Coplanar Wave guide Slot-coupled Ka-band Patch Antenna for Integration with Wafer-scale Beam-steering MEMS Control Board

A coplanar waveguide CPW slot-coupled Ka-band patch antenna is designed, constructed and tested for subsequent integration with a wafer-scale MEMS-switched antenna array beam-steering control board. The antenna is designed for fabrication on a high resistivity silicon FIRs wafer dielectric constant approximately 11.8for operation with 25-30 GHz satellite communication systems. A simulated 10 dB return loss bandwidth of 2.96 GHz 9.8 is achieved with a 4.6 dB peak gain and 110 degree half-power beamwidth RPBW. A scaled prototype at 6 GHz is constructed on RTDuroid 6010 substrate dielectric constant approx. 10.2 and yields a measured bandwidth of 360 MHz 6.0 and a peak gain of 4 dB. A CPW feedline slot misalignment sensitivity test is conducted through simulations to investigate the effects that fabrication errors may have on antenna performance during wafer-scale integration of the patch antenna onto the HRS substrate. Simulation results show that slot misalignment less than 200-400 microns should only minimally affect antenna performance, with the most significant degradation being a 2.5 - 4.0 drop in antenna bandwidth. The successful design of this patch antenna demonstrates a compact, efficient method for integration of a CPW slot-coupled Ka-band patch antenna onto a wafer-scale MEMS control board without the need for additional substrate layers or feedline interconnects, minimizing total system weight and fabrication complexity.