Design and analysis of reconfigurable antenna using PIN diodes for multi band WLAN applicaions

A patch frequency reconfigurable double slot antenna is presented. The proposed design consists of two rectangular slots and three RF PIN diodes placed symmetrically on each slot to achieve reconfigurable frequencies. Depending on the switching states (ON/OFF) of the diode switches, the various different operating frequencies were obtained [1]. The return loss obtained using simulation, for all the frequency bands, provides appreciable results (up to 20 dB or more). The patch design has the dimensions of 30 × 25 mm. Each slot is 12 mm × 2 mm and is placed symmetrically with respect to the other. The antenna can be made to operate in single band and dual band mode even without altering the size of the antenna or other dimensions, by changing the state of the RF PIN diode. Important antenna parameters such as VSWR, return loss and radiation pattern are simulated for different switching cases. The substrate for the patch is a Flame Retardant (FR4) material which has a dielectric constant of 4.4. The analyses are performed using simulation software Ansoft HFSS v13.0.