A Dual-Band CMOS CDMA Transmitter Without External SAW Filtering

A SAW-less dual-band I/Q transmitter without a driver amplifier is designed for dual-band (personal communication system (PCS)/International Mobile Telecommunications (IMT) and cellular) code division multiple access applications. The receive band noise is less than -159 dBc/Hz. It can provide up to + 5-dBm output power and meets the adjacent channel power ratio and dynamic range requirements of both PCS/IMT and cellular CDMA. The measured
S

₂₂
is better than -10 dB for both bands and it requires no external matching components. The transmitter is implemented in a 65-nm digital CMOS technology and is packaged using flip-chip technology. The transmitter signal path (RF portion) occupies 1.0 mm
²
.