Shielded HMSIW-Based Self-Triplexing Antenna With High Isolation for WiFi/WLAN/ISM Band

This brief presents a novel design of a miniaturized self-triplexing antenna (STA) based on the shielded half-mode substrate integrated waveguide (S-HMSIW) for WiFi/WLAN/ISM-band applications. The S-HMSIW is constructed by assembling one row of vias and an open slot at the open-ended side of the conventional HMSIW. This configuration increases the quality factor and minimizes unwanted radiation loss, which allows for achieving high performance. A modified inverted U-shaped slot is created on the top plane of the cavity to form three different radiating patches, which are excited by three independent
$50~\Omega $
microstrip feedlines to operate at three different frequencies. The proposed STA exhibits competitive features such as highly compact size (
$0.09\lambda _{g}^{2}$
), high isolation (>33dB), and gain (
$>4.8$
dBi), which makes it suitable for handheld communication devices. The simulated and measured circuit responses are in good agreement.