A Patch Antenna Coupling of Periodic Leak-Wave Structure With Tri-Frequency Capability

A patch antenna coupling of a periodic leak-wave structure with tri-frequency capability is proposed. The periodic offset double-sided parallel stripline (DSPSL) leaky wave structure (LWS) is embedded in the direction of the whole ground of the microstrip patch substrate, then the capability of tri-frequency could be obtained by the different Floquet mode of the propagation constant. According to the design principle, a unified formula was derived to calculate the tri-frequency points at the same time. Though applying of antenna design principle and the simple tri-frequency formula, a tri-frequency patch antenna was designed and tested. Experiment results show that the antenna operated at 1.71, 2.05, and 2.72 GHz. The measured and calculated results show high consistency.