CN104092024B - Direction backtracking system based on corner reflector antenna array - Google Patents

Abstract

The invention discloses a direction backtracking system based on an angle reflection antenna array, which belongs to the technical field of radar and communication engineering. The invention is composed of at least two planar antenna array boards perpendicular to each other, the distance between the planar antenna array boards satisfies the far-field relationship, and each planar antenna array board is composed of a planar radiation unit, a transceiver radio frequency channel and a digital frequency storage device. The present invention utilizes the specular reflection of multiple planar antenna arrays to realize the direction backtracking of radio frequency signals. During the process of realizing direction backtracking, it is not necessary to measure or estimate the incident direction of the signal; The function of the frequency converter realizes the power control and delay modulation of the return signal. The present invention is applicable to the return of common signals in radar systems and positioning systems without estimating the direction of the signal source, and is especially applicable to the fields of suppression and deceptive interference in the field of electronic countermeasures.

Description

A Direction Backtracking System Based on Angular Reflective Antenna Array

technical field

The invention belongs to the technical field of communication and radar engineering, and in particular relates to a direction backtracking system based on an angle reflection antenna array.

Background technique

Direction backtracking refers to reflecting the received electromagnetic signal back through the original direction. There are two ways to implement the direction backtracking system: active and passive. Passive direction tracking systems such as radar reflectors (also known as corner reflectors) commonly used in radar engineering, active azimuth tracking systems are usually implemented in the form of antenna arrays, currently there are mainly VanAtta arrays and phase conjugate arrays (PON arrays) ) Two implementations. The VanAtta array is composed of multiple pairs of antenna elements symmetrical to the geometric center of the array, and each pair of antenna elements is connected by a transmission line with the same electrical length. The phase conjugate array is realized based on frequency mixing technology. The radio frequency signal is mixed with the local oscillator with twice the carrier frequency, and the lower sideband part of the signal is obtained after mixing, or a radio frequency signal with the same carrier frequency as the original radio frequency signal but phase conjugated.

In a passive radar reflector, the metal wall of the radar reflector mirrors the radio frequency, and the radio frequency signal returns along the incident direction after three (or two) reflections. The reflection characteristics of the metal electric wall to the radio frequency signal can also be realized by an active antenna array. The active antenna array receives the radio frequency signal and then forwards it through the original antenna unit. The direction and incident direction of the forwarded signal are symmetrical to the normal direction of the antenna array. The axis is in a mirror reflection relationship. After the radio frequency signal is reflected three times (or twice) by the antenna array, it can return along the incident direction.

Digital Radio Frequency Memory (DRFM) is a technology widely used in the field of electronic countermeasures. The digital frequency storage converts the analog radio frequency signal into a digital signal for storage, and modulates and delays the signal as required. Then it is converted into an analog signal by a digital-to-analog converter, and then converted back to a radio frequency signal through an up-conversion operation. Digital frequency storage can be used as a signal source for deceptive jamming in electronic countermeasures.

However, passive radar transmitters have low echo power and can only reflect energy, and cannot adjust the transmission power of radio frequency energy; the design of the feed network of equal electric length of the active VanAtta array is more complicated; the active phase conjugate array is affected by Simultaneously arriving multi-frequency signals and broadband signals have a greater impact.

Contents of the invention

In order to solve the above technical problems, the present invention provides a direction backtracking system based on an angle reflective antenna array. The system implements the specular reflection of radio frequency signals in the form of antenna arrays, and completes the direction tracing of radio frequency signals by designing the positions of multiple antenna arrays. In the process of realizing direction tracing, it does not need to measure or estimate the incident direction of signals, and It is a controllable direction backtracking system.

In order to achieve the above object, the present invention adopts the following technical solution: a direction backtracking system based on an angle reflection antenna array, which is composed of at least two planar antenna array boards perpendicular to each other, and the distance between the planar antenna array boards satisfies the far-field relationship .

The planar antenna array board is composed of a planar radiation unit, a radio frequency channel and a digital frequency storage device, each antenna unit on the planar antenna array board is connected with a radio frequency channel, and the other end of the radio frequency channel is connected to the digital frequency storage device connected.

Each radio frequency channel is divided into a receiving part and a transmitting part, and the receiving part of the radio frequency channel consists of a duplexer, a low noise amplifier, a receiving end radio frequency bandpass filter, a downconverter, and an intermediate frequency bandpass filter; The transmitting part includes an intermediate frequency bandpass filter, an upconverter, a radio frequency bandpass filter, a power amplifier, and a duplexer.

The digital frequency storage device includes an analog-to-digital converter, a complex programmable logic device, a memory, a digital-to-analog converter, a power supply, and a clock unit; wherein, the analog-to-digital converter converts an analog radio frequency signal into a digital signal and transmits a complex and programmable Programmable logic devices, processed by complex programmable logic devices, converted into analog signals by digital-to-analog converters and transmitted; memory stores digital signals in complex programmable logic devices; clock units provide stable pulses for complex programmable logic devices; power supply Power the entire digital frequency storage.

There are three planar antenna array boards; or there are two planar antenna array boards.

The planar antenna array board is rectangular or circular.

The invention provides a direction tracing system based on an angle reflection antenna array, which can reflect one or more incident radio frequency signals back along the incident direction, and utilizes digital frequency storage technology to modulate the received radio frequency signals, Timing delay and other operations.

Compared with the existing passive radar reflector system and VanAtta array and phase conjugate array, these two active direction backtracking systems, the present invention has the following advantages:

1) Compared with passive radar transmitters, the present invention can process radio frequency signals, and the signal forwarding time is controllable; the present invention has higher echo power, and can modulate radio frequency echoes; passive The radar transmitter only reflects energy, and the present invention can design the transmission power of radio frequency energy according to needs; The signal that the passive radar reflector transmits is the same signal as the original signal, and the present invention can process the echo signal, this The characteristics are especially applicable in the field of radar electronic countermeasure engineering.

2) Compared with the VanAtta array, the present invention does not need to design a complex feeding network of equal electric length; since the transceiver system of each antenna unit is an independent subsystem, it is more conducive to modular design, and the VanAtta array does not have the present invention The ability to modulate and process radio frequency signals.

3) Compared with the phase conjugate array, the present invention is not affected by multi-frequency signals and broadband signals arriving at the same time; it does not need to accurately estimate the carrier frequency signal, and has the ability to simultaneously trace back multiple radio frequency signals; When the multi-frequency signal arrives, the phase conjugate array loses the ability of direction traceability. The direction traceability of the present invention is only related to the bandwidth of the antenna unit, and all signals within the antenna bandwidth can complete the direction traceability.

Description of drawings

FIG. 1 is a schematic structural diagram of Embodiment 1 of the present invention.

Fig. 2 is a structural block diagram of the planar antenna array board in the present invention.

Fig. 3 is a structural block diagram of the radio frequency channel and the digital frequency storage device of the planar antenna array board in the present invention.

Fig. 4 is a schematic diagram of the relationship between equal phase planes in the process of incident and reflected radio frequency signals according to the present invention.

Fig. 5 is a schematic structural diagram of Embodiment 2 of the present invention.

detailed description

Preferred embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the application and are used together with the embodiments of the present invention to explain the principles of the present invention.

Embodiment one

As shown in Figure 1, a direction backtracking system based on an angle reflection antenna array is composed of a planar antenna array board 1 located in the XOY plane, a planar antenna array board 2 in the XOZ plane, and a planar antenna array board 3 in the YOZ plane, three pieces The planar antenna array boards are perpendicular to each other, and the distance between every two planar antenna array boards satisfies the far-field condition, that is, the distance between the electromagnetic wave and the radiation source satisfies the relationship: ( represents the aperture of the antenna, represents the wavelength of an electromagnetic wave). The radiation surfaces of the three planar antenna array boards form a corner reflection structure. The working mode of the antenna unit on each planar antenna array board is duplex, that is, the signal received by the antenna unit is delayed or stored and then transmitted through the unit. The shape of the planar antenna array board can be rectangular, circular or any other form of plane.

The structure of each planar antenna array board in this system includes a planar radiation unit 4 , a radio frequency channel 5 and a digital frequency storage 6 , as shown in FIG. 2 . The structure and connection relationship between the radio frequency channel 5 and the digital frequency storage device 6 are shown in FIG. 3 . Each RF channel 5 can be further divided into a receiving part and a transmitting part, wherein the receiving part includes a duplexer 7, a low noise amplifier (LNA) 8, a receiving end RF bandpass filter (BPF) 9, a downconverter 10, a receiving Intermediate frequency bandpass filter (BPF) 12; the transmitting part includes transmitting intermediate frequency bandpass filter (BPF) 12, upconverter 10, transmitting radio frequency bandpass filter (BPF) 8, power amplifier (PA) 13, duplexer 7. The duplexer 7 is shared by the receiving and transmitting parts, and the local oscillator 11 is the reference signal source of the up-converter or down-converter 10 . The structure of the digital frequency storage device 6 includes an analog-to-digital converter (ADC) 14 , a digital-to-analog converter (DAC) 15 , a complex programmable logic device (CPLD) 16 , a power supply 17 , a memory 18 and a clock unit 19 .

Its working process is: when the radio frequency signal is incident on the planar antenna array board 1 from the far field, it passes through the reception of the receiving part of the radio frequency channel 5 in 1, the storage of the digital frequency storage device 6 and the forwarding of the reflection part of the radio frequency channel 5, Among them, the signal is amplified in the radio frequency channel 5, and the radio frequency signal is emitted along the direction of the mirror reflection relationship with the normal direction of the planar antenna array; the emitted signal reaches the planar antenna array board 2 perpendicular to the planar antenna array board 1, and passes through the The reception of the receiving part of the radio frequency channel 5, the re-storage of the digital frequency storage device 6 and the forwarding of the reflection part of the radio frequency channel 2; the radio frequency signal arrives at the planar antenna array board 3 that is all perpendicular to the planar antenna array boards 1 and 2, and finally, Through the reception of the receiving part of the radio frequency channel 5, the storage of the digital frequency storage 6 and the forwarding of the reflection part of the radio frequency channel 5, the radio frequency signal returns along the incident direction, thereby realizing the azimuth traceback of the radio frequency signal. The process of RF signal reflection is shown by the arrow in Figure 1 .

Assuming that the carrier frequency of the radio frequency signal transmitted by an X-band airborne radar is 10 GHz, the elevation angle and azimuth angle of the emission direction are respectively and . Select the coordinate origin O, place the centers of the three planar antenna array boards on the points with coordinates (5, 5, 0), (5, 0, 5) and (0, 5, 5) respectively, and make the three The radiating surfaces of the planar antenna array boards are perpendicular to each other, where the coordinate unit is meter. The number of array elements on each planar antenna array board is 25 (5×5), and the array element spacing in the X and Y directions is half a wavelength (1.5cm).

Convert the polar coordinates to rectangular coordinates to obtain the unit vector of the incident direction in the rectangular coordinate system:

As shown in Figure 4, the relationship between the equal phase plane 20 of the incident signal and the equal phase plane 21 of the reflected signal, after the radio frequency signal is reflected by the planar antenna array plate 1 on the XOY plane, the incident direction of the signal changes to:

Assume that after the first mirror reflection, the radio frequency signal is incident on the planar antenna array board 2 on the XOZ plane, and after mirror reflection again, the incident direction of the signal becomes:

In order to meet the mirror relationship, the signal will be incident on the planar antenna array board 3 on the YOZ plane at this time. After the third mirror reflection, the outgoing direction of the signal becomes:

Convert the unit vector of the outgoing direction into polar coordinates, and obtain the pitch angle and azimuth angle of the outgoing direction of the signal after the angular reflection antenna array direction backtracking system is and . The outgoing signal returns in the direction of the incoming signal compared to the incoming signal direction.

In this embodiment, it is assumed that the delays of the signals passing through the three planar antenna array boards are respectively , then the total delay of the system is:

use ( Indicates the speed of light), to get the distance value of distance deception in electronic countermeasures, so the total delay can be used Value to set the distance value for distance deception in electronic countermeasures.

Embodiment two

A direction-retracing system based on a corner-reflection antenna array, as shown in Figure 5, consists of two mutually perpendicular planar array boards 1 and 2, and the distance between the two planar antenna array boards satisfies the far-field condition ( represents the aperture of the antenna, represents the wavelength of the electromagnetic wave), the radiation surfaces of the two planar antenna array boards form an angular reflection structure, and the incident plane 22 is shown in FIG. 5 . The structure of each planar antenna array board, the structure and connection relationship of the radio frequency channel 5 and the digital frequency storage 6 in this system are the same as those in the first embodiment. The process of realizing azimuth backtracking by the radio frequency signal is shown by the arrow in Fig. 5 . The working mode of the antenna unit on each planar antenna array board is duplex, that is, the signal received by the antenna unit is delayed or stored and then transmitted through the unit. Wherein, the shape of the planar antenna array board may be rectangular, circular or any other form of plane.

This improvement scheme is applied to satellites, civil aviation and other systems that have fixed orbits or routes and require azimuth backtracking. By modulating the positions of the mutually perpendicular antenna array boards so that they are perpendicular to the plane where the fixed track or flight line is located, only two reflections are needed to complete the direction traceback of the radio frequency signal.

Embodiment Three

A direction backtracking system based on an angle reflection antenna array, which is composed of at least two planar antenna array boards, each two planar antenna array boards are perpendicular to each other, and the distance between each two planar antenna array boards satisfies the far-field condition, namely The distance between the electromagnetic wave and the radiation source satisfies the relation: ( represents the aperture of the antenna, Represents the wavelength of electromagnetic waves), and the radiation surface of the planar antenna array plate forms an angular reflection structure. The working mode of the antenna unit on each planar antenna array board is duplex, that is, the signal received by the antenna unit is delayed or stored and then transmitted through the unit.

The structure of one or two planar antenna array boards in the system includes a planar radiation unit 4, a radio frequency channel 5 and a phase shifter. One end of the radio frequency channel 5 is connected to the planar radiation unit 4, and the other end is connected to the phase shifter. Other structures and working process are the same as embodiment one.

In this embodiment, the phase shifter may be a delay line or other devices with a delay function.

This improved scheme still retains the ability of the digital frequency storage for signal modulation and delay, but reduces the number of digital frequency storage, which can reduce the cost of the system.

Embodiment Four

A direction backtracking system based on an angle reflection antenna array, which is composed of at least two planar antenna array boards, each two planar antenna array boards are perpendicular to each other, and the distance between each two planar antenna array boards satisfies the far-field condition, namely The distance between the electromagnetic wave and the radiation source satisfies the relation: ( represents the aperture of the antenna, Represents the wavelength of electromagnetic waves), and the radiation surface of the planar antenna array plate forms an angular reflection structure. The working mode of the antenna unit on each planar antenna array board is duplex, that is, the signal received by the antenna unit is delayed or stored and then transmitted through the unit.

The structure of each planar antenna array board in the system includes a planar radiation unit 4 , a radio frequency channel 5 and a digital frequency storage 6 , one end of the radio frequency channel 5 is connected to the planar radiation unit 4 , and the other end is connected to the digital frequency storage 5 .

The gains of the low noise amplifier 8 of the receiving part and the power amplifier 13 of the transmitting part in the radio frequency channel 5 are variable. Other structures and working process are the same as embodiment one.

This scheme is equivalent to weighting the amplitude of the radio frequency signal, and by designing a reasonable weight value, the side lobe level can be reduced and the interference can be reduced.

The above examples are only used to illustrate preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. The above embodiments provide those skilled in the art with a description of the basic functions of the present invention, and make it easy to understand and apply the present invention. For those skilled in the art, it is obvious to transplant this embodiment to make various changes, and no creative work is required. Therefore, the rights of the present invention are not limited to the solutions described in the above embodiments, but are consistent with those described in the claims.

Claims (6)

1. a kind of direction backtracking system based on corner reflector antenna array is it is characterised in that by least two pieces of orthogonal planes Antenna array strake forms, and the distance between planar array antenna strake meets far field relation:, whereindRepresentative antennas Aperture,Represent the wavelength of electromagnetic wave；The radiating surface of every block of planar array antenna strake forms corner reflection structure；Described flat plane antenna Array board is made up of planar radiating element, radio-frequency channel and digital frequency memory device, each plane on described planar array antenna strake Radiating element is respectively connected with radio-frequency channel, and the other end of described radio-frequency channel is connected with digital frequency memory device；Each described radio frequency Passage is divided into receiving portion and emitting portion, and the receiving portion of radio-frequency channel includes duplexer, the low noise amplification being sequentially connected Device, receiving terminal radio frequency band filter, low-converter, if bandpas filter；The emitting portion of radio-frequency channel includes connecting successively The if bandpas filter that connects, upconverter, radio frequency band filter, power amplifier, duplexer, if bandpas filter with Digital frequency memory device is connected, the low-converter of radio-frequency channel receiving portion, radio-frequency channel emitting portion upconverter all with this Shake and be connected.

2. the direction backtracking system based on corner reflector antenna array according to claim 1 it is characterised in that: described numeral Frequency memory device includes analog-digital converter, CPLD, memorizer, digital to analog converter, power supply and clock unit；Its In, the radiofrequency signal of simulation is converted to the incoming CPLD of digital signal by analog-digital converter, can through complexity The process of programmed logic device is converted to analogue signal through digital to analog converter and transfers out；Memory storage complex programmable logic Digital signal in device；Clock unit provides stable pulse for CPLD；Power supply is entirely numeral storage Frequency device is powered.

3. the direction backtracking system based on corner reflector antenna array according to claim 1 it is characterised in that: described plane Antenna array strake has three pieces.

4. the direction backtracking system based on corner reflector antenna array according to claim 1 it is characterised in that: described plane Antenna array strake has two pieces.

5. the direction backtracking system based on corner reflector antenna array according to claim 1 it is characterised in that: described plane Antenna array strake is rectangle.

6. the direction backtracking system based on corner reflector antenna array according to claim 1 it is characterised in that: described plane Antenna array strake is circle.