| 摘要 |
The method filters a TV signal comprising an image signal, a sound signal and an image carrier signal with an image carrier frequency whereby the TV signal is converted on an intermediate frequency to an intermediate frequency signal. The intermediate frequency signal is demodulated with a signal of the image carrier frequency to an in-phase signal and with a signal shifted by a phase angle of one half pi relative to the first signal to a quadrature signal. The in-phase signal is filtered using a first Hilbert filter of a Hilbert filter pair, which has an even symmetric pulse response, so as to provide a Hilbert filtered in-phase signal. The quadrature signal is filtered using the second Hilbert filter of the pair, which has an odd symmetric pulse response to produce a Hilbert filtered quadrature signal. The filtered in-phase and quadrature signals so as to produce an image output signal and/or the filtered quadrature signal is substratected from the filtered in-phase signal to produce a sound output signal. Independent claims also cover a circuit arrangement for carrying out the method. |
