Miniaturized novel quintuple-band microstrip patch antenna for K-band application

Microstrip K-band antennas are popular because they are inexpensive, easy to integrate, and lightweight. This paper aimed to present a novel quintuple-band scaled down microstrip patch antenna (MPA) with a substrate measuring 28 mm by 25 mm, designed using 1.6 mm thick fire retardant 4 (FR4) dielectric material for K-band application. All simulation work was performed with Ansoft high frequency structure simulator (HFSS) antenna simulation tool, and the results were confirmed using experimental data from the constructed prototype. It features two identical L-shaped patches and two U-shaped patches with different sizes. The antenna was fed via the microstrip line feeding technique. Two U-shaped patches were separated by U-shaped slits, allowing the antenna to work in quintuple-band applications. The antenna patch dimension was calculated using normal microstrip formulae, and the size was then optimised. Quintuple resonant frequencies occurred at 21 GHz, 24 GHz, 28 GHz, 31 GHz, and 34 GHz. The average return loss, scattering parameter (S11) was found to be less than -10 decibel (dB), and the average voltage standing wave ratio (VSWR) value was 1.548 for the quintuple band. The gain was 6.13 dB, and the bandwidth was 0.5 GHz, which is adequate to link to neighbouring radiators with varying heights of catch angle 35o. Directivity created by several resonant frequencies allowed the antenna to radiate equally well in all directions. The modelling and observed findings agreed almost perfectly. The results achieved are comparable to mobile communication, satellite communication, military applications, defence monitoring radar, and other fifth and sixth generation (5G/6G) communication requirements in the K band. Future research may focus on increasing bandwidth and achieving various resonance frequencies in additional operating bands for microstrip patch antennas.