A Tensor-Based Holographic Multi-Feed Antenna Synthesis for MIMO Radar Applications

A novel hologram synthesis method using the full impedance tensor for multi-feed holographic-based leaky wave antennas (HLWAs) is presented. Since, the unit cells (UCs) are shared across all feeds, all sub-holograms need to be combined into a shared holographic aperture. The shared impedance tensor is determined by minimizing the error relative to all sub-tensors for every UC. Based on the full tensorial multi-feed synthesis, a HLWA having two feeding points is fabricated on a fused silica wafer for an operational frequency of 160 GHz. The far field measurements show an antenna gain of 31.0 dBi and 31.4 dBi, corresponding to an aperture efficiency of 35 % and 38 %. The high gain and narrow beam of each feed make the antenna well-suited for an integration into a long-range MIMO radar. A polarization purity of less than 27 dB and a side-lobe level below -20.0dB were measured at 160 GHz.