Reconfigurable Microstrip Patch Antenna With Polarization Switching in Three Switchable Frequency Bands

In this paper, a polarization switchable reconfigurable microstrip patch antenna is designed first, it is extended further to get polarization switching in three switchable frequency bands by using corner connection/disconnection and additional patch connection/disconnection techniques. Three switchable operating bands are obtained with centre frequencies of 5.1 GHz (first band), 5.45 GHz (second band), and 6.3 GHz (third band) using 5 p-i-n diodes. Proposed structure is capable of being switched between left-hand circular polarization (LHCP), right-hand circular polarization (RHCP), and linear polarization (LP) in all three switchable frequency bands. A proximity coupled triangular tapered feed is used to feed the structure to get wide impedance and axial ratio bandwidths. Detailed analysis is carried out to observe the effects of various design parameters on the performance of the circuit. This also gives insight into the behavior of the circuit in terms of resonance frequency which would be useful to translate the structure at different frequency bands for various applications. Measured performance of the antenna agrees well with the simulations. The prototyped antenna has an acceptable reflection coefficient and axial ratio (AR below 3dB) in each operating band. Polarization and frequency diversities of the proposed design could enhance the reliability of modern wireless systems.