Triangular cavity for wideband antenna with large radiating aperture

In this paper, triangular cavity, as a new type of radiating cavity, is proposed and utilized for antenna design. The most important advantage of triangular cavity is to have larger radiating aperture, compared with conventional cavities, e.g., rectangular cavity. By properly periodical arrangement of the shorting strips based on the microstrip transmission line, cascaded triangular cavities are engineered for wideband antenna design. All the fringing fields at the radiating apertures of the cascaded triangular cavities are intrinsically in phase, forming the maximum available radiating aperture, for high gain and wideband performance. We have proved this novel cavity by building a prototype of five-unit cavity antenna using numerical simulation and experiment. The measured overlapped impedance and 3-dB gain fractional bandwidths is 33.11% and the peak gain is 12.55 dBi, agreeing well with the simulation results.