Dielectric waveguide slot antenna with integrated filter for automotive UWB radar applications

This paper introduces a new slot antenna based on structure of the metallized dielectric waveguide. The antenna is constructed by combining a radiating plate with a slot on the metallized dielectric waveguide. This radiating plate works as a quarter wavelength impedance transformer and so the antenna operates in wide frequency range. The simulation shows the frequency range of the single slot antenna is from 23 to 29 GHz that is desirable for the automotive UWB radar applications. Furthermore, the fact that changing the thickness of the radiating plate partially can control the antenna directivity flexibly is presented. Because the antenna is based on rectangular waveguide structure, it can be easily integrated with a high-Q filter. The prototype of the integrated antenna and filter with area of 50times30 mm² exhibits half-power beamwidth of 54.7deg in the horizontal and 16.2deg in the vertical, respectively, as well as the sharp bandpass characteristics of 25 to 28 GHz.