CN107508040B

CN107508040B - Polarization rotation direction backtracking array

Info

Publication number: CN107508040B
Application number: CN201710862379.0A
Authority: CN
Inventors: 林先其; 杨永穆; 曾姜杰; 许冬冬; 黄登祥; 贾小翠; 朱忠博; 樊勇
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2017-09-21
Filing date: 2017-09-21
Publication date: 2020-03-31
Anticipated expiration: 2037-09-21
Also published as: WO2019056825A1; CN107508040A

Abstract

The invention discloses a polarization rotation direction backtracking array which is composed of a double-fed square patch, a phase conjugation frequency mixer and a local oscillator power divider. The invention can be used in microwave and millimeter wave communication system, radio frequency identification and wireless energy transmission. Its advantages are that it can trace back the orthogonal polarized wave from any direction, simple structure of phase conjugate circuit, high suppression degree of local oscillator, low cost and short processing period.

Description

Polarization rotation direction backtracking array

Technical Field

The invention belongs to the field of microwave millimeter wave systems, and particularly relates to a direction backtracking array in a microwave millimeter wave system.

Background

The direction backtracking array automatically forwards a beam of signals pointing to the incoming wave direction on the premise that the incoming wave direction is unknown. The device has the characteristic of automatically tracking the incoming wave direction without complex signal processing equipment, so the device has a wide application prospect in the fields of wireless communication, wireless energy transmission, radio frequency transmission and the like.

The existing direction backtracking array generally receives and transmits with the same frequency, so that the receiving and transmitting isolation is mostly carried out by adopting an orthogonal polarization mode. Luxey C et al disclose a directional retrospective array for orthogonal polarized transmission and reception using a dual-port coupled feed approach (Luxey C, Lahemarte J M.A regenerative transducer with polar transmission for divided short-range communications [ J ]. IEEE Transactions on microwave therapeutics & technologies, 2014,47(9): 1910) 1915.); however, the array is not suitable for communication to a moving object because of the use of dual linear polarizations, which requires precise alignment of the transmit and receive antennas to avoid polarization loss. Choi JH et al designed a retrospective Array (Choi J H, Dong Y, Sun J S, et al. retrodirective Array immunity to incorporated Waves directive polarization [ J ]. IEEE Transactions on Antennas & Propagation,2013,61(12):6008-6013.) that transmitted orthogonal polarized Waves to Incident Waves of any polarization, which Array could reduce polarization mismatch loss without requiring the accurate alignment of the transmit-receive Antennas; however, the array feeding system is complex, each path needs four mixers, four amplifiers and two phase delay lines, and the practicability is limited.

Disclosure of Invention

The invention aims to provide a polarization rotation direction backtracking array, which backtracks orthogonal polarization waves of any incident wave, reduces polarization mismatch loss, simplifies a phase conjugate circuit structure and ensures that the whole structure is compact and reliable.

The technical scheme of the invention is as follows: a polarization rotation direction backtracking array comprises M polarization rotation direction backtracking subunits, M paths of power dividers and a local oscillation source; m is an integer more than or equal to 3; the polarization rotation direction backtracking subunit consists of a double-fed dual-polarized patch antenna and a phase conjugate mixer; the double-fed patch antenna and the phase conjugation frequency mixer are connected together through two first radio frequency cables with equal length; the phase conjugate mixer and the M-path power divider are prepared on the same dielectric substrate; and the local vibration source is connected to the input port of the M-path power divider through a second radio frequency cable.

Furthermore, the phase conjugate mixer is composed of two radio frequency filters, a 3dB coupler, a phase delay line, a local oscillator filter, a matching branch, two radio frequency coaxial ports and a diode pair, wherein the dielectric substrate is printed on the dielectric substrate; the local oscillation frequency of the phase conjugation mixer is twice of the radio frequency, and the intermediate frequency is the same as the radio frequency; the length of the phase delay line is one quarter of radio frequency wavelength; each radio frequency coaxial port, the radio frequency filter and the 3dB coupler are connected by microstrip lines with equal length and are arranged in central symmetry.

Furthermore, the radio frequency filter is composed of two asymmetric taps and two bending resonators; two C-shaped grooves are formed in the bending resonator, and the size of each C-shaped groove is properly adjusted to enable one out-of-band zero point of the radio frequency filter to fall on the local oscillation frequency.

The invention has the advantages and beneficial effects that:

(1) the invention backtracks the orthogonal polarized wave of any incident polarized wave, and avoids the loss of the common polarization duplex system caused by the polarization mismatch of the receiving and transmitting antenna.

(2) The invention has the characteristic of compact structure. The invention utilizes the inherent phase difference of two ports of the 3dB coupler and one phase delay line to realize that the two ports output the inherent phase difference of 180 degrees, and simultaneously, the receiving and transmitting antenna is realized by adopting one antenna, and the receiving and transmitting ports are also realized by adopting the same port. Therefore, the invention can realize the functions of polarization rotation and direction backtracking only by one mixer and one dual-port antenna.

(3) The radio frequency filter used by the invention has the characteristic that the out-of-band zero point can be adjusted without influencing the pass band. Because the local oscillator adopted by the invention is twice the radio frequency and the energy is larger than the radio frequency signal, in order to inhibit the radiation of the local oscillator frequency, the structure of the radio frequency filter can be adjusted to ensure that the out-of-band zero point falls on the local oscillator frequency.

Drawings

FIG. 1 is a schematic diagram of the general structure of the present invention

FIG. 2 is a block diagram of a phase conjugate mixer of the present invention

FIG. 3 is a plot of the S-parameter of the RF filter of the present invention

FIG. 4 is a directional diagram of the present invention at different incident wave angles

Detailed Description

The invention is further described with reference to the following figures and specific embodiments: as shown in fig. 1, a polarization rotation direction backtracking array includes M polarization rotation direction backtracking subunits 1, M path power splitters 2, and a local oscillation source 3; m is an integer more than or equal to 3; the polarization rotation direction backtracking subunit consists of a double-fed dual-polarized patch antenna and a phase conjugate mixer; the double-fed patch antenna and the phase conjugation frequency mixer are connected together through two first radio frequency cables with equal length; the phase conjugation frequency mixer and the M-path power divider are prepared on the same medium substrate, and an F4B plate with the thickness of 0.508mm is adopted; and the local vibration source is connected to the input port of the M-path power divider through a second radio frequency cable. The phase conjugate mixer 5 is composed of two radio frequency filters 52, a 3dB coupler 53, a phase delay line 54, a local oscillator filter 55, a matching branch 56, two radio frequency coaxial ports 57 and a diode pair 58, wherein the dielectric substrate 51 is printed on the dielectric substrate 51; the local oscillation frequency of the phase conjugation mixer 5 is twice of the radio frequency, and the intermediate frequency is the same as the radio frequency; the length of the phase delay line 54 is one quarter of the radio frequency wavelength, and the actual length is 20; each of the radio frequency coaxial port 57, the radio frequency filter 52 and the 3dB coupler 53 is connected by a microstrip line of equal length and is disposed in central symmetry. The radio frequency filter 52 consists of two asymmetric taps 521 and two bent resonators 522, and the positions of the taps are 2mm away from the edges of the resonators; two C-shaped grooves 523 are formed in the bending resonator 522, and the size of the C-shaped grooves 523 is appropriately adjusted so that an out-of-band zero of the rf filter 52 falls on the local oscillator frequency.

The principle of the invention is as follows: the phase conjugate mixer shown in fig. 2 has a total of 4 ports, and port 1 and port 2 are connected to two ports of the patch antenna by equal coaxial lines, respectively. When the input phase of port 1 is

The signal of (3) enters the 3dB coupler after being radio frequency filtered. One path of signal passes through the straight-through end of the 3dB coupler and then passes through the phase delay line, and the phase is taken as

Loading on a first diode; the other path of the signal is also in phase through the coupling end of the 3dB coupler

To the second diode. Because the two diodes are placed in reverse, the phase of the output signals of the two diodes after frequency mixing is

And

one path of signal is respectively output to a port 1 and a port 2 through a phase delay line, and the phases of the signals at the two ports are respectively

And

the other signal is directly output to the 1 port and the 2 port through the 3dB coupler, and the phases of the signals are respectively

And

from the above analysis, when the radio frequency signal is input to the port 1, the intermediate frequency signals output by the two diodes at the port 1 are reversely cancelled; the intermediate frequency signals output by the two diodes at the 2 ports are in-phase superposed and have the phase of

According to the same method, when the 2-port input radio frequency signal, the intermediate frequency signals output by the two diodes at the 1-port are superposed in phase with the phase thereof

At the 2 port, the intermediate frequency signals output by the two diodes are counteracted in opposite phases; that is, only 2 ports output the intermediate frequency signal when the 1 port inputs the radio frequency signal, and only 1 port output the intermediate frequency signal when the 2 port inputs the radio frequency signal, and the above analysis can know that the two intermediate frequency signals have an inherent phase difference of 180 °, and furthermore, the intermediate frequency signal and the radio frequency signal are conjugated in phase. The phase gradient of each antenna element is opposite to that of the incoming wave due to the phase conjugation, and the generation direction isAnd (6) backtracking. When incident waves are vertical polarized waves, the port 1 and the port 2 respectively receive radio-frequency signals with equal phases, the radio-frequency signals are respectively output by the port 2 and the port 1 after conjugate mixing, and the two signals form horizontal polarized currents on the patch due to 180-degree phase difference to radiate the horizontal polarized waves outwards; when the incident wave is a linear polarized wave with an angle of 45 degrees, only the port 1 receives a radio frequency signal and outputs the radio frequency signal through the port 2, so that the linear polarized wave with the angle of-45 degrees is radiated; when the incident wave is a horizontal polarized wave, the port 1 and the port 2 receive constant-amplitude signals but have a phase difference of 180 degrees, the 180-degree phase difference of one path of signals is compensated after conjugate mixing, and the phases of two output signals are the same, so that the vertical polarized wave is radiated; since the above process is merely rotated for circularly polarized waves, circularly polarized waves orthogonal to the incoming waves are radiated. Since each cell radiates orthogonally polarized waves, the backtracking array radiates waves that are also orthogonally polarized to the incoming waves.

It will be appreciated by those of ordinary skill in the art that the embodiments described herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited embodiments and examples. Those skilled in the art, having the benefit of this disclosure, may effect numerous modifications thereto and changes may be made without departing from the scope of the invention in its broader aspects.

Claims

1. A polarization rotation direction backtracking array comprises M polarization rotation direction backtracking subunits (1), M paths of power dividers (2) and a local oscillation source (3); the method is characterized in that: m is an integer more than or equal to 3; the polarization rotation direction retroactive subunit (1) consists of a double-fed dual-polarized patch antenna (4) and a phase conjugate mixer (5), wherein the phase conjugate mixer (5) consists of two radio frequency filters (52), a 3dB coupler (53), a phase delay line (54), a local oscillator filter (55), a matching branch (56), two radio frequency coaxial ports (57) and a diode pair (58), wherein the dielectric substrate (51) is printed on the dielectric substrate (51); the phase delay line (54) has a length of one quarter of a radio frequency wavelength; each radio frequency coaxial port (57), the radio frequency filter (52) and the 3dB coupler (53) are connected by microstrip lines with equal length and are arranged in central symmetry; the double-fed patch antenna (4) and the phase conjugate mixer (5) are connected together through two first radio frequency cables (6) with equal length; the phase conjugate mixer (5) and the M-path power divider (2) are prepared on the same dielectric substrate; the local vibration source (3) is connected to the input port of the M-path power divider (2) through a second radio frequency cable (7).

2. A polarization rotation direction backtracking array according to claim 1, wherein: the double-fed dual-polarized patch antenna (4) comprises two orthogonal coaxial feed ports (11) and is connected with two radio frequency coaxial ports (28) of the phase conjugate mixer (2) through first radio frequency cables (12) with equal lengths.

3. The polarization rotation direction backtracking array of claim 1, wherein: the radio frequency filter (52) is composed of two asymmetric taps (521) and two bending resonators (522); two C-shaped grooves (523) are formed in the bending resonator (522), and the size of each C-shaped groove (523) is properly adjusted to enable one out-of-band zero point of the radio frequency filter (52) to fall on the local frequency.