Design of voltage-controlled oscillators and frequency dividers for 60 GHZ wireless communication applications
Date of Issue2015
School of Electrical and Electronic Engineering
A frequency synthesizer which is used to provide the local oscillation (LO) frequency of a transceiver is a fundamental block in a wireless communication system. For 60 GHz applications, the voltage-controlled oscillator (VCO) and the first-stage frequency divider (FD) are the most challenging blocks of a synthesizer due to their high operation frequency and their significant influence on the overall performance of the synthesizer. As frequency increases, the trade-offs between phase noise, power consumption, and tuning range of VCO becomes more difficult. In this thesis, firstly, the Q enhancement of multiple-coupled LC-tank has been investigated, mainly for the purpose of designing VCOs with low phase noise under low power consumption for 60 GHz transceivers with a multi-conversion super-heterodyne architecture. Secondly, a Ku-band VCO using dual LC-tanks and transformer-based feedback technique is designed. Thirdly, to cater for the requirement of wide tuning range for 60 GHz applications, a new dual-mode VCO topology with switchable coupled VCO-cores has been proposed to design low phase noise and wide frequency tuning range 60 GHz VCOs. For the first-stage FD, the injection-locked frequency divider (ILFD) with high division ratio is an attractive solution for mm-wave frequency synthesizers, but normally ILFDs suffer from narrow locking ranges, making them difficult to design for 60 GHz applications. In the thesis, a V-band divide-by-4 ILFD has been proposed. With the special topology involving dual oscillation loops, a wide locking range has been achieved at 60 GHz.
DRNTU::Engineering::Electrical and electronic engineering::Electronic circuits