A Self-Steering Receiver Array Using Jointly Coupled Oscillators and Phased-Locked Loops

This paper presents an analog circuit scheme to steer phased-array receivers in the direction of an incoming signal. The proposed circuit technique utilizes a coupled-oscillator array along with a coupled-phased-locked loop to auto-align an N-element receive array towards the direction of the incident RF signal. A four-element receiver array is implemented in 45-nm CMOS SOI process and achieves auto-steering range of ±35° from broadside. A three-element version of the array demonstrates higher auto-steering angle covering ±70° range. The receiver also performs signal demodulation for the incident modulated RF signal, allowing high-data rate communication. A 60-Mbps 64-QAM modulated RF signal is demodulated with error-vector-magnitude (EVM) less than 4% across the steering angle range. The chip area is 3.45 mm² including a pad frame with 30-mW/element power consumption. To the best of authors´ knowledge, this is the first demonstration of an analog self-steering array in an integrated circuit.