An Orthogonal Decoupling Method of 2.4 GHz Wi-Fi MIMO Antennas for Smartwatch Applications

Abstract

This article investigates an orthogonal decoupling design for two multiple-input multiple-output (MIMO) antennas operating in the co-frequency 2.4 GHz Wi-Fi for unbroken housing smartwatch applications. This method is based on the cancellation of the common mode (CM) and differential mode (DM). Two high Q-factor lumped elements are applied to decouple, and they can change the common mode impedance to match the differential mode impedance. The measured results show that maximum in-band isolation of 65.5 dB and minimum band edge isolation of 33.9 dB at 2.4 GHz are attained.