CMOS polar transmitter with wide power control range

Abstract

A dual-phase pulse-modulated polar transmitter (PMPT) for wide power control range (PCR) applications is presented. For the validation of the proposed architecture, a radio-frequency (RF) PMPT chip is implemented with a standard 0.18 μm 1P6M mixed-signal CMOS process. The measurement results show that by using the proposed technique, wide PCR transmitters can be implemented accurately with low hardware requirements. An RF variable-gain amplifier with just 21 dB of dynamic range is sufficient to pass the 80 dB PCR of the CDMA2000 standard. Compared with a conventional transmitter utilising linear power amplifiers, the proposed architecture has the potential of achieving much higher efficiency while being able to achieve chip-level integration with eased circuit design specification.