Patent ID: 6061096
Filing Date: 2000-05-09
Classification: H04N

Abstract:
A radio receiver for selectively receiving one of a plurality of television signals, some of which television signals are digital television signals transmitted by amplitude-modulation of a suppressed carrier, and some of which television signals are analog television signals comprising an amplitude-modulated video carrier and a frequency-modulated audio carrier, said radio receiver comprising:a first detector comprisinga first local oscillator for supplying first local oscillations anda first mixer for generating a first detector response to the selected one of said television signals as mixed with said first local oscillations, said first detector response including a high-band intermediate frequency signal;a first high-band intermediate frequency amplifier for supplying a first amplified high-band intermediate frequency signal in response to said first detector response;a second detector for said digital television signals and for the amplitude-modulated video carriers of said analog television signals, comprisinga second local oscillator for supplying second local oscillations, anda second mixer for generating a first low-band intermediate frequency signal responsive to said first amplified high-band intermediate frequency signal as mixed with said second local oscillations;circuitry for demodulating a digital television carrier sideband component of said first low-band intermediate frequency signal when a digital television signal is selected for reception; andcircuitry for demodulating an amplitude-modulated video carrier component of said first low-band intermediate frequency signal when an analog television signal is selected for reception.