A CMOS RF Polar Transmitter of a UHF Mobile RFID Reader for High Power Efficiency

Abstract

A CMOS radio frequency (RF) polar transmitter architecture for a UHF (860-960 MHz) RF identification (RFID) reader is proposed, which consists of a switch-mode CMOS power amplifier (PA) and an analog pulse-shaping filter implemented in 0.25-m CMOS process. The amplitude modulation of a amplitude shift keying signal is performed by simply switching the common gate transistor of a cascode power amplifier. Extremely low power consumption is achieved when the PA is switched off. The power efficiency of the transmitter is enhanced not only by using switching power amplifier but also by employing this architecture.Index Terms-Amplitude shift keying (ASK), CMOS power amplifier, polar transmitter, radio-frequency identification (RFID) reader.

Design and analysis of a highly-integrated CMOS power amplifier for RFID readers

“…A comparison of the PA performance in this work and the one in Ref. [13] is shown in Table 1. It can be seen that many parameters have the same value.…”

“…It can be seen that the 10 kbps data can satisfy the spectral mask while the 40 kbps data can not. In order to satisfy the faster transmitted data rate, a corresponding filtering method should be adopted before the transmitted data enters the PA.The latest paper reported a class-E power amplifier applied in RFID readers [13] . A comparison of the PA performance in this work and the one in Ref.…”

CMOS RF Power Amplifier for UHF Stationary RFID Reader

“…However, digitally modulated on-off binary ASK signal induces high adjacent channel power of a desired band that restricts EPC global spec. To meet the specifications and obtain good, efficient performance with low complexity, the PSF is designed in Bessel fifth order low pass type that suppresses out of band component without distortion [3]. CMOS 0.25 m process is used to implement and output voltage switching from 0.3 to 3.0 V.…”

A multimode, power-adjustable transmitter for UHF mobile RFID reader

“…In order to obtain the different output power regions, it must be able to switch between the different amplifiers and combine their output efficiently. Recent studies have demonstrated the viability of a linear CMOS PA in RFID reader application [7,8], but the output power is constant and not suitable for mobile application. In order to obtain higher efficiency, two Class-E PAs with different output power are designed for its circuit simplicity and high frequency performance.…”