CN214542528U - Portable Ka-band continuous wave cloud and fog radar antenna feed source - Google Patents

Abstract

The utility model relates to a portable Ka wave band continuous wave cloud and fog radar antenna feed, including waveguide changeover portion and ripple circular cone loudspeaker, through first flange fixed connection between waveguide changeover portion and the ripple circular cone loudspeaker, the other end of waveguide changeover portion is fixed with the second flange, ripple circular cone loudspeaker front end adopts polytetrafluoroethylene film encapsulation, and this scheme adopts two segmentation structures, utilizes the waveguide changeover portion to extend ripple circular cone loudspeaker to radar antenna's the circular bore paraboloid reflector outside to basically eliminated sheltering from of feed to the plane of reflection, promoted the signal quality of antenna.

Description

Portable Ka-band continuous wave cloud and fog radar antenna feed source

Technical Field

The utility model relates to a radar field, concretely relates to portable Ka wave band continuous wave cloud and fog radar antenna feed.

Background

The Ka wave band continuous wave cloud (cloud or meteorological) radar implementation mode of current vertical scanning is different from small to large, and wherein, the isolation of radar twin antenna is higher better more, and the isolation is improved to the general fixed spacing of current patent, utilization shielding section of thick bamboo. For example, chinese patent publication No. CN207488493U discloses a weather radar system based on a continuous wave system, which includes a transmitting antenna module, a receiving antenna module, a transmitting extension, a receiving extension, a digital processing extension and a distribution extension, wherein a signal input end of the transmitting antenna module is connected to a signal output end of the transmitting extension, two signal input ends of the transmitting extension are respectively connected to a signal output end of the receiving extension and a signal output end of the digital processing extension, the receiving extension and the digital processing extension are connected in a bidirectional communication manner, a signal output end of the receiving antenna module is connected to a signal input end of the receiving extension, and the transmitting antenna module includes a transmitting antenna, a first feed source, a first shielding cylinder and a first antenna cover; the receiving antenna module comprises a receiving antenna, a second feed source, a second shielding cylinder and a second antenna housing. The prior art has the following disadvantages: the traditional antenna feed source is positioned in the center of the antenna reflecting surface to cause signal shielding, so that signal transmission is influenced.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art not enough, provide a portable Ka wave band continuous wave cloud and fog radar antenna feed for in a portable Ka wave band continuous wave cloud and fog radar, can reduce sheltering from of antenna feed to the antenna plane of reflection, thereby reinforcing signal quality.

The purpose of the utility model is realized through the following technical scheme:

the utility model provides a portable Ka wave band continuous wave cloud and fog radar antenna feed, includes waveguide changeover portion and ripple conical horn, through first flange fixed connection between waveguide changeover portion and the ripple conical horn, the other end of waveguide changeover portion is fixed with the second flange, ripple conical horn front end adopts polytetrafluoroethylene film encapsulation.

Furthermore, the corrugated conical horn is V-shaped, and a corner turning reflecting surface is formed by the corrugated conical horn at the edge of a circular-caliber paraboloid reflector of the radar antenna.

Further, the first flange and the second flange are square flange plates.

Further, the first flange is close to the edge of the circular caliber paraboloid reflector.

The utility model has the advantages that: compare with traditional antenna feed, two segmentation structures are adopted to this scheme, utilize the waveguide changeover portion to extend corrugated cone loudspeaker to radar antenna's circular bore parabolic reflector outside to basically eliminated the sheltering from of feed source to the plane of reflection, promoted the signal quality of antenna.

Drawings

FIG. 1 is a front view of a portable Ka-band continuous wave cloud radar;

FIG. 2 is a side view of a portable Ka-band continuous wave cloud radar;

FIG. 3 is a top view of a portable Ka-band continuous wave cloud radar;

FIG. 4 is a front view of the internal structure of the pitch box;

FIG. 5 is a rear view of the internal structure of the pitch case;

FIG. 6 is a top view of the pitch box;

FIG. 7 is a schematic view of a turret structure;

FIG. 8 is a top view of the turntable;

FIG. 9 is a schematic diagram of a feed structure;

FIG. 10 is a schematic diagram of the overall principle of the radar;

FIG. 11 is a functional block diagram of a transmit assembly;

FIG. 12 is a functional block diagram of a receive component;

FIG. 13 is a simulation diagram of the isolation of the transmit and receive antennas;

FIG. 14 is an antenna orientation simulation diagram;

FIG. 15 is an antenna gain simulation graph;

FIG. 16 is a schematic block diagram of a frequency source;

FIG. 17 is a functional block diagram of a signal processor;

FIG. 18 is a functional block diagram of a monitor terminal;

fig. 19 is a graph of corner code enable/clock/data waveforms.

Detailed Description

The technical solution of the present invention is described in detail with reference to the following specific embodiments, but the scope of the present invention is not limited to the following description.

A portable Ka-band continuous wave cloud and fog radar antenna feed source is used in a portable Ka-band continuous wave cloud and fog radar, and the antenna feed source is explained based on the working principle of the portable Ka-band continuous wave cloud and fog radar.

Referring to fig. 1-3, a portable Ka-band continuous wave cloud and fog radar comprises a support 1, a rotary table 2, a pitching adjusting box 3, a transmitting antenna 4 and a receiving antenna 5. The rotary table 2 is fixed on the support 1 and can rotate 360 degrees, two supporting arms 6 are respectively arranged on two sides of the rotary table 2, two sides of the pitching adjusting box 3 are hinged between the two supporting arms 6, a pitching driving motor 36 and a pitching transmitter 35 are arranged at the hinged position, and the pitching angle adjustment of the pitching adjusting box 3 is realized through the pitching driving motor 36 and the pitching transmitter 35; the structure of the turntable 2 can be seen in fig. 7, and more specifically, the turntable 2 is driven by a motor, and includes a turntable body 61 and a base 66, the motor is fixed in the base 66, an optical hinge 62 and a slip ring 63 are fixed at the center of the turntable body 61, an azimuth transmitter 64 and a motor reducer 65 are located at two sides of the optical hinge 62, and the turntable body 61 is connected with the base 66 through an azimuth bearing.

Referring to fig. 4-6, a slide rail 33 is disposed above the pitching adjusting box 3, two slide bases 34 are disposed on the slide rail 33, the transmitting antenna 4 and the receiving antenna 5 are respectively fixed on one slide base 34, and the distance between the transmitting antenna 4 and the receiving antenna 5 is adjusted by moving the slide base 34.

The isolation between the antennas is usually obtained by measuring S parameters, and directly calculating the isolation between the antennas is a very heavy and complex project, and the calculation result is not necessarily accurate, and as the performance of a computer is improved, the mutual coupling between the antennas can be calculated by using electromagnetic simulation software. According to the antenna system simulation model, firstly, two identical antennas are respectively established, the distance is temporarily set as a certain value, the S parameter size of the antennas is simulated initially, then the central distance of the two antennas is adjusted, and the optimal value is found. The calculated isolation between the two antennas is shown in fig. 13, and according to the simulation result, the isolation between the two antennas is about 70 dB. .

Optionally, a portable Ka wave band continuous wave cloud and fog radar, every single move regulating box 3 includes regulating box body 31, and a hinge 32 is respectively seted up at regulating box body 31 both ends, and 6 inboard articulated shafts that are provided with hinge 32 complex of support arm, and regulating box body 31 articulates between two support arms 6 through the cooperation of hinge 32 and articulated shaft.

Optionally, in the portable Ka-band continuous wave cloud and fog radar, the adjusting box body 31 is provided with a transceiver module 38, a monitoring terminal 301, a signal processor 302, a power supply 37, and an optical transceiver 39, and the inner wall of the adjusting box body 31 is provided with a pitch driving motor 36 and a pitch transmitter 35 at the position of the hinge joint 32.

Optionally, in the portable Ka-band continuous wave cloud and fog radar, the transceiver module 38 includes a receiving module and a transmitting module, and the transceiver module is divided into the receiving module and the transmitting module. The transmitting assembly up-converts the linear frequency modulation transmitting signal generated by the signal processor, generates a frequency modulation pulse microwave signal as a radar transmitting exciting signal, amplifies the signal by a solid-state power amplifier, and transmits the signal to the antenna through the feeder line to radiate the signal to the space. The receiving component processes the echo information collected by the antenna through a receiving front end to obtain an analog intermediate frequency echo signal, and the analog signal processing work of the receiving front end is completed. The transmitting component provides a path of test signal, and the test signal enters the echo channel of the receiving component through the radio frequency cable to serve as a transmitting power detection signal and be used for completing the online calibration detection function of the system.

The transmitting assembly is schematically shown in fig. 11, and inputs a frequency-modulated signal, outputs a ka-band frequency-modulated signal with power of 10W, generates a test signal, a power detection signal, and a transmitting sampling signal. The schematic diagram of the receiving module is shown in fig. 15, and the echo signal reflected by the input target is mixed with the transmission sampling signal and reduced to zero intermediate frequency, and then output by different gains. Meanwhile, the receiving component has the functions of gain detection, transmission power detection and the like. The transceiving component transmits the fault and control command through the RS232, and the interface is positioned at the transmitting component.

According to the demonstration result of the transceiving module, the technical scheme to be adopted is shown in fig. 12. The frequency source circuit generates a local oscillator to be mixed with the frequency modulation signal, and then 9 times frequency is carried out to obtain a 35.2-35.4 GHz high-stability signal; amplifying and transmitting a 35.2-35.4 GHz high-stability signal by using a power amplifier; the receiving component is used for enabling the echo signals received by the antenna to pass through low noise amplification and pre-selection filtering and then to be converted down to zero intermediate frequency.

Optionally, in the portable Ka-band continuous wave cloud and fog radar, a frequency source technical scheme is shown in fig. 16, narrow-band fine-step high-purity intermediate-frequency signals (200-270 MHz) output by a DDS and frequency-channel S-band are converted, and high-purity frequencies of 35.2-35.4 GHz are obtained after 9 times of frequency multiplication. Firstly, PDRO generates a high-purity signal of 3.7GHz, then the high-purity signal is mixed with a narrow-band fine-step high-purity intermediate-frequency signal generated by DDS to obtain the frequency of 3.9-3.94 GHz, the frequency of the mixed component with the frequency less than or equal to 5 orders is calculated to fall out of the band, no too large stray component exists in the frequency band, the mixed component is input into a 3-frequency multiplier HMC916LP3E after being filtered and amplified to obtain the frequency of 11.7-11.82 GHz, and then the frequency is input into the 3-frequency multiplier to finally obtain the high-purity frequency of 35.2-35.4 GHz.

Optionally, the signal processor of the portable Ka-band continuous wave cloud and fog radar is composed of an FPGA chip and a DSP chip, and completes the work of signal analysis, data transmission control and the like. The principle is as shown in fig. 17, and the signal processor and the upper computer communicate with each other through a gigabit network. The external clock inputs are 50MHz and 100 MHz. Wherein 50MHz is used for DDS clock input and 100MHz is used for AD sampling. The sampling channel comprises 2 echo receiving channels and a detection input channel. Because the dynamic range of the continuous wave radar is-165 dBm to-40 dBm, the receiver adopts a dual-channel method, and the gains of the receiver are 48dB and 110dB respectively. The two channels are simultaneously input into a signal processor for sampling and analysis respectively, when the power of the low-gain channel is more than-55 dBm, the data of the low-gain channel is selected, otherwise, the data of the high-gain channel is selected; the detection channel processes and analyzes by collecting the envelope of the transmitted signal. By adopting the DDS technology, the output parameters of the broadband frequency modulation signal can be flexibly controlled. The power supply module adopts a power supply conversion module for converting 220V alternating current into 12V direct current, and the power supply requirement of the whole signal processor is met.

Optionally, the monitoring terminal of the portable Ka-band continuous wave cloud and fog radar comprises a power module, an ARM control module, a CPLD data exchange module, a resolver, a level detection module, a serial communication module, a network communication module, a temperature monitoring module and the like, and the principle of the monitoring terminal is shown in fig. 18.

The control core of the monitoring terminal is an STM32F765VIT6 single chip microcomputer, the working dominant frequency is 216MHz, and the single chip microcomputer is connected with a CPLD and other peripheral devices to realize the control of the whole radar.

(2) Corner brace acquisition

The monitoring terminal obtains a current azimuth angle code and a current pitch angle code from the azimuth rotary transformer and the pitch rotary transformer respectively through two 14XSZ2411-02/4 type resolvers, and adds an angle code calibration value to obtain a real angle code. The angle code has 16 bits in total, the angle code obtained by the resolver is 14 bits high, and the positioning precision is 0.1 degrees, so the value of the lower two bits does not influence the control precision of the antenna.

(3) Corner brace output

The monitoring terminal sends the calibrated real angle code to the signal processor through 3 paths of +3.3V differential signals, as shown in fig. 19, the first 16 bits are azimuth angle codes, the last 16 bits are pitch angle codes, enabling efficiency is high, the monitoring terminal counts at the falling edge of the clock, the signal processor counts at the rising edge, and the clock frequency is 500 KHz.

(4) Terminal communication

The monitoring terminal is communicated with terminal software through a 10M/100M self-adaptive network port, a W5500 network chip is used in hardware, the chip integrates MAC and PHY, and the monitoring terminal is communicated with the single chip microcomputer through an SPI interface.

The communication adopts a TCP protocol, the monitoring system is used as a TCP server, and the client accesses the server to complete data interaction and control. The monitoring server defaults to an IP address and port of 192.168.1.100:8001, and the default MAC address is 07:08:04:12: CA: 4D. The data packet of single communication transmission is of fixed length, and the length is 16 bytes.

(5) Servo control

And the monitoring terminal is communicated with the azimuth driver and the pitching driver through 2 paths of RS232 serial ports respectively. The single chip microcomputer controls the rotating speed and the running direction of the driver in real time by comparing the current angle code with the angle code to which the antenna needs to point in each control cycle, so that the control on the azimuth and the pitching of the antenna is realized.

(6) Transmit-receive control

The monitoring terminal communicates with the receiving and sending component through the 1-path R232 serial port to realize the control of the receiving and sending component.

(7) Fault status reporting

The monitoring terminal collects fault state data of the transceiving component through a serial port, collects azimuth driver faults, pitching-2-degree limit states and pitching-182-degree limit states through a 4-path optical coupling chip, collects the temperature of a pitching box in real time through a temperature sensor SMT172-TO92, and reports the fault state data of the whole machine TO terminal software through a network at intervals of about 0.5 s.

The transmitting antenna 4 and the receiving antenna 5 have the same structure, and include a circular-caliber parabolic reflector 41, struts 42 and a feed source 43, the feed source 43 is turned out of the circular-caliber parabolic reflector 41 along one of the struts 42 in the opposite direction to reduce the shielding of the antenna aperture, and the structure thereof can be referred to fig. 2.

From the simulation directional diagram, the beam width of the antenna is less than 1 degree, the side lobe level is about-30 dB, the simulation result of the antenna gain is about 45.5dB, and the simulation result is basically consistent with the theoretical estimated value. The data thereof can be referred to fig. 14 and 15.

Optionally, in the portable Ka-band continuous wave cloud and fog radar, the circular-caliber parabolic reflector 41 is a standard parabolic reflecting surface formed by machining carbon fibers. The aperture of the circular aperture paraboloid reflector 41 is 0.6m, so that the reflecting surface is not damaged by secondary processing, and the reflecting surface is connected with a corresponding structural part through a pre-buried metal piece when being formed.

A portable Ka-band continuous wave cloud and fog radar feed source is characterized in that a feed source 43 comprises a waveguide transition section 11 and a corrugated conical horn 12, the waveguide transition section 11 is fixedly connected with the corrugated conical horn 12 through a first flange 13, the other end of the waveguide transition section 11 is fixedly provided with a second flange 14, the front end of the corrugated conical horn 12 is packaged by a polytetrafluoroethylene film 15, and the structure of the feed source can be shown in reference to fig. 9.

Optionally, in the portable Ka-band continuous wave cloud and fog radar feed source, the corrugated conical horn 12 is V-shaped, and the corrugated conical horn 12 forms a corner turning reflecting surface at the edge of the circular-caliber paraboloidal reflector 41. The first flange 13 and the second flange 14 are square flanges.

The radar operating principle is shown in fig. 10. The transmitting component converts the frequency modulation signal into a Ka wave band and amplifies the frequency modulation signal, and then a horizontal polarization electromagnetic wave is formed by the antenna through the feeder line and is radiated to the air; the horizontal or vertical backscattering polarization echoes of the cloud or weak precipitation target are collected by the antenna, then respectively enter the feeder line and then enter the receiving assembly, are amplified and converted by the receiving assembly, are sent to the digital intermediate frequency signal processor, are used for processing and calculating parameters such as the intensity, the speed, the spectrum width and the like of the echoes, and are output to the data processing and displaying subsystem to form a meteorological product for a forecast support staff to use. The servo subsystem drives the antenna to perform scanning detection in different modes under the control of the monitoring and calibration subsystem. The monitoring and calibration subsystem receives the command to control each subsystem, and also monitors the fault of each subsystem to protect the safe operation of the radar. In addition, the radar also has the functions of perfect fault self-checking, alarming, calibration and the like.

The foregoing is illustrative of the preferred embodiments of the present invention, and it is to be understood that the invention is not limited to the precise forms disclosed herein, and that various other combinations, modifications, and environments may be resorted to, falling within the scope of the invention as defined by the appended claims. But that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention, which is to be limited only by the claims appended hereto.

Claims (4)

1. The utility model provides a portable Ka wave band continuous wave cloud and fog radar antenna feed, its characterized in that, includes waveguide changeover portion (11) and ripple conical horn (12), through first flange (13) fixed connection between waveguide changeover portion (11) and ripple conical horn (12), the other end of waveguide changeover portion (11) is fixed with second flange (14), ripple conical horn (12) front end adopts polytetrafluoroethylene film (15) encapsulation.

2. The portable Ka-band continuous wave cloud radar antenna feed as claimed in claim 1, wherein the corrugated conical horn (12) is V-shaped, and the corrugated conical horn (12) forms a corner turning reflecting surface at the edge of a circular caliber paraboloid reflector (41) of the radar antenna.

3. The portable Ka-band continuous wave cloud radar antenna feed of claim 2, wherein said first flange (13) and said second flange (14) are square flanges.

4. The portable Ka-band continuous wave cloud radar antenna feed of claim 3, wherein said first flange (13) is adjacent to the rim of said circular aperture parabolic reflector (41).

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