Microstrip patch antenna with wide beamwidth for AESA TRM diagnostics

Active Electrically Scanned Array (AESA) requires a diagnostic system that can consists of a set of external antennas for calibration of Transceiver Modules (TRM). In this paper, a microstrip patch antenna with wide beamwidth for such a system is presented. The manufactured antenna exhibits a 180° 6-dB beamwidth with matching better than -10 dB over a 10% bandwidth. It is shown that the use of the proposed antenna results in a reduced dynamic range of diagnostic coupling between the antenna and TRMs compared to directive or omnidirectional antennas, thus the number of diagnostic antennas can be decreased and they can be placed closer to radar aperture boundaries. Furthermore, it is demonstrated that a low level of back radiation of the antenna leads to a diminished parasitic influence of radar construction elements on the desired coupling coverage.