FM-to-AM Converter for Satellite Direct Broadcast TV

In certain television applications, such as direct broadcast from satellites or interconnection between microwave links and CATV head ends, the received signal is on an FM carrier, while the ultimate user has a home television receiver which is designed for AM signals. The TV modulation may be transferred from an FM to an AM format and from the input carrier frequency to any desired output carrier frequency by means of a modulation converter consisting of an oscillator, two mixers, and an appropriate filter. This arrangement can be implemented at lower cost than the conventional approach involving demodulation followed by remodulation.