Millimeter-Wave Wireless Channel Control Using Spatially Adaptive Antenna Arrays

A wireless channel control concept based on spatially, i.e., position adaptive antenna arrays is introduced. This technique simultaneously utilizes beam-steering and spatial adaptation to enhance the wireless channel gain and system capacity. The concept is inspired by the microfluidically reconfigurable RF devices as they can enable compact systems with spatial adaptation capability. Specifically, a five element linear 28 GHz mm-wave antenna array design that can achieve beam-steering via phase shifters and spatial adaptation via microfluidics is detailed. Simulated realized gain patterns at various array positions and phase shifter states are subsequently utilized in link and system level simulations to demonstrate the advantages of the proposed concept. It is shown that a wireless communications system can achieve 51% improvement in the mean signal-to-interference ratio due to the spatial adaptation capability.

I. Introduction

Wireless channel formation is conventionally accepted as an uncontrollable phenomenon since the physical environment and propagation scenario that determine the fading and time-varying response are assumed to be random. Wireless communication techniques treat the channel response as a given parameter and try to compensate the fading and distortion via equalization [1] and/or benefit from multitudes of independent channels by employing multiple antennas [2]. This causes overall performance of the state-of-the-art techniques to depend on the randomness level of the wireless channel.