Performance Of Phased Array Antenna Research Articles

Embryonics Based Phased Array Antenna Structure With Self-Repair Ability

The reliability of phased array antenna can be improved with the self-repairing technology, and the existing self-repair method based on the TR module reconfiguration has problems such as slow calculation speed and difficulty in calculating the elements' mutual coupling, which is difficult to meet the application requirements. In this paper, a novel phased array antenna structure with self-repair ability is proposed. Based on the embryological electronics (embryonics), a novel phased array antenna structure with TR cell as the basic unit is constructed. The faulty TR cell can be detected and removed, and its influence on the phased array antenna's performance can be eliminated. The function and connection of faulty TR cell can be implemented by the normal TR cells and idle TR cells, the performance of phased array antenna can be repaired in real-time. TR cell, TR cell array and input/output switching control module are designed. The simulation tests show that, the phased array antenna with various fault conditions can be repaired in real-time based on the proposed structure, and the performance of phased array antenna can be repaired to the initial normal state with enough idle TR cells in array. Even without the idle TR cell, the performance of phased array antenna with fault can be improved through the self-repair. A new way for the design of phased array antenna design with self-repair ability is provided.

Improving Wide-Angle Scanning Performance of Phased Array Antenna by Dielectric Sheet

The method to improve the wide-angle scanning performance of the phased array antenna is studied and presented. The proposed method is realized by the dielectric sheet to reduce the size of the wide beam antenna and mutual coupling between the elements in the array antenna. The size of the antenna element is reduced by the dielectric sheet which is arranged on the top of the feed slot. The mutual coupling of the array antenna is improved by the dielectric sheet. And, the wide-angle impedance matching performance is improved by the above method. The operating frequency band of the E- and H-plane-phased array antennas is from 3.2 to 3.8 GHz. The main beams of the E-plane scanning array antenna can scan from -90° to +90° with the gain variation less than 3 dB. The main beams of the H-plane scanning array antenna can scan from -70° to +70° with the gain variation of less than 3 dB. The E- and H-plane scanning linear array antennas with nine elements are fabricated and tested. The measured results have a good agreement with the simulated results.

Electromechanical coupling modelling of distributed MEMS phase shifter for phased array antennas

ABSTRACTMEMS phase shifter has many advantages as the ‘steering wheel’ of phased array antenna beam steering. The deformation of mechanical structures of MEMS phase shifter influenced by the complex environmental factors, which became the biggest obstacle to further enhance the performance of phased array antennas. The electromechanical coupling model between the bridge height and phase shift of the distributed MEMS phase shifter is developed. The coupling model could be used to predict the phase error and determine the bridge height tolerance for the deformed MEMS phase shifter. The simulation results of four-bit distributed MEMS phase shifter with 15 bridges illustrate the validity of coupling model and demonstrate the application potential for engineering design and test.

Performance of phased-array antennas with mechanical errors

The performance of planar phase-array antennas with mechanical errors is investigated. Errors in array element positions as a result of structural distortions are considered as deterministic and predictable. Detailed calculations for two assumed modes of distortion reveal that their effects on antenna performance are the loss of peak response in the scan direction and the broadening of the mainlobe, while the far-out sidelobe structure remains relatively intact. For large antennas, performance improvement can be expected by suitable phase compensation. Performance of antennas with random errors in their element positions must be treated statistically. Expressions of average directivity and sidelobe level corresponding to arbitrary error magnitudes in element position, amplitude and phase of excitation as well as finite rate of failure of element modules were derived and verified by direct numerical calculations from the antenna directivity patterns. For a planar phased-array antenna typical for space-based radars, the standard deviation of element position errors must not exceed 1% of the operating wavelength in order to maintain a -10 dBi sidelobe level. >