FM High-fidelity processor
First Claim
1. A high-fidelity FM processor operable in response to a first signal having a plurality of subsignals therein, including a desired signal at a first frequency, and providing a signal at a second frequency, comprising:
- a first mixer for receiving only said first signal and for generating intermodulation products according to the mixing products of said subsignals;
filter means for selectively isolating a desired intermodulation product including said desired signal from all intermodulation products produced by said first mixer means;
local oscillator means; and
a second mixer receiving the output signals from said filter means and said local oscillator, and producing an output signal at said second frequency.
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Accused Products
Abstract
A processor providing high-quality audio signals from television sound channels by signal recovery using induced intermodulation between the picture carrier and the sound subcarrier signal. The resulting intermodulation products are filtered and the FM audio subcarrier is recovered and converted to the FM radio band. Subsequently the detected audio signal is enhanced by stereo synthesis and noise reduction systems, producing a high-quality reproduction of television audio signals with a minimum of distortion and noise, suitable for a full-range stereo system. The recovery of the audio subcarrier by inducing intermodulation between the signal carriers avoids the frequency shifts or phase noise induced by satellite and/or CATV translator circuits, in particular, the phase jitter of translating phase-lock loop (PLL) circuits. The converter is also applicable for use with VCR and other equipment to provide high-quality sound recovery.
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Citations
10 Claims
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1. A high-fidelity FM processor operable in response to a first signal having a plurality of subsignals therein, including a desired signal at a first frequency, and providing a signal at a second frequency, comprising:
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a first mixer for receiving only said first signal and for generating intermodulation products according to the mixing products of said subsignals; filter means for selectively isolating a desired intermodulation product including said desired signal from all intermodulation products produced by said first mixer means; local oscillator means; and a second mixer receiving the output signals from said filter means and said local oscillator, and producing an output signal at said second frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification