Miniaturized all-round looking radar

Miniaturized all-round looking radar
Miniaturized all-round looking radar

Function:

Round-the-clock automatic detection of unauthorized penetration of small-sized unmanned aerial vehicles into controlled territory.

The tasks it performs:

  • detection and tracking of moving target;
  • target position data and speed measuring;
  • flight path information recording;
  • automatic alert when a threat emerges.

Application:

Protection of airspace of closed areas, factories, infrastructure and coastline.

Distinctive features:

  • providing an all-round sector of scanning with one device;
  • long target detection range;
  • effective working on low-observable targets;
  • small dimensions and weight;
  • digital charting;
  • high resolution;
  • no impact on other radio electronic equipment;
  • low construction cost;
  • self-contained operation

Constitution:

  • antenna system with integrated transceiver modules;
  • rotator;
  • signal synchronization and processing module;
  • power supply;
  • software.

General information

The compact all-round space looking radar is an active digital antenna array. The all-round looking radar with digital antenna array in transmitting-and-receiving path uses DA converter and AD converter instead of analog phase shifters and attenuators.  It makes possible to reduce significantly the step of place scanning, increasing thereby the accuracy of target position data finding. This becomes possible due to the small discreteness of the phase change in the antenna array channels through the phase shift formation by means of a DAC. The phase change discrete in digital antenna array is 0.1 ° versus 5 ° for an analog phase shifter. There are several options for circuit solutions, which differ in the number of components used, and therefore the prime cost of the digital antenna array. The option considered is the cheapest and easiest to construct, retaining all the advantages of digital antenna array, namely:

  • reduction of internal losses in SHF path, both in transmission and in reception. The loss reduction is approximately 3–5 dB that corresponds to half of the total power supplied to the antenna array;
  • a very small discrete of phase adjustment, leading to an increase in the accuracy of beam pointing at the target;
  • possibility of automatic calibration, as a result of which the accuracy of direction finding is significantly increased in conditions of high humidity and temperatures;
  • the formation of any amplitude-phase distributions, and hence the radiation patterns of any form. This allows the formation of DN zeros, partial patterns, and ultimately makes it possible to adapt the review algorithms while functioning;
  • using the same hardware for solving various tasks by changing only the software;
  • -unification of the antenna system with the transmitting-and-receiving modules. It allows an extra reduce of the loss of input power and to increase the sensitivity of the receiver due to the close placement of the LNA to the antenna;
  • the integration of the equipment components and the rejection of wave-propagation systems can significantly reduce the weight and dimensions of the device;
  • high reliability, which is ensured by the presence of a large number of SHF channels and their functionality (failure interval of low-power solid-state amplifiers is 104-105 hours, the transmitter on the TWT is 1000 hours);
  • lack of high-voltage unreliable voltage source, which ensures ease of operation and an additional increase in system reliability;
  • – fast electron beam moving in a given angular sector.

Performance characteristics

Performance characteristics
Performance characteristics

Technical description

The electronic experimental model of the compact all-round space looking radar is presented in Figure 1. The functional part of the station is located on a rotary device and consists of an antenna array, the 16 TRM placed on the reverse side and a frequency synthesizer.  The whole structure is protected by a radio transparent cover. Separately, the station has an external connection to the unit containing the power source and the signal processing module. Radar information is displayed on a PC with integrated software.

The electronic experimental model of the compact all-round space looking radar
The electronic experimental model of the compact all-round space looking radar

A generalized structural scheme of the radar is shown in Figure 2. The control of the whole station and the space scanning algorithm is carried out by special software. In accordance with the desired operation mode, the PC sends commands to switch reception or transmission, sets the values of the rotation angle and elevation angle. By control commands the modulated signal enters the SHF path, is amplified, and enters the antenna array with the desired phase. Further, the signal reflected from the target is received by the antenna, is fed to a low-noise amplifier, and then to a mixer where it is transferred to an intermediate frequency. The selected signal envelope for each channel is digitized, summed with the other information signals in the FPGA. The total signal goes to the primary signal processing module, and then to the PC. 

Since the radar is constructed according to the digital pattern scheme, there are no phase shifters in the structure. It makes possible to have a scan discrete on elevation angle of 0.1 ° that affects positively the accuracy of target position finding.

Scanning in the azimuthal plane is carried out by a rotating device. Scanning on elevation angle is electronic due to phase changes in the antenna array channels.

Functional diagram
Functional diagram

Production cost assessment

The cost structure for the development of radar is divided into the cost of hardware and software parts. The main contribution to the hardware is made by the cost of the element base, consisting of many expensive components such as FPG, power amplifiers, DACs, ADCs, etc. However, the total number of elements is small, since the radar consists of only one transmit-receive module. The cost of components for the radar station  development is estimated at $ 60,000.

         Additional equipment includes a frequency generator, synchronization unit, rotator and a radio transparent fairing. Estimated cost of additional equipment is $ 40,000.

            The size of the program part varies widely and depends on the quality of the radar information processing.  The software consists of the internal FPGA software, synchronization software, software for extracting the target signal from the phono-target situation, software for trails establishing and target tracking, radar information display software. The minimum cost of software development is $ 200,000.

Thus, the cost of radar station developing is $ 300,000.