1.6-2.4 GHz RF MEMS tunable 3-pole suspended combline filter

This paper presents the first suspended 3-pole RF MEMS tunable filter with a frequency coverage of 1.6-2.4 GHz. The suspended topology is chosen to result in a high-Q resonator, which is essential for a low-loss 3-pole filter. The filter results in an insertion loss of 1.34-3.03 dB over the tuning range and a 3-dB bandwidth of 201-279 MHz. This design results in a tunable Q
u
of 50-150 over the frequency range, which is to our knowledge, the best report at this frequency range using any planar technology.