A Transformer Feedback Oscillator

This paper presents an LC voltage-controlled oscillator for millimeter-wave communication. The resonator of the oscillator is optimized in the design, and the gate voltage amplitude of the negative resistance transistor is slightly higher than the drain with the help of a transformer, which makes the transistor to turn on and turn off more quickly results the improve of the phase noise. The tuning range is expanded with switched capacitors. The varactor bias structure makes the capacitance change range being set appropriately within the Vtune adjustment range. The design is based on 40nm CMOS process. A compromise is get between power consumption and performance. The output frequency range is about <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$8.22-9.949 \text{GHz}$</tex>, and the FTR is 19%. When the output frequency is 9.949 GHz, the phase noise at 1 MHz offset is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-115.68 \text{dBc} / \text{Hz}$</tex>, the FoM value is −181.31 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{dBc} / \text{Hz}$</tex>, the FoMt is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-186.88 \text{dBc} / \text{Hz}$</tex>, and the power consumption is 27.072 mW.