Microwave Linear Analog Computer (MiLAC) as Efficient Next-Generation Transceiver Toward 6G and Beyond

Overview

A microwave linear analog computer (MiLAC) is a multiport microwave network of tunable linear components that, once configured, performs, at the speed of light, a linear transformation on the radio-frequency (RF) signals applied at its ports, realizing matrix-vector products and other linear operations directly in the analog domain. As a transceiver front end, a lossless reciprocal MiLAC matches the flexibility, and, for point-to-point multiple-input multiple-output (MIMO), the capacity, of fully digital beamforming while shrinking the active RF-chain count down to the data-stream count, among other benefits. This talk presents three recent advances in this direction: a unified multiuser multiple-input single-output (MISO) optimization framework for hardware-frugal stem-connected MiLAC-aided beamforming under ideal and quantized susceptances; a Cramér–Rao bound analysis revealing that two RF chains per target suffice for direction-of-arrival sensing with a MiLAC receiver; and a quantization-aware optimization of MiLAC-aided beamforming that markedly expands the spectral-efficiency–energy-efficiency frontier over digital and conventional hybrid baselines. Together, these results show that MiLAC holds the potential to simultaneously improve hardware and energy efficiency as a next-generation, multi-functional transceiver architecture toward 6G.