High Performance Ka-band Phase Shifters for Space Telecommunications

We propose a novel MEMS-based digital phase shifter targeted for Ka-band operation, but scalable down to X-band and up to W-band. This novel phase shifter will incorporate MEMtronics' state-of-the-art microencapsulated, capacitive MEMS switches to control phase. The envisioned phase shifter behaves much like a switched-line phase shifter with broadband matched impedance, but without sacrificing size normally needed to accommodate multiple signal paths. Many MEMS-based phase shifters have been created with good results utilizing a loaded line approach. While this technique works well for smaller bits, larger bits suffer from narrow bandwidths and a poor impedance match in one or both states. Additionally, cascading multiple bits results in a relatively long multi-bit phase shifter. As insertion loss is dominated by conductor loss, these long multi-bit phase shifters become rather lossy reducing advantages that MEMS-based phase shifters may offer. This proposed project seeks to overcome these limitations by maximize phase shift per unit length, while increasing bandwidth, to arrive at a low-loss Ka-band phase shifter with significant performance and size improvements over currently available technologies.