Electronically Steerable Parasitic Array Radiators (ESPAR) for Efficient Phased Array Design

Two different designs of electronically steerable parasitic array radiators (ESPAR) for low-cost K-band phased array antenna design are presented. The proposed solutions are suitable for 1-D scanning with linearly and circularly polarized arrays. In contrast to the other solutions, that implement the beam scanning operations by using dielectric resonator antennas (DRAs) or cavity-backed slot antennas (CBSAs), the proposed designs consist of simple microstrip patch antennas implemented through low-cost PCB technology. The linearly polarized (LP) ESPAR shows a continuous steering range of 70 degrees at 20 GHz within a fractional bandwidth (FBW) of 20%. The circularly polarized (CP) ESPAR allows the beam scanning from −27 to +27 degrees at 20 GHz within a fractional bandwidth (FBW) of 6%. The simulated peak gain for the LP and CP ESPAR is 7.5 dB and 7 dB, respectively.