Intermediate frequency lamb wave coupled resonator filters for RF receiver architectures

This article presents a novel IF channel for ultra-low power RF receiver architectures. These filters are based on the acoustic coupling of two high quality factor (Q above 1000) Lamb Wave resonators. Acoustical coupling is introduced to controlled filter bandwidth through a periodic guide. These small form-factor filters are above-IC compatible and potentially suitable for co-integration with FBAR BAW technology. A 233 MHz high impedance (1 kOmega) 650 kHz band pass filter with low insertion loss (-5.7 dB) and high out-of-band rejection (-35 dB) has been developed and measured.