| 摘要 |
A test signal composed of two or more harmonically related spectral lines is generated, frequency swept or stepped in fixed phase relationship and transmitted into a device under test. At the output of this device under test, the received signal is suitably amplified, and changes of the signal shape in the time domain are observed. Such changes caused by amplitude or phase misalignments of the device under test are, in turn, evaluated to unveil said misalignments. Various levels of sophistication of this evaluation are described. As simplest, the use of an ordinary oscilloscope in lieu of a receiver is explained, allowing, with certain resolution, the manual plotting of phase and amplitude misalignments. An involved version of the test setup comprises microprocessors for displaying at any desired resolution, besides amplitude, the "genuine" end-to-end phase curve including the quantity known as phase "intercept", of a device under test of any electrical or physical length.
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