2.4 GHz direct-digital binary phase shift keying modulator using MEMS switch

A novel MEMS-based binary phase shift keying direct-digital modulator operating at a carrier frequency of 2.4 GHz is presented. The circuit is composed of a rat-race coupler and a single-pole double-throw MEMS switch controlled by a digital baseband signal. The coupler divides the input waveform into two signals that are 180(degree) out of phase and the MEMS switch is used to select between these two signals. This circuit has been experimentally verified and results are reported.