No abstract

A technique is employed to reduce the size of planar dipole. The technique is consists of adding short-ended microstrip line at the top of the dipole, making the structure be inductive load, and as a result, increase the effective length. A design example for the ISM band is presented. The configuration reduces the resonance frequency of the planar dipole by 25.8% without degrading influence on antenna performance. The antenna comprising of only a single layer planar in additional to the microstrip feed line offers over a S11<-10dB bandwidth from 2.4GHz to 2.4835GHz which is wide enough to cover WLAN, BLUETOOTH, RFID, and WIFI communication bands. With this reduced size and omnidirectional pattern, it is very suitable for narrow band systems such as: WCDMA, WiMAX, among others.