Integration of PIN Diodes for Beam Steering in Compact Microstrip Antenna Arrays

A reconfigurable microstrip patch antenna array operating at 25 GHz has been designed for K-band applications such as short-range radar and IoT networks. The antenna uses a 1x2 design with PIN diodes modelled as an RLC circuit, allowing for dynamic beam steering. CST Studio Suite 2018 was used for parametric optimization of antenna dimensions and substrate properties, resulting in efficient design and performance. Experimental results show gains of up to 7.66 dB and directivity of 9.59 dB at 25 GHz with a single diode active, demonstrating the antenna's pattern flexibility. Activating both diodes reduces beamwidth and changes side-lobe levels, exhibiting effective radiation control. The combination of edge feeding and improved impedance matching makes fabrication simpler while maintaining high efficiency. This design has significant potential for high-speed, low-latency communication in 5G and IoT systems, with future enhancements focusing on improving the overall performance of advanced wireless applications.