CN116131768A

CN116131768A - Mixer circuit and microwave detection device for realizing power division phase shift and power feed by 3dB bridge

Info

Publication number: CN116131768A
Application number: CN202211615512.XA
Authority: CN
Inventors: 邹高迪; 孙毅; 邹新
Original assignee: Shenzhen Merrytek Technology Co Ltd
Current assignee: Shenzhen Merrytek Technology Co Ltd
Priority date: 2021-12-17
Filing date: 2022-12-15
Publication date: 2023-05-16

Abstract

The invention provides a mixing circuit and a microwave detection device for realizing power division phase shift and feed by a 3dB bridge, wherein based on the electrical characteristics of an input port, an isolation port and two output ports of the 3dB bridge, two paths of excitation signals with 90 DEG or 180 DEG phase difference are provided for the two output ports by connecting one path of local oscillation signals to the input port, so that at least one output port of the mixing circuit for realizing the power division phase shift and feed by the 3dB bridge is connected with a corresponding antenna, and the mixing circuit has the functions of power division, phase shift, feed and frequency mixing to realize single-path transmitting feed, single-path receiving feed and single-path receiving and receiving integral feed of a single antenna or two paths of feed of two antennas based on the same or different feed combinations, thereby having wider applicability and being capable of reducing the occupied space of the corresponding circuits of the microwave detection device, and being beneficial to the miniaturized design of the microwave detection device.

Description

Mixer circuit and microwave detection device for realizing power division phase shift and power feed by 3dB bridge

Technical Field

The invention relates to the field of Doppler microwave detection, in particular to a mixing circuit and a microwave detection device for realizing power division phase shift and power feeding by a 3dB bridge.

Background

With the development of the internet of things technology, the requirements of artificial intelligence, intelligent home and intelligent security technology on environment detection, especially on detection accuracy of motion characteristics of existence, movement and inching of people, are higher and higher, and accurate judgment basis can be provided for intelligent terminal equipment only by acquiring enough stable detection results. The radio technology, including the microwave detection technology based on the Doppler effect principle, has unique advantages in the behavior detection and existence detection technology, and can detect living animals such as motion characteristics, movement characteristics and micro motion characteristics of people, and even heartbeat and respiratory characteristic information of people without invading the privacy of the people, so that the radio technology has wide application prospect. Specifically, the Doppler microwave detection module in the prior art is fed by a local oscillator signal through a mixer to emit a detection beam corresponding to the frequency of the local oscillator signal in a corresponding detection space, and receives an echo formed by the reflection of the detection beam by at least one object in the detection space to generate a feedback signal, wherein the mixer receives the feedback signal and outputs a Doppler intermediate frequency signal corresponding to the frequency difference between the local oscillator signal and the feedback signal in a mixing detection mode, and the fluctuation of the Doppler intermediate frequency signal in amplitude theoretically corresponds to the motion of the object in the detection space based on the Doppler effect principle. The mixer of the Doppler microwave detection module in the prior art mainly adopts a balanced mixer based on the advantages of small noise and high sensitivity of the existing balanced mixer in order to ensure the feedback precision of the Doppler intermediate frequency signal on the motion of an object in the detection space.

Referring to fig. 1A and 1B of drawings in the specification of the present invention, the equivalent circuit principle of a conventional balanced mixer employing a 3dB branch line bridge and the structure of a corresponding varistor form are illustrated, respectively. Specifically, the balanced mixer includes a 3dB branch line bridge 10P, two mixer tubes 20P and an intermediate frequency output port 30P, wherein the 3dB branch line bridge 10P adopts a 3dB branch line bridge in a variable resistance form for impedance matching purposes, and has a local oscillation signal input port 101P, a feedback signal input port 102P, a first mixer port 103P, a second mixer port 104P, a first microstrip arm 11P connected between the local oscillation signal input port 101P and the feedback signal input port 102P, a second microstrip arm 12P connected between the feedback signal input port 102P and the first mixer port 103P, a third microstrip arm 13P connected between the first mixer port 103P and the second mixer port 104P, a fourth microstrip arm 14P connected between the second mixer port 104P and the local oscillation signal input port 101P, correspondingly forming the first microstrip arm 11P, the second microstrip arm 12P, the third microstrip arm 13P and the fourth microstrip arm 14P with a microstrip frame structure connected end to end, wherein the first microstrip arm 11P, the second microstrip arm 12P, the third microstrip arm 13P and the fourth microstrip arm 14P are each provided with an electrical length of λ/4, that is, the 3dB branch line bridge 10P has an electrical length of λ, where λ is an electrical length parameter of one wavelength corresponding to the frequency of the local oscillation signal, such that a phase difference of 90 degrees is provided between the first mixing port 103P and the second mixing port 104P, wherein two ends with different polarities, respectively belonging to different mixing tubes 20P, of the two mixing tubes 20P are respectively connected to the first mixing port 103P and the second mixing port 104P, the other two ends of the two mixer tubes 20P with different polarities respectively belonging to different mixer tubes 20P are connected to the same capacitance to ground, so as to ensure that the two ends are short-circuited to ground at high frequency, and the high-frequency filtering of the intermediate frequency output port 30P is formed corresponding to the state that the two grounded ends of the two mixer tubes 20P are electrically connected to the intermediate frequency output port 30P, so that the power of the local oscillation signal and the feedback signal respectively input from the local oscillation signal input port 101P and the feedback signal input port 102P can be fully loaded on the two mixer tubes 30P without leaking to the intermediate frequency output port 30P, wherein the grounded ends of the two mixer tubes 20P are electrically connected to the intermediate frequency output port 30P through two microstrip connection lines 31P with equal electrical lengths, thereby being beneficial to the cancellation of noise current in the doppler intermediate frequency signal, and presenting the advantages of low noise and high sensitivity corresponding to the balance mixer.

In particular, the balanced mixer has various variations in the structural morphology of the 3dB branch line bridge 10P based on the respective impedance matching designs, embodied as the structural morphology of the 3dB branch line bridge 10P based on the different varistor morphology designs of the 3dB branch line bridge 10A that are symmetrical with respect to the A-A section line based on the structure of the 3dB branch line bridge (also referred to as 3dB branch line directional coupler) illustrated in fig. 2A and 2B according to the respective impedance matching designs. Wherein the 3dB drop wire bridge 10A is a four-port network having an input port 101A, an isolated port 102A, a coupled port 103A and a pass-through port 104A, and a first arm 11A defined between the input port 101A and the isolated port 102A, a second arm 12A defined between the isolated port 102A and the coupled port 103A, a third arm 13A defined between the coupled port 103A and the pass-through port 104A, a fourth arm 14A defined between the pass-through port 104A and the input port 101A, a loop structure corresponding to the first arm 11A, the second arm 12A, the third arm 13A and the fourth arm 14A, wherein the first arm 11A, the third arm 13A and the fourth arm 14A are each provided with an electrical length of λ/4, and wherein the characteristic impedance of the first arm 11A and the third arm 13A are arranged to be equal to each other in a 3-Z1 and the third arm 13A, the characteristic impedance of the third arm 11A and the fourth arm 13A, the third arm 11A and the third arm 13A are arranged to be equal to each other in a-Z1, the Z1 and the third arm 14A are arranged to have a 2-Z1 and the same phase when the third arm and the third arm 13A and the fourth arm 13A and the third arm 13A are connected to each other in a and the third arm 11A and the third arm 14A is arranged to have a 2-Z1 and the third arm is equal to the phase as the third arm 11 as the third arm and the third arm 11A is a and the third arm is a 4A; the output power of the first arm 11A, branch 2, fourth arm 14A-third arm 13A-second arm 12A) to the isolated port 102A is equal based on the characteristic impedance relationship described above, and have opposite phases by λ/2 on the way so that the isolated port 102A does not output, and the output power from the input port 101A to the through port 104A and the coupled port 103A is equal based on the characteristic impedance relationship described above and has a phase difference of 90 ° by λ/4 on the way.

In other words, the 3dB branch line bridge 10A is a ring network with four ports and four arms each having an electrical length λ/4 and connected end to end, wherein the arm widths of two opposite arms are larger than the arm widths of the other two opposite arms, the two opposite arms having a narrower named arm width are two parallel arms, and the two outer two opposite arms are named as serial arms, the characteristic impedances Z1 and Z3 of the two parallel arms and the characteristic impedances Z2 and Z4 of the two serial arms satisfy z1=z3= 2z2= v2z4, so that when any one port of the 3dB branch line bridge 10A is the input signal of the input port 101A, the other end of one parallel arm terminated by the input port 101A is the isolation port 102A without output based on the characteristic impedance relationship and the electrical length relationship described above, that is, the input port 101A and the isolation port 102A are isolated from each other, corresponding to a state in which the isolation port 102A inputs a signal, the output port 101A exhibits a characteristic isolated from the isolation port 102A without outputting, both ends of the other parallel arm have the same output power and an output phase difference of 90 °, corresponding to the other end of the serial arm terminating the input port 101 being the through port 104A based on the output path of the both ends, and the other end of the serial arm terminating the isolation port 102A being the coupling port 103A, the above naming of the ports of the 3dB branch line bridge 10A is a common naming of the 3dB branch line bridge 10A and the ports of the 3dB branch line bridge 10A in a varistor configuration (a variation configuration of the 3dB branch line bridge 10A in A-A section line symmetry over the length and/or width of the parallel arm based on impedance matching and/or junction reactance effects considerations) known to those skilled in the art.

Based on the above characteristics of the 3dB branch line bridge 10A, the 3dB branch line bridge and the 3dB branch line bridge in the varistor form (the 3dB branch line bridge 10P as illustrated in fig. 1B) are widely applied to a mixing detection circuit, and specifically correspond to fig. 1A and 1B, with one of the input port 101A and the isolation port 102A of the 3dB branch line bridge or the varistor form of the 3dB branch line bridge being the local oscillation signal input port 101P, and with the other of the input port 101A and the isolation port 102A being the feedback signal input port 102P, and with the through port 104A and the coupling port 103A being the first mixing port 103P and the second mixing port 104P, the balanced mixer thus formed is applicable only to a single transceiver-integrated antenna, and with the feedback signal input port 102P being connected to the antenna to thereby increase the power-transfer impedance of the antenna and the required phase-shift circuit compared with the antenna in the antenna-to-feed network, and thus increasing the required power-transfer impedance of the antenna-to-feed network, and the phase-shift-matching circuit is more difficult; on the other hand, the mixer 20P needs to use a schottky barrier diode of expensive gallium arsenide or gallium nitride semiconductor material in practical use due to the adoption of the double mixer structure, so that the cost of the balanced mixer is high; in addition, the balanced mixer cannot separate the local oscillator signal from the feedback signal in a state that the local oscillator signal and the feedback signal are mixed, so that the optimization design of the corresponding circuit in a discrete component form or an integrated circuit form based on the purposes of anti-interference and circuit simplification is limited.

That is, the existing balanced mixer formed by the 3dB branch line bridge or the coupling port 103A and the first mixing port 103P and the second mixing port 104P has a single application range, and cannot realize the power division phase shift and the feeding function, so that the occupied area of the corresponding circuit is difficult to be reduced and the corresponding impedance matching design is difficult to be simplified, and the balanced mixer has the defects of limited space and high cost.

Disclosure of Invention

It is an object of the present invention to provide a mixer circuit and a microwave probe apparatus for performing power division phase shift and feeding in a 3dB bridge, wherein the mixer circuit for performing power division phase shift and feeding in a 3dB bridge allows a single mixer tube structure to be adopted to facilitate miniaturization design of the microwave probe apparatus and reduce cost of the microwave probe apparatus.

Another object of the present invention is to provide a mixing circuit and a microwave detection device for implementing power division phase shift and power feed by using a 3dB bridge, wherein the mixing circuit for implementing power division phase shift and power feed by using a 3dB bridge has functions of power division, phase shift, power feed and mixing, so that the design of the power division, phase shift and power feed network of the microwave detection device can be simplified, thereby reducing the occupied space of the corresponding circuit of the microwave detection device, and thus being beneficial to the miniaturized design of the microwave detection device.

Another object of the present invention is to provide a mixing circuit and a microwave detection device for implementing power division phase shift and power feed by using a 3dB bridge, wherein the mixing circuit for implementing power division phase shift and power feed by using a 3dB bridge has functions of power division, phase shift, power feed and mixing, so that an impedance matching design of the microwave detection device can be simplified, thereby being beneficial to guaranteeing a transmission efficiency and a detection precision of the microwave detection device.

Another object of the present invention is to provide a mixing circuit and a microwave detection device for implementing power division phase shift and feeding with a 3dB bridge, wherein the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge is suitable for single-path transmission feeding, single-path reception feeding, single-path transceiving integrated feeding, and two-path feeding for a single antenna or two antennas based on the same or different feeding combinations, thereby having wider applicability.

Another object of the present invention is to provide a mixer circuit and a microwave detection device for implementing power division phase shift and power feeding by using a 3dB bridge, where the mixer circuit for implementing power division phase shift and power feeding by using a 3dB bridge is adapted to provide two excitation signals with a phase difference of 90 ° for a single antenna by using one local oscillation signal, so as to form a circularly polarized power feeding for the antenna in a state that access points of the antenna corresponding to the two excitation signals are orthogonally arranged, and facilitate a miniaturized design of the microwave detection device in a circularly polarized form due to a simple structure.

The invention further aims to provide a frequency mixing circuit and a microwave detection device which realize power division phase shift and feed by a 3dB bridge, wherein the frequency mixing circuit which realizes power division phase shift and feed by the 3dB bridge is suitable for providing excitation signals which are different by 90 degrees for two antennas by one local oscillation signal so as to ensure the isolation between the two antennas and ensure the stability and detection precision of the microwave detection device, and in the state that the polarization directions of the two antennas are orthogonal, the isolation between the two antennas is further ensured so as to ensure the stability and detection precision of the microwave detection device, and the circuit structure is simple, thereby being beneficial to reducing the occupied space of the corresponding circuit, and having wide applicability.

Another object of the present invention is to provide a mixing circuit and a microwave detecting device for implementing power division phase shift and feeding with a 3dB bridge, wherein the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge is adapted to provide two antennas with excitation signals having a phase difference of 90 ° with one local oscillation signal, and the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge is adapted to provide four antennas with two opposite local oscillation signals having a phase difference of 90 ° with two opposite local oscillation signals, so as to allow implementing a circular polarization form of the microwave detecting device based on two mixing circuits for implementing power division phase shift and feeding with a 3dB bridge, and facilitate a miniaturized design of the microwave detecting device having a circular polarization form due to a simple structure.

Another object of the present invention is to provide a mixer circuit and a microwave detection device for implementing power division phase shift and power feeding by using a 3dB bridge, where the mixer circuit for implementing power division phase shift and power feeding by using a 3dB bridge is adapted to provide excitation signals 180 ° different for a single antenna with one local oscillation signal, so as to form inverted double-fed to the antenna in a state that access points of the antenna corresponding to the two excitation signals are set in opposite polarization directions, thereby improving stability of the microwave detection device, and being beneficial to miniaturized design of the microwave detection device due to simple structure.

Another object of the present invention is to provide a mixing circuit and a microwave detection device for implementing power division phase shift and feeding with a 3dB bridge, wherein the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge is adapted to provide two antennas with excitation signals 180 ° different from one another by one local oscillation signal, and the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge is adapted to provide four antennas with excitation signals 90 ° different from one another by two local oscillation signals 90 ° corresponding to the state of the microwave detection device, so as to allow implementing a circular polarization form of the microwave detection device based on two mixing circuits for implementing power division phase shift and feeding with a 3dB bridge, and facilitate a miniaturized design of the microwave detection device in a circular polarization form due to a simple structure.

Another object of the present invention is to provide a mixing circuit and a microwave detection apparatus for implementing power division phase shift and feeding with a 3dB bridge, wherein the feedback signal mixed with the local oscillation signal in the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge can be separated to allow the feedback signal in an independent state to be obtained based on the transceiving integral feeding to the same antenna, and the occupation space of the corresponding circuit and antenna of the microwave detection apparatus can be reduced with respect to the feedback signal in an independent state obtained by transceiving integral feeding, thereby facilitating the miniaturized design of the microwave detection apparatus.

Another object of the present invention is to provide a mixing circuit and a microwave detection device for implementing power division phase shift and feeding with a 3dB bridge, in which the feedback signal mixed with the local oscillation signal in the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge can be separated to allow the feedback signal in an independent state to be obtained based on the transceiving integral feeding to the same antenna, so that the microwave detection device can be integrated with a microwave chip having a transmitting end and a receiving end directly using the existing transceiving integral feeding-based manner, thereby facilitating the miniaturized design of the microwave detection device.

It is another object of the present invention to provide a mixing circuit and a microwave detection apparatus for implementing power division phase shift and feeding with a 3dB bridge, wherein the feedback signal mixed with the local oscillation signal in the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge can be separated to allow the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge to optimally design a mixing network between the feedback signal and the local oscillation signal in an independent state based on an anti-interference purpose and/or a circuit simplification purpose, thereby facilitating miniaturization design and anti-interference performance optimization of the microwave detection apparatus.

Another object of the present invention is to provide a mixing circuit and a microwave detection apparatus for implementing power division phase shift and feeding with a 3dB bridge, wherein the feedback signal mixed with the local oscillation signal in the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge can be separated, so that the mixing network for mixing the feedback signal and the local oscillation signal in the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge can be separated from the structural limitation of the conventional balanced mixer and have more flexible and diverse arrangement design relative to the conventional balanced mixer, thereby being beneficial to simplifying the design and miniaturizing the circuit of the microwave detection apparatus.

Another object of the present invention is to provide a mixing circuit and a microwave detecting device for implementing power division phase shift and feeding with a 3dB bridge, wherein the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge is adapted to provide electrical characteristics of two excitation signals different by 90 ° with one local oscillation signal at the through port and the coupling port respectively, so that the state that the through port and/or the coupling port of the mixing circuit for implementing power division phase shift and feeding with a 3dB bridge is connected with corresponding antennas is correspondingly implemented in a state that the 3dB bridge is implemented as a 3dB branch line bridge or a 3dB coupled line bridge, and the single line receiving and transmitting and receiving integrated circuit is implemented as a single line transmitting and receiving integrated circuit or a single line receiving and receiving integrated circuit by a single line receiving and coupling signal by a single line or a single line receiving and coupling signal receiving two antennas based on the same or different combinations thereof.

Another object of the present invention is to provide a mixing circuit and a microwave probe apparatus for implementing power division phase shift and feeding in a 3dB bridge, wherein the mixing circuit for implementing power division phase shift and feeding in a 3dB bridge is adapted to provide electrical characteristics of excitation signals having two circuits 180 ° different from each other in one local oscillation signal respectively at the through port and the coupling port based on electrical characteristics of an input port, a through port, a coupling port and an isolation port of the 3dB bridge (including the 3dB bridge in a variable resistance configuration), and in a state where the 3dB bridge is implemented as a 3dB loop bridge, the mixing circuit for implementing power division phase shift and feeding in a 3dB bridge is adapted to provide single-circuit transmitting feeding, single-circuit receiving feeding, single-circuit integral feeding and two-circuit feeding to a single antenna or two antennas based on the same or different combinations thereof in a state where the through port and the coupling port is connected with corresponding antennas, so that the mixing circuit for implementing power division phase shift and feeding in a 3dB bridge is more applicable.

Another object of the present invention is to provide a mixer circuit and a microwave detection device for implementing power division phase shift and feeding with a 3dB bridge, in which the mixer circuit for implementing power division phase shift and feeding with a 3dB bridge has functions of power division, phase shift and feeding, and can simplify design of power division, phase shift and feeding network of the microwave detection device by connecting the through port and/or the coupling port of the mixer circuit for implementing power division phase shift and feeding with a 3dB bridge to corresponding antennas, corresponding to implementing single-pass transmission feeding, single-pass reception feeding, single-pass transceiving integral feeding for a single antenna, and two-pass feeding for a single antenna or two antennas based on the same or different feeding combinations.

Another object of the present invention is to provide a mixer circuit and a microwave probe apparatus for implementing power division phase shift and feed in a 3dB bridge, wherein the feedback signal, which is input from the through port and/or the coupling port to the mixer circuit for implementing power division phase shift and feed in a 3dB bridge, can be separated and extracted from the isolation port by connecting the through port and/or the coupling port of the mixer circuit for implementing power division phase shift and feed in a 3dB bridge to a corresponding antenna, based on the isolation characteristics of the isolation port to the local oscillator signal input from the input port, thereby allowing the mixer circuit for implementing power division phase shift and feed in a 3dB bridge to optimally design a mixing network between the feedback signal and the local oscillator signal in an independent state based on the anti-interference purpose and/or the circuit simplification purpose.

Another object of the present invention is to provide a mixer circuit and a microwave probe apparatus for implementing power division phase shift and feeding with a 3dB bridge, wherein the mixer circuit for implementing power division phase shift and feeding with a 3dB bridge is connected to the local oscillator signal at the input port and the feedback signal at the isolation port, respectively, different from the existing balanced mixer in which the input port and the isolation port are connected to the local oscillator signal based on the characteristic of mutual isolation between the input port and the isolation port, and the feedback signal output from the corresponding antenna is connected to the input port based on the characteristic of mutual isolation between the input port and the isolation port, so as to allow the corresponding mixer circuit for implementing power division phase shift and feeding with a 3dB bridge to access the local oscillator signal at the input port, and the mixer circuit for implementing power division phase shift and feeding with a 3dB bridge is connected to the corresponding antenna, so as to allow the corresponding mixer circuit to be designed to be more flexibly and flexibly limited with respect to the local oscillator signal and the differential between the two-side-channel mixer circuit and the 3dB bridge by the two-channel mixer circuit and the differential carrier wave mixer circuit.

Another object of the present invention is to provide a mixer circuit and a microwave probe apparatus for implementing power division phase shift and feeding with a 3dB bridge, wherein the mixer circuit for implementing power division phase shift and feeding with a 3dB bridge accesses the local oscillator signal at the input port, and the through port and/or the coupling port feed of the mixer circuit for implementing power division phase shift and feeding with a 3dB bridge is connected to a corresponding antenna, so as to feed the antenna based on quadrature/anti-phase output of the through port and the coupling port for equal power distribution of the local oscillator signal, and the feedback signal outputted from the corresponding antenna is accessed based on the characteristic that the through port and/or the coupling port are mutually isolated in the state of accessing signal, while allowing the isolation characteristic of the local oscillator signal inputted from the input port based on the isolation port to be separated from the through port and/or the coupling port input, and the mixer circuit for implementing power division phase shift and feeding with the local oscillator signal at the 3dB bridge is connected to the corresponding antenna, so as to allow the frequency of the mixer circuit for implementing power division phase shift and feeding with the local oscillator signal to be more flexibly balanced than the 3dB bridge, and the number of the mixer circuit can be reduced by the number of the mixer circuit can be more flexibly distributed with respect to the mixer circuit at the 3dB phase shift point and the frequency of the mixer circuit.

Another object of the present invention is to provide a mixing circuit and a microwave detection device for implementing power division phase shift and power feeding with a 3dB bridge, wherein the mixing circuit for implementing power division phase shift and power feeding with a 3dB bridge further includes a mixing network, wherein the mixing network is configured in a single tube form and includes a mixing tube and a ground capacitor, wherein one end of the mixing tube is electrically connected to the 3dB bridge, and the other end of the mixing tube is electrically connected to the ground capacitor and is grounded via the ground capacitor, so as to ensure that a loop is formed by high frequency pairing of the mixing tube, thereby outputting the doppler intermediate frequency signal processed by high frequency filtering at the end of the mixing tube electrically connected to the ground capacitor, thereby ensuring the accuracy of the doppler intermediate frequency signal, and correspondingly improving the detection accuracy of the microwave detection device.

Another object of the present invention is to provide a mixer circuit and a microwave detection device for implementing power division phase shift and power feeding by using a 3dB bridge, where the microwave detection device has two paths of the mixer circuit for implementing power division phase shift and power feeding by using a 3dB bridge, where in a state where the 3dB bridge is implemented as a 3dB branch line bridge or a 3dB coupled line bridge, the microwave detection device is disposed in two paths of the mixer circuit for implementing power division phase shift and power feeding by using a 3dB bridge, and two paths of local oscillation signals in opposite phases are respectively connected to the mixer circuit for implementing power division phase shift and power feeding by using a 3dB bridge, so that a circular polarization form of the microwave detection device is implemented by using excitation signals whose four paths of phases are different from each other by 90 ° as corresponding antenna feeds based on quadrature outputs of equal power distribution of the local oscillation signals by using the through ports and the coupling ports.

Another object of the present invention is to provide a mixer circuit and a microwave detection device for implementing power division phase shift and power feeding by using a 3dB bridge, wherein based on a state that the 3dB ring bridge is connected to the local oscillator signal at the input port, two paths of electrical characteristics of the local oscillator signal can be outputted in equal power inversion at the through port and the coupling port, and the microwave detection device is disposed at the input ports of the two paths of mixer circuits for implementing power division phase shift and power feeding by using the 3dB bridge, and is connected to the through port and the coupling port of the 3dB ring bridge, respectively, so that an excitation signal with a phase difference of 90 ° in four paths is provided by using one path of local oscillator signal, so that a circular polarization form of the microwave detection device can be implemented by combining the 3dB ring bridge with the two paths of mixer circuits for implementing power division phase shift and power feeding by using the 3dB bridge.

The invention further provides a mixing circuit and a microwave detection device for realizing power division phase shift and feeding by using a 3dB bridge, wherein the microwave detection device is provided with two paths of local oscillation signals which are output in opposite phases by using a microwave chip, and the input ports of the two paths of mixing circuits for realizing power division phase shift and feeding by using the 3dB bridge are respectively connected with the ports of the two paths of local oscillation signals which are output in opposite phases by using the 3dB bridge, so that excitation signals with 90 degrees of phase sequence difference are provided, and the mixing circuit for realizing power division phase shift and feeding by using the 3dB bridge is externally arranged on the microwave chip, so that the state that the mixing circuit for realizing power division phase shift and feeding by using the 3dB bridge is integrated on the microwave chip in an integrated circuit mode is avoided, and the material limitation of the microwave chip corresponding to the material of the mixing tube is caused by a chip manufacturing process, thereby being beneficial to reducing the material cost and the process difficulty of the microwave chip, and being beneficial to guaranteeing the stability of the microwave detection device and reducing the cost of the microwave detection device.

Another object of the present invention is to provide a mixing circuit and a microwave detection device for implementing power division phase shift and power feeding by using a 3dB bridge, wherein the microwave detection device has two paths of the mixing circuit for implementing power division phase shift and power feeding by using a 3dB bridge, and in a state that the 3dB bridge is implemented as a 3dB ring bridge, the microwave detection device is disposed in two paths of the mixing circuit for implementing power division phase shift and power feeding by using a 3dB bridge, and two paths of local oscillation signals different by 90 ° are respectively connected to the mixing circuit for implementing power division phase shift and power feeding by using a 3dB bridge, so that the circular polarization mode of the microwave detection device is implemented by outputting four excitation signals different by 90 ° in phase sequence as corresponding antenna feeds at the two paths of the through ports and the two coupling ports based on the reverse output of equal power distribution of the local oscillation signals by the through ports and the coupling ports of the mixing circuit for implementing power division phase shift and power feeding by using a 3dB bridge.

Another object of the present invention is to provide a mixer circuit and a microwave probe apparatus for implementing power division phase shift and power feeding by using a 3dB bridge, wherein based on a state that the 3dB branch line bridge and the 3dB coupling line bridge are connected to the local oscillation signal at the input port, two paths of electrical characteristics of the local oscillation signal can be output in equal power quadrature by the through port and the coupling port, and the microwave probe apparatus is disposed at the input port of the two paths of mixer circuit for implementing power division phase shift and power feeding by using a 3dB bridge, and the input port of the mixer circuit for implementing power division phase shift and power feeding by using a 3dB bridge is connected to the through port and the coupling port of the 3dB branch line bridge, respectively, so that an excitation signal with four paths of phase sequences different by 90 ° is provided by using one path of local oscillation signal, so that a circular polarization of the microwave probe apparatus can be implemented by using a combination of the 3dB branch line bridge or the 3dB coupling line bridge and the two paths of mixer circuit for implementing power division phase shift and power feeding by using a 3dB bridge.

The invention further provides a mixing circuit and a microwave detection device for realizing power division phase shift and feeding by using a 3dB bridge, wherein the microwave detection device is provided with two paths of local oscillation signals which are orthogonally output by using a microwave chip, and the input ports of the two paths of mixing circuits for realizing power division phase shift and feeding by using the 3dB bridge are respectively connected with the ports of the two paths of local oscillation signals which are orthogonally output by the corresponding microwave chip, so that an excitation signal with 90 degrees of phase sequence difference is provided, and the mixing circuit for realizing power division phase shift and feeding by using the 3dB bridge is externally arranged on the microwave chip, so that the state that the mixing circuit for realizing power division phase shift and feeding by using the 3dB bridge is integrated on the microwave chip in an integrated circuit mode is avoided, and the material limitation of the microwave chip corresponding to the material of the mixing tube is caused by a chip manufacturing process, thereby being beneficial to reducing the material cost and the process difficulty of the microwave chip, and being beneficial to guaranteeing the stability of the microwave detection device and reducing the cost of the microwave detection device.

According to one aspect of the present invention, there is provided a mixer circuit for performing power division phase shift and feeding in a 3dB bridge, the mixer circuit for performing power division phase shift and feeding in a 3dB bridge being adapted to be connected to a corresponding antenna feed, to feed and receive a feedback signal to and from the antenna in a state of being connected to a local oscillator signal, and to output a doppler intermediate frequency signal corresponding to a frequency/phase difference between the local oscillator signal and the feedback signal in a manner of mixing detection, comprising:

The 3dB bridge is one of a 3dB annular bridge, a 3dB branch line bridge and a 3dB coupling line bridge which are arranged in a microstrip line mode, wherein a port of the 3dB bridge, which is connected with the local oscillation signal, is used as an input port of the 3dB bridge, the 3dB bridge is further defined with an isolation port and two output ports based on the electrical characteristics of the 3dB bridge, at least one output port of the 3dB bridge is connected with the antenna feed so as to feed the antenna based on the distribution output of the two output ports to the local oscillation signal connected with the input port, and the feedback signal is connected with the antenna from the corresponding output port based on the characteristic that the two output ports are mutually isolated in the state of the connected signal; and

a mixing network, wherein in a state that the mixing network is arranged in a single mixing tube mode, the mixing network comprises a mixing tube and a grounding capacitor, one end of the mixing tube is electrically connected to the 3dB bridge, the other end of the mixing tube is electrically connected to the grounding capacitor and is grounded through the grounding capacitor, so as to ensure that a loop is formed through a high frequency pair of the mixing tube, and the Doppler intermediate frequency signal subjected to high frequency filtering is output at the end of the mixing tube electrically connected with the grounding capacitor; the mixing network is arranged in a double mixing pipe mode, the mixing network comprises two mixing pipes and a grounding capacitor, two ends, which are respectively different in polarity, of the mixing pipes are respectively connected to two points of the 3dB branch line bridge, the other two ends, which are respectively different in polarity, of the mixing pipes are electrically connected to the grounding capacitor and are grounded through the grounding capacitor, and therefore a loop is formed through high frequency of the mixing pipes, and Doppler intermediate frequency signals subjected to high frequency filtering processing are output at the end, which is electrically connected with the grounding capacitor, of the mixing pipes.

In an embodiment, wherein the 3dB bridge is a 3dB branch line bridge arranged in the form of a microstrip line.

In an embodiment, wherein the mixing network is arranged in a single mixer-pipe configuration.

In an embodiment, an end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the isolation port.

In an embodiment, an end of the mixer tube electrically connected to the 3dB bridge is disposed to be electrically connected to the 3dB bridge through a microstrip line structure at the isolation port.

In an embodiment, one end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at one of the output ports.

In an embodiment, an end of the mixer tube electrically connected to the 3dB bridge is disposed through a microstrip line structure, and the output port of the mixer tube is electrically connected to the 3dB bridge.

In an embodiment, an end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the input port.

In an embodiment, an end of the mixer tube electrically connected to the 3dB bridge is disposed to be electrically connected to the 3dB bridge via a microstrip line structure at the input port.

In an embodiment, one end of the mixer tube electrically connected to the 3dB bridge is electrically connected to two points of the 3dB bridge.

In an embodiment, one end of the mixer tube electrically connected to the 3dB bridge is disposed at two points with a lambda/4 electrical length of the 3dB bridge and electrically connected to the 3dB bridge, wherein lambda is a wavelength parameter corresponding to the frequency of the local oscillation signal.

In an embodiment, one end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the isolation port of the 3dB bridge and one of the output ports is electrically connected to the 3dB bridge.

In an embodiment, one end of the mixer tube electrically connected to the 3dB bridge is disposed on the isolation port and one of the output ports of the 3dB bridge via a two-way microstrip line structure, and is electrically connected to the 3dB bridge.

In an embodiment, one end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the input port of the 3dB bridge and one of the output ports is electrically connected to the 3dB bridge.

In an embodiment, one end of the mixer tube electrically connected to the 3dB bridge is disposed on the input port and one of the output ports of the 3dB bridge via a two-way microstrip line structure, and is electrically connected to the 3dB bridge.

In an embodiment, one end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at two output ports of the 3dB bridge.

In an embodiment, an end of the mixer tube electrically connected to the 3dB bridge is disposed to be electrically connected to the 3dB bridge through two microstrip line structures at two output ports of the 3dB bridge.

In an embodiment, one end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the input port and the isolation port of the 3dB bridge.

In an embodiment, an end of the mixer tube electrically connected to the 3dB bridge is disposed in electrical connection with the 3dB bridge via a two-way microstrip line structure at the input port and the isolation port of the 3dB bridge.

In an embodiment, wherein the mixing network is arranged in a double mixer-pipe configuration.

In an embodiment, two ends of the two mixer tubes electrically connected to the 3dB bridge are disposed at two points of the 3dB bridge having a lambda/4 electrical length and electrically connected to the 3dB bridge, wherein lambda is a wavelength parameter corresponding to the frequency of the local oscillation signal.

In an embodiment, two ends of the two mixer tubes electrically connected to the 3dB bridge are electrically connected to the 3dB bridge at two output ports of the 3dB bridge, respectively.

In an embodiment, two ends of the two mixer tubes electrically connected to the 3dB bridge are respectively electrically connected to the 3dB bridge through two output ports of the 3dB bridge and a microstrip line structure.

In an embodiment, two ends of the two mixer tubes electrically connected to the 3dB bridge are electrically connected to the 3dB bridge at the isolation port and one of the output ports of the 3dB bridge, respectively.

In an embodiment, two ends of the two mixer tubes electrically connected to the 3dB bridge are respectively disposed on the isolation port and one of the output ports of the 3dB bridge via a microstrip line structure, and are electrically connected to the 3dB bridge.

In an embodiment, two ends of the two mixer tubes electrically connected to the 3dB bridge are electrically connected to the 3dB bridge at the input port and one of the output ports of the 3dB bridge, respectively.

In an embodiment, two ends of the two mixer tubes electrically connected to the 3dB bridge are respectively disposed on the input port and one of the output ports of the 3dB bridge via a microstrip line structure, and are electrically connected to the 3dB bridge.

In an embodiment, two ends of the two mixer tubes electrically connected to the 3dB bridge are electrically connected to the 3dB bridge at the input port and the isolation port of the 3dB bridge, respectively.

In an embodiment, two ends of the two mixer tubes electrically connected to the 3dB bridge are respectively disposed in electrical connection with the 3dB bridge through a microstrip line structure at the input port and the isolation port of the 3dB bridge.

According to another aspect of the present invention, there is provided a microwave probe apparatus comprising:

the local oscillation circuit unit is arranged in a power supply state and outputs local oscillation signals;

the 3dB bridge is selected from the group consisting of a 3dB annular bridge, a 3dB branch line bridge and a 3dB coupling line bridge which are arranged in a microstrip line mode, wherein a port of the 3dB bridge, which is connected with the local oscillation signal, is an input port of the 3dB bridge, and the 3dB bridge is further defined with an isolation port and two output ports based on the electrical characteristics of the 3dB bridge; and

an antenna, wherein the antenna is fed to at least one of the output ports of the 3dB bridge, to feed the antenna based on a distributed output of the two output ports of the 3dB bridge to the local oscillation signal accessed from the input port, and to access a feedback signal from the antenna based on a characteristic that the two output ports are isolated from each other in a state of accessing a signal.

In an embodiment, two of the output ports of the 3dB bridge are respectively feed connected to two feed points of the same antenna orthogonal in the polarization direction.

In an embodiment, the 3dB bridge is configured as a 3dB branch line bridge or a 3dB coupled line bridge, to form a circularly polarized feed to the antenna based on quadrature outputs of the two output ends of the 3dB branch line bridge or the 3dB coupled line bridge, which are 90 ° different from the local oscillator signal accessed from the input port.

In an embodiment, the 3dB bridge is configured as a 3dB loop bridge, wherein the two output ports of the 3dB loop bridge are respectively fed to two feed points of the same antenna which are inverted in polarization direction, so as to form inverted double feed to the antenna based on 180 ° phase-different inverted outputs of the local oscillation signals which are accessed from the input ports by the two output ports of the 3dB loop bridge.

In an embodiment, the 3dB bridge is configured as a 3dB branch line bridge or a 3dB coupled line bridge, wherein two output ports of the 3dB bridge are respectively connected to different antennas in a feeding manner, so as to improve isolation between the two antennas based on quadrature outputs of the two output ports of the 3dB branch line bridge or the 3dB coupled line bridge, which are different from each other by 90 ° for the local oscillation signal received from the input port.

In an embodiment, the two antennas respectively fed to the two output ports of the 3dB bridge are orthogonally arranged in a polarization direction, so that an orthogonal output of the two output ports of the 3dB branch line bridge or the 3dB coupled line bridge, which is different from the local oscillation signal accessed from the input port by 90 °, is formed to orthogonally feed the two antennas, thereby further improving isolation between the two antennas.

In an embodiment, the microwave detection device comprises one path of the 3dB bridge configured as a 3dB ring bridge, two paths of the 3dB bridge configured as a 3dB branch line bridge or a 3dB coupled line bridge, and four antennas respectively connected to four output ports of the 3dB bridge configured as a 3dB branch line bridge or a 3dB coupled line bridge, wherein the input ports of the 3dB bridge configured as a 3dB ring bridge are electrically connected to the local oscillation circuit unit to access the local oscillation signals from the local oscillation circuit unit, and wherein two output ports of the 3dB bridge configured as a 3dB ring bridge are electrically connected to two input ports of the 3dB bridge configured as a 3dB branch line bridge or a 3dB coupled line bridge, respectively, so as to provide the four output ports of the 3dB bridge configured as a 3dB branch line bridge or a 3dB coupled line bridge with the respective antennas with a circular polarization phase difference of 90 ° by the detection device.

In an embodiment, the microwave detection device comprises one path of the 3dB bridge configured as a 3dB branch line bridge or a 3dB coupled line bridge, two paths of the 3dB bridge configured as a 3dB ring bridge, and four antennas respectively connected to four output ports of the two paths of the 3dB bridge configured as a 3dB ring bridge, wherein the input ports of the 3dB bridge configured as a 3dB branch line bridge or a 3dB coupled line bridge are electrically connected to the local oscillation circuit unit to access the local oscillation signals from the local oscillation circuit unit, wherein two output ports of the 3dB bridge configured as a 3dB branch line bridge or a 3dB coupled line bridge are electrically connected to two input ports configured as a 3dB ring bridge, respectively, so that the four output ports configured as a 3dB ring bridge provide excitation signals for the respective antennas which are sequentially different from 90 ° to realize circular polarization feeding of the microwave detection device.

In an embodiment, the local oscillation circuit unit is configured to invert the microwave chip outputting two local oscillation signals in a powered state, wherein the microwave detection device comprises two 3dB bridges configured as 3dB branch line bridges or 3dB coupling line bridges, and four antennas respectively connected to four output ports of the two 3dB bridges configured as 3dB branch line bridges or 3dB coupling line bridges, so that the two 3dB bridges respectively access the two local oscillation signals outputted from the microwave chip in an inverted state at two input ports of the two 3dB bridges configured as 3dB branch line bridges or 3dB coupling line bridges, and then the four output ports of the two 3dB bridges configured as 3dB branch line bridges or 3dB coupling line bridges provide excitation signals differing in sequence by 90 ° for the corresponding antennas, thereby realizing circularly polarized feeding of the microwave detection device.

In an embodiment, the microwave chip includes a low dropout linear regulator, a voltage controlled oscillator, an oscillator, two amplifiers and a logic control unit, wherein the low dropout linear regulator provides a constant voltage for the voltage controlled oscillator in a powered state, wherein the oscillator provides a basic clock signal for the logic control unit and is externally arranged with a quartz crystal oscillator or is integrally arranged with an internal oscillating circuit in the logic control unit, wherein the logic control unit is arranged with a DSP or an MCU and has a frequency calibration unit electrically connected with the voltage controlled oscillator, wherein the voltage controlled oscillator outputs two output signals having a pulse frequency proportional to a voltage provided by the low dropout linear regulator and controlled and calibrated by the frequency calibration unit based on its own characteristics, wherein the two amplifiers are electrically connected to a positive terminal and a negative terminal of the voltage controlled oscillator, respectively, to amplify two output signals outputted from the positive terminal and the negative terminal of the voltage controlled oscillator, so that the two amplifiers provide two output signals directly.

Drawings

Fig. 1A is a schematic diagram of an equivalent circuit of a conventional balanced mixer employing a 3dB drop line bridge.

Fig. 1B is a schematic diagram of a conventional balanced mixer employing a 3dB branch line bridge of a varistor type.

Fig. 2A is a schematic structural diagram of a conventional square 3dB branch line bridge.

Fig. 2B is a schematic structural diagram of a conventional round 3dB branch line bridge.

Fig. 3A is a schematic diagram of a part of an equivalent circuit of a mixer circuit for implementing power division phase shifting and feeding with a 3dB bridge according to an embodiment of the present invention.

Fig. 3B is a schematic diagram of a part of an equivalent circuit of a mixer circuit for implementing power division phase shifting and feeding with a 3dB bridge according to another embodiment of the present invention.

Fig. 3C is a schematic diagram of a part of an equivalent circuit of a mixer circuit for implementing power division phase shifting and feeding with a 3dB bridge according to another embodiment of the present invention.

Fig. 4A is a schematic diagram of an equivalent circuit principle of the mixer circuit based on a single-tube mixing mode for implementing power division phase shift and feeding with a 3dB bridge according to the above embodiment of the present invention.

Fig. 4B is a schematic diagram of another equivalent circuit principle of the mixer circuit based on a single-tube mixing mode for implementing power division phase shift and feeding with a 3dB bridge according to the above embodiment of the present invention.

Fig. 4C is a schematic diagram of another equivalent circuit principle of the mixer circuit based on the single-tube mixing mode for implementing the power division phase shift and feeding with the 3dB bridge according to the above embodiment of the present invention.

Fig. 4D is a schematic diagram of another equivalent circuit principle of the mixer circuit based on the single-tube mixing mode for implementing the power division phase shift and feeding with the 3dB bridge according to the above embodiment of the present invention.

Fig. 5A is a schematic diagram of another equivalent circuit principle of the mixer circuit based on a single-tube mixing mode for implementing power division phase shift and feeding with a 3dB bridge according to the above embodiment of the present invention.

Fig. 5B is a schematic diagram of another equivalent circuit principle of the mixer circuit based on a single-tube mixing mode for implementing power division phase shift and feeding with a 3dB bridge according to the above embodiment of the present invention.

Fig. 5C is a schematic diagram of another equivalent circuit principle of the mixer circuit based on a single-tube mixing mode for implementing power division phase shift and feeding with a 3dB bridge according to the above embodiment of the present invention.

Fig. 5D is a schematic diagram of another equivalent circuit principle of the mixer circuit based on a single-tube mixing mode for implementing power division phase shift and feeding with a 3dB bridge according to the above embodiment of the present invention.

Fig. 6A is a schematic diagram of an equivalent circuit principle of the mixing circuit based on the dual-tube mixing mode for implementing the power division phase shift and feeding with the 3dB bridge according to the above embodiment of the present invention.

Fig. 6B is a schematic diagram of another equivalent circuit principle of the mixing circuit based on the dual-tube mixing mode for implementing the power division phase shift and feeding with the 3dB bridge according to the above embodiment of the present invention.

Fig. 6C is a schematic diagram of another equivalent circuit principle of the mixing circuit based on the dual-tube mixing mode for implementing the power division phase shift and feeding with the 3dB bridge according to the above embodiment of the present invention.

Fig. 6D is a schematic diagram of another equivalent circuit principle of the mixing circuit based on the dual-tube mixing mode for implementing the power division phase shift and feeding with the 3dB bridge according to the above embodiment of the present invention.

Fig. 7A is a schematic diagram of a partial equivalent circuit of a microwave probe device according to an embodiment of the invention.

Fig. 7B is a schematic diagram of a partial equivalent circuit of a microwave probe device according to another embodiment of the invention.

Fig. 7C is a schematic diagram of a partial equivalent circuit of a microwave probe device according to another embodiment of the invention.

Fig. 7D is a schematic diagram of a partial equivalent circuit of a microwave probe device according to another embodiment of the invention.

Fig. 8A is a schematic diagram of a partial equivalent circuit of a microwave probe device according to another embodiment of the invention.

Fig. 8B is a schematic diagram of a partial equivalent circuit of a microwave probe device according to another embodiment of the invention.

Fig. 8C is a schematic diagram of a partial equivalent circuit of a microwave probe device according to another embodiment of the invention.

Fig. 8D is a schematic diagram of a partial equivalent circuit of a microwave probe device according to another embodiment of the invention.

Fig. 9 is a schematic block diagram illustrating a configuration of a local oscillation circuit unit of a microwave probe apparatus according to another embodiment of the present invention when the local oscillation circuit unit is configured in an integrated circuit.

Detailed Description

The following description is presented to enable one of ordinary skill in the art to make and use the invention. The preferred embodiments in the following description are by way of example only and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

It will be appreciated by those skilled in the art that in the present disclosure, the terms "longitudinal," "transverse," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," etc. refer to an orientation or positional relationship based on that shown in the drawings, which is merely for convenience of description and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore the above terms should not be construed as limiting the present invention.

It will be understood that the terms "a" and "an" should be interpreted as referring to "at least one" or "one or more," i.e., in one embodiment, the number of elements may be one, while in another embodiment, the number of elements may be plural, and the term "a" should not be interpreted as limiting the number.

The invention provides a frequency mixing circuit and a microwave detection device for realizing power division phase shift and power feed by a 3dB bridge, wherein the frequency mixing circuit for realizing power division phase shift and power feed by the 3dB bridge has the functions of power division, phase shift, power feed and frequency mixing, is suitable for single-channel transmitting power feed, single-channel receiving power feed and single-channel receiving power feed of a single antenna and two-channel power feed of the single antenna or two antennas based on the same or different power feed combinations, has wider applicability, can reduce the occupied space of corresponding circuits of the microwave detection device, and is beneficial to microminiaturization design of the microwave detection device.

Specifically, the mixer circuit for implementing power division phase shift and feeding by using a 3dB bridge provides two excitation signals with phase difference of 90 ° or 180 ° for two output ports by accessing one local oscillation signal to the input port based on the electrical characteristics of the input port, the isolation port and the two output ports of the 3dB bridge, so that at least one output port of the mixer circuit for implementing power division phase shift and feeding by using the 3dB bridge is connected with a corresponding antenna, and the mixer circuit has the functions of power division, phase shift, feeding and mixing to implement single-path transmitting feeding, single-path receiving and transmitting integrated feeding of a single antenna, and two-path feeding of the single antenna or two antennas based on the same or different feeding combinations.

It is worth mentioning that the 3dB bridge is one selected from the group consisting of a 3dB ring bridge, a 3dB branch line bridge and a 3dB coupled line bridge and is arranged in a microstrip line configuration, wherein one end of an access signal of the 3dB bridge is an input port of the 3dB bridge, the isolation port is one end of the 3dB bridge which is isolated from the input port without output, the output port is two ends of an equal power output of the 3dB bridge, in particular in a state in which the 3dB bridge is arranged as the 3dB branch line bridge or the 3dB coupled line bridge, the equal power output of the output port differs by 90 ° and in a state in which the 3dB bridge is arranged as the 3dB ring bridge, the equal power output of the output port differs by 180 ° and is inverted, wherein naming the isolation port and the output port for the input port is the 3 ring bridge of a configuration common to a person skilled in the art, the 3dB branch line bridge and the 3dB bridge are respectively named as the 3dB bridge configuration allowing to be distinguished based on the naming of the equal power output port and the 3dB bridge coupling line configuration. That is, the 3dB ring bridge, the 3dB branch line bridge, and the 3dB coupled line bridge have well-known definitions of the respective microstrip structures and electrical characteristics as terms of the 3dB bridge (also referred to as 3dB directional coupler) known to those skilled in the art, wherein one end of an access signal of the 3dB bridge is taken as an input port of the 3dB bridge, and the isolation port and the two output ports (the through port and the coupled port) are well-known as terms known to those skilled in the art corresponding to the respective ports of the 3dB bridge, and the electrical characteristics and the correspondence relationship with the respective ports of the 3dB bridge are well-known to those skilled in the art.

In particular, as shown in FIG. 3A of the drawings referring to the description of the invention, with the 3dB bridge set as the 3dB branch line bridge example, the principle of a partial equivalent circuit of a mixer circuit implementing power division phase shift and feed with the 3dB bridge is illustrated, wherein with one end of an access local oscillation signal of the 3dB branch line bridge as the input port, the corresponding relationship between the pass-through port and the coupling port of the 3dB branch line bridge and the corresponding port of the 3dB branch line bridge is well known and defined, the corresponding 3dB branch line bridge can respectively provide two excitation signals which are 90 DEG different from each other and orthogonal to the pass-through port and the coupling port so as to realize the state that the corresponding antenna is connected to the pass-through port and/or the coupling port feed of the mixer circuit implementing power division phase shift and feed with the 3dB bridge, feeding the corresponding antenna based on orthogonal output of equal power distribution of the through port and the coupling port to the local oscillation signal, and accessing the feedback signal output from the corresponding antenna based on the characteristic that the through port and the coupling port are mutually isolated in the state of accessing signals, correspondingly realizing single-way transmission feeding, single-way receiving feeding and single-way receiving and transmitting integrated feeding of a single antenna and two-way feeding of the single antenna or two antennas based on the same or different feeding combination, and separating and leading out the feedback signal mixed with the local oscillation signal in the mixing circuit which realizes power division phase shifting and feeding in a 3dB bridge from the through port and/or the coupling port based on the isolation characteristic of the isolation port to the local oscillation signal input from the input port, and further, the mixing circuit for realizing power division phase shift and feeding by the 3dB bridge is allowed to optimally design a mixing network between the feedback signal and the local oscillation signal in an independent state based on the anti-interference purpose and/or the circuit simplification purpose.

As shown in fig. 3B corresponding to the drawings referring to the description of the present invention, a part of the equivalent circuit principle of the 3dB coupled line bridge in which the 3dB bridge is used to implement the power division phase shift and feed mixer circuit is illustrated, wherein the isolation port of the 3dB coupled line bridge is defined by using one end of the 3dB coupled line bridge to which the local oscillation signal is connected as the input port, the correspondence between the pass-through port and the coupling port and the corresponding port of the 3dB coupled line bridge is well known, the 3dB coupled line bridge is capable of providing two excitation signals orthogonal by 90 ° to the pass-through port and the coupling port, respectively, to implement the power division phase shift and feed mixer circuit in which the 3dB bridge is connected with the state of the corresponding antenna by the pass-through port and/or the coupling port feed, feeding the corresponding antenna based on orthogonal output of equal power distribution of the through port and the coupling port to the local oscillation signal, and accessing the feedback signal output from the corresponding antenna based on the characteristic that the through port and the coupling port are mutually isolated in the state of accessing signals, correspondingly realizing single-way transmission feeding, single-way receiving feeding and single-way receiving and transmitting integrated feeding of a single antenna and two-way feeding of the single antenna or two antennas based on the same or different feeding combination, and separating and leading out the feedback signal mixed with the local oscillation signal in the mixing circuit which realizes power division phase shifting and feeding in a 3dB bridge from the through port and/or the coupling port based on the isolation characteristic of the isolation port to the local oscillation signal input from the input port, and further, the mixing circuit for realizing power division phase shift and feeding by the 3dB bridge is allowed to optimally design a mixing network between the feedback signal and the local oscillation signal in an independent state based on the anti-interference purpose and/or the circuit simplification purpose.

As shown in fig. 3C corresponding to the drawings referring to the description of the present invention, a part of the equivalent circuit principle of a mixer circuit which implements power division phase shift and feeding by a 3dB ring bridge is illustrated by setting the 3dB ring bridge as the 3dB ring bridge example, wherein when one end of an incoming local oscillation signal of the 3dB ring bridge is taken as the input port, the correspondence between the isolation port and two output ports of the 3dB ring bridge and the corresponding ports of the 3dB ring bridge is well-known and defined, two excitation signals which are 180 degrees different and opposite in phase can be provided to the two output ports respectively corresponding to the 3dB ring bridge to feed the state of being connected with the corresponding antenna to at least one of the output ports of the mixer circuit which implements power division phase shift and feeding by the 3dB ring bridge, feeding the corresponding antenna based on the inverse output of equal power distribution of the two output ports to the local oscillation signals, accessing the feedback signals output from the corresponding antennas based on the characteristic that the two output ports are mutually isolated in the state of accessing signals, correspondingly realizing single-channel transmitting feeding, single-channel receiving feeding and single-channel receiving and transmitting integrated feeding of a single antenna, feeding the single antenna or two paths of two antennas based on the same or different feeding combinations, separating and leading out the feedback signals mixed with the local oscillation signals in the mixing circuit which realizes power division phase shifting and feeding in a 3dB bridge from any output port based on the isolation characteristic of the isolation ports to the local oscillation signals input from the input ports, and further, the mixing circuit for realizing power division phase shift and feeding by the 3dB bridge is allowed to optimally design a mixing network between the feedback signal and the local oscillation signal in an independent state based on the anti-interference purpose and/or the circuit simplification purpose.

It is worth mentioning that the state of the balanced mixer is different from the state of the existing balanced mixer that the local oscillation signal is respectively connected to the input port of the 3dB branch line bridge and the feedback signal is connected to the isolation port based on the characteristic that the input port and the isolation port of the 3dB branch line bridge are isolated from each other. The 3dB bridge-implemented power division phase-shifting and feeding mixer circuit of the present invention is defined in a known manner by taking one end of an access local oscillator signal of the 3dB bridge as the input port, and the correspondence between the isolation port of the 3dB bridge and the corresponding ports of the two output ports and the 3dB bridge, wherein the corresponding antenna is fed based on the equal-power distributed quadrature/inverse output of the local oscillator signal by the two output ports in a manner of feeding at least one output port to the corresponding antenna, and the feedback signal outputted from the corresponding antenna is accessed based on the characteristic that the two output ports are mutually isolated in the state of the access signal, while the isolation characteristic of the local oscillator signal inputted from the input port is allowed to be separated and introduced from any one of the input ports, the mixer circuit implementing the power division and feeding with the local oscillator signal is separated and introduced from any of the isolation port, so as to allow the corresponding mixer network to feed the corresponding to the 3dB bridge to perform the phase-shifting and feeding, the mixer circuit to perform the phase-shifting and the phase-shifting with the 3dB bridge, the mixer circuit is designed to have the same frequency as the mixer circuit with the 3dB mixer signal, the difference between the mixer circuit and the 3dB mixer circuit is reduced in the number of the mixer circuit, the mixer circuit is designed to have the difference between the mixer signal and the mixer circuit and the 3dB signal is more flexibly and the mixer signal is designed to be balanced based on the mixer signal, the mixing network is further allowed to mix the local oscillation signal and the feedback signal with a single mixing tube at any two points of the 3dB bridge to output the Doppler intermediate frequency signal, or mix the local oscillation signal and the feedback signal with a double mixing tube at any two points of the 3dB bridge to output the Doppler intermediate frequency signal, so that the influence of equal power distribution output of the feedback signal accessed from any one of the output ports on the output power of the Doppler intermediate frequency signal at the input port and the isolation port is reduced, the output power of the Doppler intermediate frequency signal is correspondingly improved, and the output power of the Doppler intermediate frequency signal is further ensured at the two output ports in a state of being respectively connected to the same antenna or different antennas in a feeding way, thereby ensuring the detection precision of the microwave detection device.

As an example, referring to fig. 4A to 4D of drawings in the specification of the present invention, as an example in which the 3dB bridge is set as the 3dB branch line bridge, the equivalent circuit principle of the mixing circuit for implementing power division phase shift and feeding in the 3dB bridge according to the different embodiments is respectively illustrated based on that the corresponding mixing network mixes the local oscillation signal and the feedback signal with a single mixing tube at any point of the 3dB bridge to output a doppler intermediate frequency signal. The mixing circuit for implementing power division phase shift and feeding by using a 3dB bridge further includes a mixing network 10, where the mixing network 10 is configured in a single mixing tube form and includes a mixing tube 11 and a ground capacitor 12, where one end of the mixing tube 11 is electrically connected to the 3dB bridge, and the other end of the mixing tube 11 is electrically connected (including direct electrical connection and electrical connection via a corresponding resistor) to the ground capacitor 12 and is grounded via the ground capacitor 12, so as to ensure a high-frequency opposite-form loop via the mixing tube 11, thereby outputting the doppler intermediate frequency signal processed by high-frequency filtering at the end of the mixing tube 11 electrically connected to the ground capacitor 12, further ensuring the accuracy of the doppler intermediate frequency signal, and correspondingly improving the detection accuracy of the microwave detection device.

It should be noted that in these embodiments of the present invention, the mixer 11 is electrically connected to the 3dB bridge at one end, and the other end of the mixer 11 is grounded via the capacitor 12, which does not limit the polarity direction of the mixer 11. That is, in the embodiments of the present invention corresponding to fig. 4A to 4D, the positive electrode of the mixer 11 is electrically connected to the 3dB bridge, the negative electrode of the mixer is grounded via the capacitance to ground 12, and in other embodiments of the present invention, the negative electrode of the mixer 11 is electrically connected to the 3dB bridge, and the positive electrode of the mixer is grounded via the capacitance to ground 12, which is not limited by the present invention.

Specifically, as shown in fig. 4A, one end of the mixer tube 11 electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the isolation port, wherein based on the isolation characteristic of the isolation port to the local oscillation signal input from the input port, the one end of the mixer tube 11 electrically connected to the 3dB bridge is preferably configured to be electrically connected to the 3dB bridge at the isolation port via a microstrip line structure, so as to increase the output power of the doppler intermediate frequency signal.

Corresponding to fig. 4B and 4C, one end of the mixer tube 11 electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at different output ports, wherein, based on the characteristic that the two output ports are isolated from each other for the feedback signals that are connected, the one end of the mixer tube 11 electrically connected to the 3dB bridge is preferably configured to be electrically connected to the 3dB bridge at the corresponding output port via a microstrip line structure, so as to increase the output power of the doppler intermediate frequency signal.

Corresponding to fig. 4D, one end of the mixer tube 11 electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the input port, wherein, based on equal power distribution of the two output ports to the local oscillation signals accessed from the input port and equal power distribution of the input ports and the isolation ports to the feedback signals accessed from any one of the output ports, one end of the mixer tube 11 electrically connected to the 3dB bridge is preferably configured to be electrically connected to the 3dB bridge at the input port via a microstrip line structure, so as to increase output power of the doppler intermediate frequency signal.

As an example, referring to fig. 5A to 5D of drawings in the specification of the present invention, as an example in which the 3dB bridge is also set as the 3dB branch line bridge, the equivalent circuit principle of the mixer circuit for implementing power division phase shift and feeding in the 3dB bridge according to the different embodiments is respectively illustrated based on the respective mixer networks to output the doppler intermediate frequency signal by mixing the local oscillation signal and the feedback signal with a single mixer tube at any two points of the 3dB bridge. The mixing circuit for implementing power division phase shift and feeding by using a 3dB bridge further includes a mixing network 10, wherein the mixing network 10 is configured in a single mixing tube form and includes a mixing tube 11 and a ground capacitor 12, wherein one end of the mixing tube 11 is electrically connected to two points of the 3dB bridge at the same time, the other end of the mixing tube 11 is electrically connected to the ground capacitor 12 and is grounded via the ground capacitor 12, so as to ensure a high-frequency opposite-forming loop via the mixing tube 11, thereby outputting the doppler intermediate frequency signal subjected to high-frequency filtering processing at the end of the mixing tube 11 electrically connected to the ground capacitor 12, further ensuring the accuracy of the doppler intermediate frequency signal, and improving the output power of the doppler intermediate frequency signal based on the structural state that one end of the mixing tube 11 electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at two points of the 3dB bridge, so as to further improve the detection accuracy of the microwave detection device.

Also, in these embodiments of the present invention, the state that one end of the mixer 11 is electrically connected to two points of the 3dB bridge at the same time, and the other end of the mixer 11 is grounded via the capacitance to ground 12 is not limited to the polarity direction of the mixer 11. That is, in the embodiments of the present invention corresponding to fig. 5A to 5D, the positive electrode of the mixer 11 is electrically connected to two points of the 3dB bridge, the negative electrode of the mixer is grounded via the ground capacitor 12, and in other embodiments of the present invention, the negative electrode of the mixer 11 is electrically connected to the 3dB bridge, and the positive electrode of the mixer is grounded via the ground capacitor 12.

Specifically, corresponding to fig. 5A, one end of the mixer tube 11 electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the isolation port of the 3dB bridge and one of the output ports, specifically, the isolation port of the 3dB bridge and the output port adjacent to the isolation port are electrically connected to the 3dB bridge, wherein the end of the mixer tube 11 electrically connected to the 3dB bridge is preferably configured to be electrically connected to the 3dB bridge via a two-path microstrip line structure based on the isolation characteristics of the isolation port to the local oscillation signal input from the input port and the characteristics of the two output ports to the feedback signal connected thereto, so as to increase the output power to the doppler intermediate frequency signal.

Corresponding to fig. 5B, one end of the mixer tube 11 electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at two output ports of the 3dB bridge, wherein based on the characteristic that the two output ports are isolated from each other by the feedback signal that is connected to the mixer tube 11, the one end of the mixer tube 11 electrically connected to the 3dB bridge is preferably configured to be electrically connected to the 3dB bridge via a two-path microstrip line structure at the two output ports of the 3dB bridge, so as to increase the output power of the doppler intermediate frequency signal.

Corresponding to fig. 5C, one end of the mixer tube 11 electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the isolation port and the input port of the 3dB bridge, wherein the one end of the mixer tube 11 electrically connected to the 3dB bridge is preferably configured to be electrically connected to the 3dB bridge at the isolation port and the input port of the 3dB bridge via a two-way microstrip line structure based on the isolation characteristic of the isolation port to the local oscillation signal input from the input port, so as to increase the output power to the doppler intermediate frequency signal.

Corresponding to fig. 5D, one end of the mixer tube 11 electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the input port and one of the output ports of the 3dB bridge, specifically, the input port of the 3dB bridge and the output port adjacent to the input port are electrically connected to the 3dB bridge, wherein the end of the mixer tube 11 electrically connected to the 3dB bridge is preferably configured to be electrically connected to the 3dB bridge via a two-path microstrip line structure at the input port of the 3dB bridge and the output port adjacent to the input port based on the characteristic that the two output ports are isolated from each other for the feedback signal to be connected to, and the equal power distribution of the input port and the isolation port to the feedback signal to be connected from any one of the output ports is preferably configured to increase the output power of the doppler intermediate frequency signal.

It should be noted that, in these embodiments of the present invention, the end of the mixer 11 electrically connected to the 3dB bridge is preferably disposed at two points with a lambda/4 electrical length of the 3dB bridge and electrically connected to the 3dB bridge, where lambda is a wavelength parameter corresponding to the frequency of the local oscillation signal, so as to ensure isolation between two signals and increase the output power of the doppler intermediate frequency signal.

As an example, referring to fig. 6A to 6D of drawings in the specification of the present invention, as an example in which the 3dB bridge is also set as the 3dB branch line bridge, the equivalent circuit principle of the mixing circuit for implementing power division phase shift and feeding in the 3dB bridge according to the different embodiments is respectively illustrated based on the corresponding mixing network to mix the local oscillation signal and the feedback signal with a double mixing tube at any two points of the 3dB bridge to output a doppler intermediate frequency signal. The mixing circuit for implementing power division phase shift and feeding by using a 3dB bridge further includes a mixing network 10, where the mixing network 10 is configured in a dual-mixing-tube manner and includes two mixing tubes 11 and a capacitor 12 to ground, where two ends of the two mixing tubes 11 having different polarities, which are respectively divided by the different mixing tubes 11, are connected to two points of the 3dB branch line bridge, the other two ends of the two mixing tubes 11 having different polarities, which are respectively divided by the different mixing tubes 11, are electrically connected to the capacitor 12 to ground via the capacitor 12, so as to ensure that a loop is formed by high frequency alignment of the mixing tubes 11, thereby outputting the doppler intermediate frequency signal processed by high frequency filtering at the end of the mixing tubes 11 electrically connected to the capacitor 12, further ensuring the accuracy of the doppler intermediate frequency signal, and further ensuring the accuracy of the doppler intermediate frequency signal based on the two points of the two sides of the mixing tubes 11 having different polarities, which are respectively connected to the two points of the 3dB branch line bridge, respectively, thereby improving the accuracy of the output signal by further improving the microwave device.

Corresponding to fig. 6A, two ends of the two mixer tubes 11 electrically connected to the 3dB bridge are respectively electrically connected to the 3dB bridge at two output ports of the 3dB branch line bridge, wherein based on the characteristic that the two output ports are isolated from each other by the feedback signals connected to the mixer tubes 11, two ends of the two mixer tubes 11 electrically connected to the 3dB bridge are preferably configured to be respectively electrically connected to the 3dB bridge at two output ports of the 3dB bridge via a microstrip line structure, so as to improve the output power of the doppler intermediate frequency signal.

Corresponding to fig. 6B, two ends of the two mixer tubes 11 electrically connected to the 3dB bridge are electrically connected to the 3dB bridge respectively at the isolation port and one of the output ports of the 3dB bridge, and specifically, the isolation port of the 3dB bridge and the output port adjacent to the isolation port are electrically connected to the 3dB bridge, wherein the two ends of the two mixer tubes 11 electrically connected to the 3dB bridge are preferably configured to be electrically connected to the 3dB bridge respectively via a microstrip line structure at the isolation port of the 3dB bridge and the output port adjacent to the isolation port, so as to increase the output power of the doppler intermediate frequency signal based on the isolation characteristic of the isolation port to the local oscillation signal input from the input port and the mutual isolation characteristic of the two output ports to the feedback signal connected thereto.

Corresponding to fig. 6C, two ends of the two mixer pipes 11 electrically connected to the 3dB bridge are electrically connected to the 3dB bridge at the isolation port and the input port of the 3dB bridge, respectively, wherein based on the isolation characteristic of the isolation port to the local oscillation signal input from the input port, two ends of the two mixer pipes 11 electrically connected to the 3dB bridge are preferably configured to be electrically connected to the 3dB bridge at the isolation port and the input port of the 3dB bridge via a microstrip line structure, respectively, so as to increase the output power of the doppler intermediate frequency signal.

Corresponding to fig. 6D, two ends of the two mixer tubes 11 electrically connected to the 3dB bridge are respectively electrically connected to the 3dB bridge at the input port and one of the output ports of the 3dB bridge, specifically, the input port of the 3dB bridge and the output port adjacent to the input port are electrically connected to the 3dB bridge, wherein the two ends of the two mixer tubes 11 electrically connected to the 3dB bridge are preferably configured to be electrically connected to the 3dB bridge through a microstrip line structure respectively at the input port of the 3dB bridge and the output port adjacent to the input port based on the characteristic that the two output ports are isolated from each other for the feedback signal to be connected to, and the equal power distribution of the input port and the isolation port to the feedback signal to be connected from any one of the output ports is preferably configured to increase the output power of the doppler intermediate frequency signal.

Also, in these embodiments of the present invention, two ends of the mixer tube 11 electrically connected to the 3dB bridge are preferably disposed at two points of the 3dB bridge having a lambda/4 electrical length, where lambda is a wavelength parameter corresponding to the frequency of the local oscillation signal, electrically connected to the 3dB bridge, so as to ensure isolation between two signals and increase the output power of the doppler intermediate frequency signal.

That is, the input port of the mixer circuit for implementing power division phase shift and feeding with the 3dB bridge in the above embodiments is electrically connected to the corresponding local oscillator circuit unit to access the local oscillator signal, and is connected to the corresponding antenna through at least one of the output ports, and the mixer circuit for implementing power division phase shift and feeding with the 3dB bridge can implement single-channel transmitting feeding, single-channel receiving feeding, single-channel transceiving integral feeding, and two-channel feeding for a single antenna or two antennas based on the same or different feeding combinations, and meanwhile, the mixer network 10 of the mixer circuit for implementing power division phase shift and feeding with the 3dB bridge has flexible and various arrangement designs, thus having wide applicability and being capable of reducing the occupied space of the corresponding circuit of the microwave detection device.

Correspondingly, the microwave detection device comprises the local oscillation circuit unit, the 3dB bridge and at least one antenna, wherein the local oscillation circuit unit is arranged to output the local oscillation signal in a power supply state, one end of the 3dB bridge connected with the local oscillation signal is taken as an input port of the 3dB bridge, the isolation port of the 3dB bridge and two output ports are well-known and defined, at least one output port of the 3dB bridge is connected with the antenna in a feeding way, so that single-path transmitting feeding to the antenna is realized based on equal power distribution output of the two output ports to the local oscillation signal connected with the input port, or single-path transmitting feeding to the antenna is realized based on the characteristic that the two output ports are mutually isolated from each other, and the isolation port is used for isolating the local oscillation signal input from the input port, the single-path receiving to the antenna is realized by separating the feedback signal mixed with the feedback signal in the 3dB bridge from the isolation port, and accordingly, the single-path receiving and single-phase-or two-phase-shifting single-or single-phase-or two-phase-single-feeding or two-phase-single-or single-phase-feeding combined-phase-or single-phase-feed or combined-phase-antenna transmitting/receiving and/single-phase-or combined-phase-or two-phase-antenna device can be arranged in the 3dB bridge.

Specifically, referring to fig. 7A to 7D of drawings of the specification of the present invention, as an example in which the 3dB bridge is provided as the 3dB branch line bridge, partial equivalent circuit schematic diagrams of the microwave probe apparatus of various embodiments are illustrated based on the connection relationship between two output ports of the 3dB bridge and the corresponding antennas 30 in a state in which the input ports of the mixing circuit implementing power division phase shift and feeding in the 3dB bridge are electrically connected to the corresponding local oscillation circuit units 20 to access the local oscillation signals.

Corresponding to fig. 7A, in this embodiment of the present invention, one of the output ports of the 3dB bridge is feed-connected to the antenna 30, specifically the output port of the 3dB bridge adjacent to the input port is feed-connected to the antenna 30, corresponding to the state in which the 3dB bridge is set to the 3dB branch line bridge, the through port of the 3dB branch line bridge is feed-connected to the antenna 30, so that the single-pass transmission feed to the antenna 30 is realized based on the equal power distribution output of the two output ports to the local oscillation signal inputted from the input port, or based on the characteristic that the two output ports are mutually isolated from the inputted signal, and the isolation characteristic of the isolation port to the local oscillation signal inputted from the input port, the feedback signal mixed with the local oscillation signal in the 3dB bridge is separated and output from the isolation port to realize single-path receiving and feeding of the antenna 30, or based on the arrangement of the corresponding frequency mixing network on the 3dB bridge, the receiving and transmitting integrated feeding of the antenna is realized, or based on the isolation characteristic of the isolation port on the local oscillation signal input from the input port, the feedback signal mixed with the local oscillation signal in the 3dB bridge is separated and output from the isolation port, so that when the local oscillation circuit unit 20 adopts the existing microwave chip which is integrated with the corresponding frequency mixing network and has a transmitting end and a receiving end based on the receiving and transmitting separated feeding mode, the transmitting end of the microwave chip is connected to the input port of the 3dB bridge, the receiving end of the microwave chip is connected to the isolation port of the 3dB bridge, therefore, the receiving and transmitting separated feed of the antenna 30 is realized by a single antenna 30, so that the volume of the microwave detection device is reduced, and the detection precision of the microwave detection device based on the receiving and transmitting separated feed is guaranteed.

Corresponding to fig. 7B, in this embodiment of the present invention, one of the output ports of the 3dB bridge is feed-connected to the antenna 30, specifically, the output port of the 3dB bridge adjacent to the isolation port is feed-connected to the antenna 30, and the coupling port of the 3dB branch line bridge is feed-connected to the antenna 30 in a state in which the 3dB bridge is set to the 3dB branch line bridge, so that a single-pass transmission feed to the antenna 30 is realized based on the equal power distribution output of the two output ports to the local oscillation signal inputted from the input port, or based on the characteristic that the two output ports are mutually isolated from the inputted signal, and the isolation characteristic of the isolation port to the local oscillation signal inputted from the input port, the feedback signal mixed with the local oscillation signal in the 3dB bridge is separated and output from the isolation port to realize single-path receiving and feeding of the antenna 30, or based on the arrangement of the corresponding frequency mixing network on the 3dB bridge, the receiving and transmitting integrated feeding of the antenna is realized, or based on the isolation characteristic of the isolation port on the local oscillation signal input from the input port, the feedback signal mixed with the local oscillation signal in the 3dB bridge is separated and output from the isolation port, so that when the local oscillation circuit unit 20 adopts the existing microwave chip which is integrated with the corresponding frequency mixing network and has a transmitting end and a receiving end based on the receiving and transmitting separated feeding mode, the transmitting end of the microwave chip is connected to the input port of the 3dB bridge, the receiving end of the microwave chip is connected to the isolation port of the 3dB bridge, therefore, the receiving and transmitting separated feed of the antenna 30 is realized by a single antenna 30, so that the volume of the microwave detection device is reduced, and the detection precision of the microwave detection device based on the receiving and transmitting separated feed is guaranteed.

Corresponding to fig. 7C, in this embodiment of the present invention, the two output ports of the 3dB bridge are fed and connected to the same antenna 30, that is, the antenna 30 has two feeding points (corresponding to feeding point a and feeding point b in the figure), wherein the two output ports of the 3dB bridge are fed and connected to the two feeding points of the antenna 30, so as to distribute output based on equal power of the two output ports to the local oscillation signals inputted from the input ports, two excitation signals differing by 90 ° are provided for a single antenna 30 in one local oscillation signal in the state of the 3dB branch bridge, to form circular polarization feeding to the antenna 30 in the state that the two feeding points of the antenna 30 corresponding to the two excitation signals are orthogonally arranged, to realize the circular polarization form of the microwave detection device, and is advantageous to the miniaturization design of the microwave probe in the circular polarization form due to the simple structure, and the capability of separating the feedback signal mixed with the local oscillation signal in the 3dB bridge from the isolation port based on the isolation characteristic of the isolation port to the local oscillation signal inputted from the input port, so that when the local oscillation circuit unit 20 adopts the existing microwave chip having a transmitting end and a receiving end integrated with a corresponding mixing network in a mode based on the transceiving separation feed, the transmitting end of the microwave chip is connected to the input port of the 3dB bridge, the receiving end of the microwave chip is connected to the isolation port of the 3dB bridge, thereby realizing the transceiving separation feed to the antenna 30 in a single antenna 30, therefore, the volume of the microwave detection device is reduced, and the detection precision of the microwave detection device based on receiving and transmitting separated feed is guaranteed.

Corresponding to fig. 7D, in this embodiment of the present invention, the two output ports of the 3dB bridge are respectively connected to the feed points of the different antennas 30 (including two antennas formed by two independent radiation sources sharing a reference ground, equivalently), so as to distribute output based on equal power of the two output ports to the local oscillation signals accessed from the input ports, in a state where the 3dB bridge is set as the 3dB branch line bridge, excitation signals differing by 90 ° are provided for the two antennas 30 with one local oscillation signal, so as to ensure isolation between the two antennas 30 to ensure stability and detection accuracy of the microwave detection device, and further ensure stability and detection accuracy of the microwave detection device in a state where polarization directions of the two antennas 30 are orthogonal, and so as to separate output the local oscillation signals mixed with the local oscillation signals in the 3dB bridge based on isolation characteristics of the isolation ports to the local oscillation signals input from the input ports, so as to realize simultaneous isolation between the two input ports of the 3dB bridge and the microwave detection device at the receiving end and the receiving end of the microwave receiving chip by adopting a separate feed circuit of the existing integrated circuit, so as to realize the isolation between the microwave receiving end and the microwave receiving end of the microwave detection device at the receiving end of the 3dB bridge, the microwave receiving end has the integrated circuit, and the microwave receiving end is connected to the receiving end of the microwave receiving end, and the microwave receiving end is connected to the microwave end, and the microwave end is separated by the microwave end, and the microwave end is separated from the microwave end, therefore, the volume of the microwave detection device is reduced, and the detection precision of the microwave detection device based on receiving and transmitting separated feed is improved.

It should be noted that, in the state that the 3dB bridge is set as the 3dB ring bridge, based on the connection relationship between the two output ports of the 3dB bridge and the corresponding antennas 30, an excitation signal with a phase difference of 180 ° can be provided for a single antenna 30 by using one local oscillation signal, so that in the state that two feeding points of the antenna 30, to which the two excitation signals are connected, are set in opposite polarization directions, an opposite phase double feed to the antenna 30 is formed, thereby improving the stability of the microwave detection device.

Further, in a state that the 3dB bridge is set as the 3dB branch line bridge or the 3dB coupled line bridge, based on quadrature output of equal power difference of 90 ° for the local oscillation signals accessed from the input ports by two output ports of the 3dB bridge, one local oscillation signal is used for providing excitation signals of difference of 90 ° for two antennas 30, and the microwave detection device is correspondingly provided with two states that the mixing circuit for realizing power division phase shift and feeding by the 3dB bridge is used for providing excitation signals of difference of 90 ° in phase sequence for four antennas 30 by two opposite local oscillation signals; or in a state that the 3dB bridge is set as the 3dB ring bridge, based on the inverted output of 180 DEG phase difference of equal power of the local oscillation signals accessed from the input ports by two output ports of the 3dB bridge, one local oscillation signal is used for providing excitation signals 180 DEG phase difference for two antennas 30, and the microwave detection device is correspondingly provided with two states of the mixing circuits for realizing power division phase shifting and feeding by the 3dB bridge, and is suitable for providing excitation signals 90 DEG phase difference in sequence for four antennas 30 by two orthogonal local oscillation signals. Therefore, the circular polarization mode of the microwave detection device is realized by the mixer circuit which is based on two paths and realizes power division phase shift and feed by the 3dB bridge, and the miniaturized design of the microwave detection device in the circular polarization mode is facilitated due to the simple structure.

Specifically, as shown in fig. 8A to 8D of drawings of the specification of the present invention, a principle of a partial equivalent circuit of the microwave probe apparatus of the different embodiments is illustrated based on the purpose of realizing a circularly polarized form of the microwave probe apparatus.

In these two embodiments of the present invention, corresponding to fig. 8A and 8B, the microwave detection device includes three 3dB bridges, specifically including one 3dB ring bridge and two 3dB branch line bridges or 3dB coupled line bridges, where the input ends of the 3dB ring bridge are electrically connected to the local oscillation circuit unit 20 to access the local oscillation signals from the local oscillation circuit unit 20, and based on the two output ports of the 3dB ring bridge, the equal power phase-different 180 ° of the local oscillation signals accessed from the input ports is outputted in opposite phase, two paths of signals with equal power phase-different 180 ° are provided for two input ports of the 3dB branch line bridge or the 3dB coupled line bridge, so that the four-phase excitation circuit is provided for the two input ports of the 3dB branch line bridge or the 3dB coupled line bridge, based on the equal power phase-different 90 ° of the local oscillation signals accessed from the input ports, and the corresponding microwave detection device is implemented in a state of being polarized in a four-circle.

In these two embodiments of the present invention, corresponding to fig. 8C and 8D, the microwave detecting device includes three 3dB bridges, specifically includes one 3dB branch line bridge or 3dB coupled line bridge, and two 3dB ring bridges, wherein the input ends of the 3dB branch line bridge or 3dB coupled line bridge are electrically connected to the local oscillation circuit unit 20 to access the local oscillation signals from the local oscillation circuit unit 20, and based on the quadrature output of the two output ports of the 3dB ring bridge for the local oscillation signals accessed from the input ports, two signals with equal power differing by 90 ° are provided for the two input ports of the two external two 3dB bridges set as the 3dB ring bridge, so as to provide four-phase excitation-circuit-sequential excitation-phase-differing by 180 ° for the local oscillation signals accessed from the input ports based on the two output ports of the 3dB ring bridge, thereby providing the corresponding circularly polarized antenna device with a circularly polarized antenna configuration.

It should be noted that, based on the purpose of realizing the circular polarization mode of the microwave detection device, in some embodiments of the present invention, the microwave detection device is configured to be configured in an integrated circuit mode and configured to directly provide two local oscillation signals with opposite phase outputs from the local oscillation circuit unit 20 of a microwave chip, and two input ports of two paths of the 3dB bridge configured with the 3dB branch line bridge or the 3dB coupling line bridge are correspondingly connected to the two local oscillation signals respectively, so as to provide four excitation signals with phase differences of 90 ° for feeding corresponding antennas 30 to realize the circular polarization mode of the microwave detection device, and avoid the material limitation corresponding to the material of the mixer tube caused by the chip manufacturing process on the basis of the state that the mixer circuit for realizing power division phase shift and feeding with the 3dB bridge is integrated with the microwave chip in the integrated circuit mode, thereby being beneficial to reducing the material difficulty of the microwave chip and the material of the mixer tube, and being beneficial to reducing the stability of the microwave detection device.

Specifically, referring to fig. 9 of the drawings, a basic block diagram of the local oscillation circuit unit 20 provided in the form of an integrated circuit and configured as a microwave chip is illustrated, wherein the local oscillation circuit unit 20 includes a low dropout linear regulator (internal LDO), a Voltage Controlled Oscillator (VCO), an oscillator (Osc), two amplifiers (PA 1 and PA 2), and a logic control unit, wherein the low dropout linear regulator supplies a constant voltage to the voltage controlled oscillator in a power-supplied state, wherein the oscillator is configured to supply a basic clock signal to the logic control unit and is externally configured with a quartz crystal oscillator or integrally configured to the logic control unit with an internal oscillation circuit, wherein the logic control unit is arranged by a DSP or MCU and is provided with a frequency calibration unit electrically connected with the voltage-controlled oscillator, the voltage-controlled oscillator outputs two paths of output signals with pulse frequencies corresponding to the voltage provided by the low dropout linear voltage regulator in proportion to the voltage provided by the low dropout linear voltage regulator on the basis of the characteristics of the logic control unit, the two amplifiers are electrically connected with the positive end and the negative end of the voltage-controlled oscillator respectively to amplify the two paths of output signals outputted from the positive end and the negative end of the voltage-controlled oscillator, thus the two amplifiers directly provide two paths of local oscillator signals with opposite phase output, the two input ports of the two paths of the 3dB bridge arranged as the 3dB branch line bridge or the 3dB line coupling bridge are respectively connected with the two paths of local oscillator signals, the four-way excitation signal with the phase sequence difference of 90 degrees is provided to feed the corresponding antenna 30 to realize the circular polarization form of the microwave detection device, and the mixing circuit which realizes the power division phase shift and feed by using the 3dB bridge can be externally arranged on the microwave chip, so that the material limitation of the microwave chip corresponding to the material of the mixing tube caused by the chip manufacturing process is avoided, namely, the microwave chip can be prevented from adopting expensive gallium arsenide or gallium nitride semiconductor materials, thereby being beneficial to reducing the material cost and the process difficulty of the microwave chip, and being beneficial to ensuring the stability of the microwave detection device and reducing the cost of the microwave detection device.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are by way of example only and are not limiting. The objects of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been shown and described in the examples and embodiments of the invention may be modified or practiced without departing from the principles described.

Claims

1. A mixer circuit for performing power division phase shift and feeding with a 3dB bridge, wherein the mixer circuit for performing power division phase shift and feeding with a 3dB bridge is adapted to be connected to a corresponding antenna feed, to feed and receive a feedback signal to and from the antenna in a state of being connected to a local oscillator signal, and to output a doppler intermediate frequency signal corresponding to a frequency/phase difference between the local oscillator signal and the feedback signal in a manner of mixing detection, comprising:

2. The mixing circuit for implementing power splitting phase shifting and feeding in a 3dB bridge according to claim 1, wherein the 3dB bridge is a 3dB branch line bridge arranged in the form of a microstrip line.

3. The mixing circuit of claim 2 implementing power splitting phase shifting and feeding in a 3dB bridge, wherein the mixing network is arranged in a single mixing tube configuration.

4. The mixing circuit of claim 3 wherein one end of the mixing tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the isolation port.

5. The mixer circuit of claim 4 wherein an end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge via a microstrip line structure at the isolation port.

6. The mixing circuit of claim 3 wherein one end of the mixing tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at one of the output ports.

7. The mixer circuit of claim 6 wherein an end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge via a microstrip line structure at one of the output ports.

8. The mixing circuit of claim 3 wherein one end of the mixing tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the input port.

9. The mixer circuit of claim 8 wherein an end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge via a microstrip line structure at the input port.

10. The mixing circuit of claim 3, wherein one end of the mixing tube electrically connected to the 3dB bridge is simultaneously electrically connected to two points of the 3dB bridge.

11. The mixing circuit of claim 10, wherein one end of the mixing tube electrically connected to the 3dB bridge is disposed at two points of the 3dB bridge having a λ/4 electrical length and electrically connected to the 3dB bridge, wherein λ is a wavelength parameter corresponding to a frequency of the local oscillation signal.

12. The mixer circuit of claim 10 wherein one end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the isolation port and one of the output ports of the 3dB bridge.

13. The mixer circuit of claim 12 wherein an end of the mixer tube electrically connected to the 3dB bridge is disposed in electrical communication with the 3dB bridge via a two-way microstrip line structure at the isolated port and one of the output ports of the 3dB bridge.

14. The mixer circuit of claim 10 wherein one end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge at the input port and one of the output ports of the 3dB bridge.

15. The mixer circuit of claim 14 wherein an end of the mixer tube electrically connected to the 3dB bridge is disposed in electrical communication with the 3dB bridge via a two-way microstrip line structure at the input port and one of the output ports of the 3dB bridge.

16. The mixer circuit of claim 10 wherein the mixer tube is electrically connected to one end of the 3dB bridge and to the 3dB bridge at both of the output ports of the 3dB bridge.

17. The mixer circuit of claim 16 wherein an end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge via a two-way microstrip line structure at two of the output ports of the 3dB bridge.

18. The mixing circuit of claim 10, wherein the mixer tube is electrically connected to one end of the 3dB bridge at the input port and the isolation port of the 3dB bridge and the 3dB bridge.

19. The mixer circuit of claim 18 wherein an end of the mixer tube electrically connected to the 3dB bridge is electrically connected to the 3dB bridge via a two-way microstrip line structure at the input port and the isolation port of the 3dB bridge.

20. The mixing circuit of claim 2 implementing power splitting phase shifting and feeding in a 3dB bridge, wherein the mixing network is arranged in a double mixing tube configuration.

21. The mixing circuit of claim 20, wherein two of the mixing tubes are electrically connected to the 3dB bridge at two points of the 3dB bridge having a λ/4 electrical length, where λ is a wavelength parameter corresponding to a frequency of the local oscillator signal.

22. The mixer circuit of claim 20 wherein two of the mixer tubes are electrically connected to the 3dB bridge at two ends of the 3dB bridge, and the two output ports of the 3dB bridge are electrically connected to the 3dB bridge.

23. The mixer circuit of claim 22, wherein two ends of the two mixer tubes electrically connected to the 3dB bridge are respectively electrically connected to the 3dB bridge via a microstrip line structure at two output ports of the 3dB bridge.

24. The mixer circuit of claim 20 wherein two of the mixer tubes are electrically connected to the 3dB bridge at two ends of the 3dB bridge, respectively, at the isolation port and one of the output ports of the 3dB bridge, and are electrically connected to the 3dB bridge.

25. The mixer circuit of claim 24 wherein two ends of the two mixer tubes electrically connected to the 3dB bridge are respectively electrically connected to the 3dB bridge via a microstrip line structure at the isolation port and one of the output ports of the 3dB bridge.

26. The mixer circuit of claim 20 wherein two of the mixer tubes are electrically connected to the 3dB bridge at two ends of the 3dB bridge, respectively, at the input port and one of the output ports of the 3dB bridge, and are electrically connected to the 3dB bridge.

27. The mixer circuit of claim 26 wherein two ends of the two mixer tubes electrically connected to the 3dB bridge are electrically connected to the 3dB bridge via a microstrip line structure at the input port and one of the output ports of the 3dB bridge, respectively.

28. The mixer circuit of claim 20 wherein two of the mixer tubes are electrically connected to the 3dB bridge at opposite ends of the 3dB bridge, the input port and the isolation port of the 3dB bridge being electrically connected to the 3dB bridge, respectively.

29. The mixer circuit of claim 28 wherein two ends of the two mixer tubes electrically connected to the 3dB bridge are electrically connected to the 3dB bridge via a microstrip line structure at the input port and the isolation port of the 3dB bridge, respectively.

30. The microwave detection device is characterized by comprising:

31. A microwave probe device in accordance with claim 30, wherein the two output ports of the 3dB bridge are respectively feed connected to two feed points of the same antenna orthogonal in the polarization direction.

32. The microwave detection device of claim 31, wherein the 3dB bridge is configured as a 3dB branch line bridge or a 3dB coupled line bridge to form a circularly polarized feed to the antenna based on orthogonal outputs of the two outputs of the 3dB branch line bridge or 3dB coupled line bridge that are 90 ° different from the local oscillator signal that is accessed from the input port.

33. The microwave detection device according to claim 30, wherein the 3dB bridge is configured as a 3dB ring bridge, wherein two of the output ports of the 3dB ring bridge are respectively fed to two feed points of the same antenna that are inverted in a polarization direction to form inverted double feeding to the antenna based on inverted outputs of the two output ports of the 3dB ring bridge that are 180 ° different from the local oscillation signal that is inputted from the input ports.

34. The microwave detection device of claim 30, wherein the 3dB bridge is configured as a 3dB branch line bridge or a 3dB coupled line bridge, wherein two of the output ports of the 3dB bridge are respectively feed-connected to different ones of the antennas to improve isolation between the two antennas based on quadrature outputs of the two output ports of the 3dB branch line bridge or the 3dB coupled line bridge that differ from the local oscillation signal that is accessed from the input ports by 90 °.

35. The microwave detection device according to claim 34, wherein the two antennas respectively fed to the two output ports of the 3dB bridge are orthogonally arranged in a polarization direction to form orthogonal feeds to the two antennas based on orthogonal outputs of the two output ports of the 3dB branch line bridge or the 3dB coupled line bridge, which are 90 ° different from the local oscillation signal accessed from the input port, to further improve isolation between the two antennas.

36. The microwave detection device according to claim 30, wherein the microwave detection device includes one of the 3dB bridges configured as a 3dB ring bridge, and two of the 3dB bridges configured as a 3dB branch line bridge or a 3dB coupled line bridge, and four of the antennas respectively fed to four of the output ports of the 3dB bridges configured as a 3dB branch line bridge or a 3dB coupled line bridge, wherein the input ports of the 3dB bridges configured as a 3dB ring bridge are electrically connected to the local oscillation circuit unit to access the local oscillation signals from the local oscillation circuit unit, wherein the two of the output ports of the 3dB bridges configured as a 3dB ring bridge are electrically connected to the two input ports of the 3dB bridges configured as a 3dB branch line bridge or a 3dB coupled line bridge, respectively, so that the four output ports of the 3dB bridges configured as a 3dB branch line bridge or a 3dB coupled line bridge provide the respective antennas with a circular polarization difference of the fed device in order of 90 °.

37. The microwave detecting device according to claim 30, wherein the microwave detecting device includes one of the 3dB bridges provided as a 3dB branch line bridge or a 3dB coupled line bridge, and two of the 3dB bridges provided as a 3dB ring bridge, and four of the antennas respectively fed to four of the output ports of the two 3dB bridges provided as a 3dB ring bridge, wherein the input ports of the 3dB bridge provided as a 3dB branch line bridge or a 3dB coupled line bridge are electrically connected to the local oscillation circuit unit to access the local oscillation signals from the local oscillation circuit unit, wherein two of the output ports of the 3dB bridge provided as a 3dB branch line bridge or a 3dB coupled line bridge are electrically connected to two of the input ports provided as a 3dB ring bridge, respectively, to realize the feeding polarization of the microwave detecting device by sequentially providing excitation signals different from 90 ° to the respective antennas to the four of the output ports provided as a 3dB ring bridge.

38. The microwave detecting device according to claim 30, wherein the local oscillation circuit unit is configured to invert the microwave chip outputting two local oscillation signals in a power supply state, wherein the microwave detecting device includes two 3dB bridges configured as 3dB branch line bridges or 3dB coupled line bridges, and four antennas respectively fed to four output ports of the two 3dB bridges configured as 3dB branch line bridges or 3dB coupled line bridges, to achieve circular polarization feeding of the microwave detecting device in a state in which the two 3dB bridges configured as 3dB branch line bridges or 3dB coupled line bridges respectively access the two local oscillation signals outputted from the microwave chip in inverted directions at the two input ports, in which the four output ports of the two 3dB bridges configured as 3dB branch line bridges or 3dB coupled line bridges provide excitation signals sequentially differing by 90 ° to the respective antennas.

39. The microwave detection device according to claim 38, wherein the microwave chip comprises a low dropout linear regulator, a voltage controlled oscillator, an oscillator, two amplifiers and a logic control unit, wherein the low dropout linear regulator provides a constant voltage to the voltage controlled oscillator in a powered state, wherein the oscillator provides a basic clock signal to the logic control unit and is arranged externally with a quartz crystal oscillator or is arranged integrally with an internal oscillating circuit to the logic control unit, wherein the logic control unit is arranged with a DSP or an MCU and has a frequency calibration unit electrically connected to the voltage controlled oscillator, wherein the voltage controlled oscillator outputs two output signals having a pulse frequency proportional to a voltage provided by the low dropout linear regulator and controlled and calibrated by the frequency calibration unit, respectively, based on its own characteristics, at the positive and negative terminals of the voltage controlled oscillator, respectively, to amplify two output signals outputted from the positive and negative terminals of the voltage controlled oscillator, respectively, such that the two voltage controlled oscillators provide two local oscillation signals directly.