| 摘要 |
A wideband irregular signal is decomposed into respective frequency bands, the ratio of the highest to the lowest frequency within each band being in the ratio of approximately 3:1 and the total number of bands being 3 or 4. The wideband signal, or a re-constituted wideband signal formed by combining the decomposed components, is transmitted as a interrogating signal. A reflection of the interrogation signal is decomposed into respective frequency bands, and within each frequency bands the different components are compared. The results of the comparisons are combined to determine whether an object has been detected and, if so, its range. Decomposition of the wideband signal can be achieved by using a bank of low-pass filters in respective frequency bands, the output of each low-pass filter having subtracted there from the output from the filter with the next-lower frequency cut-off characteristic. Delay circuits are used within each channel so that the total delays in each individual channel are equal.
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