Communication tuning system utilizing local oscillator frequency selection for maximum RF filter bandwidth and method thereof

摘要

The local oscillator frequency in a communication tuning system is selected to either high side mix or low side mix as appropriate to place the local oscillator frequency and image frequency outside the bandpass range of the bandpass filter. This allows bandpass filters having a frequency range equal to approximately twice the IF frequency in a transmitter, and approximately four times the IF frequency in a receiver.