Performance Analysis of Beamforming with Conjugate Field Matching in Phased Array Receiver

Conjugate field matching is a commonly used beamforming method for phased array receiver of reflector antenna. This article establishes a array antenna model of rectangular arrangement by 7 × 7 at 1.25 GHz, combined with a reflector with a diameter of 4meters and a focal diameter ratio of 0.3. Based on the field of view setting of off-axis two beams, a focal field simulation analysis is carried out. The final element spacing is set to 0.5 times the wavelength. The five elements arranged in a cross pattern can be combined into one beam, and the phased array receiver can achieve the function of off-axis scanning two beams. According to the conjugate field matching, axial beam and off-axis 1 and 2 beams are excited separately, and the radiation efficiency and other performance parameters of the forming beam are compared with the situation of uniform excitation. Finally, it is found that the conjugate field matching beamforming method performs better in terms of gain and sidelobe level than uniform excitation, and is more suitable for the practical application of phased array receiver with reflector antenna.