| Antennas play an integral part in wireless communication system. Microstrip patch antennas are versatile in terms of their geometrical shapes and implementations. Inhibiting characteristics of a single microstrip patch, like low gain and smaller bandwidth, make it more popular for array configuration. The aim of this work is to design and implement a microstrip phased array antenna, printed on a composite ferrite-dielectric substrate. Four rectangular radiating patches on a low dielectric constant substrate are arranged in linear configuration to achieve required radiation properties. The microstrip array feeder network, consisted of integrated power divider and phase shifters, is realized on an externally magnetized ferrite substrate. Tunable progressive phase shift is produced by varying the magnetic bias that changes the permeability of ferrite material, which in turn changes the phase velocity and, hence, the insertion phase of the propagating microwave signal. The four-way power splitter is attained using Wilkinson type power dividers, which improves the isolation and matching of the ports. The antenna array is designed using standard equations and simulated by professional software called, High Frequency Structural Simulator (HFSS). Among many antenna simulators, HFSS is selected as it allowed the inclusion of anisotropic ferrite material in the simulation process. The antenna prototype is printed using the PCB plotter and manually transferred on the composite substrate, which introduced some inaccuracy. Finally, the simulated reflection response and radiation characteristics of the designed antenna array are corroborated using experimental results obtained from the Network Analyzer and the Antenna Transmission & Measurement System, respectively. The designed array exhibited very close radiation response to that of design objective. |
