A dual frequency reconfigurable patch antenna for polarization diversity

A novel design of a reconfigurable patch antenna using PIN diodes is proposed to achieve frequency reconfigurable The operating frequency is electronically tuned by changing the state of diodes. If all the diodes is on the current directly go through the switch and current patch will reduce and antenna resonates at higher frequency and diverse effect has been observed for OFF condition of the PIN diode. If all the diodes are ON, the bigger one becomes the main radiation unit, which as we can see two corners is cut, which is mainly used to generate right-hand circular polarization (RHCP) and operates at L-band When all the diodes are OFF the inner patch containing U-slot is the main radiation unit, which can radiate with linear polarization (LP) and operate at S-band. As we all know the U-slot cut in the smaller patch is used to broaden the bandwidth, which significantly makes up the disadvantage of narrow-band of microstrip patch antenna. Notably, when the antenna operates at low-frequency, the U-slot is filled up in order to get an available radiation pattern. In the above cases, it should be worth mentioning that two-port cross-polarization isolation degree is less than -15 dB and -11 dB, respectively. It is also deserved to be mentioned that the location of diodes overwhelmingly influences the antenna performances. The methods to achieve frequency and polarization diversities have ever been put forward before, which could potentially improve the reliability of wireless communication systems.