Experimental Study on Isolation Characteristics Between Adjacent Microstrip Lines Employing Periodically Perforated Ground Metal for Application to Highly Integrated GaAs MMICs

Using a periodically perforated ground metal (PPGM) on GaAs monolithic microwave integrated circuit (MMIC), a microstrip line structure with a high isolation characteristic between lines was developed. The high isolation characteristic was originated from a resonance between adjacent microstrip lines employing PPGM. According to experimental results, a much better isolation characteristic was observed from the adjacent microstrip lines employing PPGM compared with conventional microstrip lines, and the frequency range for high isolation was easily controlled by changing the PPGM structure. Above results indicate that microstrip lines employing PPGM are very useful for application to compact signal/bias lines of highly integrated MMIC requiring a high isolation characteristics between lines.     

Accurately Approximate Formula of Effective Filling Fraction for Microstrip Line with Isotropic Substrate and its Application to the Case with Anisotropic Substrate

The accurately approximate formula of effective filling fraction q/sub w/ is obtained for the microstrip line with zero-thickness strip and isotropic substrate. The line capacitance per unit length C/epsilon/sub 0/ for the case with anisotropic substrate can easily be obtained by using the approximate formula of q/sub w/ and C/sub 0//epsilon/sub 0/ tabulated for the wide range of shape ratio w/h. The parameters Z, v, and lambda for such a line can be calculated by using C/ epsilon/sub 0/ and C/sub 0//espsilon/sub 0/.     

双模He-Ne激光器强度差的时谱特性及其在稳频稳幅中的可能应用

本文重点导出了双纵模He-Ne激光强度差ΔI(t)的时谱公式,分析了ΔI(Δv)的调谐特性,并在此基础上提出了一种实现双频双模He-Ne激光器稳频稳幅的简单方法一一扫描干涉仪法。文章还介绍了相应的稳频稳幅原理及其原理性方案。分析与研究表明,该方法不仅装置简单,成本低下,而且稳频精度较高。