Signal separation networks

In a television receiver having a common detector for producing, at an output, detected video frequency signal components and an intercarrier sound signal occupying a given range of frequencies exclusive of said video frequency signal components, means, having an input terminal, for processing said video frequency signal components, and means, having an input, for processing said intercarrier sound signal;

• a network for separating said video and intercarrier sound signal components comprising:
• first and second parallel signal paths coupled between the output of said detector and the input terminal of said video signal processing means and including a reactive impedance element of one sign;
• a third signal path, including a reactive impedance element of an opposite sign, coupled between an intermediate point on said first signal path and a point of reference potential, and
• means for coupling the signal developed across said reactive impedance element in said third signal path to the input of said intercarrier sound signal processing means,
• said first, second and third signal paths comprising a tuned circuit tuned to exhibit a transfer function having a zero within said given range of frequencies at said input terminal, and exhibiting a pole within said given range of frequencies at the junction of said third signal path and said coupling means, wherein said video frequency signal components occupy a second given range of frequencies, and said third signal path further includes means for producing a minimum response at a frequency included within said second given range of frequencies at said junction.

In a television receiver having a common detector for producing, at an output, detected video frequency signal components and an intercarrier sound signal, means, having an input terminal, for processing said video frequency signal components, and means, having an input, for processing said intercarrier sound signal;

• a network for separating said video and intercarrier sound signal components comprising:
• first and second parallel signal paths coupled between the output of said detector and the input terminal of said video signal processing means;
• a third signal path, including an impedance element, coupled between an intermediate point on said first signal path and a point of reference potential, and
• means for coupling the signal developed across said impedance element in said third signal path to the input of said intercarrier sound signal processing means,
• said first, second and third signal paths comprising a tuned circuit for attenuating said intercarrier sound signal at said input terminal,
• wherein said video frequency signal components occupy a given range of frequencies including a color subcarrier frequency, and that portion of said third signal path which is coupled between the junction of said coupling means and said third signal path and said point of reference potential is tuned to provide attenuation at approximately said color subcarrier frequency at said junction.

In a television receiver having a common detector for producing, at an output, detected video frequency signal components and an intercarrier sound signal, means having an input terminal, for processing said video frequency signal components, and means, having an input, for processing said intercarrier sound signal;

• a network for separating said video and intercarrier sound signal components comprising:
• first and second parallel signal paths coupled between the output of said detector and the input terminal of said video signal processing means;
• a third signal path, including an impedance element, coupled between an intermediate point on said first signal path and a point of reference potential, and
• means for coupling the signal developed across said impedance element in said third signal path to the input of said intercarrier sound signal processing means,
• said first, second and third signal paths comprising a tuned circuit for attenuating said intercarrier sound signal at said input terminal,
• wherein said video frequency signal components occupy a given range of frequencies including a frequency which is half the frequency of said intercarrier sound signal, and that portion of said third signal path which is coupled between the junction of said coupling means and said third signal path and said point of reference potential is tuned to provide attenuation at approximately said half intercarrier sound signal frequency at said junction.

In a television receiver having a common detector for producing, at an output, detected video frequency signal components and an intercarrier sound signal occupying a given frequency range, means, having an input terminal, for processing said video frequency signal components, and means, having an input, for processing said intercarrier sound signal;

• a bridged-T network for separating said video and intercarrier sound signal components comprising:
• a first signal path, including a resistive impedance, and a second signal path, including a first reactive impedance of one sign, coupled in parallel between the output of said detector and the input terminal of said video signal processing means;
• a third signal path, including a second reactive impedance of an opposite sign, coupled between said second signal path and a point of reference potential, and having a terminal at which said intercarrier sound signal is developed;
• and
• means for coupling said third signal path terminal to the input of said intercarrier sound signal processing means,
• wherein said first, second, and third signal paths comprise a tuned circuit for attenuating said intercarrier sound signal at the input terminal of said video signal processing means and for peaking the response at said third signal path terminal at a frequency within said given frequency range,
• wherein said video frequency signal components occupy a second given range of frequencies, and said third signal path includes a third reactive impedance serially coupled between said third signal path terminal and said point of reference potential,
• wherein that portion of said third signal path which is coupled between said third signal path terminal and said point of reference potential comprises a circuit which is tuned to produce a point of maximum attenuation at said third signal path terminal at a frequency which is included within said second given range of frequencies.