Frequency reconfigurable antenna for two ways radio at VHF band

Frequency reconfigurable antenna for VHF two ways radio is designed. The frequency band for the VHF antenna is from 135 MHz to 174 MHz will be designed in this paper. The meander line antenna and the frequency reconfigurable circuits are printed on the FR4 substrate with size 20 mm × 174 mm × 0.8 mm. The antenna is mounted on the structure with size 60 mm × 140 mm × 40 mm. There are three parallel frequency reconfigurable circuits as part of the antenna. Each circuit includes PIN diode series with lump inductor. By using the ADS tool to design the proper inductor values for the desired frequency, three reconfigurable bands to cover 135 MHz to 174 MHz can be achieved. The results of simulation and measurement are very close.