Low-power High-efficiency Wireless Transmitters with Injection-locked Technique for Biomedical Applications
Date Issued
2015
Date
2015
Author(s)
Yeh, Tzu-Yu
Abstract
In recent years, injection-locking technique and phase-MUX technique is widely adopted in low-power transmitter design. However, the spurious tones at the output of transmitter induced by injection signal may disturb the transmission quality of adjacent channels. In addition, phase-MUX technique is not suitable for injection-locked transmitters with high-order phase modulation, and it is also not preferred for low-power application because of the requirement for generating multi-phase high-frequency carriers at the same time. In this thesis, two low-power energy-efficient 400-MHz injection-locked transmitters are proposed to deal with the above mentioned issues. The first work presents injection-spur-suppression technique to decrease the level of injection spur. The second work introduces a novel injection-locked transmitter architecture for BPSK/QPSK modulation. With the proposed injection-phase-MUX technique, phase modulation can be accomplished by changing the phase of injection signal. In this way, only single-end ring oscillator can generate output signal with different phases according to the phase of injection signal, so the power consumption can be further reduced. The first work is fabricated in TSMC 0.18 μm CMOS technology. The total power consumption is 390 μW, and the EVM is 13.68 % at 20-Mbps data rate. The proposed injection-spur-suppression technique can decrease the spurious tones by more than 11.7 dB. The second work is fabricated in TSMC 0.18 μm CMOS technology. The total power consumption is 345 μW, which reduces 11 % of system power. BPSK EVM is 13.6 % at 10-Mbps data rate, and QPSK EVM is 20% at 1-Mbps data rate.
Subjects
Injection-locked
Transmitter
Low Power
Type
thesis