Design and Validation of a Compact Printed Antenna for 2.4 GHz WLAN Applications with USB Wi-Fi Dongle Integration

Abstract

This work presents a compact low profile printed antenna useful for operation in the 2.4 GHz Wireless local area network (WLAN) band. The antenna is fabricated on an FR4 substrate, which provides a low-cost platform suitable for practical communication systems. The dimensions for initial antenna were obtained using conventional microstrip antenna design equations and were later optimized through parametric simulations available in CST Microwave Studio.  The importance of main geometrical parameters was investigated to obtain improved impedance matching at the resonance frequency. An antenna prototype was fabricated using a PCB etching process and measured using vector network analyzer. The antenna has a measured return loss of approximately −38 dB at 2.45 GHz, a bandwidth of about 350 MHz (VSWR ≤ 3), and a measured gain of 2.2 dBi. The measured reflection coefficient (S₁₁) shows a good agreement with the simulated results, which confirms that the antenna resonates at 2.45 GHz with acceptable bandwidth and stable radiation characteristics. To check the antenna performance for practical applications, it was integrated with a commercially available 
USB Wi-Fi dongle connected to a laptop, the received signal (in dBm) strength was monitored using a laptop and a  hotspot-enabled mobile phone is used as the wireless source. The measurement results prove that a reliable wireless connectivity link is established under both short-range and long-range conditions. These results indicate that the proposed antenna not only provides a simple structure but also suitable for practical solution useful for compact portable wireless communication systems.