Low power saw‐less WCDMA transmitter with quadrature driver amplifier and injection‐locked frequency divider

A direct conversion transmitter with low noise and low power is presented in this article.A quadrature driver amplifier is used to remove the Inphase‐Quadrature crosstalk in a passive mixer operating with 50% duty cycle local oscillator (LO). In the quadrature LO generation, an inductor‐less injection‐locked frequency divider is utilized to reduce the phase noise contribution with cost of a small current and area. Fabricated in 65 nm CMOS process, a transmitter prototype is designed for wideband code division multiple access (WCDMA) application. Measurement results show that the proposed transmitter achieves 1 dBm maximum output power at 2.53 GHz, 1.7% error vector magnitude (EVM), and −158.5 dBc/Hz output noise at the receiver (RX) band, eliminating the need for the surface acoustic wave (SAW) filter in a traditional transmitter design, with an area of 0.18 mm 2 and a total power consumption of 37.8 mW. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1217–1221, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27571