A 13 pJ/bit 900 MHz QPSK/16-QAM Band Shaped Transmitter Based on Injection Locking and Digital PA for Biomedical Applications

作者：Liu Xiayun^*; Izad Mehran M; Yao Libin; Heng Chun Huat

来源：IEEE Journal of Solid-State Circuits, 2014, 49(11): 2408-2421.

DOI：10.1109/JSSC.2014.2354650

• Digital power amplifier
• frequency multiplication
• injection-locked oscillator
• mismatch filter
• phase-shift keying (PSK)
• quadrature amplitude modulation (QAM)
• spur

This paper presents a 900 MHz highly digital transmitter capable of providing band shaped QPSK/16-QAMmodulation for high data-rate applications with high energy efficiency. Injection-locked ring oscillator is used for multi-phase carrier generation which eliminates the use of power-hungry phase-locked loop. It also provides fast settling time that enables heavy duty cycling to maximize energy conservation. Direct modulation at power amplifier is adopted to simplify the transmitter architecture. Fabricated in 65 nm CMOS, the transmitter achieves maximum data rate of 50 Mbps/100 Mbps for QPSK/16-QAM with effective side-band suppression more than 38 dB. The chip occupies an active area of 0.08 mm(2) and achieves a settling time of less than 88 ns. Under 0.77 V supply, it achieves an energy efficiency of 26 pJ/bit and 13 pJ/bit with and without band shaping respectively. The measured EVM is better than 6% for QPSK (at 50 Mbps) and 16-QAM (at 100 Mbps) while delivering 15 dBm of output power.

• 出版日期2014-11