Current-Recycling Complex Filter for Bluetooth-Low-Energy Applications

This brief presents a flexible gm-C complex filter for Bluetooth-low-energy receivers. Each complex pole is realized sharing a bias current among transconductors, leading to an ultralow-power solution. The filter, which is designed in the 130-nm complimentary metal-oxide-semiconductor technology, has a power dissipation of only 42 μW from a 0.8-V supply voltage. With a center frequency and a passband of 2 and 1 MHz, respectively, the simulated filter provides a rejection of the adjacent channel of 34 dB and a spurious-free dynamic range of 52.7 dB.