A single-chip 900-MHz spread-spectrum wireless transceiver in 1-μm CMOS. I. Architecture and transmitter design

Abstract

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-/spl mu/m CMOS. It combines a digital frequency synthesizer, a double quadrature upconverter, an integrated oscillator, and a power amplifier with variable output. Data modulates a carrier hopping 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.