A novel waveguide fed array antenna with shorted microstrip patch elements

A novel waveguide fed array antenna with shorted microstrip patch elements is proposed in this paper. The proposed antenna is different from conventional slotted waveguide antennas and other waveguide fed antennas in two folds. Firstly, slots, each loaded with a shorted microstrip patch element and a shorted parasitic element, are placed along the center axis of the waveguide. Secondly, the antenna elements are directly fed by the waveguide, not through aperture coupling. The waveguide is easily realized using substrate integrated waveguide (SIW) technology. The proposed antenna, operating at 35 GHz, has a wide impedance bandwidth of 10.2% (VSWR <; 2), a maximum gain of around 12 dBi and directional symmetric radiation pattern.