A low-voltage low-power injection-locked oscillator for wearable health monitoring systems
This paper reports a low-voltage low-power injection-locked oscillator suitable for short range wireless transmitter applications in a wireless body area network (WBAN). Low-power transmitter with high efficiency is a major design challenge for short range wireless communication. Unlike conventional transmitters used for cellular communication, injection-locked transmitter shows reduced power consumption and high transmitter efficiency. The core block of an injection-locked transmitter is an injection-locked oscillator. In this work a low-voltage low-power injection-locked LC oscillator has been designed and fabricated employing self-cascode structure and body-terminal coupling. The proposed oscillator has been realized using 0.18-μm RF CMOS process. Experimental results indicate that the prototype oscillator can operate with a supply voltage as low as 0.9 V and consumes only 1.4 mW of power. The relatively low-voltage and low-power operation of the design makes it highly suitable for low-power transmitter applications.
KeywordsLow-power transmitter Injection-locked oscillator Self-cascode structure Body coupling
The authors would like to acknowledge MOSIS for providing the opportunities for fabricating the integrated circuit chip under MOSIS Educational Program (MEP).
- 1.Dupire, T., Tanguay, L. F., & Sawan, M. (2006). Low power CMOS transmitter for biomedical sensing devices. 13th IEEE International Conference on Electronics, Circuits and Systems (pp. 339–342).Google Scholar
- 3.Porret, A.-S., Melly, T., Vittoz, E. A., & Enz, C. C. (2000). Tradeoffs and design of an ultra low power UHF transceiver in a standard digital CMOS process. Proceedings of the 2000 International Symposium on Low Power Electronics and Design (pp. 273–278), Rapallo, Italy.Google Scholar
- 4.Choi, P., Park, H., Nam, L., Kang, K., Ku, Y., Shin, S., Park, S., Kim, T., Choi, H., Kim, S., Min, S., Kim, M., Park, S., & Lee, K. (2003). An experimental coin-sized radio for extremely low power WPAN (IEEE 802.15.4) application at 2.4 GHz. Digest of Technical Papers, 2003 International Solid State Circuits Conference (ISSCC) (pp. 92–93).Google Scholar
- 5.Molnar, A. et al. (2004). An ultra-low power 900 MHz RF transceiver for wireless sensor networks. IEEE CICC (pp. 401–404).Google Scholar
- 7.Hajimiri, A., & Lee, T. H. (1999). The design of low noise oscillators. Norwell, MA: Kluwer.Google Scholar
- 13.Ahmed, H., De Vries, C., & Mason, R. (2003). A Digitally Tuned 1.1 GHz Subharmonic Injection-Locked VCO in 0.18 μm CMOS. Proceedings of the 29th European Solid-State Circuit Conference (pp. 81–84).Google Scholar
- 20.Hsieh, H.-H., Chung, K.-S., & Lu, L.-H. (2005). Ultra-low-voltage mixer and VCO in 0.18-μm CMOS. IEEE RFIC Symposium (pp. 167–170).Google Scholar
- 22.Choi, T.-Y., Lee, H., Katehi, L. P. B., & Mohammadi, S. (2005). A low phase noise 10 GHz VCO in 0.18-μm CMOS process. 2005 European Microwave Conference (Vol. 3, pp. 4).Google Scholar
- 23.Mostafa, A. H., & El-Gamal, M. N. (2001). A CMOS VCO architecture for sub-1 volt high frequency (8.7–10 GHz) RF applications. 2004 International Symposium of Low Power Electronics and Design (pp. 247–250).Google Scholar