Gain improvement for conventional rectangular horn antenna with additional EBG structure

The conventional rectangular horns have been used for microwave antennas a long time. Its gain can be increased by enlarging the construction of horn to flare exponentially. This paper presents the new technique for improving its gain for conventional horn without construction enlargement. The quadratic-shaped of woodpile Electromagnetic Band Gap (EBG) and the mushroom-like EBG have been utilized to improve the gain instead. The important technique for gain improvement of this method that is, the electromagnetic fields from horn antenna will be transferred through its normal structure, then, 1×22 unit cells of mushroom-like EBG located on two side-wing slabs will help gain the energy of EM fields and suppress some surface waves that occurred on each side-wing slabs. The yielding waves will be transferred forward to the woodpile EBG for increasing gain in the last step. The proposed technique has the advantages of low profile, low cost for fabrication and light weight. The antenna characteristics such as reflection coefficient (S₁₁), radiation patterns and gain of antenna are simulated by using A Computer Simulation Technology (CST) software. The gain at dominant frequency of 10 GHz is 27 dB that higher than the gain of the basic rectangular horn antenna around 9 dB with adding only one appropriated EBG structure.