A K-band frequency scanning microstrip array using SIW

A K-band microstrip array is designed for the continuous beam scanning from backward to forward direction with consistent gain. In this structure, substrate integrated waveguide (SIW) is used as slow-wave transmission line, and the array is fed by aperture coupling from the slotted SIW. The antenna with 20 unit cells exhibits the simulated beam scanning angle of -45° to 40° in the frequency range from 23.5GHz to 25.5 GHz. The simulated gain is above 15dB at all the working bandwidth and the peak gain can reach 19dB.