A novel compact leaky wave antenna incorporating the dual-periodical loading

Abstract

This paper presents a novel leaky wave antenna (LWA) loaded by periodical open stubs and holes. The complex propagation constants of the first higher order mode of the periodically loaded microstrip, so-called the EH1 mode, are extracted by the field eigenvalue approach, leading to control the radiation characteristics by changing the loading conditions. By doubling the length of open stub, the operating frequency of the LWA can be shifted 8.9% toward to the lower frequency. The comparison of the dispersion curves between the loaded and conventional microstrips shows 20% width reduction on synthesizing the EH1 mode. Two 9 GHz and 10 GHz practical prototypes are designed based on the proposed methodology and fabricated by using the multilayer printed circuit board (PCB) technology. The measured return-losses of two LWA prototypes are lower than 10 dB. The measured antenna gains of two LWA are 5.37 dBi and 6.89 dBi. The maximum gains are 6.05 dBi and 7.43 dBi at 9.2 and 10.1 GHz. The beam scanning angles are 7 degrees and 4 degrees when the frequency is increased 0.2 GHz.