Patent ID: 7376396
Filing Date: 2008-05-20
Classification: H04B

Abstract:
1. Ratiometric transmit path circuitry for a communication system operable in at least two frequency bands comprising: mixing circuitry configured to convert I and Q baseband input signals to a combined output signal at an intermediate frequency (IF); transmit circuitry coupled to receive the combined IF signal from the mixing circuitry and to output a transmit signal at a desired output frequency within at least two frequency bands, the transmit circuitry comprising offset phase lock loop (PLL) circuitry comprising: oscillator circuitry configured to output a local oscillator (LO) signal; first divider circuitry coupled to receive the LO signal and to output an IF mixing signal to the mixing circuitry, the divider value for the first divider circuitry being a single divider value such that the single divider value is used for the first frequency band and the second frequency band; and second divider circuitry coupled to receive the LO signal and to output the mixing signal to the transmit circuitry, the divider value for the second divider circuitry being selectable between to divider values such that a first divider value is used for the first frequency band and a second divider value being used for the second frequency band.