Stacked proximity coupled square and h-shape microstrip patch antenna design

Abstract

Simulation and measurement of stacked proximity coupled square and Hshape microstrip patch antennas were conducted with the objective to find the antenna designs that capable of resonating at ISM 2.4 and ISM 5.8 bands. Series of simulation were conducted to explore the effects of design variables such as antenna feed techniques (proximity couple line feed and inset feed), physical structure variations (H-shape), and configurations (stack and array) on antenna properties. Based on the simulated results, antennas that fulfilled performance requirements were selected for fabrication and measurement for verification and validation. Performance comparison between simulated and fabricated antenna results were analyzed in order to highlight the strengths and weaknesses in term of return loss, resonant frequencies, bandwidth, radiation pattern, gain and polarization. Simulation results shown that, lower number of antenna element produces wider beamwidth, has higher return loss and lower gain as compared to the performance of higher number antenna elements. Based on observation, return loss is influenced by the feeding techniques and varies with frequency. In terms of gain, it is positively correlated with the number of antenna elements and configurations. Simulation results indicated that gain difference of 2 dB from each configuration is achieved. For beamwidth, it is negatively correlated with the number of antenna element and configuration. Simulation results indicated that beamwidth difference of 30° from each configuration is achieved. For resonant frequency, the measured results have positive correlation with the simulated results with slight frequency offset. In conclusion, regardless of the differences in the exact values, this research work has highlighted several factors affecting antenna performance and it can be used as general guidelines in selecting the stacked proximity coupled square and H-shape microstrip patch antennas that suits operational requirements and applications.