新颖的非对称马刺线谐振器设计及应用

A Design of New Asymmetrical Spurline Resonators and Its Application

提出了一种有双阻带特性的新颖马刺线结构,它是由两个内嵌到微带线的非对称马刺线谐振器构成。这种非对称马刺线谐振器具有双带隙特性以及良好的慢波效应,可以通过调节上下马刺线的长度差调整双带隙特性。马刺线电路模型可以等效为LCR并联谐振器,其中电路参数可以从电磁仿真中获取。在NeuroModeler软件的帮助下,建立神经网络从而优化这种非对称马刺线谐振器,并且快速精确地获得两个谐振频率。同时该结构的马刺线有助于抑制微波功率放大器的高次谐波。通过设计制造两个InGaP HBT功率放大器具体地分析非对称马刺谐振器对它的影响。其中1个InGaP HBT功率放大器的非对称马刺结构位于输出端,另外1个InGaP HBT功率放大器的输出端仅用传统的50Ω传输线。实验结果显示:在输出端加入这种非对称马刺结构可以很好地将二次以及三次谐波抑制在27 dB以下,在需要放大的频率上,PAE(Power Added Efficiency)分别增加了6%-8%和1%-4%。

An improved spurline structure with two rejection bands is presented in this paper, which consists of asym- metrical spurline resonators and is embedded directly into microstrip line. Asymmetrical spurline resonators provide du- al-bandgap characteristics and slow-wave effect. Additionally, the dual-bandgap characteristics can be adjusted by changing the length difference between upper spurline and lower spurline. A simple circuit model is set up for the new spurline structure by using two LCR resonators and the circuit parameters can be extracted from electromagnetic simula- tions. Then, with the aid of NeuroModeler software, a radial-based function neural network model is built up to optimize asymmetrical spurline resonators design and search for the two resonant frequencies fast and accurately. Furthermore, asymmetrical spurline structure with dual rejection bands is proposed to reduce the higher harmonics of microwave pow- er mnplifiers. To evaluate the effect of asymmetrical spurline resonators on microwave amplifiers, two InGaP HBT power amplifiers are designed and fabricated. One of them has asymmetrical spurline structure at the output section, while the other has a conventional 50 Ω microstrip line only. Results show that asymmetrical spurline structure suppresses the second and third harmonics more than 27 dB at the output and yields improved power added efficiency （PAE） and out- put power by 6%-8% and 1%-4%, respectively.