Differential Phase Measurement Accuracy of a Monobit Receiver

Abstract

Differential phase measurements using two receiver channels are used to calculate the angle of arrival of a target signal. A monobit receiver architecture is a desirable receiver type due to its low hardware complexity, sampling rate, and power efficiency. The application motivating this paper benefits from the use of automatic gain control circuitry and sensitivity offered by the monobit architecture. However, the one-bit sampling of the input signal introduces undesirable non-linear effects. This paper analyzes the effects of a monobit receiver architecture on the differential phase accuracy. Simulated results are compared to measurement data collected from prototype monobit receiver hardware. The measured data had good agreement with the simulated results. At a high-input signal-to-noise ratio of 30 dB, the differential phase measurement sigma was approximately 0.66° for input phase shifts of 0°, 45°, and 90°. While the differential phase measurement accuracy is less than predicted by the Cramer–Rao lower bound, it is sufficient for the low cost, power, and size constrained sensor application motivating this paper.