KR101572184B1 - vhf array radar antenna system - Google Patents

Abstract

The present invention relates to a VHF array radar antenna system capable of detecting a stealth object having a low reflection area (RCS) and capable of introducing high gain into a low altitude by combining reception antennas of a plurality of VHF frequency bands. The antenna system of the present invention includes: one transmission antenna for transmitting one transmission frequency signal (f ₀ ) of a VHF band of 100 MHz to 700 MHz at a high output; A plurality of reception antennas for receiving a signal (f ₀ ) of a transmission frequency wave directly received by a transmission output of the transmission antenna and a signal reflected from a stealth vehicle; A plurality of antenna signal output receiving apparatuses for mixing I, Q Doppler signals by mixing a total sum signal received from the plurality of reception antennas, a horizontal difference signal and a vertical difference signal directly; And a signal processing device for processing the I, Q Doppler signals of the plurality of antenna signal output reception devices to detect a stealth flight. The VHF array radar antenna according to the present invention receives a signal reflected from a propeller of a stealth vehicle or a cable wiring line using a TV or FM broadcasting transmitter or a high output VHF frequency transmission antenna and a plurality of NxM array receiving antennas, (Low altitude stealth airplane (UAV) with low radar reflection area (RCS) is extracted, thereby protecting national important facilities from the enemy and improving national security.

Description

[0001] VHF ARRAY RADAR ANTENNA SYSTEM [0002]

The present invention relates to a search radar antenna, and more particularly, to a search radar antenna that combines receive antennas of a plurality of VHF frequency bands (100 MHz to 700 MHz) to draw a high gain and penetrate low altitude, To a detectable VHF array radar antenna system.

Generally, the detection radar is classified into airborne detection radar, sea surface navigation radar, and battlefield surveillance / control radar according to the target target. The detection radar is divided into short distance, medium / long distance and long distance distance radar according to detection distance, It is divided into two dimensional (azimuth, distance) or three dimensional (azimuth, distance, altitude) radar according to information extraction ability.

The ground-mounted long-range airborne detection radar is the radar with the least restriction according to its operation. It is mainly installed at high altitude and detects long-distance high-level target (aircraft, missile, etc.), extracts the target specification, It is a detection radar that is operated continuously for alarm / aerial field monitoring and control.

In recent years, low penetration using stealth airplane, especially UAV, which is made of FRP with extremely low reflection of the air, has been frequently occurred. Such a small stealth air vehicle penetrating into the air has a problem that it is difficult to detect with conventional airborne radar have. (RCS) means the amount of the reflected wave of the own wave with respect to the propagation of the enemy. The stealth machine reduces the reflection area. Examples of the method of reducing the RCS include a radio wave absorbing material (RAM) and a radio wave absorbing structure (RAS) . Stealth aircraft, which are expected to infiltrate in the future, are made of FRP and reduce the reflection area (RCS: Radar Cross Section), which is difficult to detect with conventional radar. For example, recently, unmanned aerial vehicles such as those found in the forefront areas of Paju City and Baekryeong Island have been able to fly 2 ~ 3km in length with a length of 2 ~ 3km and the radar reflection area (RCS) is extremely small. Do.

As a conventional detection radar technology, there is disclosed a detection and tracking radar with a registration number 10-1213043 in the Korean Patent Registration Gazette, a moving object defense system equipped with the detection and tracking radar, and a high speed moving object tracking method of a detection tracking radar, Radar receivers are available.

An object of the present invention is to provide a method and apparatus for accurately detecting an unmanned stealth vehicle, which is difficult to detect with conventional airborne detection radar, by combining a plurality of receiving antennas of VHF (100MHz to 700MHz) And to provide a VHF array radar antenna system capable of detecting a stealth vehicle having a small reflection area (RCS) penetrating into a VHF array.

According to an aspect of the present invention, there is provided an antenna system including: a transmission antenna for transmitting one transmission frequency signal f ₀ of a VHF band of 100 MHz to 700 MHz at a high output; A plurality of reception antennas for receiving a signal (f ₀ ) of a transmission frequency wave directly received by a transmission output of the transmission antenna and a signal reflected from a stealth vehicle; A plurality of antenna signal output receiving apparatuses for mixing I, Q Doppler signals by mixing a total sum signal received from the plurality of reception antennas, a horizontal difference signal and a vertical difference signal directly; And a signal processing device for processing the I, Q Doppler signals of the plurality of antenna signal output reception devices to detect a stealth flight.

The reception antenna includes an N-ary × M array element, a direct reception antenna for directly receiving a transmission signal of the transmission antenna, a band-pass filter for band-passing a reception signal of the array elements arranged in each row, Pass filter for passing the f ₀ reception frequency of the direct reception antenna and a f ₀ pass filter for passing the reception signal on the left half side shifted in phase in the left half passive phase shifter, A right phase synthesizer for synthesizing the right phase synthesized signal and a right phase synthesized signal received from the right phase shifter, a phase phase compensator for phase compensating the output of the right synthesizer, The sum of the outputs of the hybrid coupler outputting the sum signal and the differential signal, and the sum of the signals of the upper half-side hybrid coupler arranged in the row A lower sum signal synthesizer for summing up the sum signals of the upper sum signal synthesizer for outputting the summing signal and the sum signals of the lower half hybrid couplers arrayed in rows and the lower sum signal synthesizer for outputting the sum of the outputs of the upper sum signal synthesizer and the lower sum signal synthesizer An upper differential signal synthesizer for summing up the difference signals of the total sum hybrid coupler for obtaining the sum and difference of the total sum hybrid and the differential difference signal and outputting the summed signal and the vertical difference signal and the upper half side hybrid clutches arranged in rows, A lower differential signal coupler for summing the differential signals of the lower half hybrid coupler and outputting a lower differential signal; a horizontal differential hybrid coupler for summing the outputs of the upper differential signal synthesizer and the lower differential signal synthesizer to output a total horizontal difference signal; A low noise amplifier for amplifying the vertical difference signal, a low noise amplifier for amplifying the total sum signal, A low-noise amplifier for amplifying the differential signal, and an automatic switching device for automatically switching the output after a low-noise amplifier is attached.

That is, in the N × M stage receiver of the present invention, the upper left N / 2 summing signal is synthesized by the synthesizer 230-3, the lower left N / 2 summing signal is synthesized by the synthesizer 230-4, Coupler 240-2 to extract a sum signal and a vertical difference signal, and amplifies the sum signal and the vertical difference signal by a vertical difference signal low noise amplifier (EΔ LNA) 250-1 and a total sum signal low noise amplifier (LNA) 250-2.

The upper right N / 2 synthesizer output is input to the upper hybrid couplers and synthesized by the output difference signal synthesizer 230-5. The lower right N / 2 synthesizer output is input to the lower hybrid couplers, -6) and then synthesized by the hybrid coupler 240-3 to extract a horizontal difference signal (Az?) And amplified by the Az? LNA 250-3.

That is, the left side of the N-stage M receiving antenna (phase shifter output) of the present invention is composed of N / 2 upper hybrid couplers 240 -1), and the right side is synthesized by M / 2 right antennas in the upper N / 2 combiner 230-2 and then added to the same N / 2 hybrid coupler 240-1 by the phase compensator 220 ' And inputs the N / 2 horizontal sum signal (?) And the difference signal (?).

The sum signals (?) Among these signals are input to the combiner 230-3 and then input to the final hybrid coupler 240-2.

Further, the left lower M / 2 antenna is synthesized by the left lower N / 2 synthesizer 230-1, and the output is input to the lower N / 2 hybrid coupler 240-1. The lower right M / 2 antennas are combined in the lower right N / 2 in the synthesizer 230-2, and the output in the lower N / 2 hybrid coupler 240-1 and the lower N / 2 phase compensator 220 ' ). The hybrid of the N / 2 is drawn out of the output sum signal (A _Z Σ) and difference signal (A _Z Δ). The horizontal sum signal N / 2 (A _Z Δ) at each end is input to the final hybrid coupler 240-2 after being synthesized by the lower left synthesizer 230-4, and the total synthesized signal Σ and the vertical difference signal E?).

The upper hybrid carpurea N / 2 differential output (?) Is synthesized by the synthesizer 230-5, the output is inputted to the hybrid car coupler 240-3, the lower hybrid car coupler N / 2 differential output? Is synthesized by the combiner 230-6 and the output is inputted to the same hybrid coupler 240-3 to fetch the total horizontal difference signal A _Z Σ.

The summed vertical difference signal E? Outputted in this way is amplified in the low noise amplification 250-1 and amplified in the low noise amplifier 250-2 and the summed horizontal signal (A _Z? ) Is amplified in the low noise amplifier 250-2. And then amplified by the low-noise amplifier 250-3 and sent to the receiving device 270. [

The low-loss phase shifter attached to these antennas sends a signal controlled by the receiver control device to the beam steering device, sends back the control signal from the beam steering device to the overall phase shifter, phase shifts it, The direction, altitude, and distance data of the steering receiving aircraft are detected and sent to the computing device built in the receiver device for automatic calculation.

A VHF array radar antenna according to the present invention receives a signal reflected from a propeller of a stealth vehicle or a wire wiring line using a high-power VHF frequency transmitting antenna and a plurality of N-ary x M array antennas and extracts a Doppler signal By detecting low altitude stealth vehicles (UAVs) with low radar reflection area (RCS), it is possible to protect national important facilities from enemies and improve national security.

FIG. 1 is a layout diagram of a VHF array radar antenna system according to the present invention, in which FIG. 1A is a vertical high-gain vertical, horizontal and steering antenna, FIG. 1B is a low-
FIG. 2 is an external view of a VHF array radar antenna according to the present invention,
3 is a structural block diagram of a VHF array radar antenna according to the present invention,
4 is a block diagram of an output signal receiving apparatus of a VHF array radar antenna according to the present invention,
5 is a schematic view showing an array element of a VHF array radar antenna according to the present invention,
FIG. 6 is a schematic view showing a band-pass filter of a VHF array radar antenna according to the present invention,
7 is a schematic view showing a phase shifter of a VHF array radar antenna according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. The following examples are merely illustrative of the present invention and are not intended to limit the scope of the present invention.

First, the stealth vehicle, which is expected to penetrate in the future, is made of UAV FRP, and the RCS (Radar Cross Section) is extremely small, so that the RF power must be very large for detection. Therefore, And the AVE power that is copied to a high output power of a TV or FM broadcast antenna or a separate high-power transmitter is reflected from a flying object, so that a Doppler frequency and a transmission frequency reflected from a moving object (A, B, C) more than two antennas (A, B, C) to receive the received signals at the same time. It is an antenna device that calculates automatically the altitude, direction, and distance of a flight.

In addition, the present invention provides a set of LNA (including a reserve unit) for eliminating a fault in EMP attack using a passive element phase shifter, It is an antenna that drastically reduces the thermal noise and improves the signal-to-noise ratio than an RF module and improves reception sensitivity.

FIG. 1 is a layout diagram of a VHF array radar antenna system according to the present invention, FIG. 2 is an external view of a reception antenna of a VHF array radar antenna system according to the present invention, and FIG. Fig.

Of: (100 Tx) and said transmitting antenna (100) VHF array radar antenna system of 100MHz ~ one transmit antenna for transmitting a VHF high-power radio signal (f ₀₎ of 700MHz as shown in FIG. 1 according to the invention (A, B, and C) 200-1 to 200-3 that receive a signal reflected from a flight (Q) 300, and a plurality of receiving antennas (A, B, and C) And transmits the received antenna signals to the antenna signal output receiving apparatus 270 (FIG. 4). Referring to FIG. 1, the high power wireless transmission antenna 100 may be a TV broadcasting transmission antenna or an FM broadcasting transmission antenna, or may be a transmission antenna that separately transmits a VHF transmission power with a high output of 10 kW (Average) or higher.

As shown in FIG. 2, the receiving antenna 200 according to the present invention is a box type having a height of about 11 m, a width of about 10 m, and a width of about 2 mm and includes an N x M array antenna 202, an IFF antenna 204 and a single direct receiving antenna 206 for directly receiving the transmission signal f ₀ of the transmission antenna 100. The front surface of the direct receiving antenna 206 is covered with an insulator and disguised as a lightening, .

3, the receiving antenna 200 includes a 10 x 10 array element 202, a single direct receiving antenna 206 for directly receiving the transmitting signal f ₀ of the transmitting antenna 100, A band pass filter 210 for band-passing a received signal of the array elements 202 arranged in each row, a phase shifter 220 for phase-shifting a received signal through the band-pass filter 210, A left synthesizer 230-1 for synthesizing the left reception signal phase-shifted by the phase shifter 220, a f ₀ pass filter 210 'for passing the f ₀ reception frequency of the antenna 206, A right phase synthesizer 230-2 for synthesizing the right received signal phase-shifted in the crisis 220, a line phase compensator 220'for phase-compensating the output of the right synthesizer 230, an output of the left synthesizer 230-1 Compensated right synthesizer 230-2 to output a horizontal sum (AzΣ) signal or a horizontal difference (AzΔ) signal An upper sum signal synthesizer 230-3 for summing up the horizontal sum signals of the upper hybrid couplers arranged in rows and the upper sum signal synthesizer 230-3 and a horizontal sum signal synthesizer 230-3 of the lower hybrid couplers arranged in rows, And a sum of the outputs of the upper sum signal combiner 230-3 and a sum of the outputs of the lower sum signal combiner 230-4 to obtain a sum An upper sum signal mixer 230-2 for summing the difference signals of the upper hybrid couplers 240-2 arranged in rows and the upper hybrid coupler 240-2 for outputting a sum signal (Σ) signal and a vertical difference (EΔ) 5), a lower differential signal synthesizer 230-6 for summing up the difference signals of the lower hybrid couplers arranged in rows and outputting a lower differential signal, an output of the upper differential signal synthesizer 230-5, (230-6) to obtain a total horizontal difference Az A low-noise amplifier 250-1 for amplifying a vertical difference (E DELTA) signal, a low-noise amplifier 250-2 for amplifying a sum signal (? A low noise amplifier 250-3 for amplifying a horizontal difference (Az DELTA) signal, and an automatic switching unit 260 for automatically switching the failure with a spare LNA added to each LNA.

4 is an output signal receiving apparatus of the VHF array radar antenna system according to the present invention.

As shown in FIG. 4, the output signal receiving apparatus 270 of the VHF array radar antenna according to the present invention includes a distributor 276 for distributing a transmission direct wave (f ₀ ) reception signal, a low noise A mixer 272-1 for mixing the low noise amplified total sum signal and the transmitted direct wave received signal, a low band filter 274-1 for passing only the Doppler signal at the output of the mixer, A Doppler signal amplifier 275-1 for amplifying the I-Doppler signal of the low-band filtered sum-sum signal, a phase adjuster 273-1 for changing the phase of the transmitted direct-wave received signal by 90 °, A low-pass filter 274-2 for passing only the Doppler signal at the output of the mixer, and a low pass filter 274-2 for mixing the Q A Doppler amplifier 275-2 for amplifying the Doppler signal, A low noise amplifier 271-2, a mixer 272-3 for mixing the low-noise amplified vertical difference signal and the transmitted direct wave reception signal, a low-pass filter 274-3 for passing only the Doppler signal at the output of the mixer, A Doppler signal amplifier 275-3 for amplifying the I-Doppler signal of the low-pass filtered vertical difference signal, a phase adjuster 273-2 for changing the phase of the transmitted direct wave reception signal by 90 °, A low pass filter 274-4 for passing only the Doppler signal at the output of the mixer, and a low pass filter 274-4 for passing only the Doppler signal at the output of the mixer, A Doppler signal amplifier 275-4 for amplifying a Q-Doppler signal, a low noise amplifier 271-3 for amplifying a horizontal difference signal, a mixer 272-2 for mixing a low-noise amplified horizontal difference signal and a transmission direct wave reception signal, 5, a low-pass filter 274-5 for passing only the Doppler signal at the output of the mixer, A Doppler signal amplifier 275-5 for amplifying the I-Doppler signal of the low-pass filtered horizontal difference signal, a phase adjuster 273-3 for changing the phase of the transmitted direct wave reception signal by 90 °, A low pass filter 274-6 for passing only the Doppler signal at the output of the mixer, and a low pass filter 274-6 for passing only the low pass filtered low pass filtered signal A Doppler signal amplifier 275-6 for amplifying the Q-Doppler signal, and a signal processor 280 for processing the I and Q signals received from the three antennas to detect the stealth flight. The signal processing device 280 may include a receiving device, a digital converter, a controller, a beam steering device, a peer identification device, a signal processor, an all-rounder, an automatic computing device, and automatic ABC signal receiving devices.

FIG. 5 is a schematic view showing an array element of a VHF array radar antenna according to the present invention, FIG. 6 is a schematic view showing a band-pass filter of a VHF array radar antenna according to the present invention, Fig. 2 is a schematic view showing a phase shifter of a radar antenna.

As shown in FIG. 5, the array element 202 of the VHF array radar antenna according to the present invention is an LP type element with a frequency of 100 MHz to 700 MHz, and uses vertical and horizontal bi-polarized waves.

As shown in FIG. 6, the band pass filter 210 of the VHF array radar antenna according to the present invention is a multi-band insulated type in which f ₀ is removed using a rotation replacing method, f ₀ + f _d and f _0- Let f _d pass. 1 to 4 bands are used depending on the broadcasting frequency band of each region.

As shown in FIG. 7, the phase shifter 220 of the VHF array radar antenna according to the present invention uses an automatic variable rotation rotation method as a broadband phase shifter. 1 to 4 bands are used depending on the broadcasting frequency band of each region.

The operation of the VHF array radar system according to the present invention will now be described.

The configuration of the stealth vehicle 300 is mainly a UAV, and it is automatically adjusted by a remote control or a program GPS, and it is difficult to detect by using a conventional microwave radar because the entire body of the aircraft is configured by a FRP or the like which is not reflected by a wave.

Therefore, in order to detect weak reflected power due to a weak propagation reflection area (RCS) reflected from the inner engine, the electric wire conductor, or the rotating propeller among the components of the air vehicle 300, . In case that the transmission signal to the air vehicle 40 is received using the same antenna as the existing detection radar and the reflected signal from the airplane is received again after the pulsed power transmission, the average power is too low for the pulse power, . In case of pulse propagation from the detection antenna, the pulse width must be extremely small (1us or less) at the time of detecting the proximity approach to the national important facilities. Therefore, it is impossible to receive the detection antenna because the average radiation power is very small.

In order to receive such a weak radio wave, the receiving antenna 200 of the present invention receives only a transmission signal having an average power of 10 KW or more using an existing TV broadcast wave or FM broadcast wave or a separate large-output VHF transmission antenna radiation year, vehicle wiring lines or wires is reflected while moving, etc. propeller frequency due to the Doppler effect a conversion fo ± f _D (fo: transmission frequency, f + _D: Doppler frequency by the vehicle proximity -f _D: Doppler frequency due to the spacing ) Frequency is received by the reception antenna 200 of the detection radar and is frequency-converted by the reception antenna 200 directly to the TV transmission signal output fo + f _D (close movement) or -f _D Only the frequency is received, and the fo frequency is removed by the filter.

The radar reflection area (RCS) of the stealth unmanned aerial vehicle is extremely small, so the reflected power is weak and the incoming radio waves must be strong. Therefore, when transmitting and receiving with a single VHF antenna, pulse power must be emitted. Since the pulse power needs to be detected at a short distance, the pulse strength is narrow and the average power is extremely small. State.

In order to prevent such a disconnection, a continuous power of a large power (AVE power CW) is emitted to the existing broadcasting TV broadcasting transmitter or a separate VHF transmitter, so that the power of the radio waves coming from the airplane is large, The power is reflected at a much larger power than when the peak power of the antenna pp is reached, so that the reception antenna 200 can receive the reflected signal of the flight.

In order to increase the gain, the receiving antenna 200 of the present invention has a structure in which a single radiation receiving antenna is vertically, horizontally, bi-polarized and slightly polarized and has a gain of more than 7db, A gain of 25 dB or more and a gain of 30 dB or more, which is obtained by outputting a difference signal (ΔE), a horizontal difference (ΔAz), and a sum signal (Σ) If only one set of the receiving antenna 200 is used, it is possible to detect the direction, but it is impossible to identify the distance and the altitude. Therefore, it is possible to simultaneously receive two or more (200-1 to 200-3) And inputs it to the reception arithmetic unit 280 so that the direction angle, distance, altitude and peer of the airplane can be automatically identified.

As described above, the detection radar antenna of the present invention is required to form a high gain, a high backward ratio, a wide beam width, a reflection element of a flight body mainly reflects a horizontal polarization by a power supply line, and a vertical polarization is expected to reflect from a propeller. Polarization was adopted, and the LP broadband type was selected as the array element 202 in the wide frequency range.

The band-pass filter 210 removes the TV transmission frequency and passes through only the Doppler frequency reflected from the moving object. Thus, the filter can be selected as four frequency band rotation type. The phase shifter 220 is configured as a passive 6-bit type so that it can be operated with four frequency bands. The hybrid coupler 240 is composed of a 3-dB type for extracting a monopulse signal. The hybrid coupler 240 is composed of 4 bands, and is connected to a necessary band It can be used for switching.

The LNA 250 uses a low-noise broadband type booster amplifier and automatically switches to a standby mode when the EMP attack is broken.

The Doppler filter 274 is designed to meet the expected Doppler frequency by filtering at a relatively low speed when infiltrating an unmanned aerial vehicle into a national important facility and rotating at a high speed of the propeller. The Doppler filter 274 filters the TV broadcast frequency, , Computing devices, and display functions.

FIG. 1A shows a configuration in which, when the reflected power of the RCS of the airplane is weak or remote, a large number of arrays are mounted on the receiving antenna to increase the gain. However, when the RCS of the airplane is large or several kilometers, have. 1A and 1B, D2 and? 2 are indicated by D1 and? 1 in the A antenna 200-1 and D2 and? 2 in the B antenna 200-2, respectively, and the altitude H is automatically calculated, Direction, and altitude are automatically calculated and detected through the process shown in Table 1 below.

The frequency deviation f _D of the Doppler signal reflected from the flying object is the frequency displacement f _D = + fo 2 / c when the transmitting station is in the same position or in the proximity position when approaching from the air vehicle, f _D = -fo 2? ₁ / c, and the reflection frequency is expressed by the following equation (2).

Here, fo is the transmitter frequency, υ shows a close-up velocity, υ ₁ spaced speed, f _D frequency shift.

As discussed, the antenna configuration of the present invention is a vertical type LP horizontal use of redundant vertically polarized antenna 10, the horizontal column 10, and a combined total of 100 pieces, each device fo suppression, Doppler frequency fo + f _D, fo- f _D pass filter, passes through the passive phase shifter, passes through the hybrid and then passes through the LNA 271 after outputting the sum (?) signal, the vertical difference (? E) signal and the horizontal difference (? In downconverting the amplified signal and the antenna output signal fo received directly from the transmitting station, one of the two mixers is down-converted by 90 ° phase delay, and then the fo frequency is suppressed in the Doppler filter and the low frequency Doppler frequency is extracted . At this time, one side extracts the I signal by mixing the transmission direct waves fo in phase, and the other side passes the fo through the 90 ° phase delay, mixes the Q signal, and finally outputs the Doppler I signal and the Doppler Q signal .

The vertical difference (ΔE) signal and the horizontal difference (ΔAz) signal are also obtained by subtracting the vertical differential Doppler I and Q signals and the horizontal differential Doppler I and Q signals from the receiver, After the processing, it is inputted into the display unit to monitor the flying object. A, B, and C Receive antenna (200-1 ~ 200-3) One A antenna among the devices Central processing Receive data sent from the B antenna and C antenna to the receiving device by wire or wireless.

For example, when the distance between the transmitter and the aircraft is 20 km, the distance between the aircraft and the receiving antenna is 20 km, the receiving antenna gain is 26 dB = total loss 3 dB, If the reflectance is assumed to be 1x (assuming that the RCS is undetermined) when receiving the TV transmission signal from the internal wire of the aircraft, the electric field intensity E at the reception detection antenna B _R can be obtained as shown in Table 2 below.

The Table 2 E: received field strength, E _0: free space, the electric field strength, r '(coskΔd-jsinΔd) : low level when signal, P caused by ground reflections phase: transmission power, d: distance, H _T: high transmission antenna , H _R : Receive antenna altitude.

; B 수신안테나에서는 Doppler 주파수 = f₀ ±

; C 수신안테나에서는 Doppler 주파수 = f₀ ±

와 같이 수신되어 A, B, C 사이 간격거리 수평각과 수직앙각과 각각의 수신된 Doppler 주파수 속도 GPS데이터를 주연산장치 있는 A수신국에 보내서 도 1a의 [표1]의 공식 이용하여 A수신 데이타와 함께 연산 자동계산 program 작성하여 비행체 고도방향 거리를 감지할 수 있다. 그러나 이 방식은 비행체 반사이득(RCS) 극히 작을 경우 A, B, C 안테나 이득이 작아 감지하기 힘들어 TV방송출력을 높이거나 수신안테나 이득을 도 1a와 같이 대폭 올려야 한다.
또한 수신장치 도 4의 신호처리장치(DSP)에 의한 신호처리에 있어서 Digital Signal Processor는 Doppler 미약신호를 검출하기 위해서 Digital Filter Bank를 이용한 특정 또는 원하지 않는 신호를 사전 준비한 알고리즘으로 제거하고, FFT(Fast Fourier Transform) 또는 Coherent Integration 이용하여 Doppler 편이신호만 검출토록 한다. On the other hand, aircraft reflection gain (RCS) only low gain omni-directional receive as little greater than or 1b in some cases near the antenna A, B, the distance C L _1, L _2, L _3, the azimuth angle α _1, α _2, α ₃ elevation angle β _1, β _2, when the to-output propagation copied from place a to place a β ₃ position to the TV broadcast transmitter frequency f ₀ when vehicle traveling direction when each receiving antenna vector velocity air vehicle velocity ν ₁ = cosθ _1, ? ₂ = cos? ₂ , and? ₃ = cos? ₃ . Therefore, the Doppler frequency in each receiving antenna is Doppler frequency = f ₀ ±

; B receive antenna, Doppler frequency = f ₀ ±

; C receive antenna, Doppler frequency = f ₀ ±

And the received distance data Doppler frequency velocity GPS data of A, B and C distance horizontal angle, vertical elevation angle and each received GPS data to the A receiving station having the main calculating unit, and using the formula of [Table 1] And can calculate the distance of the flight altitude direction by creating an automatic calculation program. However, this method is difficult to detect because the A, B and C antenna gains are small when the RCS is extremely small, so that the TV broadcast output must be increased or the receiving antenna gain should be increased as shown in FIG. 1A.
Also, in the signal processing by the signal processing device (DSP) of FIG. 4, the digital signal processor removes a specific or unwanted signal using a digital filter bank by a pre-prepared algorithm to detect a weak signal of Doppler, Fourier Transform) or Coherent Integration to detect only the Doppler deviation signal.

On the other hand, in order to identify the pilots of the airplane, the IFF antenna is attached separately, and the horizontal beam is steered to be transmitted and received, and an automatic response signal is transmitted from the flight vehicle. This technique is known and will not be described any further.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

100: transmitting antennas 200-1 to 200-3: receiving antenna
300: air vehicle 202: antenna array element
204: IFF antenna 206: transmission signal direct reception antenna
210: band pass filter 210 ': f ₀ signal pass filter
220: Phase shifter 220 ': Line phase compensator
230-1 to 230-5: Compositers 240-1 to 240-3: Hybrid couplers
250-1 to 250-3: Low Noise Amplifier 260: Automatic Transfer Unit
270: Antenna signal output receiving device 280: Signal processing device
271-1 to 271-3: Low-Noise Amplifiers 272-1 to 272-6: Mixer
273-1 to 273-3: 90 ° phase adjusters 274-1 to 274-6: low-pass filter
275-1 to 275-6: Low frequency Doppler signal amplifier 276: Dispenser

Claims (10)

One transmission antenna for transmitting one transmission frequency signal (f ₀ ) out of the VHF band of 100 MHz to 700 MHz at a high output;
A plurality of reception antennas for receiving a signal (f ₀ ) of a transmission frequency wave directly received by a transmission output of the transmission antenna and a signal reflected from a stealth vehicle;
A plurality of antenna signal output receiving apparatuses for mixing I, Q Doppler signals by mixing a total sum signal received from the plurality of reception antennas, a horizontal difference signal and a vertical difference signal directly; And
And a signal processing unit for processing the I, Q Doppler signals of the plurality of antenna signal output reception apparatuses to detect a stealth flight body. delete 2. The receiver of claim 1,
An N × M array element, a direct reception antenna for directly receiving the transmission signal of the transmission antenna, a band-pass filter for band-passing the reception signal of the array elements arranged in each row, and the left synthesizer for synthesizing a passive phase-shifting groups, f ₀ pass filter, and a reception signal of the left half side of the passive phase shifting side of the phase shift left half of the crisis to directly pass through the f ₀ the reception frequency of the receiving antenna to, right half side phase A line phase compensator for phase-compensating the output of the right synthesizer when the frequency of the output signal is changed, and a sum of the outputs of the left synthesizer and the phase synthesized right synthesizer, And a sum of signals of the upper half-side hybrid couplers arranged in rows are summed together to output an upper half sum signal Side sum signal synthesizer for summing the sum signals of the sum signal of the upper half sum signal synthesizer and the sum of the signals of the lower half half hybrid coupler arranged in rows and the sum of the outputs of the upper sum signal synthesizer and the lower sum signal synthesizer An upper half side differential signal synthesizer for summing up the difference signals of the total sum hybrid coupler for obtaining the differential sum and the difference to output the summed signal and the vertical difference signal and the upper half side hybrid clutch arranged in the row to output the upper differential signal, A lower half side differential signal synthesizer for summing up the difference signals of the lower half half hybrid coupler and outputting the lower half differential signals, a horizontal differential signal synthesizer for summing the outputs of the upper half differential signal synthesizer and the lower half differential signal synthesizer, A hybrid coupler, a low noise amplifier for amplifying the vertical difference signal, and an amplifier for amplifying the sum signal Sound amplifier and, after attaching a low-noise amplifier and a low-noise pre-amplifier for amplifying the level difference signal VHF array radar antenna system, it characterized in that a group consisting of automatic transfer of automatically switching the event of a fault. delete The apparatus of claim 3, wherein the bandpass filter
Wherein the VHF array radar antenna system comprises a plurality of frequency band rotatable type filters for removing a TV transmission frequency and passing only a Doppler frequency reflected from a moving object. delete The apparatus as claimed in claim 1, wherein the antenna signal output receiving apparatus
A mixer for mixing the low noise amplified total sum signal and the transmitted direct wave received signal; a mixer for mixing the low noise amplified total sum signal and the transmitted direct wave received signal; a mixer for mixing the Doppler signal An I-Doppler signal amplifier for amplifying and outputting an I-Doppler signal of the low-band filtered sum-sum signal, a phase adjuster for changing the phase of the transmitted direct-wave received signal by 90 °, a low- And a Q-Doppler signal for amplifying and outputting a Q-Doppler signal of the total sum signal passed through the low-pass filter, and a low-pass filter for passing only a Doppler signal An amplifier, a low noise amplifier for amplifying the vertical difference signal, a mixer for mixing the low noise amplified vertical difference signal and the transmitted direct wave reception signal, An I-Doppler signal amplifier for amplifying and outputting an I-Doppler signal of the vertical difference signal passed through the low-pass filter, a phase adjuster for changing the phase of the transmitted direct wave reception signal by 90 °, A mixer for mixing the amplified vertical difference signal and the transmitted direct wave reception signal adjusted in 90 ° phase, a low pass filter for passing only the Q Doppler signal at the output of the mixer, and a Q Doppler signal of the vertical difference signal passed through the low pass filter A low noise amplifier for amplifying a horizontal difference signal; a mixer for mixing a low noise amplified horizontal difference signal and a transmission direct wave reception signal; a low pass filter for passing only a Doppler signal at an output of the mixer; An I-Doppler signal amplifier for amplifying an I-Doppler signal of a horizontal difference signal passed through the low-pass filter, a phase adjuster A mixer for mixing the low-noise amplified horizontal difference signal and the transmitted direct wave reception signal adjusted for 90 ° phase, a low-pass filter for passing only the Q-Doppler signal at the output of the mixer, a Q- And a Q Doppler signal amplifier for amplifying and outputting a signal. delete delete The signal processing apparatus according to claim 1, wherein the signal processing apparatus
In order to detect a weak signal of a Doppler, a digital signal processor removes a specific or unwanted signal using a digital filter bank with a predetermined algorithm, and detects only a Doppler shift signal using an FFT (Fast Fourier Transform) or Coherent Integration VHF array radar antenna system.

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