form a pair of continuous
conductive paths, the lengths of which are extended or shortened simultaneously by
rotating the secondary PCB 104 relative to the primary PCB 102. The conductive paths
formed by the tracks 106, 108, 116, 118 may be used for a pair of orthogonal polarised
antenna component signals. Similarly to before, the central pivot pin cap 127 and
the lug caps 129, 131 ensure that a sufficient amount of pressure is maintained between
the primary PCB 102 and the secondary PCB 104 so that the continuous conductive paths
which are created by the arcuate co-centric unconnected double tracks 106, 108 on
the primary PCB 102 overlapping with the arcuate co-centric tracks 116, 118 on the
secondary PCB 104.
[0024] Referring now to Figs. 4(a) and 4(b), there is provided a nine-element phase array
indicated generally by the reference numeral 400. The phase array 400 is formed on
a primary PCB substrate 402 upon which is printed a plurality of pairs of opposing
arcuate co-centric unconnected double tracks 404A-404H. Each pair of opposing arcuate
co-centric unconnected double tracks 404A-404H is associated with a corresponding
secondary PCB 104A-104H to form a phase shifter respectively. The nine elements are
used for nine antenna component signals and the nine component signals are sent to
nine corresponding radiators (not shown) on an antenna. These radiators may be simple
dipoles or patch arrays. Eight of the nine component signals are phase shifted by
phase shifters according to the present invention.
[0025] The phase shifters may have arcuate tracks 404A-404H of varying arc sizes which will
give rise to different amounts of phase shift. For example, a relatively small secondary
PCB 104D having arcuate tracks with a relatively restricted arc having a small "diameter"
will not extend a conductive path as much as a larger secondary PCB 104A having arcuate
tracks with a larger arc length and hence a wider "diameter", when both secondary
PCBs 104A, 104D are rotated by the same angular displacement.
[0026] Referring now to Figs. 5(a) and 5(b), there is shown an array 500 of phase shifters
comprising eight secondary PCBs 104A-104H on a nine-element array. Each secondary
PCB 104A-104H comprises a radially outwardly projecting arm 502 which is rotatably
connected to a sliding arm 504. The secondary PCBs 104A-104H rotate, as indicated
by reference arrows A, as the sliding arm 504 slides back and forth, as indicated
by reference arrow B, in response to an actuator 506. The sliding arm 504 comprises
guide slots 508 through which guide pins 510 protrude. These guide slots 508 and guide
pins 510 direct and restrict the sliding motion of the sliding arm 504 to one dimension
as indicated by reference arrow B. Furthermore, the guide slots 508 and the guide
pins 510 may be preferably used in replacement of the guide slots 122, 124 and the
lug stops 128, 130 to restrict the rotational movement of the secondary PCBs 104A-104H
about their central pivot pins 126 relative to the primary PCB substrate 402 although
it will be appreciated that they may be used in conjunction with one another. Guide
pin caps (not shown) are also provide in a similar capacity as the central pivot pin
cap 127 and the lug caps 129, 131.
[0027] Each radially outwardly projecting arm 502 comprises an elongated slot 514. A lug
512 projects upwardly (out of the page) from the sliding arm 504 and extends through
the elongated slot 514. The distance of the lug 512 from the central pivot pin of
each phase shifter when the phase shifters are in the neutral position as shown in
Figs. 5(a) and 5(b) will determine the angle of rotation imparted to the phase shifters
by the movement of the sliding arm 504. This is explained in greater detail below.
[0028] Referring in particular to Figs. 6(a) and 6(b), two phase shifters of the array 500
are shown. The lugs 512 for both phase shifters 100 are positioned at the same distance
along the outwardly projecting arm 502 from the centre pivot point 604 of each secondary
PCB 104. Thus, both phase shifters will be rotated by the same angular displacement
when the sliding arm 504 is moved back and forth, as can be seen in Fig. 6(b).
[0029] As both phase shifters comprise arcuate conductive paths of differing arc lengths
(i.e. differing "diameters"), the conductive paths on both phase shifters will not
be extended by the same distance as a result of the same angular displacement. Thus,
the component signals on the conductive paths of the phase shifters will be phase
shifted by different degrees in this example. Referring now to Figs. 7(a) and 7(b),
the two phase shifters of a second embodiment of an array 700 according to a further
embodiment are shown. Both phase shifters are of the same diameter. The lugs 512 for
both phase shifters are positioned at different distances along the outwardly projecting
arm 502 from the centre pivot point 604 of each secondary PCB 104. The phase shifter
on the left side of the array 700 has its lug 512 positioned at a point along the
outwardly projecting arm 502 which is further away from the centre pivot point 604
of the associated secondary PCB 104 when compared to the position of the lug 512 for
the phase shifter on the right side of the array 700.
[0030] Thus, when the sliding arm 504 is moved left by a predetermined distance both phase
shifters will be rotated by different angular displacements, Φ
1 and Φ
2, as can be seen in Fig. 7(b). In this embodiment, both phase shifters comprise arcuate
conductive paths of the same arc length (i.e. the same "diameter"), but as the phase
shifters are rotated by differing degrees, the conductive paths on both phase shifters
will be extended by different distances. Thus, the component signals on the conductive
paths of both of the phase shifters will still be phase shifted by different amounts.
Examples determining the amount of phase shift achieved per degree of rotation of
the secondary PCB
1st Example (secondary PCB 104A/104H of Fig. 5(a))
[0031] Let the tracks on the PCBs (102, 104) have a mean radius of 28mm.
[0032] The circumference of the mean circle between the double tracks on the PCB is therefore
approximately 176mm (2.π.r).
[0033] This equates to an actual distance of 176mm/360° =0.488mm per degree
[0034] If the guide slots in the secondary PCB allow for a ±25° rotation of the secondary
PCB, then a total actual movement of
is achievable
[0035] Using a PCB material which has a dielectric constant of 2.2, and with the PCB material
operating at 2.5GHz, a 1mm amount of movement is equivalent to a 4.1° phase shift
for the component signal travelling along the conductive path formed by the printed
tracks on the primary and secondary PCBs,
[0036] Thus, the total amount of possible phase shift is 4.1° x 24.4 = 100° phase shift
[0037] So, at 2.5GHz for a ±25° rotation of a dk2.2 material having printed arcuate tracks
with a mean radius of 28mm, 1° of angular rotation of the secondary PCB = 4° of phase
shift of the signal travelling on the printed tracks, due to each track having a double
loop.
2nd Example (secondary PCB 104B/104G of Fig. 5(a))
[0038] Let the tracks on the PCBs (102, 104) have a mean radius of 21 mm.
[0039] The circumference of the mean circle between the double tracks on the PCB is therefore
approximately 132mm (2.π.r).
[0040] This equates to an actual distance of 132mm/360° =0.366mm per degree
[0041] If the guide slots in the secondary PCB allow for a ±25° rotation of the secondary
PCB, then a total actual movement of
is achievable
[0042] Using a PCB material which has a dielectric constant of 2.2, and with the PCB material
operating at 2.5GHz, a 1mm amount of movement is equivalent to a 4.1° phase shift
for the component signal travelling along the conductive path formed by the printed
tracks on the primary and secondary PCBs,
[0043] Thus, the total amount of possible phase shift is 4.1° x 18.3 = 75° phase shift
[0044] So, at 2.5GHz for a ±25° rotation of a dk2.2 material having printed arcuate tracks
with a mean radius of 21 mm, 1° of angular rotation of the secondary PCB = 3° of phase
shift of the signal travelling on the printed tracks, due to each track having a double
loop.
3rd Example (secondary PCB 104C/104F of Fig. 5(a))
[0045] Let the tracks on the PCBs (102, 104) have a mean radius of 14mm.
[0046] The circumference of the mean circle between the double tracks on the PCB is therefore
approximately 88mm (2.π.r).
[0047] This equates to an actual distance of 88mm/360° =0.244mm per degree
[0048] If the guide slots in the secondary PCB allow for a ±25° rotation of the secondary
PCB, then a total actual movement of
is achievable
[0049] Using a PCB material which has a dielectric constant of 2.2, and with the PCB material
operating at 2.5GHz, a 1mm amount of movement is equivalent to a 4.1° phase shift
for the component signal travelling along the conductive path formed by the printed
tracks on the primary and secondary PCBs,
[0050] Thus, the total amount of possible phase shift is 4.1° x 12.2 = 50° phase shift
[0051] So, at 2.5GHz for a ±25° rotation of a dk2.2 material having printed arcuate tracks
with a mean radius of 14mm, 1° of angular rotation of the secondary PCB = 2° of phase
shift of the signal travelling on the printed tracks, due to each track having a double
loop.
4th Example (secondary PCB 104D/104E of Fig. 5(a))
[0052] Let the tracks on the PCBs (102, 104) have a mean radius of 7mm.
[0053] The circumference of the mean circle between the double tracks on the PCB is therefore
approximately 44mm (2.π.r).
[0054] This equates to an actual distance of 44mm/360° =0.122mm per degree
[0055] If the guide slots in the secondary PCB allow for a ±25° rotation of the secondary
PCB, then a total actual movement of
is achievable
[0056] Using a PCB material which has a dielectric constant of 2.2, and with the PCB material
operating at 2.5GHz, a 1mm amount of movement is equivalent to a 4.1° phase shift
for the component signal travelling along the conductive path formed by the printed
tracks on the primary and secondary PCBs,
[0057] Thus, the total amount of possible phase shift is 4.1° x 6.1 = 25° phase shift
[0058] So, at 2.5GHz for a ±25° rotation of a dk2.2 material having printed arcuate tracks
with a mean radius of 7mm, 1° of angular rotation of the secondary PCB = 1° of phase
shift of the signal travelling on the printed tracks, due to each track having a double
loop. The above examples show that the mean radius of the arcuate double tracks on
the PCBs controls the phase shift achieved per degree of angular rotation imparted
to the secondary PCB.
[0059] Referring now to Figs. 8 to 10, wherein like parts previously described have been
assigned the same reference numerals, there is provided a differential phase shifter
indicated generally by the reference numeral 800. The differential phase shifter 800
comprises the primary printed circuit board (PCB) 102 and the secondary PCB 104. The
secondary PCB 104 is rotatably mounted on the primary PCB 102 as before. This is indicated
by the construction line 103. Many of the features of the differential phase shifter
800 remain the same as the variable phase shifter 100 shown in preceding drawings
including the central pivot pin 126, the central hole 120, the central pivot pin cap
127, the holes 112, 114 in the primary PCB 102, the guide slots 122, 124, the lug
stops 128, 130 and the lug caps 129, 131.
[0060] The difference between the differential phase shifter 800 and the variable phase
shifter 100 is found in the pattern that is formed by the tracks 802, 804, 806, 808,
810 on the primary PCB 102 and the secondary PCB 104 of the differential phase shifter
800 compared to the printed tracks 106, 108, 116, 118 on the primary PCB 102 and the
secondary PCB 104 of the variable phase shifter 100.
[0061] The primary PCB 102 comprises a power input 811 which is input to a power divider
indicated by reference numeral 812. By varying the widths of the branches 814, 816
emanating from the power divider 812, the ratio of the division of power can be altered.
In this example, the branches 814, 816 are of substantially equal width and thus the
input signal is divided substantially equally between the two branches 814, 816. The
branches 814, 816 extend into arcuate tracks 818, 820 respectively which are co-centric
with but separate from unconnected arcuate tracks 804, 806.
[0062] The secondary PCB 104 comprises a pair of arcuate co-centric double tracks 808, 810
printed on the underside of the secondary PCB 104. Each arcuate co-centric double
track 808, 810 comprises an outer arcuate track 105 and an inner arcuate track 107
connected by a radially extending link track 109 between neighbouring ends of the
arcuate inner and outer tracks 105, 107. The arcuate co-centric double tracks 808,
810 are arranged so that by rotating the secondary PCB 104 relative to the primary
PCB 102, one of the conductive paths formed by the arcuate tracks 806, 808, 820 is
extended whilst the other conductive path formed by the other arcuate tracks 804,
810, 818 is shortened.
[0063] A differential output may be thus taken across the differential outputs 824, 826.
[0064] The differential phase shifter 800 may be used in a variable tilt antenna which is
designed to operate at low antenna frequencies, below 1 GHz. At these frequencies
the spacings between the radiating elements on the antenna need to be relatively large.
As the spacing between the elements will be large, it would be uneconomical to printed
the radiating elements on a PCB as may be done in the afore-mentioned example, and
it is thus envisaged that the differential phase shifter 800 itself will be printed
on a PCB but the outputs 824, 826 will be fed to the radiating elements using coaxial
cables (not shown). Each output 824, 826 may be fed to the top half radiating elements
of the antenna or the bottom half radiating elements of the antenna as appropriate.
If the differential shift which is applied to the signal applies a positive phase
shift to the radiating elements on the top half of the antenna and a negative phase
shift to the radiating elements on the bottom half of the antenna, then a down tilt
of the radiation pattern emitted from the antenna will be achieved.
[0065] As previously described, the secondary PCB 104 is shown in a substantially circular
form however, the secondary PCB 104 does not need to be circular in order for any
embodiments of the present invention to be carried out.
[0066] In the illustrated embodiments hereinbefore described, the phase shifter 100 has
been shown to be double pole phase shifter 100 as the phase shifter comprises a pair
of diametrically opposed arcuate conductive paths, one path for two separate signals
in an antenna signal. It will be appreciated that a plurality of conductive paths
may be formed on the phase shifter 100.
[0067] It will be readily appreciated that although reference has been made to a primary
PCB and a secondary PCB throughout many parts of the description hereinbefore and
the claims hereinafter, the terms primary and secondary have been used for illustrative
and explanatory purposes only and do not limit the construction of the phase shifters
in any way. Indeed, the tracks as shown to be printed on the secondary PCB may alternatively
be printed on the primary PCB and the tracks shown to be printed on the primary PCB
may be printed on the secondary PCB.
[0068] Moreover, although the secondary PCBs have been described as the PCBs which move
relative to the primary PCB, either or both of the PCBs, or portions of the PCBs,
may be articulated so as to cause movement of the tracks on the PCBs relative to one
another.
[0069] In the specification the terms "comprise, comprises, comprised and comprising" or
any variation thereof and the terms "include, includes, included and including" or
any variation thereof are considered to be totally interchangeable and they should
all be afforded the widest possible interpretation.
[0070] The invention is not limited to the embodiments hereinbefore described which may
be varied in both construction and detail within the scope of the appended claims.
1. A phased array (400) formed by a plurality of phase shifters (100, 800) arranged in
series; each of the plurality of phase shifters (100, 800) comprising a primary printed
circuit board (102) having at least a pair of arcuate co-centric unconnected double
tracks (106, 108) printed thereon, and, a secondary printed circuit board (104) having
at least a pair of arcuate co-centric double tracks (116, 118) printed thereon, each
(105, 107) of the pairs of arcuate co-centric double tracks (116, 118) on the secondary
printed circuit board (104) being connected by a link track (109) located at neighbouring
ends of the arcuate co-centric double tracks (116, 118); whereby,
the secondary printed circuit board (104) is rotatably mounted on the primary printed
circuit board (102) such that the arcuate co-centric double tracks (106, 108, 116,
118) on both printed circuit boards (102, 104) overlap one another to be in electrical
communication with one another forming a pair of conductive paths, and, the overlap
between the arcuate tracks may be varied by rotating the secondary printed circuit
board (104) relative to the primary printed circuit board (102) so as to impart a
variable phase shift on a signal travelling along the conductive paths;
characterised in that,
at least two of the plurality of phase shifters in the phased array (400) comprise
arcuate co-centric double tracks of a substantially equal diameter, and, the secondary
printed circuit boards (104) of the at least two phase shifters are rotated to differing
angles to form a plurality of scaled phase shifts in the phased array (400);
whereby, in order to rotate the at least two phase shifters to differing angles, each
secondary printed circuit board (104) of the at least two phase shifters comprises
a radially outwardly projecting arm (502) which is rotatably connected to a sliding
arm (504);
such that,
as the sliding arm (504) slides back and forth, the secondary printed circuit boards
(104) rotate about a centre pivot point (604);
each radially outwardly projecting arm (502) comprising an elongated slot (514), and,
the sliding arm (504) comprising a lug (512) which projects away from the sliding
arm (504) and extends through the elongated slot (514), whereby,
the distance of the lug (512) from the centre pivot point (604) is different for the
at least two phase shifters respectively, such that a different angle of rotation
is imparted to the secondary printed circuit boards of the at least two phase shifters
and causes the secondary printed circuit boards of the at least two phase shifters
to rotate to differing angles to form the plurality of scaled phase shifts in the
phased array (400).
2. A phased array as claimed in claim 1, wherein,
the link track (109) is a radially extending link track.
3. A phased array as claimed in any preceding claim, wherein,
the secondary printed circuit board (104) comprises arcuate slots (122, 124) through
which lug stops, mounted on the primary printed circuit board (102), protrude such
as to limit the amount of rotation of the secondary printed circuit board (104) relative
to the primary printed circuit board (102).
4. A phased array as claimed in claim 3, wherein,
lug caps are connected atop lug stops mounted on the primary printed circuit board
(102) as to maintain an operationally efficient pressure between the secondary printed
circuit board (104) and the primary printed circuit board (102).
5. A phased array as claimed in any preceding claim, wherein,
the phase shifter is a differential phase shifter such that one of the pair of conductive
paths is extended by a distance as the other conductive path is shortened by substantially
the same distance.
6. A variable tilt antenna comprising a phased array as claimed in any preceding claim.
7. A variable tilt antenna as claimed in claim 6 such that a pair of opposing tracks
conduct a pair of polarised antenna signals respectively.
8. A variable tilt antenna as claimed in claims 6 or 7, wherein,
at least one of the plurality of phase shifters is connected to at least one radiator
in an antenna array by at least one phase cable.
9. A variable tilt antenna as claimed in claims 6 or 7, wherein,
at least one of the plurality of phase shifters is connected to at least one radiator
in an antenna array by conductive tracks forming a radio frequency (RF) substrate
on the primary printed circuit board (102).
1. Gruppenantenne (400), die durch eine Vielzahl von Phasenschiebern (100, 800), die
in Reihe angeordnet sind, gebildet wird; wobei jede der Vielzahl von Phasenschiebern
(100, 800) eine primäre Leiterplatte (102) mit mindestens einem Paar bogenförmiger
kozentrischer unverbundener doppelter Bahnen (106, 108), die darauf gedruckt sind,
und eine sekundäre Leiterplatte (104) mit mindestens einem Paar bogenförmiger kozentrischer
doppelter Bahnen (116, 118), die darauf gedruckt sind, umfasst, wobei jedes (105,
107) der Paare bogenförmiger kozentrischer doppelter Bahnen (116, 118) auf der sekundären
Leiterplatte (104) durch eine Kulissenbahn (109) verbunden ist, die sich an den benachbarten
Enden der bogenförmigen kozentrischen doppelten Bahnen (116, 118) befindet;
wobei
die sekundäre Leiterplatte (104) drehbar auf der primären Leiterplatte (102) befestigt
ist, sodass die bogenförmigen kozentrischen doppelten Bahnen (106, 108, 116, 118)
auf beiden Leiterplatten (102, 104) einander überlappen, sodass sie in elektrischer
Verbindung miteinander stehen, um ein Paar leitender Pfade zu bilden, und die Überlappung
zwischen den bogenförmigen Bahnen durch Drehen der sekundären Leiterplatte (104) relativ
zu der primären Leiterplatte (102) veränderbar ist, um eine variable Phasenverschiebung
auf einem Signal, das sich entlang der leitenden Pfade bewegt, aufzuweisen;
dadurch gekennzeichnet, dass
mindestens zwei der Vielzahl von Phasenschiebern in der Gruppenantenne (400) bogenförmige
kozentrische doppelte Bahnen mit einem im Wesentlichen gleichen Durchmesser umfassen,
und die sekundären Leiterplatten (104) der mindestens zwei Phasenschieber zu unterschiedlichen
Winkeln gedreht werden, um eine Vielzahl skalierter Phasenverschiebungen in der Gruppenantenne
(400) zu bilden; wobei, um die mindestens zwei Phasenschieber zu verschiedenen Winkeln
zu drehen, jede sekundäre Leiterplatte (104) der mindestens zwei Phasenschieber einen
radial nach außen hervorstehenden Arm (502) umfasst, der drehbar mit einem Gleitarm
(504) verbunden ist;
sodass,
da der Gleitarm (504) vor- und zurückgleitet, die sekundären Leiterplatten (104) sich
um einen mittigen Schwenkpunkt (604) drehen;
wobei jeder radial nach außen hervorstehende Arm (502) einen länglichen Schlitz (514)
umfasst und der Gleitarm (504) einen Ansatz (512) umfasst, der von dem Gleitarm (504)
wegragt und sich durch den länglichen Schlitz (514) erstreckt,
wobei
der Abstand des Ansatzes (512) von dem mittigen Schwenkpunkt (604) für die mindestens
zwei Phasenschieber jeweils anders ist, sodass den sekundären Leiterplatten der mindestens
zwei Phasenschieber ein unterschiedlicher Drehwinkel verliehen wird, was dazu führt,
dass die sekundären Leiterplatten der mindestens zwei Phasenschieber sich zu verschiedenen
Winkeln drehen, um die Vielzahl von skalierten Phasenverschiebungen in der Gruppenantenne
(400) zu bilden.
2. Gruppenantenne nach Anspruch 1, wobei die Kulissenbahn (109) eine sich radial erstreckende
Kulissenbahn ist.
3. Gruppenantenne nach einem der vorstehenden Ansprüche, wobei die sekundäre Leiterplatte
(104) bogenförmigen Schlitze (122, 124) umfasst, durch die Ansatzanschläge, die auf
der primären Leiterplatte (102) befestigt sind, vorstehen, um das Ausmaß der Drehung
der sekundären Leiterplatte (104) relativ zu der primären Leiterplatte (102) zu begrenzen.
4. Gruppenantenne nach Anspruch 3, wobei Ansatzkappen oben auf Ansatzanschlägen verbunden
sind, die auf der primären Leiterplatte (102) befestigt sind, um einen operativ effizienten
Druck zwischen der sekundären Leiterplatte (104) und der primären Leiterplatte (102)
beizubehalten.
5. Gruppenantenne nach einem der vorstehenden Ansprüche, wobei der Phasenschieber ein
differentieller Phasenschieber ist, sodass eines der Paare leitender Pfade um einen
Abstand verlängert ist, während der andere leitende Pfad um im Wesentlichen den gleichen
Abstand verkürzt ist.
6. Variable Neigungsantenne, ein Phased Array nach einem der vorstehenden Ansprüche umfassend.
7. Variable Neigungsantenne nach Anspruch 6, sodass ein Paar gegenüberliegender Bahnen
jeweils ein Paar polarisierter Antennensignale leitet.
8. Variable Neigungsantenne nach Anspruch 6 oder 7, wobei mindestens eine der Vielzahl
von Phasenschiebern mit mindestens einem Kühler in einer Antennenanordnung durch mindestens
ein Phasenkabel verbunden ist.
9. Variable Neigungsantenne nach Anspruch 6 oder 7, wobei mindestens eine der Vielzahl
von Phasenschiebern mit mindestens einem Kühler in einer Antennenanordnung durch leitende
Bahnen verbunden ist, die ein Radiofrequenz-(RF)-Substrat auf der primären Leiterplatte
(102) bilden.
1. Antenne réseau à commande de phase (400) formée par une pluralité de déphaseurs (100,
800) agencés en série : chacune de la pluralité de déphaseurs (100, 800) comprenant
une carte de circuit imprimé principale (102) ayant au moins une paire de pistes doubles
non connectées, concentriques et arquées (106, 108) imprimées dessus et une carte
de circuit imprimé auxiliaire (104) ayant au moins une paire de pistes doubles concentriques
et arquées (116, 118) imprimées dessus, chacune (105, 107) des paires de pistes doubles
concentriques et arquées (116, 118) sur la carte de circuit imprimé auxiliaire (104)
étant connectée par une piste de liaison (109) située à des extrémités voisines des
pistes doubles concentriques et arquées (116, 118) ; moyennant quoi
la carte de circuit imprimé auxiliaire (104) est montée de manière rotative sur la
carte de circuit imprimé principale (102) de manière que les pistes doubles concentriques
et arquées (106, 108, 116, 118) sur les deux cartes de circuit imprimé (102, 104)
se chevauchent mutuellement pour être en communication électrique l'une avec l'autre
en formant une paire de chemins conducteurs et le chevauchement entre les pistes arquées
peut être modifié par rotation de la carte de circuit imprimé auxiliaire (104) par
rapport à la carte de circuit imprimé principale (102) de manière à appliquer un déphasage
variable sur un signal se propageant le long des chemins conducteurs ;
caractérisé en ce
qu'au moins deux de la pluralité de déphaseurs dans l'antenne réseau à commande de phase
(400) comprennent des pistes doubles concentriques et arquées d'un diamètre sensiblement
égal et les cartes de circuit imprimé auxiliaires (104) des au moins deux déphaseurs
sont tournées avec des angles différents pour former une pluralité de déphasages échelonnés
dans l'antenne réseau à commande de phase (400) ;
moyennant quoi, afin de tourner les au moins deux déphaseurs avec des angles différents,
chaque carte de circuit imprimé auxiliaire (104) des au moins deux déphaseurs comprend
un bras faisant saillie radialement vers l'extérieur (502) qui est connecté de manière
rotative à un bras coulissant (504) ;
de manière que
lorsque le bras coulissant (504) coulisse en avant et en arrière, les cartes de circuit
imprimé auxiliaires (104) tournent autour d'un point de pivot central (604) ;
chaque bras faisant saillie radialement vers l'extérieur (502) comprenant une fente
allongée (514) et le bras coulissant (504) comprenant une patte (512) qui fait saillie
en s'éloignant du bras coulissant (504) et s'étend à travers la fente allongée (514),
moyennant quoi
la distance de la patte (512) par rapport au point de pivot central (604) est différente
respectivement pour les au moins deux déphaseurs, de manière qu'un angle de rotation
différent soit appliqué aux cartes de circuit imprimé auxiliaires des au moins deux
déphaseurs et amène les cartes de circuit imprimé auxiliaires des au moins deux déphaseurs
à tourner d'angles différents pour former la pluralité de déphasages échelonnés dans
l'antenne réseau à commande de phase (400).
2. Antenne réseau à commande de phase selon la revendication 1, dans laquelle
la piste de liaison (109) est une piste de liaison s'étendant radialement.
3. Antenne réseau à commande de phase selon une quelconque revendication précédente,
dans laquelle
la carte de circuit imprimé auxiliaire (104) comprend des fentes arquées (122, 124)
à travers lesquelles des butées de patte, montées sur la carte de circuit imprimé
principale (102), font saillies de manière à limiter la quantité de rotation de la
carte de circuit imprimé auxiliaire (104) par rapport à la carte de circuit imprimé
principale (102).
4. Antenne réseau à commande de phase selon la revendication 3, dans laquelle
des capuchons de patte sont connectés au sommet de butées de patte montées sur la
carte de circuit imprimé principale (102) de manière à maintenir une pression fonctionnellement
efficace entre la carte de circuit imprimé auxiliaire (104) et la carte de circuit
imprimé principale (102).
5. Antenne réseau à commande de phase selon une quelconque revendication précédente,
dans laquelle
le déphaseur est un déphaseur différentiel de manière qu'un de la paire de chemins
conducteurs soit allongé d'une distance alors que l'autre chemin conducteur est raccourci
sensiblement de la même distance.
6. Antenne à inclinaison variable comprenant une antenne réseau à commande de phase selon
une quelconque revendication précédente.
7. Antenne à inclinaison variable selon la revendication 6, telle qu'une paire de pistes
opposées conduisent respectivement une paire de signaux d'antenne polarisés.
8. Antenne à inclinaison variable selon les revendications 6 ou 7, dans laquelle
au moins un de la pluralité de déphaseurs est connecté à au moins un élément rayonnant
dans une antenne réseau par au moins un câble de phase.
9. Antenne à inclinaison variable selon les revendications 6 ou 7, dans laquelle
au moins un de la pluralité de déphaseurs est connecté à au moins un élément rayonnant
dans une antenne réseau par des pistes conductrices formant un substrat à fréquences
radio (RF) sur la carte de circuit imprimé principale (102).