32-Element Array Receiver for 2-D Spatio-Temporal Δ-Σ Noise-Shaping

The concept of two-dimensional (2-D) space-time Δ-Σ noise-shaping for radio frequency (RF) array processing systems has been proposed in earlier work. This approach can provide supralinear improvements in the overall noise figure (NF), linearity, and resolution of an N-port receiver at the cost of a linear increase in the number of elements. This paper describes a proof-of-concept 32-element array receiver that is suitable for driving first-order spatio-temporal Δ-Σ noise-shaping analog-to-digital converters (ADCs). The design has been realized using board-level components. It operates at a center frequency of 2.6 GHz and uses an on-board dense sleeve monopole antenna array with a spatial oversampling factor of 4. Calibration is achieved to decrease the mismatch between channels, resulting in gain mismatch reduction by a factor of 1.8 and phase mismatch reduction by a factor of 2.9. Over-the-air measurement results prove the functionality of the proposed array receiver.