Patent ID: 6236371
Filing Date: 2001-05-22
Classification: G01R,H04B

Abstract:
A method for testing frequency response of a linear, time-invariant unit-under-test comprising:generating a test signal at a selected frequency;modulating the test signal with a spread spectrum input excitation signal to produce a broad band test signal that is substantially wider than the bandwidth of a device-under-test;transmitting the test signal from one of either the unit-under-test or a test device to a respective test device or unit-under-test; anddemodulating the broad band test signal by mixing an input excitation signal that is delayed and increased in steps such that the difference in time generates an estimate of the impulse response of the unit-under-test, the step of demodulating also including the step of correlating and integrating the test signal, thereby filtering out unwanted interference and reflections.