A foam‐base surface‐mountable shorted monopole antenna for WLAN application

A surface‐mountable shorted monopole antenna, constructed by folding a branch‐line metal strip onto a foam base for 2.4/5.2/5.8‐GHz WLAN operation, is presented. The branch‐line metal strip is comprised of a longer arm, a shorter arm, and a matching arm. The longer and shorter arms generate, respectively, a lower resonant mode covering the 2.4‐GHz band (2400–2484 MHz) and an upper resonant mode covering the 5.2‐GHz (5150–5350 MHz) and 5.8‐GHz (5725–5875 MHz) bands, and good impedance matching for frequencies across the two resonant modes is easily achieved by adjusting the distance between the feeding point and the shorting point in the matching arm. Experimental results of a constructed prototype of the proposed antenna are presented.