Frequency and circular‐polarization switchable microstrip antenna for dynamic spectrum allocation

This article presents a novel frequency‐reconfigurable microstrip antenna supported with an opposite circular polarization sense for dynamic spectrum allocation. The degenerate TM10 and TM01 frequencies are designed by using the distinctly separated electrical delay depending on the H‐shaped slot along the feeding positions for generating circularly polarized waves. In addition, the circularly polarization sense is controlled by changing the status of the pin diode because the switched vertical path affects only TM10 frequency without changing horizontal TM01 frequency. To verify the feasibility of the proposed antenna, the conceptual equivalent circuit is established and the experimental validation is carried out. The implemented antenna successfully demonstrates frequency‐reconfigurable capability with opposite circular polarizations and shows a good agreement with the simulation results.