Narrow Band Micro-Machined Band Pass Filter and a Surface-Mountable Topology

A 27.88 three-pole 1.8% bandwidth silicon micro-machined filter with 50 dB rejection is presented. On a single resonator, a quality factor of 602 has been measured and the filter exhibits 2.9 dB of insertion losses. A 30.04 GHz two-pole silicon micro-machined filter with a simple planar integration is also proposed. The excitation is made from the top of the shielding substrate of a membrane supported micro-machined filter. Packaging and inter-connection are included in the design. The whole filter exhibits 1.8 dB of insertion losses. Such filter can be easily integrated by flip-chip technology.