Design of the Crossed Slot Antenna Array for 24 GHz Short Range Radars

This paper presents the design of a parallel-series fed crossed slot antenna array intended for 24 GHz short range radar application. The antenna consists of 16 dual polarized crossed slot antennas fed in the middle by 50Ω feeding line with appropriate λ/4 impedance transformers to provide exponential amplitude distribution along the feeding line. The proposed antenna has maximum gain of 18.7 dBi and sidelobe suppression of 18.9 dB at the centre frequency 24 GHz. It achieves impedance bandwidth of 2.25 GHz (S11 < −10 dB from 22 GHz to 24.25 GHz) while gain is higher than 18.5 dBi and side lobe suppression is better than 16 dB in the range between 23.75 GHz and 24.5 GHz.