Holographic Conical Beam Scanning Antenna for mm-Wave Radars Using Glass Technology

A novel concept of a holographic antenna with a high-gain conical beam pattern is presented. The antenna is realized on glass, which has advantages in terms of losses and dispersion compared to Teflon-based materials at mm-wave frequencies. This allows applications such as the usage in harsh environments. The performance of the proposed holographic antenna has been analyzed both by an analytic model and full wave simulations. Using the holographic principle, a frequency-dependent beam scanning over a bandwidth of up to 20 GHz is achieved and thus allows a low-cost 2D-radar imaging. The measurements of the fabricated antenna show an excellent agreement with the simulations. The optimized antenna has a uniform gain of about 15.8 dBi in the azimuth plane, a side lobe level below −16.5 dB, and a 3-dB-beamwidth of 8° at the center frequency of 77 GHz.