A Pencil Beam Parabolic Reflector Antenna Using LSE-NRD Guide at 140 GHz

Automotive radars have been investigated at 140 GHz to improve the angular resolution of radars. However, microstrip antenna arrays, which are commonly used for automotive radars, have large losses in the higher frequency bands. Furthermore, antennas with very narrow beamwidth can prevent radar artifacts. In this paper, the parabolic reflector antenna with the tapered aperture at 140 GHz with a pencil beam is considered. The antenna has a primary radiator and a parabolic reflector between metal plates. The primary radiator with desired radiation characteristics was designed by using LSE-NRD guide based radiating element. The linear tapers were introduced to the metal plates to widen the aperture. It was calculated that the proposed antenna has a half power beamwidth (HPBW) of around 1o in the H-plane and a boresight gain of 32.9 dBi.