Wideband chrominance signal filter

Claim 1

In a system for processing a video signal including a wideband chrominance signal component comprising a chrominance subcarrier component exhibiting a frequency unsymmetrically disposed in the range of frequencies occupied by said chrominance signals, apparatus comprising: a source of video signals exhibiting an amplitude chacteristic with a decreasing slope over a frequency range including frequencies associated with said wideband chrominance component; comb filter means responsive to said video signals and to switching signals for deriving said wideband chrominance component from said video signal, said derived chrominance component exhibiting said amplitude characteristic of decreasing slope; and filter means responsive to said derived wideband chrominance signals and exhibiting a passband wherein said chrominance subcarrier frequency is unsymmetrically disposed in said passband, for providing output chrominance signals in accordance with the amplitude-versus-frequency response of said filter means; wherein said filter means imparts to said chrominance signals an amplitude characteristic with an increasing slope for substantially compensating for said amplitude characteristic with said decreasing slope; said filter means comprises an input resonant section including a capacitance for suppressing high frequency signals above the range of chrominance signal frequencies; a resistance couples said derived chrominance signals to said input section of said filter means, said resistance forming a low pass filter with said capacitance; said filter means comprises plural mutually interactive resonant sections including said input section; said input section comprises an inductance arranged as a parallel resonant circuit with said capacitance; and said input section coacts with other of said plural resonant sections to produce a peaked filter amplitude response at a frequency below said range of chrominance signal frequencies.