A Small-Reconfigurable Low-Pass Filter for Analog Front-End Receivers

Some applications in communications have multiple bandwidths, requiring circuits with more flexibility in the radio receiver. This work proposes a reconfigurable, fully integrated Sixth Order Butterworth filter for these front-end receivers. To achieve this, the circuit uses a transistor-based structure to act as a voltage-controlled resistor. The resulting circuit is simulated using a 65nm CMOS technology. It attains a footprint of 0.015mm2 and a frequency step of 1 MHz in filter selectivity. The designed filter is compared to State-of-the-Art works, proving it can be used in multiple applications and configurations from 40 MHz down to 1 MHz channel bandwidth.