RECEIVER CIRCUIT FOR R.F. MODEM

摘要

IMPROVED RECEIVER CIRCUIT FOR R.F. MODEM A modem for operating in the radio frequency range and for connection to a CATV cable reduces the leakage of interferring signals, such as the receiver local oscillator signal, onto the cable by using a single local oscillator but providing for double conversion of the incoming signal. The local oscillator signal is mixed at two mixers in sequence to provide two intermediate frequency stages. This provides a local oscillator frequency that is well separated from the frequency of the incoming signal and it is easier to reduce leakage of the oscillator frequency.