A CMOS quadrature baseband frequency synthesizer/modulator

A quadrature baseband frequency synthesizer/modulator IC has been designed and fabricated in a 0.5 mu m CMOS. This quadrature baseband frequency synth esizer/modulator is intended for use in a wide variety of indoor/outdoor po rtable wireless applications in the 2.4-2.4835 GHz ISM frequency band. This frequency synthesizer/modulator is a capable of frequency and phase modula tion. The major components are: a quadrature direct digital synthesizer, di gital-to-analog converters and lowpass filters. By programming the quadratu re direct digital synthesizer, adaptive channel bandwidths, modulation form ats, frequency hopping and data rates are easily achieved. The quadrature b aseband direct digital synthesizer produces an 80 MHz frequency band. The q uadrature baseband spectrum could be upconverted with off-chip mixers into the 2.4 GHz ISM frequency band. The chip has a complexity of 17,803 transis tors with a die area of 24 mm(2) and a con area of 9 mm(2). The power dissi pation is 496 mW at 3.3 V.