TRIM FOR DUAL-PORT FREQUENCY MODULATION

摘要

Various methods provide for trimming the gain in a dual-port phase-locked loop (PLL) of a radio transceiver. Use is made of the radio's demodulator to perform modulation accuracy measurements, thereby reducing the cost and complexity of external test equipment.

主权项

1. A method for trimming analog gain of a transceiver of a radio, comprising:
modulating a signal generated by a phase-locked loop of the transceiver to generate a modulated signal; generating by the transceiver a modulated intermediate frequency signal from an RF signal and the modulated signal; processing the modulated intermediate frequency signal by a demodulator of the transceiver to determine modulation accuracy of the modulated intermediate frequency signal; and monitoring the determined modulation accuracy of the modulated intermediate frequency signal and responsive to the determined modulation accuracy falling outside an acceptable range of modulation accuracy, adjusting the analog gain value of the transceiver to bring the modulation accuracy of the modulated intermediate frequency signal within the acceptable range of modulation accuracy.