| 摘要 |
<p>A doppler sensor with a frequency generator (1) with a transmission and reception unit (2) connected thereto via a waveguide (12) and with two diodes (D1, D2) acting as mixer which receive the signals in the waveguide (12) at intervals of an eighth of a wavelength, so that, when these signals are not linearly superimposed, signals phase-shifted through 90 DEG are obtained at the outputs of the diodes (D1, D2) from which, by differentiation in a differentiator (4), is obtained a sufficiently low-noise signal which contains the difference between the frequency generated by the frequency generator (1) and the doppler-shift frequency of the reflected and received signal as an intermediate frequency, from which the amount of the relative speed to be measured is determined in an evaluation unit (5).</p> |
