Surface-Micromachined Dual Ka-Band Cavity Backed Patch Antenna

A dual Ka-band rectangular coaxial line fed cavity backed patch antenna fabricated by a sequential surface micromachining process with ten structural layers is presented in this letter. The antenna bandwidth is 4.1% around 36 GHz, with gain and radiation efficiency of 5.7 dBi and 95%, respectively. The lower band is characterized with 5.1% bandwidth around 28 GHz and a monopole-like radiation pattern with 5.1 dBi maximum gain. Analysis and design are conducted with a finite element code and good agreement with measurements is demonstrated.