University of Oulu

Voltage controlled oscillator for mm-wave radio systems

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Author: Shafiullah, Yasir1
Organizations: 1University of Oulu, Faculty of Information Technology and Electrical Engineering, Communications Engineering
Format: ebook
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 8.6 MB)
Pages: 76
Persistent link: http://urn.fi/URN:NBN:fi:oulu-202006212612
Language: English
Published: Oulu : Y. Shafiullah, 2020
Publish Date: 2020-06-26
Thesis type: Master's thesis
Tutor: Pärssinen, Aarno
Reviewer: Pärssinen, Aarno
Kursu, Olli-Erkki
Description:

Abstract

The advancement in silicon technology has accelerated the development of integrated millimeter-wave transceiver systems operating up to 100 GHz with sophisticated functionality at a reduced consumer cost. Due to the progress in the field of signal processing, frequency modulated continuous wave (FMCW) radar has become common in recent years. A high-performance local oscillator (LO) is required to generate reference signals utilized in these millimeter-wave radar transceivers. To accomplish this, novel design techniques in fundamental voltage controlled oscillators (VCO) are necessary to achieve low phase noise, wide frequency tuning range, and good power efficiency. Although integrated VCOs have been studied for decades, as we move higher in the radio frequency spectrum, there are new trade-offs in the performance parameters that require further characterization.

The work described in this thesis aims to design a fully integrated fundamental VCO targeting to 150 GHz, i.e., D-Band. The purpose is to observe and analyze the design limitations at these high frequencies and their corresponding trade-offs during the design procedure. The topology selected for this study is the cross-coupled LC tank VCO. For the study, two design topologies were considered: a conventional cross-coupled LC tank VCO and an inductive divider cross-coupled LC tank VCO. The conventional LC tank VCO yields better performance in terms of phase noise and tuning range. It is observed that the VCO is highly sensitive to parasitic contributions by the transistors, and the layout interconnects, thus limiting the targeted frequency range. The dimensions of the LC tank and the transistors are selected carefully. Moreover, the VCO performance is limited by the low Q factor of the LC tank governed by the varactor that is degrading the phase noise performance and the tuning range, respectively. The output buffer loaded capacitance and the core power consumption of the VCO are optimized. The layout is drawn carefully with strategies to minimize the parasitic effects. Considering all the design challenges, a 126 GHz VCO with a tuning range of 3.9% is designed. It achieves FOMT (Figure-of-merit) of -172 dBc/Hz, and phase noise of -99.14 dBc/Hz at 10 MHz offset, Core power consumption is 8.9 mW from a 1.2 V supply. Just falling short of the targeted frequency, the design is suitable for FMCW radar applications for future technologies. The design was done using Silicon-on-Insulator (SOI) CMOS technology.

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Copyright information: © Yasir Shafiullah, 2020. This publication is copyrighted. You may download, display and print it for your own personal use. Commercial use is prohibited.