Microwave Lens Using Periodic Dielectric Sheets for Antenna-Gain Enhancement

A microwave lens designed using only 13 periodic dielectric sheets is proposed for gain enhancement of linearly polarized antenna. A 3-D-patch antenna with dual-fed and operating in the frequency band from 8-9 GHz is used for studies. The microwave lens is placed above the patch antenna to form a microwave-lens antenna. The final design is fabricated and measured using the Satimo Starlab system. Results show that the microwave lens has little effect on impedance bandwidth and efficiency of the patch antenna, but can increase the boresight gain by 11.9 dB from 5.1 to 17 dBi in simulation and by 11.6 dB from 5.2 to 16.8 dBi in measurement at the center frequency of 8.5 GHz. Compared with commercially available standard-gain horn antennas having the same center frequency of 8.5 GHz, the proposed microwave-lens antenna has a much smaller volume but higher gain.