Printed 4x4 Butler Matrix for Beam-Steering and MIMO Applications in 2.4 GHz ISM Band

Abstract

This paper focuses on simulation of the planar 4x4 butler matrix functioning at 2.4 GHz and then its implementation to an array of four slotted microstrip patch antennas resonating at 2.4 GHz. For that, we have simulated and implemented microwave devices such as 3 dB quadrature hybrid couplers and cross-couplers, newly proposed 45 0 phase shifters, microstrip patch antennas using an epoxy substrate (FR4) having a dielectric constant 4.4 and a thickness of 1.6 mm. Combining the above components presented, The butler matrix circuit with patch antennas as a load is designed and tested by using dual channel Rohde and Schwarz make 14 GHz VNA. All the simulations are done in HFSS.