A low power bandpass /spl Sigma/ /spl Delta/ modulator injection locked synthesizer

A fully integrated 0.13-mum CMOS RFIC PLL transmitter for GFSK/GMSK modulation at 2.4-GHz ISM band is presented. A bandpass SigmaDelta direct digital frequency synthesized (BPSADDFS) reference oscillator is developed to provide a wideband RF PLL with a frequency modulated signal. The RF PLL-transmitter uses a single-bit bandpass SigmaDelta modulated injection locked oscillator as a reference signal. The measurement results show that the transmitter achieves a 0-dBm output power at 1-Mbit/sec data-rate when using a 0.5BT GFSK modulation. The ring oscillator VCO has a measured phase noise of -104dBc/Hz at 1-MHz offset from the RF carrier at 2.4GHz. The digital transmitter complies with Bluetooth Class 3 requirements and occupies 1.73mm2 silicon area