Antenna development and a stepped-frequency GPR system for landmine detection
A project for developing a compact size GPR system for landmine detection was started. It will be based on stepped-frequency radar system for wider application in various kinds of soil conditions. We have developed a prototype stepped-frequency for fundamental evaluation of the system. This system uses a broadband Vivalidi antenna and operates at 2-6 GHz. The system was tested in laboratory and could be used for imaging buried mine-like targets by high resolution. Series of tests were carried out by using sand with rough surface and inhomogeneous soil. We discuss the ability of GPR for landmine detection.
Impulse radar subsampling for imaging of subsurface objects
The implementation of time-domain radar modules for imaging of subsurface targets will be addressed in this work. The radar modules have been used originally in process industry for fill level measurements. In this contribution we will show that these industry radar modules for C-Band and K-Band frequencies, can be adapted in order to apply them for sensing buried objects. The measurement of the reflected pulse unveils information about buried objects and the structure of the ground surface. The radar signal is evaluated by subsampling the carrier modulated Gaussian pulses. The envelope of the consecutive samples, that represents a stretched replica of the high frequency radar signal, is digitized and transferred to a post processing computer. Post processing techniques have been applied on the measured data in order to increase the image resolution. Experiments carried out with the radar modules underline their capability for detection and remote sensing of subsurface objects.
A New Integrated Waveguide-Microstrip Transition (Short Papers)
A new waveguide-microstrip transition is described. This design provides wide-band performance (18-26 GHz) and very good reproducibility without the need for variable elements. The circuit is fully integrated on the substrate and the characteristics are much less sensitive to small variations in the dimensions than other known transitions. A narrow-band version has been made for the telecommunication band in particular (17.7-19.7 GHz) with a VSWR less than 1.1 and an attenuation less than 0.25 dB. The design can easily be scaled to other frequencies and is especially useful at frequencies above 10 GHz.