Motorola Corporation

Serge Drogi

Albert H Higashi

James S Mielke

A transceiver ( ) includes a transmitter ( ) that receives a digital data stream from a digital signal processor ( ) to delay lines ( ). The delay lines ( ) provide an address to a ROM look-up table ( ). Another input of the look-up table ( ) receives a signal that selects protocols such as TDMA, CDMA, and GSM. A multi-accumulator fractional-N synthesizer ( ) receives phase derivative coefficients and a DAC ( ) receives amplitude modulation coefficients from the look-up table ( ) based on the selected protocol. The analog output signals from the DAC ( ) and the synthesizer ( ) are received by a variable gain amplifier ( ) that generates an RF amplitude and frequency modulated output signal for transmission from the transmitter ( ).

Digital transmitter circuit and method of operation

A transceiver (,) includes a transmitter (,) that receives a digital data stream from a digital signal processor (,) to delay lines (,). The delay lines (,) provide an address to a ROM look-up table (,). Another input of the look-up table (,) receives a signal that selects protocols such as TDMA, CDMA, and GSM. A multi-accumulator fractional-N synthesizer (,) receives phase derivative coefficients and a DAC (,) receives amplitude modulation coefficients from the look-up table (,) based on the selected protocol. The analog output signals from the DAC (,) and the synthesizer (,) are received by a variable gain amplifier (,) that generates an RF amplitude and frequency modulated output signal for transmission from the transmitter (,). The look-up table (,) stores phase derivative coefficients and amplitude modulation coefficients that correct for non-linearity in the variable gain amplifier (,).

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Phoenix, AZ, United States of America

Serge Drogi