Microwave frequency detectors enable immediate determination of an unknown microwave signal frequency. Measurement is possible if the output characteristic of a frequency detector is unequivocal in a selected band of operation. The paper presents a method for obtaining unequivocal output characteristics for a given band of frequency detector operation.

The analysis of the autocorrelation function of a noise signal in a limited band of a microwave frequency range is described in the paper. On the basis of this analysis the static characteristic of the detector for object movement was found. The measurement results for the correlation function of noise signals are shown and the application of such solution in a noise radar for the precise determination of distance variations and the velocity of these changes is presented in the paper. The construction, working principle and measurement results for through-thewall noise radar demonstrator have been presented in the paper. A broadband noise signal in microwave S frequency band has been chosen, for high sensitivity getting. The broadband noise signal together with correlation receiver provides high sensitivity and moderate range for low transmitted power level. The experimental results obtained from 2.6-3.6 GHz noise-like waveform for the signal of a breathing human are presented. Conclusions and future plans for application of the presented detection technique in broadband noise radars conclude the paper

A real narrowband noise signal representation in the form of an analytical signal in the Hilbert space is presented in the paper. This analytical signal is illustrated in a variable complex plane as a mark with defined amplitude, phase, pulsation and instantaneous frequency. A block diagram of a broadband product detector in a quadrature system is presented. Measurement results of an autocorrelation function of a noise signal are shown and the application of such solution in a noise radar for precise determination of distance changes as well as velocities of these changes are also presented. Conclusions and future plans for applications of the presented detection technique in broadband noise radars bring the paper to an end.