CN107508040A - Recall array in a kind of polarized rotation direction - Google Patents

Abstract

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

Description

A Polarization Rotation Direction Retrospective Array

technical field

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

Background technique

The direction backtracking array can automatically forward a signal pointing to the direction of the incoming wave without knowing the direction of the incoming wave. Because it has the characteristic of automatically tracking the incoming wave direction without complex signal processing equipment, it has a great application prospect in the fields of wireless communication, wireless energy transmission, radio frequency transmission and so on.

The existing direction traceback arrays generally transmit and receive at the same frequency, so the orthogonal polarization method is often used for transceiver isolation. Luxey C et al. disclose a retrodirective transponder with polarization duplexing for dedicated short-range communications [J]. IEEE Transactions on Microwave Theory & Techniques , 2014,47(9):1910-1915.); However, due to the use of dual-linear polarization, the array requires accurate alignment of the transmitting and receiving antennas to avoid polarization loss and is not suitable for communication with moving targets. Choi JH et al. designed a retrodirective array that emits orthogonally polarized waves for incident waves of any polarization (Choi J H, Dong Y, Sun J S, et al. Retrodirective Array Immune to Incident Waves With Arbitrary Polarizations[J ]. IEEE Transactions on Antennas & Propagation, 2013, 61(12): 6008-6013.), this array can reduce the polarization mismatch loss without accurate alignment of the transmitting and receiving antennas; however, the array feeding system is complicated, and each path Requires four mixers, four amplifiers, and two phase delay lines, limiting its practicality.

Contents of the invention

The purpose of the present invention is to propose a polarization rotation direction backtracking array, which can backtrack its orthogonal polarization wave for any incident wave, reduce the polarization mismatch loss, simplify the phase conjugate circuit structure at the same time, and make the whole structure compact and reliable.

The technical solution of the present invention is: a polarization rotation direction backtracking array, including M polarization rotation direction backtracking subunits, M power dividers, and local oscillator sources; said M is an integer greater than or equal to 3; said The polarization rotation direction traceback subunit is composed of a double-fed dual-polarized patch antenna and a phase conjugate mixer; the double-fed patch antenna and the phase conjugate mixer pass through two equal-length first radio frequency cables Lines are connected together; the phase conjugate mixer and the M-way power divider are prepared on the same dielectric substrate; the local oscillator source is connected to the input port of the M-way power divider through the second radio frequency cable .

Further, the phase conjugate mixer is composed of two radio frequency filters printed on the dielectric substrate, a 3dB coupler, a phase delay line, a local oscillator filter, a matching stub, and two radio frequency coaxial ports , Diode pair; The local oscillator frequency of the phase conjugate mixer is twice the RF frequency, and the intermediate frequency is the same as the RF frequency; the length of the phase delay line is a quarter of the RF wavelength; each RF coaxial Ports, RF filters and 3dB couplers are connected by microstrip lines of equal length and placed symmetrically about the center.

Further, the radio frequency filter is composed of two asymmetric taps and two bent resonators; two C-shaped slots are opened on the bent resonators, and the size of the C-shaped slots is properly adjusted to make the radio frequency filter An out-of-band zero of is at the local oscillator frequency.

Advantages and beneficial effects of the present invention:

(1) The present invention has the ability to trace back the orthogonal polarized wave for any incident polarized wave, avoiding the loss caused by the polarization mismatch of the transmitting and receiving antennas in the ordinary polarization duplex system.

(2) The present invention has the characteristic of compact structure. The invention utilizes the inherent phase difference of two ports of the 3dB coupler and a phase delay line to realize the inherent phase difference of 180° output by the two ports, and at the same time, the transmitting and receiving antenna is realized by using one antenna, and the transmitting and receiving ports are also realized by using the same port. Therefore, the present invention only needs a mixer and a two-port antenna to realize the functions of polarization rotation and direction backtracking.

(3) The radio frequency filter used in the present invention has the characteristic that the out-of-band zero point can be adjusted without affecting the passband. Since the local oscillator used in the present invention is twice the frequency of the radio frequency and its energy is greater than that of the radio frequency signal, in order to suppress the radiation of the local oscillator frequency, the structure of the radio frequency filter can be adjusted so that its out-of-band zero point falls on the local oscillator frequency.

Description of drawings

Fig. 1 is the overall structural representation of the present invention

Fig. 2 is a structural diagram of a phase conjugate mixer of the present invention

Fig. 3 is the radio frequency filter S parameter curve of the present invention

Fig. 4 is the direction diagram of the present invention under different incident wave angles

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments: As shown in Figure 1, a polarization rotation direction traceback array includes M polarization rotation direction traceback subunits 1, M-way power splitters 2, local oscillators Source 3; said M is an integer greater than or equal to 3; said polarization rotation direction backtracking subunit is composed of a double-fed dual-polarized patch antenna and a phase conjugate mixer; said double-fed patch antenna It is connected with the phase conjugate mixer through two equal-length first radio frequency cables; the phase conjugate mixer and the M-way power divider are prepared on the same dielectric substrate, here the thickness is 0.508mm The F4B plate; the local oscillator source is connected to the input port of the M-way power divider through the second radio frequency cable. The phase conjugate mixer 5 is printed on the dielectric substrate 51 by a dielectric substrate 51, two radio frequency filters 52, a 3dB coupler 53, a phase delay line 54, a local oscillator filter 55, a matching stub 56, two A radio frequency coaxial port 57 and a diode pair 58; the local oscillator frequency of the phase conjugate mixer 5 is twice the radio frequency, and the intermediate frequency is the same as the radio frequency; the length of the phase delay line 54 is 1/4 A radio frequency wavelength, the actual length is 20; each radio frequency coaxial port 57, radio frequency filter 52 and 3dB coupler 53 are connected by a microstrip line of equal length and placed symmetrically about the center. The radio frequency filter 52 is composed of two asymmetric taps 521 and two bent resonators 522, the tap position is 2 mm away from the edge of the resonator; two C-shaped grooves 523 are opened on the bent resonator 522, and the C-shaped The dimensions of slot 523 are appropriately adjusted so that an out-of-band null of RF filter 52 falls at the local oscillator frequency.

The principle of the present invention is: the phase conjugate mixer as shown in Fig. 2 has 4 ports in total, port 1 and port 2 are respectively connected to two ports of the patch antenna by equal-length coaxial lines. When the port 1 input phase is When the signal is filtered by RF, it enters the 3dB coupler. One of the signals passes through the through end of the 3dB coupler and then through the phase delay line. Loaded on the first diode; the other way through the coupling end of the 3dB coupler is also in phase loaded onto the second diode. Since the two diodes are placed in reverse, the phase of the output signals of the two diodes after mixing is and One signal is output to port 1 and port 2 respectively through the phase delay line, and the signal phases at the two ports are respectively and The other signal is directly output to port 1 and port 2 through the 3dB coupler, and the signal phases are and From the above analysis, it can be seen that when the RF signal is input to port 1, the intermediate frequency signal output by two diodes at port 1 cancels in reverse; the intermediate frequency signal output by two diodes at port 2 is superimposed in phase, and its phase is According to the same analysis method, when the RF signal is input to the 2 port, the intermediate frequency signal output by the two diodes at the 1 port is superimposed in the same phase, and its phase is The IF signal output by two diodes at the 2 port is reversed and canceled; that is to say, when the 1 port inputs the RF signal, only the 2 port will output the IF signal, and when the 2 port inputs the RF signal, only the 1 port will output the IF signal. From the above analysis, it can be known that the two IF signals have an inherent phase difference of 180°. In addition, the IF signal and the RF signal are phase conjugated. Due to the characteristics of phase conjugation, the phase gradient on each antenna element is exactly opposite to the phase gradient formed by the incoming wave, so the direction backtracking occurs. When the incident wave is a vertically polarized wave, port 1 and port 2 respectively receive RF signals of equal phase, which are output by port 2 and port 1 respectively after conjugate mixing. These two signals have a phase difference of 180° Therefore, a horizontally polarized current is formed on the patch to radiate horizontally polarized waves; when the incident wave is a 45° angle polarized wave, only port 1 receives the RF signal and is output by port 2, so the radiation is -45° linearly polarized wave at an angle; when the incident wave is a horizontally polarized wave, port 1 and port 2 receive equal-amplitude signals but their phase difference is 180°, and the 180° phase difference of one of the signals is compensated after conjugate mixing , the two output signals have the same phase, so the vertically polarized wave is radiated; for the circularly polarized wave, the above process is just rotated, so the circularly polarized wave orthogonal to the incoming wave is radiated. Since each element radiates orthogonally polarized waves, the retroactive array also radiates waves that are polarized orthogonally to the incoming wave.

Those skilled in the art will appreciate that the embodiments described here are to help readers understand the principles of the present invention, and it should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical revelations disclosed in the present invention without departing from the present invention, and these modifications and combinations are still within the protection scope of the present invention.

Claims (4)

1. A polarization rotation direction retrospective array, comprising M polarization rotation direction retrospective subunits (1), M road power splitters (2), local oscillator sources (3); it is characterized in that: described M is An integer greater than or equal to 3; the polarization rotation direction traceback subunit (1) is composed of a double-fed dual-polarized patch antenna (4) and a phase conjugate mixer (5); the double-fed patch The antenna (4) and the phase conjugate mixer (5) are connected together by two equal-length first radio frequency cables (6); the phase conjugate mixer (5) and the M road power divider ( 2) prepared on the same dielectric substrate; the local oscillator source (3) is connected to the input port of the M-way power divider (2) through the second radio frequency cable (7). 2. A kind of polarization rotation direction traceback array according to claim 1, characterized in that: the phase conjugate mixer (5) is printed on the dielectric substrate (51) by the dielectric substrate (51) Two radio frequency filters (52), 3dB coupler (53), phase delay line (54), local oscillator filter (55), matching stub (56), two radio frequency coaxial ports (57), diode pair ( 58) composition; the local oscillator frequency of the phase conjugate mixer (5) is twice the radio frequency, and the intermediate frequency is the same as the radio frequency; the phase delay line (54) has a length of 1/4 radio frequency wavelength; Each radio frequency coaxial port (57), radio frequency filter (52) and 3dB coupler (53) are connected by microstrip lines of equal length and placed symmetrically about the center. 3. A kind of polarization rotation direction traceback array according to claim 1, is characterized in that: described double-fed dual-polarized patch antenna (4) contains two coaxial feeding ports (11) that are placed orthogonally ), and adopt the first radio frequency cable (12) of equal length to connect with the two radio frequency coaxial ports (28) of the phase conjugate mixer (2). 4. The polarization rotation direction retroactive array according to claim 1, characterized in that: the radio frequency filter (52) is composed of two asymmetric taps (521) and two bent resonators (522); Two C-shaped slots (523) are opened on the bent resonator (522), and the size of the C-shaped slots (523) is properly adjusted so that an out-of-band zero point of the radio frequency filter (52) falls on the local vibration frequency.