Ku/Ka Dual-Band Shared-Aperture Leaky-Wave Antenna With Fixed-Frequency and Wide-Angle Beam Scanning Based on Ridged SIW

In this communication, a novel ridged substrate integrated waveguide (RSIW) structure is reported to realize the transmission of electromagnetic waves in dual bands in a shared aperture. The structure is consisting of two substrate integrated waveguides (SIWs) operating in Ka- and Ku-bands, respectively, by integrating the Ka-SIW into the Ku-SIW like an embedded ridge. Therefore, the Ku-SIW operates like a ridge waveguide with single-mode transmission. Based on the RSIW structure, a leaky-wave antenna (LWA) is developed with fixed-frequency and wide-angle beam scanning in dual bands (Ka and Ku). Two types of slot arrays are arranged on the RSIW, and p-i-n diodes are adopted to control the states of slots. Two transitions from waveguide to SIW have been designed in Ka- and Ku-bands, respectively, to excite the RSIW. A binary holographic method based on isotropic-point-source array is developed to quickly obtain the excitation schemes of the slot array for desired beam angles. The measured results verify that the LWA can achieve beam scanning ranges of −72° to 39° and −48° to 42° at 31.5 and 12.1 GHz, respectively. The proposed RSIW LWA has the feature of dual-band compact shared aperture and may have a potential application in the dual-band communication systems.