Apparatus and method for generating RF without harmonic interference

摘要

A transmitter capable of operating according to a first standard that does not interfere with a nearby frequency generator operating according to a second standard. The transmitter comprises an oscillator, a frequency divider, a mixer, and a filter. The oscillator is configured to output a first frequency that is outside of a frequency harmonic of the frequency generator. The frequency divider is coupled to the oscillator and divides the first frequency by a selective divide ratio to produce a second frequency. The mixer is configured to receive the first and second frequencies, which combines them to produce a mixed frequency. The filter is then used to filters the mixed frequency to obtain the higher portion of the mixed frequency. The divide ratio of the frequency divider is selected base on the desired output frequency of the transmitter such that a 2.4 GHz or 5 GHz ISM band frequency is achieved.

主权项

1. A transmitter system, comprising:
a first transmitter comprising a first oscillator operating within a first frequency range, wherein the first transmitter is configured to provide a first signal according to a first communication standard; and a second transmitter, comprising:
a second oscillator, operating within a second frequency range, to generate a second signal, wherein the second frequency range is outside of a frequency range of a second harmonic of the first frequency range,a variable frequency divider, coupled to an output of the second oscillator, configured to selectively divide the second signal by a divide ratio to produce a divided signal, wherein the divide ratio is a first ratio if a desired channel frequency of the second transmitter is at a first frequency, and wherein the divide ratio is a second ratio if the desired channel frequency of the second transmitter is at a second frequency,a mixer configured to combine the second signal and the divided signal, anda filter, coupled to an output of the mixer, configured to provide a third signal according to a second communication standard.