| 摘要 |
<p>The method of single measurement for displaying and qualifying linearity related to the non-linearity of a modulated wave transmission channel having a maximum wave peak level Nc and a maximum frequency band (F1, F2) consists in transmitting a composite signal containing a signal with a carrier frequency close to one of the band ends, modulated by a low frequency signal of variable level from 0 to peak, and two signals with carrier frequencies at the other end of the band spaced from an intercarrier frequency, and in detecting and ascertaining the possible presence of the intercarrier frequency signal at the channel output in accordance with the variation in the level of the signal to be transmitted. Linearity is present when the intercarrier frequency signal is null (or less than a set value) regardless of the level of the signal to be transmitted in space /0,/Nc//. Application in all fields where linearity is necessary for transmission channels. 'Compatible' with analogue or digital video-frequency baseband television transmission.</p> |
