一個使用相位切換之CMOS雙頻段壓控振盪器

Abstract

廣調諧範圍壓控振盪器的常見架構為：切換電感、切換電容和切換多個壓控振盪器等。但上述架構多半在壓控振盪器輸出路徑上使用金氧半導體場效電晶體做為開關。 然而，使用電晶體做為開關在高頻時的損耗相當可觀，另外對相位雜訊的影響亦需納入考慮。 基於上述理由，本論文提出了：一個利用交連耦合對產生 相位差、具雙頻模態、操作在14GHz和6GHz的壓控振盪器，以期能應用於現今多頻段、具GHz等級頻段切換上之無線通訊應用。

The common architectures of wide tuning range’s voltage controlled oscillators are inductor-switching, capacitor-switching and oscillator-switching. The above architectures use MOSFETs as switches on the signal path of oscillating nodes. Nevertheless, using MOSFETs as switches has heavy loss when oscillators are in high frequency operation. Also, using MOSFETs as switches will cause serious degradation in phase noise. Base on these, we propose a dual-band voltage controlled oscillator which can operate at dual frequencies：14GHz and 6GHz for nowadays wireless communication applications. This dual-band voltage controlled oscillator uses cross-coupled pairs which can produce extra phase shift to switch to a different oscillating frequency. And oscillating signals will not go through these switches directly.