A polarization insensitive third harmonic radar system and signal transmission method

Abstract

The present invention discloses a polarization insensitive third harmonic radar system and a signal transmission method, wherein the system comprises a base station and a terminal, wherein the polarization insensitive third harmonic radar base station comprises an oscillator, a directional coupler, a frequency multiplier, a mixer, a low-pass filter, a dual-frequency orthogonal coupler, and a dual-frequency dual-line polarization antenna; and the terminal comprises a dual-frequency dual-line polarization antenna and a diode. The present invention realizes polarization insensitivity of fundamental wave excitation and third harmonic feedback of the radar base station and the terminal, can solve the technical problem of antenna polarization mismatch, and can be widely used in the fields of aerospace, deep sea rescue, outdoor adventure rescue, and wearable electronic devices.

Description

Technical Field

[0001] The invention relates to a radar system, and in particular to a polarization insensitive third harmonic radar system and a signal transmission method. Background Art

[0002] In the existing technology, harmonic radar has the problem of antenna polarization mismatch, and a special circuit structure is urgently needed to meet the requirements of polarization-insensitive harmonic radar system. Summary of the invention

[0003] Based on the above problems, the present invention proposes a polarization insensitive third harmonic radar system.

[0004] The present invention provides the following technical solutions:

[0005] On the one hand, the present invention provides a polarization insensitive third harmonic radar system, the system comprising a base station and a terminal;

[0006] The base station includes an oscillator (VCO), a directional coupler (Coupler), a frequency multiplier (Multiplexer), a mixer (Mixer), a low-pass filter (LPF), a dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler), and a dual-frequency dual-linear polarization antenna (DLP) (including vertical (TX_VP) and horizontal (TX_HP) polarization ports);

[0007] The terminal comprises a dual-frequency dual-linear polarization antenna (DLP'), a first diode (D1), and a second diode (D2).

[0008] Furthermore, the dual-band dual linear polarization antenna (DLP) includes a vertical polarization port (TX_VP) and a horizontal polarization port (TX_HP).

[0009] Further, the output end of the oscillator (VCO) is connected to the input port of the directional coupler (Coupler); the output port of the directional coupler (Coupler) is connected to the input port of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler), the coupling port of the directional coupler (Coupler) is connected to the input port of the frequency multiplier (Multiplexer), and the output port of the frequency multiplier (Multiplexer) is connected to the local oscillator port (LO) of the mixer (Mixer); the radio frequency port (RF) of the mixer (Mixer) is connected to the isolation port (ISO) of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler), the intermediate frequency port (IF) of the mixer (Mixer) is connected to the input port of the low-pass filter (LPF), and the output port of the low-pass filter (LPF) outputs; the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid The through port (DIR) of the dual-frequency dual-linear polarization antenna (DLP) is connected to the horizontal polarization port (TX_HP) of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler), and the coupling port (COU) of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler) is connected to the vertical (TX_VP) polarization port of the dual-frequency dual-linear polarization antenna (DLP);

[0010] The horizontal polarization port (RX_HP) and the vertical polarization port (RX_VP) of the dual-frequency dual-linear polarization antenna (DLP) are connected to a first (D1) and a second diode (D2), and the first and second diodes convert a fundamental wave (ω0) signal into a third harmonic (3ω0) signal.

[0011] Furthermore, the coupling transmission characteristics of the fundamental frequency (ω0) and the third harmonic frequency (3ω0) of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler) are represented by a scattering parameter matrix, as shown in formula (1, 2):

[0012]

[0013]

[0014] Furthermore, the input port signal of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler) is coupled and transmitted to the DIR and COU ports through the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler), and the output of the DIR port and the COU port is calculated by formula (1):

[0015]

[0016]

[0017] Furthermore, the dual-polarized antenna in the terminal captures v in vertical and horizontal polarization directions. s signal, where the v s The signal is the input signal of the orthogonal coupler port IN, and the free space transmission coefficient is κ(d). The vertical and horizontal polarization direction signals of the dual-polarization antenna in the terminal are calculated, as shown in formulas (5, 6):

[0018]

[0019]

[0020] Furthermore, the first and second diodes at the vertical and horizontal polarization ports of the dual-polarization antenna in the terminal generate third harmonics, and the third harmonic signals generated by the first and second diodes are shown in formulas (7) and (8):

[0021]

[0022]

[0023] Furthermore, the third harmonic signals generated by the first and second diodes are input again as third harmonic signals into the vertical and horizontal polarization directions of the dual-polarization antenna in the terminal, and transmitted through free space to the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler) DIR and COU ports in the base station:

[0024]

[0025]

[0026] Furthermore, the signal is transmitted to IN and ISO ports through a dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler) for calculation:

[0027] v' IN =0 (11)

[0028]

[0029] The third harmonic is completely transmitted to the ISO port of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler).

[0030] On the other hand, the present invention further proposes a signal transmission method, characterized in that the method comprises:

[0031] Step 201, the oscillator (VCO) in the base station excites the input port (IN) of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler), and transmits it to the vertical (TX_VP) and horizontal (TX_HP) polarization ports of the dual-frequency dual-linear polarization antenna (DLP) through the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler) as the fundamental wave (ω0) excitation signal;

[0032] Step 202: The vertical (RX_VP) and horizontal (RX_HP) polarization ports of the dual-frequency dual-linear polarized antenna (DLP') in the terminal receive the fundamental wave (ω0) signal from the radar base station, and transmit it to the first and second diodes. The first and second diodes convert the fundamental wave (ω0) signal into a third harmonic (3ω0±3Δω) signal as the third harmonic (3ω0±3Δω) feedback signal of the vertical (RX_VP) and horizontal (RX_HP) polarization ports of the dual-frequency dual-linear polarized antenna (DLP');

[0033] Step 203, the vertical (TX_VP) and horizontal (TX_HP) polarization ports of the dual-frequency dual-linear polarization antenna (DLP) in the base station receive the third harmonic (3ω0±3Δω) feedback signal from the terminal, transmit it to the isolation port (ISO) through a dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler), and output the intermediate frequency signal 3Δω through a mixer (Mixer) and a low-pass filter (LPF).

[0034] The present invention discloses a polarization insensitive third harmonic radar system, the system includes a base station and a terminal, the polarization insensitive third harmonic radar base station includes an oscillator, a directional coupler, a frequency multiplier, a mixer, a low-pass filter, a dual-frequency orthogonal coupler, and a dual-frequency dual-line polarization antenna; the terminal includes a dual-frequency dual-line polarization antenna and a diode. The present invention realizes polarization insensitivity of fundamental wave excitation and third harmonic feedback of the radar base station and the terminal, can solve the technical problem of antenna polarization mismatch, and can be widely used in aerospace, deep sea rescue, outdoor adventure rescue, wearable electronic devices and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Attached Figure 1 This is a schematic diagram of a polarization insensitive third harmonic radar system;

[0036] Attached Figure 2 It is the polarization mismatch diagram of transmitting and receiving dual-polarization antenna; DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0038] Example

[0039] Figure 1Schematic diagram of a polarization-insensitive third harmonic radar system, where the terminal is the harmonic tag. Figure 2 is the polarization mismatch diagram of the transmitting and receiving dual-polarization antennas. The input signal v of the input port (i.e., port IN) of the dual-frequency (ω0, 3ω0) orthogonal coupler (HybridCoupler) in the base station s The coupling transmission characteristics of the fundamental frequency (ω0) and the third harmonic frequency (3ω0) of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler) can be expressed by its scattering parameter matrix (ie, S parameters), as shown in formulas (1, 2).

[0040]

[0041]

[0042] The IN port signal is coupled and transmitted to the DIR and COU ports via a dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler), and is calculated using formula (1) to obtain formulas (3, 4).

[0043]

[0044]

[0045] The dual-polarized antenna in the terminal captures v in vertical and horizontal polarization directions s Signal (v s The signal is the input signal of the orthogonal coupler port IN), the free space transmission (spacing d) coefficient is κ(d), and the vertical and horizontal polarization direction signals of the dual-polarization antenna in the terminal are calculated, as shown in formulas (5, 6).

[0046]

[0047]

[0048] Diodes D1 and D2 at the vertical and horizontal polarization ports of the dual-polarization antenna in the terminal generate third harmonics (Taylor expansion, the third harmonics are generated by the cube of the input signal). The third harmonic signals generated by diodes D1 and D2 are shown in formulas (7, 8).

[0049]

[0050]

[0051] Formula (7, 8) is input again as the third harmonic signal into the vertical and horizontal polarization directions of the dual-polarization antenna in the terminal, and is transmitted through free space to the DIR and COU ports of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler) in the base station (the DIR and COU ports correspond to the vertical and horizontal polarization direction capture signals of the dual-polarization antenna in the base station, respectively), as shown in formula (9, 10).

[0052]

[0053]

[0054] It is further transmitted to the IN and ISO ports through a dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler), as shown in formulas (11, 12).

[0055] v' IN =0 (11)

[0056]

[0057] The third harmonic is completely transmitted to the ISO port (isolation port) of the dual-frequency (ω0, 3ω0) orthogonal coupler (Hybrid Coupler), thereby realizing a polarization-insensitive third harmonic radar system.

[0058] The invention discloses a polarization insensitive third harmonic radar system, the system comprises a base station and a terminal, the polarization insensitive third harmonic radar base station comprises an oscillator, a directional coupler, a frequency multiplier, a mixer, a low-pass filter, a dual-frequency orthogonal coupler, and a dual-frequency dual-line polarized antenna; the terminal comprises a dual-frequency dual-line polarized antenna and a diode (D1, D2). The invention realizes polarization insensitivity of fundamental wave (ω0) excitation and third harmonic (3ω0±3Δω) feedback of the radar base station and the terminal, can solve the technical problem of antenna polarization mismatch, and can be widely used in aerospace and other fields.

[0059] The above-mentioned embodiments of the present invention are combinations of elements and features of the present invention. Unless otherwise mentioned, the elements or features may be considered as optional. Each element or feature may be put into practice without being combined with other elements or features. In addition, embodiments of the present invention may be constructed by combining some elements and / or features. The order of operations described in the embodiments of the present invention may be rearranged. Some constructions of any one embodiment may be included in another embodiment, and may be replaced by the corresponding construction of another embodiment. It is obvious to those skilled in the art that claims that do not have a clear reference relationship to each other in the attached claims may be combined into embodiments of the present invention, or may be included as new claims in the amendment after submitting the present invention.

[0060] In a firmware or software configuration, the embodiments of the present invention may be implemented in the form of modules, procedures, functions, etc. The software code may be stored in a memory unit and executed by a processor. The memory unit is located inside or outside the processor and may send data to and receive data from the processor via various known means.

[0061] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A polarization insensitive third harmonic radar system, characterized in that: The system includes a base station and a terminal; The base station includes an oscillator, a directional coupler, a frequency multiplier, a mixer, a low-pass filter, a dual-frequency orthogonal coupler, and a dual-frequency dual-linear polarization antenna DLP, wherein the dual-frequency dual-linear polarization antenna DLP includes a vertical polarization port and a horizontal polarization port; The oscillator output end is connected to the directional coupler input port; the directional coupler output port is connected to the dual-frequency orthogonal coupler input port, the directional coupler coupling port is connected to the frequency multiplier input port, and the frequency multiplier output port is connected to the mixer local oscillator port; the mixer radio frequency port is connected to the dual-frequency orthogonal coupler isolation port, the mixer intermediate frequency port is connected to the low-pass filter input port, and the low-pass filter output port outputs; the dual-frequency orthogonal coupler through port is connected to the dual-frequency dual-linear polarization antenna DLP horizontal polarization port, and the dual-frequency orthogonal coupler coupling port is connected to the dual-frequency dual-linear polarization antenna DLP vertical polarization port; The terminal comprises a dual-frequency dual-linear polarization antenna DLP', a first diode, and a second diode; The dual-frequency dual-linear polarization antenna in the terminal captures the vs signal in the vertical and horizontal polarization directions, wherein the vs signal is the input signal of the orthogonal coupler port IN, and the free space transmission coefficient is κ(d). The vertical and horizontal polarization direction signals of the dual-frequency dual-linear polarization antenna in the terminal are calculated, as shown in formulas (5) and (6): 。 2. According to the polarization-insensitive third harmonic radar system of claim 1, the horizontal polarization port and the vertical polarization port of the dual-frequency dual-linear polarization antenna DLP are connected to a first diode and a second diode, and the first diode and the second diode convert the fundamental wave signal into a third harmonic signal.

3. According to the polarization insensitive third harmonic radar system of claim 1, the coupling transmission characteristics of the fundamental frequency and the third harmonic frequency of the dual-frequency orthogonal coupler are represented by a scattering parameter matrix, as shown in formulas (1) and (2): 。 4. The polarization insensitive third harmonic radar system according to claim 3, characterized in that: The input port signal of the dual-frequency orthogonal coupler is coupled and transmitted to the DIR and COU ports by the dual-frequency orthogonal coupler, and the output of the DIR and COU ports is calculated by formulas (3) and (4): 。 5. The polarization insensitive third harmonic radar system according to claim 4, characterized in that: The first diode and the second diode at the vertical polarization port and the horizontal polarization port of the dual-frequency dual-linear polarization antenna in the terminal generate third harmonics. The third harmonic signals generated by the first diode and the second diode are shown in formulas (7) and (8): 。 6. The polarization insensitive third harmonic radar system according to claim 5, characterized in that: The third harmonic signals generated by the first diode and the second diode are input again as third harmonic signals into the vertical and horizontal polarization directions of the dual-frequency dual-linear polarization antenna in the terminal, and transmitted to the DIR and COU ports of the dual-frequency orthogonal coupler in the base station through free space: 。 7. The polarization insensitive third harmonic radar system according to claim 6, characterized in that: The third harmonic signal passing through the dual-frequency orthogonal coupler is further transmitted to the IN and ISO ports for calculation: The third harmonic is fully transmitted to the ISO port of the dual-band quadrature coupler.

8. A signal transmission method, characterized in that: The method is applied to the system according to any one of claims 1 to 7, and the method comprises: Step 201, an oscillator in a base station excites an input port of a dual-frequency orthogonal coupler, and transmits the signal to a vertical polarization port and a horizontal polarization port of a dual-frequency dual-linear polarization antenna DLP through the dual-frequency orthogonal coupler as a fundamental wave excitation signal; Step 202: The vertical polarization port and the horizontal polarization port of the dual-frequency dual-linear polarization antenna DLP' in the terminal receive the fundamental wave signal from the radar base station, and transmit it to the first diode and the second diode. The first diode and the second diode convert the fundamental wave signal into a third harmonic signal as the third harmonic feedback signal of the vertical polarization port and the horizontal polarization port of the dual-frequency dual-linear polarization antenna DLP'; Step 203: The vertical polarization port and the horizontal polarization port of the dual-frequency dual-linear polarization antenna DLP in the base station receive the third harmonic feedback signal from the terminal, transmit it to the isolation port through the dual-frequency orthogonal coupler, and output the intermediate frequency signal 3 through the mixer and the low-pass filter. .

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