Frequency Reconfigurable U-shaped and Inverted U-shaped Microstrip Patch Antenna Design using Pin Diode for S-band and C-band Applications

In this paper, a frequency reconfigurable microstrip patch antenna is proposed for s-band and c-band applications. A RF pin diode is used to reconfigure the frequency. Here, U-shaped patch and inverted U -shaped patch are used. The pin diode is placed between the two patches. FR4 _epoxy substrate material is used whose relative permittivity is 4.4. Firstly, the diode is set as ON condition and finally the diode is set as OFF condition. When it is on condition, it works as C-band applications that is cut at 4.756 GHz and its return loss, Voltage Standing Wave Ratio (VSWR), bandwidth, gain and directivity are -24.12 dB, 1.09 dB, 200 MHz, 6.039 dBi and 6.394 dBi respectively. When it is off condition, it works as S-band applications that is cut at 2.38 GHz and its return loss, VSWR, bandwidth, gain and directivity are -21.08 dB, 1.19 dB, 51 MHz, 5.95 dBi and 6.309 dBi respectively.