A SINGLE-CHIP 900-MHZ SPREAD-SPECTRUM WIRELESS TRANSCEIVER IN 1-MU-M CMOS - PART I - ARCHITECTURE AND TRANSMITTER DESIGN

A single-chip transceiver for frequency-hopped code division multiple access (CDMA) in the 900 MHz industrial, scientific and medical (ISM) band is implemented in 1-mu m CMOS. It combines a digital frequency sy nthesizer, a double quadrature upconverter, an integrated oscillator, and a power amplifier with variable output, Data modulates a carrier h opping at 20 kHz with quaternary frequency-shift keying (4-FSK). At an output power level of +3 dBm, the harmonics and spurious tones lie at -52 dBc or below. When active, the transmitter drains 100 mA from 3 V .