A Digital Filtering ADC With Programmable Blocker Cancellation for Wireless Receivers

This paper presents a long-term evolution (LTE) receiver (RX) front end with a digital filtering analog to digital converter (ADC) in the baseband to perform multi-band blocker cancellation. The digital filtering ADC has a digitally defined transfer function that is highly reconfigurable and insensitive to PVT variations. The dynamic range requirement of the blocker cancellation feedback digital to analog converter (DAC) is relaxed with a trivial uncalibrated first-order passive high-pass filter. The programmable digital filter provides 34.9-dB attenuation of transmitter leakage and variable attenuation of an additional blocker anywhere in the frequency range 17.5-107.5 MHz. A blocker detection algorithm for this RX is presented and takes approximately 26 μs to converge. The RX front end operates at 1.8 GHz with a noise figure of 3.9 dB and IIP3 of -5 dBm, and consumes only 20.4-37.5 mW, the lowest among the state-of-the-art designs.