Research of the Frequency Characteristics of the Semiconductor Linear Microstrip Patch Antenna

This study evaluates the multiband performance of a five-element, series-fed microstrip patch antenna fabricated on n-type germanium substrates. Full-wave simulations were carried out in CST Microwave Studio across the 2.4 GHz and 5 GHz Wi-Fi bands. Three doping densities: 3.2 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup>, 2.7 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">16</sup> and 1.2 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">17</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">–3</sup> were implemented by introducing group 5 donor impurities. The resulting S11 characteristics confirm stable dual-band operation, while far-field patterns reveal that increasing free-carrier density progressively broadens the main beam. These findings demonstrate the feasibility of germanium-based, doped-substrate antennas for Wi-Fi generations 4, 5 or 6 provide quantitative guidance on doping limits for maintaining radiation efficiency and directivity in semiconductor-integrated radio frequency (RF) modules.