Jochen Schafer

Holographic mmW-Antennas With

This paper presents three different kinds of planar holographic antennas optimized for the usage in frequency-modulated-continuous-wave (FMCW)-radar systems. The antennas use different kinds of surface-wave modes (TE- and TM-modes), created by planar surface-wave launchers. Due to these feeds the antennas are very well suited for integration into millimeter-wave-systems. The radiation performance is calculated on the basis of holographic theory and the results are verified by full-wave simulations and measurements. Bidirectional radiation of the

{\rm TE}_0

{\bf{TE}}_0

and

-antennas is avoided by using artificial-magnetic-conductor (AMC) structures as antenna reflectors. This novel approach allows a holographic antenna with great integration qualifications and a highly directive and frequency-scanning main lobe and is compared with the also unidirectional

{\rm TM}_0

{\bf{TM}}_0

Surface Wave Launchers for Frequency-Scanning FMCW-Radars

-mode antenna.

W-band short distance CW-radar antenna optimized by housing design

A highly integrated W-Band Vivaldi antenna for radar systems in LTCC is presented. The antenna properties are optimized for high accuracy CW radar short distance measurements by the housing design. The presented technique allows to reduce the phase error resulting by multipath reflections and a non-linear phase front in the near field by decreasing the beamwidth using a tapered horn around the planar Vivaldi antenna. The paper describes the phase error sources and the influence of the metallic horn around the antenna. The electrical field propagation is explained and the limitations of the optimization because of higher propagating modes in the housing are determined. All results are verified by measurements.

Planar frequency scanning holographic antenna for FMCW-radar applications at 240 GHz

This paper presents a planar frequency scanning leaky wave antenna for use from 200 GHz to 260 GHz. The frequency scan and small beamwidth of the antenna are designed for simultaneous measurements of angle and distance to target objects, when combined with an FMCW radar. The paper describes the design process of the antenna, verification by EM-simulation and measurement results. The antenna has a return loss of -10 dB over the full bandwidth and scans over a range of 23° with an average half power beamwidth of 6°.

Novel TM0 surface wave launcher for integrated planar leaky wave antennas

In this paper a novel directive TM0 surface wave launcher for integrated planar leaky wave antennas is presented. As proof of concept the launcher is designed for a frequency modulated continuous wave radar at 120 GHz. Simulations for launcher and antenna are presented, as well as verification measurements of a prototype. Being well matched over the whole WR6 band from 110 GHz to 170 GHz, the designed launcher covers a large bandwidth. The antenna prototype incorporating the new launcher scans over a range of 18° when fed from 110 GHz to 130 GHz.