A MEMS programmable power divider/combiner for reconfigurable antenna systems

A programmable power divider/combiner is proposed for applications to low-cost reconfigurable antenna systems. The circuit employs two 3dB branch line couplers and a programmable reflection-type phase shifter that produces the required power ratio. A 5-state programmable power divider has been designed using microstrip technology and 8 RF MEMS devices. The circuit has been designed on a 525 μm high resistivity silicon substrate using a well established micromachining process at ITC-irst in Trento, Italy. The circuit is presently being fabricated; the simulated results show return loss better than 25 dB and isolation better than 20 dB with power ratios of 1:0, 4:1, 1:1, 1:4, and 0:1 with a maximum error in the power ratio lower than 4.5%. An example of reconfigurable antenna system based on the proposed device is shown.