US Patent 7920835 FM transmitter

An FM transmitter with improved degree of freedom in parts selection comprises: an oscillator connected with a crystal oscillator; a clock generating circuit uses a signal formed by frequency-dividing an oscillator output as a reference frequency, and which generates a clock having a frequency of an integer multiple of the frequency of the reference frequency; a DSP operates synchronously with the clock performing stereo modulation processing, FM modulation processing, and IQ modulation processing to inputted stereo data by digital processing; a frequency synthesizer generates a reference having a frequency an integer multiple of the frequency of the reference; mixers which mix signals outputted from the DSP with signals generated by the frequency synthesizer, respectively; an adder which adds outputs of the mixers; and an amplifier which amplifies an output signal of the adder and transmits the amplified signal from an antenna.