We present the realization of an frequency-modulated continuous-wave radar target simulator, based on a modulated-reflector radar system. The simulator, designed for the 24 GHz frequency band, uses low-cost modulated-reflector nodes and is capable to simultaneously generate multiple targets in a real-time environment. The realization is based on a modular approach and thus provides a high scalability of the whole system. It is demonstrated that the concept is able to simulate multiple artificial targets, located at user-selectable ranges and even velocities, utilized within a completely static setup. The characterization of the developed hardware shows that the proposed concept allows to dynamically and precisely adjust the radar cross-section of each single target within a dynamic range of 50 dB. Additionally, the provided range-proportional target frequency bandwidth makes the system perfectly suitable for fast and reliable intermediate frequency-chain calibration of multi-channel radar systems. Within this paper we demonstrate the application of the concept for a linear sweeped frequency-modulated continuous-wave radar. The presented approach is applicable to any microwave-based measurement system using frequency differences between transmit- and receive signals for range- and velocity evaluation, such as (non-)linear sweeped as well as pure Doppler radar systems.

We present the realization of a cooperative radar system for ranging applications with integrated data-transmission capability. The simultaneous transmission is performed by the radar-hardware without the necessity of additional components or an auxiliary data-link. Therefore, the data are directly embedded in the transmitted chirp of a frequency-modulated continuous-wave radar sensor. A second station, acting as receiver, uses an identical, but unmodulated chirp for down-conversion. The resulting signal then is processed by a non-coherent demodulator setup, extracting the communication data. Measurement results from transmission of messages with different bit-rates are shown. By utilizing existing radar-hardware a transmission rate of up to 256 kbps is possible, without the need of a dedicated transceiver. Additionally, a method to optimize the ranging results by variable distribution of the available signal power between distance-measurement and communication system is presented.

In this paper, we present the results of using a frequency-stepped continuous-wave radar system to estimate the position of overlapping and electrically good conductive plates. We especially focus on polarimetric scattering effects caused by the step of a lap joint, which is a common welding-geometry. To model the step's contribution to the overall scattered signal, we use a two-dimensional combined field integral equation (CFIE) approach. For demonstrating its practical applicability, the implemented scattering model is verified by measurements. To emphasize the improvements of position estimation by using a CFIE approach, the outcomes of the model are compared to a commonly used point scattering model. Finally, the numerical signal is utilized to precisely estimate the position of the lap joint.