A 4-path 4th order BPF dedicated to SAW less receivers

A tunable 4-path 4th order BPF which is based on the structure of the N-path filter is proposed in CMOS 65nm technology. The center frequency of each 4-path is slightly shifted relative to it’s clock frequency by a gm-c technique.The filter has a constant -3dB bandwidth of 21MHz and can be tuned from 0.4GHz up to 1.3GHz.The ultimate rejection of the filter is> 65 dB .The NF and in-band IIP3 of the filter are 8.5 dB and +11dBm respectively. The static power consumption is 7.3mW over the tuning band and the dynamic power consumption varies from 5.5mW to 14.7mW.

Keywords:

Bandpass filters(BPF) , N-path filters , shifting the center frequency , gm-c technique , complex baseband impedance