使用基板合成波導諧振器之30GHz諧波振盪器設計

Abstract

為了滿足現今對於無線通訊應用與日劇增的需求，毫米波系統中各組件的研發成為非常重要。振盪器在射頻電路中往往扮演著關鍵的角色，然而，受到元件可操作頻率的限制，以及元件隨頻率上升而增加的寄生效應，要設計一個高度穩定的高頻訊號源，則相當具有挑戰性。諧波振盪器已證明是一個產生高頻訊號源的有效電路；另外，擁有低損耗及高度微波毫米波電路整合特性的基板合成波導技術，也在最近被提出，因此，為了達到低相位雜訊的響應，基板合成波導諧振器可應用於諧波振盪器的設計。 本論文採用兩種諧波振盪器架構：其一為推-推式振盪器，另一者為振盪倍頻器(osciplier)。藉由適當地激發諧振器之諧振模態，則可利用該諧振模態的特性，設計所需的諧波振盪器。在推-推式振盪器中，其兩個子振盪器之耦合網路為一基板合成波導諧振器，其TE102模態設計於15 GHz用以造成基頻振盪。而在振盪倍頻器中，作為振盪器迴授網路的基板合成波導諧振器，其15 GHz諧振頻率設計在TE101模態。這兩個振盪器都設計成輸出30 GHz訊號，也就是二次諧波的頻率，並且以平面印刷電路板製程實現。

To fulfill the increasing demand for wireless communication applications nowadays, the research and development of millimeter-wave components and modules are becoming essential. Oscillators are key components in such radio frequency (RF) systems. However, generating highly stable signals at high frequencies is challenging because of the frequency limitation of device and the rising influences of device parasitic effects. Harmonic oscillators have been proven to be an efficient way to generate high frequency signals; furthermore, the substrate integrated waveguide (SIW) technique was proposed recently, which possesses the properties of low-loss and high-density integration of microwave/millimeter-wave circuits. Thus, a SIW cavity resonator can be incorporated into the oscillator design to achieve a low phase noise response. In this thesis, two topologies of harmonic oscillators are employed: one is the push-push oscillator and the other one is the osciplier. Then, by properly exciting the resonant mode of the cavity resonator, certain mode characteristics are applicable to the oscillator design. In the push-push oscillator, a SIW cavity resonator of its TE102 mode at 15 GHz for the fundamental oscillation is designed and acts as the coupling network of the two sub-oscillators. In the osciplier, the SIW cavity resonator is, on the other hand, designed with its TE101 mode at 15 GHz and acts as the feedback network of the oscillator. Both harmonic oscillators are designed to generate 30 GHz output signals, which are the second harmonic, and fabricated in printed-circuit-board (PCB) process.