Compact SIW Leaky-Wave Antenna With Open-Stopband Suppression

A compact double periodic leaky-wave antenna is designed in this letter, which has been developed to suppress the open-stopband (OSB). This antenna is loaded with shorting vias and folded slots on a substrate-integrated waveguide (SIW) periodically. The proposed antenna can scan from backward to forward continuously with a high radiation gain at broadside. The double periodic cell made the overall size only 2.6 wavelengths. Compared with traditional SIW leaky-wave antennas (LWAs), the size is conspicuously reduced. The equivalent circuits of several different types of cell are analyzed to understand the mechanism of OSB suppression. This antenna realized the steering range from -20(degrees) to 30(degrees) Results showed that radiation gain of the antenna varies from 8.6 to 10.8 dBi in the frequency range from 13.5 to 17 GHz while 9 dBi gain achieved at broadside. The simulation results agree well with the measured results. The compact LWA operates in a large scanning range with the high directivity of continuous beam scanning.