Slot-Excited Wideband Horn Antenna with Microstrip Line Feeding for Ka-Band Applications

An exponentially tapered horn antenna for symmetrical radiation patterns in E/H-planes is presented. The horn antenna is incorporated with the planar feeding network. The antenna is excited through a slot engraved in the ground plane that is transverse to the packaged microstrip feed line (MSL). The single antenna element provides 46% (S
₁₁
<; -10 dB) bandwidth in the Ka-band with a gain value of 10.3 dBi. An array of 2×2 elements with an MSL corporate-feeding network achieves the gain of 15.7 dBi. The antenna/array shows an excellent radiation performance across the frequency band of 25~40 GHz.