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.     

Basic RF Characteristics of Fishbone‐Type Transmission Line Employing Comb‐Type Ground Plane (FTLCGP) on PES Substrate for Use in Flexible Passive Circuits

In this work, a fishbone‐type transmission line employing a comb‐type ground plane (FTLCGP) was fabricated on polyethersulfone (PES) substrate, and its RF characteristics were thoroughly investigated. According to the results, it was found that the FTLCGP on PES showed periodic capacitance values much higher than other types of transmission lines due to a coupling capacitance between the signal line and ground, which resulted in a reduction of wavelength and line width. Using the theoretical analysis, we also extracted the bandwidth characteristic of the FTLCGP on PES. According to the result, the FTLCGP structure showed a cut‐off frequency of 280 GHz.     

Study on Characteristics of Various RF Transmission Line Structures on PES Substrate for Application to Flexible MMIC

In this work, the coplanar waveguide is fabricated on a PES (poly[ether sulfone]) substrate for application to a flexible monolithic microwave integrated circuit, and its RF characteristics were thoroughly investigated. The quality factor of the coplanar waveguide on PES is 40.3 at a resonance frequency of 46.7 GHz. A fishbone‐type transmission line (FTTL) structure is also fabricated on the PES substrate, and its RF characteristics are investigated. The wavelength of the FTTL on PES is 5.11 mm at 20 GHz, which is 55% of the conventional coplanar waveguide on PES. Using the FTTL, an impedance transformer is fabricated on PES. The size of the impedance transformer is 0.318 mm × 0.318 mm, which is 69.2% of the size of the transformer fabricated by the conventional coplanar waveguide on PES. The impedance transformer showed return loss values better than –12.9 dB from 5 GHz to 50 GHz and an insertion loss better than –1.13 dB in the same frequency range.     

二茂铁有机磁体/陶瓷的电磁特性研究及其在微带天线中的应用

制备了一类未见报道的二茂铁有机磁体/陶瓷(简称OPM/CM)缩波磁性材料,用相位延迟法测定了材料的缩波因子,研究了OPM/CM中组分含量与缩波因子的关系.结果表明:当OPM/CM缩波磁性材料中OPM含量约60%时,缩波因子达到最大值(5.5),与国内外介质基材比较,OPM/CM缩波磁性材料有良好的缩波功能及驻波比(VSWR).因此,可用最简单的结构设计,实现微带天线高增益、低频化、小型化和宽带化,在军工和高科技产品的小型化、轻量化和多功能化上起重要作用.     

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。     

电阻网络元模拟算法及其在IC设计中的应用

提出了一种模拟任意形状的薄层电阻的方法－－电阻网络元模拟算法。将模拟值和计算值进行比较表明，该方法具有精度高和操作简单的优点，从而在ＩＣ的设计中获得广泛的应用。     

基于罗朗级数的矩量匹配技术及其在去耦电容选择中的应用

提出一种新型的矩量匹配技术,不同于传统的基于泰勒级数的矩量匹配,该技术基于罗朗级数展开,考虑了负幂项的作用;通过灵活选择展开阶次,可以在指定区域内或外,非常有效地逼近所给函数.本文针对电源分配系统的去耦电容选择问题,将该型矩量匹配技术应用于这一领域.结果表明,利用该方法可以快速选择合适的电容大小,降低系统的端口阻抗,进而达到优化设计的目的.