Arbitrary Near-Field Spatial Signal Processing

Abstract

Electromagnetic waves have been widely exploited as signal, carrier, and power for wireless and wireline systems over the electromagnetic spectrum. As the classical approach, parametric interactions among localized or discrete signal processing devices are usually accomplished by electromagnetic fields or waves guided in conductor and/or dielectric bounded structures. These structures feature specific circuit functions in an electronic or photonic manner. Such electromagnetic circuits now face a number of application issues, such as geometrical complexity, power handling capability, and flexible reconfigurability, when they are used in certain large-scale electromagnetic systems, like in a massive multiple-input and multiple-output (MIMO). In this work, we propose and present an unconventional approach to realize a desired interaction or operation among devices. Such an interaction relies on wave or field interferences induced by a set of coherent antenna array over their near-field region where signal processing can be accomplished spatially. Fundamental functions and operation mechanisms of the proposed spatial signal processing approach are discussed and demonstrated in this work. It is worth mentioning that the proposed approach is universally applicable to all physical wave devices and systems, such as acoustic and electromagnetic waves.