Triple-Beam Leaky-Wave Antenna Based on Spoof Surface Plasmon Polaritons With Hybrid Periodic Modulation

In this letter, a triple-beam leaky-wave antenna (LWA) based on modulated spoof surface plasmon polaritons transmission line (TL) with hybrid period is presented. The one side of SSPPs TL is modulated sinusoidally with period of P 1, and another side is modulated with composite period of P 2 and P 3. The analysis of dispersion curves indicates that the modulated periods at each side of the TL is independent and hence the radiation beams can be controlled independently by adjusting the modulation periods. In this design, the LWA radiates three beams simultaneously. From 7.8 to 9.1 GHz, the gain difference of beams is lower than 3 dB, which have cover range from 49° to 149°. To validate the performance of the designed LWA, a prototype is fabricated and measured. The measured results are in good agreement with the simulated ones.