Next-generation ISAC systems need antennas that can communicate and sense across heterogeneous channels while coping with blockage and mobility. Low frequencies (e.g. sub-6GHz) provide robust control/coverage and deeper penetration; 28 GHz supplies high-throughput, fine-resolution sensing/links. Realizing both bands with multi-beam agility in a compact front end is challenging because per-element phased arrays are power-hungry and bulky, and separate apertures inflate size and create co-site interference.
