Abstract :
To carry out measurements in frequency domain (FD) indoors the expensive anechoic chambers are necessary. Time domain (TD) method allows to eliminate the reflections from adjacent objects. Therefore it is possible to carry out TD measurements indoors without anechoic chamber. The TD method [1-3, 6-8, 11] lets to use considerably cheap signal generator and receiver than those used in FD. The frequency responses of device under test parameters are calculated using fast Fourier algorithms. The additional advantage of outdoor TD measurement systems is interference immunity. The report contains indoor and outdoor TD antenna measurement and radar imaging (ISAR and SAR) UWB systems. A description of the development results of various UWB antennas for the above-mentioned measurements is given. Other Geozondas JSC equipment (sampling converters, pulse generators, positioners, etc.) being a part of UWB time domain measurement systems is described. It is possible to use the same signal receiver, i.e. sampling oscilloscope, both in frequency and time domain measurements. The TD antenna and radar measurements are possible to carry out in far and near fields. The equipment bandwidth is fro DC to 26 GHz. The resolution of radar imaging is 1.5 mm.
Keywords :
anechoic chambers (electromagnetic); fast Fourier transforms; frequency response; frequency-domain analysis; microwave antennas; radar imaging; signal generators; time-domain analysis; ultra wideband communication; UWB time domain measurements; anechoic chambers; antenna measurements; device under test parameters; equipment bandwidth; fast Fourier algorithms; frequency 26 GHz; frequency domain indoors; frequency responses; indoor antenna measurement; interference immunity; outdoor TD antenna measurement; radar imaging; receiver; sampling oscilloscope; signal generator; signal receiver; time domain method; ultra wideband band systems; Antenna Measurements; ISAR; Radar Imaging; Time Domain;