TECHNICAL FIELD
[0001] The present invention relates to the field of antenna technologies, and in particular,
to a feeding apparatus.
BACKGROUND
[0002] With development of wireless communications technologies, bandwidth of microwave
frequency bands cannot satisfy requirements. Therefore, developers begin to pay attention
to an electromagnetic wave having a higher frequency band such as a millimetric wave.
A free space loss is in direct proportion to a square of a radio-frequency frequency
in a transmission process. For example, when a frequency is higher than 100 GHz, a
free space loss caused by using an electromagnetic wave having a high frequency band
such as a millimetric wave is above 40 dB. Output power of a device using an electromagnetic
wave having a high frequency band such as a millimetric wave is relatively low. Therefore,
an antenna with a higher gain needs to be designed to compensate the caused free space
loss, so as to ensure normal communication.
SUMMARY
[0003] Embodiments of the present invention provide a feeding apparatus, which can reduce
a transmission loss and ensure an antenna gain.
[0004] To resolve the foregoing technical problems, a first aspect of the present invention
provides a feeding apparatus, which may include a horn antenna, a dielectric substrate,
and a transmission line 30 and a grounding portion 40 that are disposed on the dielectric
substrate, where
the horn antenna 10 includes a horn opening end 11 and a horn feeding input end 12
that are disposed opposite to each other and includes a cavity located between the
horn opening end 11 and the horn feeding input end 12, where the cavity includes a
first inner surface 13; and
the transmission line 30 includes a straight portion 31 and a bent portion 32, where
the grounding portion 40 is laid at two sides of the straight portion 31, the straight
portion 31, the bent portion 32, and the grounding portion 40 extend into the cavity
through the horn feeding input end 12, the straight portion 31 is attached to the
first inner surface 13, and a particular angle is formed between the bent portion
32 and the first inner surface 13.
[0005] Based on the first aspect, in a first feasible implementation manner of the first
aspect, the horn feeding input end 12 is provided with a through hole 121, and the
straight portion 31, the bent portion 32, and the grounding portion 40 extend into
the cavity through the through hole 121.
[0006] Based on the first feasible implementation manner of the first aspect, in a second
feasible implementation manner of the first aspect, the through hole 121 is of a square,
where a side length of the square ranges from 1/16 of a wavelength to 1/4 of the wavelength,
and the wavelength is an wavelength of an electromagnetic wave.
[0007] Based on the first feasible implementation manner of the first aspect or the second
feasible implementation manner of the first aspect, in a third feasible implementation
manner of the first aspect, a covering portion 50 configured to cover the straight
portion 31 and the grounding portion 40 is disposed on the first inner surface 13,
where a passage is formed between the covering portion 50 and the first inner surface
13, and the passage includes a first opening end and a second opening end, where the
first opening end is connected to the through hole 121, and the second opening end
faces the bent portion 32.
[0008] Based on the third feasible implementation manner of the first aspect, in a fourth
feasible implementation manner of the first aspect, the first opening end has a shape
and size the same as those of the through hole 121.
[0009] Based on the third feasible implementation manner of the first aspect, in a fifth
feasible implementation manner of the first aspect, a length of the passage is equal
to a distance between the second opening end and the bent portion 32.
[0010] Based on the third feasible implementation manner of the first aspect, in a sixth
feasible implementation manner of the first aspect, a length of the passage ranges
from 1/8 of the wavelength to 1/5 of the wavelength, and the wavelength is the wavelength
of the electromagnetic wave.
[0011] Based on the first aspect, the first feasible implementation manner of the first
aspect, the second feasible implementation manner of the first aspect, the third feasible
implementation manner of the first aspect, the fourth feasible implementation manner
of the first aspect, the fifth feasible implementation manner of the first aspect,
or the sixth feasible implementation manner of the first aspect, in a seventh feasible
implementation manner of the first aspect, the particular angle is 90 degrees.
[0012] Based on the first aspect, the first feasible implementation manner of the first
aspect, the second feasible implementation manner of the first aspect, the third feasible
implementation manner of the first aspect, the fourth feasible implementation manner
of the first aspect, the fifth feasible implementation manner of the first aspect,
or the sixth feasible implementation manner of the first aspect, in an eighth feasible
implementation manner of the first aspect, a distance between the through hole 121
and the bent portion 32 is 1/4 of the wavelength, and the wavelength is the wavelength
of the electromagnetic wave.
[0013] Based on the first aspect, the first feasible implementation manner of the first
aspect, the second feasible implementation manner of the first aspect, the third feasible
implementation manner of the first aspect, the fourth feasible implementation manner
of the first aspect, the fifth feasible implementation manner of the first aspect,
or the sixth feasible implementation manner of the first aspect, in a ninth feasible
implementation manner of the first aspect, a height of the bent portion 32 is 1/4
of the wavelength.
[0014] It can be known from the foregoing descriptions that a straight portion, a grounding
portion, and a bent portion of a transmission line directly extend into a cavity of
a horn antenna through a horn feeding input end of the horn antenna, the straight
portion is attached to a first inner surface of the horn antenna, the bent portion
is used as a feeding probe, and a particular angle is formed between the bent portion
and the first inner surface of the cavity, so as to directly couple energy into the
horn antenna. A transmission structure for sending a signal to the antenna is simplified
and a transmission distance is shortened, so that a free space loss is reduced in
a transmission process. In addition, the transmission line and the horn antenna with
a high gain are coplanar, and integration of the horn antenna on a circuit board is
facilitated.
BRIEF DESCRIPTION OF DRAWINGS
[0015] To describe the technical solutions in the embodiments of the present invention or
in the prior art more clearly, the following briefly describes the accompanying drawings
required for describing the embodiments. Apparently, the accompanying drawings in
the following description show merely some embodiments of the present invention, and
a person of ordinary skill in the art may still derive other drawings from these accompanying
drawings without creative efforts.
FIG. 1 is a schematic diagram of a view of a feeding apparatus according to an embodiment
of the present invention;
FIG. 2 is a schematic diagram of another view of a feeding apparatus according to
an embodiment of the present invention; and
FIG. 3 is a schematic diagram of a covering portion 50 according to an embodiment
of the present invention.
DESCRIPTION OF EMBODIMENTS
[0016] The following clearly and completely describes the technical solutions in the embodiments
of the present invention with reference to the accompanying drawings in the embodiments
of the present invention. Apparently, the described embodiments are merely some but
not all of the embodiments of the present invention. All other embodiments obtained
by a person of ordinary skill in the art based on the embodiments of the present invention
without creative efforts shall fall within the protection scope of the present invention.
[0017] Referring to FIG. 1 and FIG. 2, FIG. 1 and FIG. 2 show a feeding apparatus according
to an embodiment of the present invention. The feeding apparatus includes a horn antenna
10, a dielectric substrate 20, and a transmission line 30 and a grounding portion
40 that are disposed on the dielectric substrate 20.
[0018] The horn antenna 10 includes a horn opening end 11 and a horn feeding input end 12
that are disposed opposite to each other and includes a cavity located between the
horn opening end 11 and the horn feeding input end 12, where the cavity includes a
first inner surface 13.
[0019] The horn antenna 10 is a microwave antenna having a gradient wide waveguide opening
plane and a round or rectangular section, and generally includes: a conical horn,
an E-plane sectoral horn, an H-plane sectoral horn, and a pyramidal horn. The horn
feeding input end 12 is an end having a relatively small opening, and the horn opening
end 11 is an end having a relatively large opening. This embodiment of the present
invention mainly uses a pyramidal horn antenna as an example to implement coplanarity
of one surface of the pyramidal horn antenna (the surface is the first inner surface
13) and the dielectric substrate 20. When the antenna works in a main mode, an aperture
field is in a cosine descending distribution on an H-plane and in a uniform distribution
on an E-plane. Therefore, when an aperture phase difference of the pyramidal horn
between the H-plane and the E-plane satisfies SH=3/8, SE=1/4, that is, when corresponding
Φ
M,H=3π/4 and Φ
M,E=π/2, a maximum far-field gain value can be obtained.
[0020] In an implementation manner of the present invention, using a coplanar waveguide
as an example, the transmission line 30 is a central conductor strip disposed on one
surface of the dielectric substrate of the coplanar waveguide, and the grounding portion
40 is disposed at two sides of the central conductor strip. Compared with a normal
microstrip transmission line, the coplanar waveguide has advantages that manufacture
is simple and it is easy to implement a serial connection and a parallel connection
(there is no need to perforate on a substrate) of a passive or active device in a
circuit and easy to improve a circuit density.
[0021] The transmission line 30 includes a straight portion 31 and a bent portion 32, where
the grounding portion 40 is laid at two sides of the straight portion 31, the straight
portion 31, the bent portion 32, and the grounding portion 40 extend into the cavity
through the horn feeding input end 12, the straight portion 31 is attached to the
first inner surface 13, and a particular angle is formed between the bent portion
32 and the first inner surface 13.
[0022] Specifically, the bent portion 32 is a bent part of the transmission line 30 after
the transmission line 30 extends into the cavity for a given distance, a function
of which is to form a feeding structure of a probe. The particular angle formed by
the bent portion 32, that is, the probe, and the first inner surface 13 is generally
90 degrees, that is, the bent portion 32 is perpendicular to the first inner surface
13 (an unavoidable error may occur during a manufacturing process, and the error needs
to be within an acceptable range so that an overall effect is not affected). A signal
and energy transmitted by the straight portion 31 are directly fed to the horn antenna
10 by using the probe, which simplifies a signal transmission structure and shortens
a transmission distance, thereby reducing a transmission loss.
[0023] Specifically, the horn feeding input end 12 is provided with a through hole 121,
and the straight portion 31 and the bent portion 32 of the transmission line 30 and
the grounding portion 40 extend into the cavity through the through hole 121. Preferably,
the through hole 121 is of a square, and a side length of the square ranges from 1/16
of a wavelength to 1/4 of the wavelength. When the through hole 121 is set to square,
higher bandwidth is obtained, and the square through hole facilitates an operation
during processing, and may have a more precise size. It should be noted that, it should
be avoided as far as possible to design the side length of the square to 1/8 of the
wavelength within the range, because when the length is exactly 1/8 of the wavelength,
an impedance matching status of an input port obviously deteriorates.
[0024] Certainly, in other implementation manners, the through hole 121 may be round.
[0025] During a practical design process, lengths of the straight portion 31 and the grounding
portion 40 in the cavity matches a length of the bent portion 32 (that is, a size
of the probe). In an implementation manner, a distance between the through hole 121
and the bent portion 32 is 1/4 of the wavelength, that is, the lengths of the straight
portion 31 and the grounding portion 40 in the cavity are 1/4 of the wavelength. For
example, when a frequency is 140 GHz, the distance between the through hole 121 and
the bent portion 32 is 0.56 mm.
[0026] A height of the bent portion 32 (the probe) that is perpendicular to the first inner
surface 13 and that performs feeding in the horn antenna 10 mainly affects a resonance
frequency. A feeding end of the horn antenna 10 needs to match the probe. Therefore,
not only the height of the probe affects the resonance frequency, but also a length
of a reflection cavity (that is, the lengths of the straight portion 31 and the grounding
portion 40 in the cavity) also affect impedance bandwidth. In an implementation manner,
when the height of the bent portion 32 and the lengths of the straight portion 31
and the grounding portion 40 in the cavity are both 1/4 of the wavelength, good impedance
bandwidth can be obtained. For example, when the frequency is 140 GHz, the height
of the bent portion 32 is 0.56 mm.
[0027] Further, referring to FIG. 2 and FIG. 3, a covering portion 50 configured to cover
the straight portion 31 and the grounding portion 40 is further disposed on the first
inner surface 13, where a passage is formed between the covering portion 50 and the
first inner surface 13, and the passage includes a first opening end and a second
opening end, where the first opening end is connected to the through hole 121, and
the second opening end faces the bent portion 32.
[0028] It should be noted that the covering portion 50 covers parts of the straight portion
31 and the grounding portion 40 in the cavity, that is, the parts of the straight
portion 31 and the grounding portion 40 in the cavity is located in the passage formed
between the covering portion 50 and the first inner surface 13. In this embodiment,
a length of the passage, that is, a covered length, may be set to be equal to a distance
between the second opening end and the bent portion 32 (that is, a half of the lengths
of the straight portion 31 and the grounding portion 40 in the cavity), or the length
ranges from 1/8 of the wavelength to 1/5 of the wavelength.
[0029] The first opening end has a shape and size the same as those of the through hole
121, and the passage may be cylindrical, that is, the second opening end also has
a shape and size the same as those of the first opening end or the through hole 121.
[0030] In an implementation manner, the covering portion 50 may be provided with a hollow
portion that matches the covering portion 50 according to the shape and size of the
through hole 121. For example, when the through hole 121 is of a square having a side
length of 1/4 of the wavelength, a cross section of the hollow portion is of a square
having a side length of 1/4 of the wavelength, and the length is equal to the length
of the passage.
[0031] The covering portion 50 is added on the parts of the straight portion 31 and the
grounding portion 40 in the cavity, a function of which is to widen the impedance
bandwidth. After the horn antenna 10 uses a probe structure to perform feeding, the
bandwidth is relatively narrow. Therefore, addition of the covering portion 50 can
cause an additional resonant peak, and a status of matching between the additional
resonant peak and an original resonant peak can be correspondingly adjusted by adjusting
the length of the passage. The reflection cavity generally has a requirement of 1/4
of the wavelength (that is, the lengths of the straight portion 31 and the grounding
portion 40 in the cavity), and an impedance matching bandwidth characteristic is relatively
good when the length of the passage is within a particular range less than 1/4 of
the wavelength. Therefore, the range may be set to 1/8 of the wavelength to 1/5 of
the wavelength.
[0032] It should be noted that the wavelengths involved above are all a wavelength of an
electromagnetic wave, where a propagation speed of the electromagnetic wave is equal
to a speed of light c (3×10^8 m/s), that is, a product of the wavelength and a frequency
f.
[0033] It can be known from the foregoing descriptions that a straight portion, a grounding
portion, and a bent portion of a transmission line directly extend into a cavity of
a horn antenna through a horn feeding input end of the horn antenna, the straight
portion is attached to a first inner surface of the horn antenna, the bent portion
is used as a feeding probe, and a particular angle is formed between the bent portion
and the first inner surface of the cavity, so as to directly couple energy to the
horn antenna. A transmission structure for sending a signal to the antenna is simplified
and a transmission distance is shortened, so that a free space loss is reduced in
a transmission process. In addition, the transmission line and the horn antenna with
a high gain are coplanar, and integration of the horn antenna on a circuit board is
facilitated.
[0034] With descriptions of the foregoing embodiments, a person skilled in the art may clearly
understand that the present invention may be implemented by hardware, firmware or
a combination thereof. When the present invention is implemented by software, the
foregoing functions may be stored in a computer-readable medium or transmitted as
one or more instructions or code in the computer-readable medium. The computer-readable
medium includes a computer storage medium and a communications medium, where the communications
medium includes any medium that enables a computer program to be transmitted from
one place to another. The storage medium may be any available medium accessible to
a computer. The following provides an example but does not impose a limitation: The
computer-readable medium may include a RAM, a ROM, an EEPROM, a CD-ROM, or another
optical disc storage or disk storage medium, or another magnetic storage device, or
any other medium that can carry or store expected program code in a form of an instruction
or a data structure and can be accessed by a computer. In addition, any connection
may be appropriately defined as a computer-readable medium. For example, if software
is transmitted from a website, a server or another remote source by using a coaxial
cable, an optical fiber/cable, a twisted pair, a digital subscriber line (DSL) or
wireless technologies such as infrared ray, radio and microwave, the coaxial cable,
optical fiber/cable, twisted pair, DSL or wireless technologies such as infrared ray,
radio and microwave are included in a definition of a medium to which they belong.
For example, a disk (Disk) and disc (disc) used by the present invention includes
a compact disc (CD), a laser disc, an optical disc, a digital versatile disc (DVD),
a floppy disk and a Blu-ray disc, where the disk generally copies data by a magnetic
means, and the disc copies data optically by a laser means. The foregoing combination
should also be included in the protection scope of the computer-readable medium.
[0035] What is disclosed above is merely exemplary embodiments of the present invention,
and certainly is not intended to limit the protection scope of the present invention.
Therefore, equivalent variations made in accordance with the claims of the present
invention shall fall within the scope of the present invention.
1. A feeding apparatus, comprising a horn antenna 10, a dielectric substrate 20, and
a transmission line 30 and a grounding portion 40 that are disposed on the dielectric
substrate 20, wherein
the horn antenna 10 comprises a horn opening end 11 and a horn feeding input end 12
that are disposed opposite to each other and comprises a cavity located between the
horn opening end 11 and the horn feeding input end 12, wherein the cavity comprises
a first inner surface 13; and
the transmission line 30 comprises a straight portion 31 and a bent portion 32, wherein
the grounding portion 40 is laid at two sides of the straight portion 31, the straight
portion 31, the bent portion 32, and the grounding portion 40 extend into the cavity
through the horn feeding input end 12, the straight portion 31 is attached to the
first inner surface 13, and a particular angle is formed between the bent portion
32 and the first inner surface 13.
2. The feeding apparatus according to claim 1, wherein the horn feeding input end 12
is provided with a through hole 121, and the straight portion 31, the bent portion
32, and the grounding portion 40 extend into the cavity through the through hole 121.
3. The feeding apparatus according to claim 2, wherein the through hole 121 is of a square,
wherein a side length of the square ranges from 1/16 of a wavelength to 1/4 of the
wavelength, and the wavelength is a wavelength of an electromagnetic wave.
4. The feeding apparatus according to claim 2 or 3, wherein a covering portion 50 configured
to cover the straight portion 31 and the grounding portion 40 is disposed on the first
inner surface 13, a passage is formed between the covering portion 50 and the first
inner surface 13, and the passage comprises a first opening end and a second opening
end, wherein the first opening end is connected to the through hole 121, and the second
opening end faces the bent portion 32.
5. The feeding apparatus according to claim 4, wherein the first opening end has a shape
and size the same as those of the through hole 121.
6. The feeding apparatus according to claim 4, wherein a length of the passage is equal
to a distance between the second opening end and the bent portion 32.
7. The feeding apparatus according to claim 4, wherein a length of the passage ranges
from 1/8 of the wavelength to 1/5 of the wavelength, and the wavelength is the wavelength
of the electromagnetic wave.
8. The feeding apparatus according to any one of claims 1 to 7, wherein the particular
angle is 90 degrees.
9. The feeding apparatus according to any one of claims 1 to 7, wherein a distance between
the through hole 121 and the bent portion 32 is 1/4 of the wavelength.
10. The feeding apparatus according to any one of claims 1 to 7, wherein a height of the
bent portion 32 is 1/4 of the wavelength, and the wavelength is the wavelength of
the electromagnetic wave.