A broadband microstrip array antenna with rectangular waveguide mode transition at millimeter-wave band

In this paper, a broadband microstrip array antenna with rectangular waveguide mode transition operating at lower E-band is proposed. The microstrip array antenna is corporate-feed structure configured by microstrip line with a mode transition from rectangular waveguide. Broadband operation can be achieved by using a slit in the transition and employing a set of feed point in the center of microstrip-line feeder which also results in fixed-beam radiation. Validity is confirmed by the evaluation of a fabricated antenna. This antenna is suitable for E-band applications such as mobile back-haul.