A traditional whip antenna is suitable for terrestrial wireless communication due to its omnidirectional radiation pattern which capable of transmitting and receiving signals from all directions. However, the length a long very high frequency (VHF) band applications; example, ideal 80 cm at 90 MHz, restrains mobility when mounted on vehicle. Many studies have been conducted develop low-profile ...

A substrate-integrated waveguide (SIW) antenna is an implementation of a in microstrip antenna. The antenna, as low-profile suffers from narrow impedance bandwidth. This paper proposes novel bandwidth enhancement method for solving Bandwidth was achieved by using quad-resonant frequencies. frequencies are resulted the hybrid half-mode (HMSIW) cavities between inner and outer cavities. HMSIW cav...

Circularly-polarized antenna is built based on a new SIW (substrate integrated waveguide)structure which contains cavity-backed resonator and a conventional polarized ring with twosquare slits in inner and outer ring that differ 90° at position and is proposed for right-handedcircular polarization (RHCP) and fabricated in two separate layers. A broadband impedancebandwidth of 13.9% and a RHCP a...