Performance Enhancement of Circularly Polarized Microstrip Antenna Using Single-Layer Foam Substrate for 5.8 GHz ISM Band Applications

Abstract

Abstract Since last decade microstrip patch antenna has played a very important role in industrial, scientific, and medical (ISM) band applications, but single-layer antennae suffer from low gain, low radiation efficiency. For an ISM band, there is always a trade-off between these parameters, so maintaining it on a single-layer microstrip antenna is a big challenge. Hence this paper designs a circularly polarized (CP) microstrip antenna using a single-layer Foam Substrate for 5.8 GHz ISM band which offers high gain, improved radiation efficiency, and a lightweight design. It is constructed as a low-profile, single coaxial feed microstrip antenna on a foam substrate, achieving circular polarization by integrating two slots into the radiating patch antenna has dimensions of 0.98 λ0 × 0.98 λ0 × 0.096 λ0, impedance bandwidth of 600 MHz (5.56–6.16) GHz, which underscores its adaptability across a wide range of frequencies within the specified band. Furthermore, it elaborates the axial ratio bandwidth which extends over 130 MHz (5.77–5.90) GHz, showing the antenna's ability to maintain circular polarization characteristics over a significant frequency range with a gain of 8.87 dB. The experimental and simulation results confirmed a remarkable radiation efficiency of 95.62%, showing its superior effectiveness compared to any existing single-layer microstrip antenna.