A 20Mbps sub-0.1nJ/b Transmitter for Capsule Endoscope Application

Byeong Seol Kim; Joon Sung Bae

doi:10.23075/jicas.2021.7.4.004

Byeong Seol Kim Kangwon National University
Joon Sung Bae Kangwon National University

DOI: https://doi.org/10.23075/jicas.2021.7.4.004

Keywords: Class-E switching power amplifier, FSK modulator, FSK Transmitter, Implantable Medical Devices(IMD)

Abstract

In this paper presents a high-speed and low-power transmitter for capsule endoscope application in CMOS 65nm process. The transmitter consists of a FSK modulator for high speed, low power modulation and a class-E Power Amplifier that can effectively transfer power to the antenna. The modulator has to secure sufficient loop bandwidth for high speed operation. Therefore, we implemented the fast FSK modulator using two frequency synthesizers(PLL). The frequency band used is the 420-440MHz band, which is a frequency that can minimize loss, and two frequency synthesizers are switched to 20Mbps. The power amplifier using series resonance at the output network, with frequency selective characteristics, a class-E switching power amplifier with 87% power efficiency at the output power of -16dBm. 1V was used for the supply voltage, and the DC power consumption was 1.7mW. The phase noise of the FSK modulator is -85dBc at 420MHz. The fabricated chip occupied a core area of 0.3mm*0.36mm, achieving sub-0.1nJ/b energy efficiency.

Author Biographies

Byeong Seol Kim, Kangwon National University

Byeong Seol Kim received the B.S. and M.S. degrees in electrical and electronics engineering from Kangwon National University, Chuncheon, Korea, in 2019 and 2021, respectively. His research interest includes RF circuits and linear RF transmitters for wireless communications. And wireless power transfer for biomedical devices.

Joon Sung Bae, Kangwon National University

Joon Sung Bae (M’14) received the B.S. degree from the Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea, in 2007, and the M.S. and Ph.D. degrees in electrical engineering from KAIST, in 2009 and 2013, respectively. His Ph.D. dissertation concerned circuits and systems for wireless body area network. He was an Analog Circuit Designer with IMEC, Leuven, Belgium, where he investigated ultra-lowpower biomedical circuits. Since 2017, he has been with the Department of Electrical and Electronics Engineering, Kangwon National University, Chuncheon, South Korea, where he is currently an Assistant Professor. His current research interests include energy-efficient mixed-signal circuits and systems for the Internet of Things, biomedical sensors, and body area networks. Dr. Bae is currently a Technical Program Committee Member of the International Solid-State Circuits Conference. He was a recipient of Asian Solid-State Circuits Conference Best Design Awards in 2011 and 2014.

Homepage : https://sites.google.com/view/kwbics