Dual-Beam Leaky-Wave Antenna Array With Capability of Fixed-Frequency Beam Switching

A novel fixed-frequency beam switchable dual-beam antenna array is presented, which consists five dual-beam leaky-wave antenna (LWA) elements designed on substrate integrated waveguide (SIW) and integrated together on a common substrate. The LWAs work on fundamental wave and -1th spatial harmonic wave simultaneously and excite two symmetrical radiation beams in forward and backward direction respectively. In order to realize beam switching, three voltage-driven radio frequency chip switches (CSW-RFs) are used and integrated behind the antenna aperture. Since the periodic slot in LWA causes open stopband at the operating frequency, so the staggered radius amplification of local vias in the via walls of SIW is performed to suppress the open stopband. In addition, electromagnetic band-gap (EBG) structures, capable of reducing coupling between neighboring antenna elements, are embedded in between LWAs. The proposed dual-beam antenna array with beam switching capability between ±35, ±45, ±55, ±65 and ±75 degrees at 28 GHz are simulated, fabricated and measured. Both analysis and measurement results show that the proposed antenna array exhibits an excellent performance, which can be used in fixed-frequency beam-switching millimeter wave communication.