An Energy Efficient and Fast Triple-Interferer Sensor Based on Digitally Controlled Injection-Pulled Oscillator

This letter presents an interferer detector and digital-coder. Leveraging LC digitally controlled oscillator's (DCO) injection pulling, the injection detector senses the frequency offset between an interferer and the DCO's intrinsic frequency (f
_OSC
) which is quantized by the frequency resolution of the DCO and digitally coded by a counter and arithmetic logic to identify the interferer by the relative frequency from f
_OSC
. The presented interferer sensor implemented in 0.13-μm CMOS achieves fast scanning time of 0.8 μs for diagnosing maximum triple interferers at a frequency span ranging from 2.74 to 3.75 GHz. The energy consumption is 12 nJ per scan time, which is 41.7× smaller than prior state-of-the-arts. The sensor consumes 15.6 mW from 1.3-V supply. The chip area is 0.56 mm
²
.