Patent ID: 7424271

Claim:
A multimode communications method comprising: generating an oscillating signal by determining a control signal, the oscillating signal having a frequency corresponding the control signal; generating a compare signal according to the oscillating signal and a dividing ratio, the compare signal having a frequency equal to a product of the frequency of the oscillating signal and the dividing ratio; modulating the dividing ratio and selectively enabling the oscillating signal to have its frequency change with a variety of contents of a first communications signal on a modulating mode by modulating the dividing ratio according to the contents of the first communications signal and enabling the oscillating signal to have its frequency constant on a constant frequency mode by keeping the dividing ratio unchanged in a constant frequency mode; adjusting the control signal according to the frequency of the compare signal; selectively transmitting the oscillating signal either to a transmission module when operating on the modulating mode or to a receiving end when operating on the constant frequency mode; and mixing a receiving signal received by the receiving end with a second communications signal and generating a third communications signal carried over the receiving signal.