RU2293405C1 - Shipboard radar station - Google Patents

Abstract

FIELD: radar engineering.

SUBSTANCE: novelty is that proposed shipboard radar station that has transceiving antenna and state identification system antenna, multichannel revolving joint, high-frequency waveguide circuit, transmitting device, high-frequency switching device, high-frequency receiving device, and signal shaper, as well as low-frequency receiving device, secondary processing device, and radar control device is built as three-coordinate unit incorporating provision for spatial selectivity; antenna is of small-size waveguide-slit design with frequency scanning on waveguides; power splitter is mounted directly on radiating strips by means of constant truss on rotating body of antenna station which also mounts horizontal rotation drive incorporating induction motor whose acceleration and braking speeds are frequency-controlled; transmitting device is made in the form of solid-state three-stage power amplifier unit with great number of parallel-running amplifiers.

EFFECT: enhanced target detection range, noise immunity, information update rate, and operating reliability, reduced turn-on time.

6 cl, 1 dwg

Description

The invention relates to the field of radar and can be used on ships of medium and large displacement. The radar is designed to detect air and surface targets and provide target designation.

The requirements for modern shipborne radar stations include an increase in the range of detection of targets, noise immunity, the rate of updating information, reliable operation and a reduction in turn-on time.

The closest analogue of the invention is a naval early warning radar of the United States Navy AN / SPS-49. According to the reference book "The Naval Institute Guide to World Naval Weapons Systems 1997-1998", the AN / SPS-49 radar is a two-coordinate station operating in the C-frequency band (850-942 MHz). The review of space is carried out by circular rotation in the horizontal plane of the antenna, which has a "cosecansquare" radiation pattern. The antenna has electromechanical stabilization in the horizontal plane during ship rolling. The radar transmitter AN / SPS-49 is made on electrovacuum devices.

The use of an antenna in the AN / SPS-49 radar, which forms one wide beam in the vertical plane for transmission and reception, causes the following disadvantages:

- insufficient spatial selectivity;

- the inability to determine the elevation angle of targets;

- the presence of dips in the station detection zone caused by interference of direct and reflected radio waves from the sea surface;

- low detection characteristics of targets flying at high elevation angles (see. Handbook on radar. - M .: Soviet Radio, 1979, vol. 3, p. 344);

- low noise immunity.

The use of a transmitting device made on electrovacuum devices in the AN / SPS-49 radar determines:

- low reliability;

- large weight and size characteristics of the transmitting device, the need for high-voltage power sources, as well as the complexity of its control and maintenance system;

- longer turn on time of the station.

The aim of the invention is the creation of a C-band radar, in which these disadvantages are eliminated or significantly mitigated.

The structural diagram of the proposed radar is presented in the drawing and includes the following main devices:

- antenna device 1 with its constituent transceiver antenna 2, state recognition antenna 3, waveguide rotating joint 4, three-channel coaxial rotating joint 5 and horizontal rotation drive 6;

- waveguide path 7;

- high-frequency switching device 8 with its included waveguide switch 9, waveguide circulator-switch 10, waveguide load 11 and power limiter 12;

- a transmitting device 13 with its three amplification stages 14, 15, 16 and a power source 17;

- a high-frequency receiving device and a shaper of microwave signals 18 with its constituent high-frequency receiving device 19, a local oscillator 20, a shaper of signals 21 and a power amplifier 22;

- low-frequency receiving device 23;

- a device for the secondary processing of information 24;

- radar control device, reproduction and display of information 25.

In the proposed radar, these disadvantages of the prototype were eliminated or significantly weakened by the use of a transceiver waveguide-slot antenna array 2 and a solid-state transmitting device 13. The space is examined by circular rotation of the antenna in the horizontal plane with simultaneous frequency scanning by a group of beams in the vertical plane, which ensures high spatial selectivity, allowing to measure the elevation angle of targets, significantly reduce the impact on the characteristics of P LS reflections from the sea surface echo signals, intentional and natural interference. This method of scanning DNDs also made it possible to carry out electronic stabilization in space during ship rocking, which significantly simplified and reduced the weight and size characteristics of the antenna device and the waveguide path.

The use of a solid-state transmitting device in the proposed radar significantly increased the reliability of the radar, simplified the control circuit of the transmitting device as much as possible, reduced the voltage of power supplies hundreds of times, reduced safety requirements for adjusting and working with the transmitting device, reduced the dimensions of the transmitting device, and significantly reduced the time the station was turned on .

It is known that C-band antennas have large dimensions and mass, which significantly limits their use for shipborne radar, where there are restrictions on the weight and dimensions of antenna systems due to the need to work with large wind loads.

The proposed radar used a relatively light waveguide slot antenna with frequency scanning 2, in which maximum measures were taken to reduce the weight and dimensions that affect wind loads.

A flat waveguide slot antenna consists of waveguide lines with radiating slots on a narrow wall. The rulers are connected to the waveguide power divider included in the antenna, made in the form of a sinusoidal waveguide using waveguide-coaxial directional couplers. The antenna uses waveguides of reduced cross section with reduced wall thickness. The waveguides are part of the supporting structure, which has greatly simplified the antenna farm. The antenna is mounted on the rotary device using hinge rods (rods) based on the housing structure, which also significantly simplified the design and reduced the total weight of the antenna device.

The horizontal rotation of the radar antenna device is carried out using a variable frequency drive 6, consisting of a three-phase induction motor and a frequency converter.

Such an electric drive allows smooth acceleration and braking of the antenna while maintaining maximum torque on the motor shaft, which eliminates jerking and shock, significantly reduces the mechanical stress on the structural elements of the antenna device. In addition, with smooth acceleration and braking, there are no starting currents of the electric motor, reaching 7 times the nominal values in an unregulated electric motor, which significantly reduces the electrical load on the rotating contact device and the electric motor itself.

The use in the rotation drive 6 of the antenna device of a linear gear located on a fixed housing, and a horizontal rotation reducer together with a horizontal rotation motor rolling around a stationary linear gear, made it possible to simplify the design of the drive, reduce its size and weight, and also increase strength and reliability drive rotation antenna device.

The use in the radar of electronic stabilization of the beam of a transceiver antenna significantly simplified the design of the antenna device, since there was no need to use waveguide rotary joints. Electronic stabilization is carried out on the basis of data obtained from the inertial navigation and stabilization system (SINS) and the angular position of the rays of the radar antenna.

The high-frequency switching device 8, through which communication is made between the transceiver antenna 2, the transmitting device 13, and the high-frequency receiving device 19, is made using a four-armed waveguide circulator-switch 10, which, when operating on the antenna, connects the output of the transmitter to the input of the antenna and commutes the signals received by the antenna in the direction of the receiver. A waveguide load 11 is connected to the fourth arm of the circulator, which acts as an antenna equivalent when tuning and adjusting the radar without radiation into space.

The power limiter 12 (two-stage semiconductor protective device) reduces the level of microwave power leaking into the receiving path at the time of emitting a powerful pulse to a level acceptable for the receiving device. In addition, the limiter protects the receiving device from powerful non-synchronous emissions induced in the antenna from neighboring radars. In this case, the limiter operates in self-government mode.

The transmitting three-stage device 13 is made using a large number of transistor amplification microwave modules. In this case, the division and summation devices are made in a parallel herringbone pattern using a 3-decibel directional coupler on connected strip lines as a bridge device. The power of all amplifier modules is provided from universal power sources 17 so that if any of the power sources fails, the signal power at the output of the transmitting device is reduced to a minimum. To stabilize the output power of the transmitting device as a whole, if one of the two adjacent amplifiers fails, 120-degree phase shifters are included in the even outputs of the dividers. The use of a transmitting device on transistor amplifiers made it possible to reduce the radar turn-on time to the load time of a computer operating system.

The high-frequency receiving device 19 is made in the form of a microblock and consists of a low-noise transistor amplifier, a double balanced mixer with signal suppression at the frequency of the mirror channel, and an adder-amplifier at an intermediate frequency.

The device for generating the microwave signal 21 is made in the form of a microblock and is intended to transfer the spectrum of the LFM signal generated in the low-frequency receiving device to the microwave signal with a level sufficient for the operation of the transmitting device.

The heterodyne device 20 consists of two microblocks and is constructed according to the scheme of the amplification multiplier line with switchable multipliers and continuously operating master quartz oscillators.

The low-frequency receiving device 23 of the superheterodyne type receives and processes signals and includes devices:

- two-time adaptive digital selection of moving targets (SDC) with a wobble of the repetition frequency of the probing signals;

- gating unambiguous signals and blanking ambiguous in range;

- accumulation of signals;

- reproduction of information.

The radar control device 25 provides electronic stabilization of the field of view when the ship is rocking, calculating the coordinates of the rays in a stabilized (terrestrial) coordinate system and issuing them to devices for processing and displaying radar information. On the control panel, the desired operating mode is selected, the radar is turned on and off.

The secondary processing device 24 is a hardware-software complex that provides:

- detection of signals against the background of the receiver noise and interference;

- measurement of coordinates and motion parameters of objects;

- display of primary and secondary radar information;

- classification of objects ("own" / "alien", "air" / surface ");

- management of the scanning program and the type of sounding signal when tracking objects;

- formation and issuance to external systems of data on the coordinates and parameters of the movement of objects through digital exchange channels.

The device is made on the basis of a specialized computer, which includes radar interface modules and a set of interface modules via digital communication channels.

On the device’s monitor screen, a multi-window mode for displaying radar information, tabular information, a set of menus and on-screen buttons is provided, which ensures the operator’s work. The electrical connections between the functional units of the radar are indicated by arrows.

The formation of a complex LFM signal at an intermediate frequency occurs in a low-frequency receiving device 23, from the output of which this signal is fed to a high-frequency signal conditioner 21, where the spectrum of the LFM signal at an intermediate frequency is transferred to the microwave range. After the necessary amplification in the power amplifier 22, the signal is fed to the input of the transmitting device 13. From the output of the transmitting device, the amplified signal is transmitted through the switching device 10, the waveguide path 7, and the rotating joint 4 to the antenna 2 and is radiated.

The echo signal received by the antenna 9 through the waveguide rotating joint 4, the waveguide path 7, the waveguide switch 9, the waveguide circulator 10 and the power limiter 12 is fed to the input of the high-frequency receiving device 19, where it is amplified, converted into a signal at an intermediate frequency and then fed to the input low-frequency receiving device 23, where it is the primary processing. From the low-frequency receiving device, the signal enters the secondary information processing device 24, where it multiplies and enters the consumers of this information. Management of operating modes is carried out in the radar control device, reproduction and display of information 25.

Claims (6)

1. A shipborne radar station containing a transmitting antenna and antennas of the state recognition system, a multi-channel rotating joint, a high-frequency waveguide path, a transmitting device, a high-frequency switching device, a high-frequency receiving device and a signal conditioner, a low-frequency receiving device, a secondary processing device and a radar control device, characterized the fact that the radar is made three-coordinate, it implemented spatial selectivity, ant The antenna was made with a waveguide slot with frequency scanning on waveguides with reduced dimensions along wide and narrow walls and reduced wall thickness, the power divider is mounted directly on the emitting rulers, the antenna is mounted by means of an unchanged truss of rods with hinges at the ends, which rests on a rotating housing of the antenna post , the horizontal rotation reducer together with the electric motor are located on the rotating casing of the antenna post and run around the running gear, located married on a fixed housing, the rotation drive is equipped with an asynchronous electric motor with frequency regulation of the acceleration and braking speeds, the transmitting device is made in the form of a three-stage solid-state power amplifier with a large number of parallel amplifiers, and the power division and addition device is made using 3-dB directional couplers, and stabilization of the output power is ensured by a 120-degree phase shift of the signals at the inputs of even amplifiers. 2. The device according to claim 1, characterized in that the multichannel rotating joint contains in addition to the waveguide detection channel three coaxial channels of the recognition system. 3. The device according to claim 1, characterized in that the waveguide circuit breaker is included in the waveguide path, which is made in the form of a system of plugs that rotate 90 °. 4. The device according to claim 1, characterized in that the high-frequency switching device is combined with the Antenna-Equivalent operating mode switch and is made in the form of a four-arm waveguide circulator, in the fourth arm of which a waveguide load is included. 5. The device according to claim 1, characterized in that the heterodyne device is constructed according to the amplifier-multiplier line with switchable multipliers and continuously operating master quartz oscillators and provides high coherence of the emitted and received signals, the accuracy of determining the coordinates of the target, reducing the switching time of operating frequencies, improving the purity of the spectrum of the signal, high efficiency selection of a moving target. 6. The device according to claim 1, characterized in that the power limiter is designed as a two-stage protective device on semiconductor diodes, controlled during the probing pulse by current pulses from the radar control device, during a pause, the limiter goes into self-control mode and is controlled by powerful pulses from third-party radars.