一种新型SMA型相位可调射频连接器的设计

为了满足相控阵技术对连接器件相位一致性的要求,文中提出了一种新型SMA 型相位可调射频连接器。通过调节连接器内导体和外导体的物理长度,实现整个电缆组件相位的连续可调。通过共面补偿优化设计以及对影响连接器电性能和相位特性指标的关键因素进行分析,设计了SMA 型相位可调连接器,并配接相位稳定射频同轴电缆加工了电缆组件。通过对实物进行测量,所设计的相位可调射频连接器在DC ~18 GHz 频率范围内,通过调节物理长度,相位可实现0°~15°的连续调节,测试的电压驻波比VSWR<1.3。所提出的SMA 型相位可调射频连接器结构简单,相位调节方便,可以有效解决电缆组件的相位一致性问题。电缆组件的测试结果与仿真结果具有较好的一致性,验证了设计的有效性。     

某波导组件连接器内导体焊接结构及工艺

某毫米波波导组件壳体内部结构复杂,与射频连接器焊接时,内导体焊接部位处于深腔内不可见,易出现焊接质量问题.基于焊接结构工艺性设计及工艺优化,提出了一种深盲腔射频连接器内导体焊接结构及焊接方法,实现了深盲腔内内导体的通孔回流焊接,解决了焊接质量差的问题,满足了波导组件的高指标要求.     

CSRR微带线的等效电路模型研究

首先借助三维全波电磁仿真软件HFSS对CSRR微带线进行了仿真,并引入慢波因子（SWF）分析了其慢波特性。然后根据CSRR微带线幅频曲线的单极点低通特性,以一阶巴特沃斯低通滤波器为原型,建立了CSRR微带线的等效电路模型,通过高频电磁仿真结果和电路仿真结果的对比,二者吻合较好,从而验证了该等效电路模型的正确性和有效性。最后,基于该等效电路模型研究了CSRR的结构变化对其电路特性的影响。CSRR微带线必将在未来微带电路设计中具有广泛的应用前景。     

逆开环谐振器在微带天线谐波抑制中的应用

介绍了一种利用逆开环谐振器实现微带天线谐波抑制的方法.在传统逆开环谐振器的开口处添加一对缝隙,可有效的降低传输零点的位置.提出了加载逆开环谐振器微带线的等效电路模型,电路模型结果与仿真结果相吻合,证明了所提电路模型的正确性,并从等效电路模型的角度分析了传输零点下降的原因.将不同传输零点的结构单元级联起来制作在微带线的接地板上,很好地实现了微带天线的谐波抑制.仿真结果与测试结果相吻合,证明了所采用方法的有效性和正确性.该设计方法结构紧凑,简单易行.     

基于ADS的微带线不连续性分析与应用

射频电路印制电路板（PCB）中出现的微带线拐角是微带线不连续结构之一,而微带线的不连续性会影响信号传输质量。为降低微带线不连续性对信号传输质量的影响,利用ADS（Advanced Design System）软件对不同拐角进行仿真,从两个角度分析了它们对电路性能的影响。在此基础上,将研究结果应用于5.8 GHz RFID（Radio Frequency Identification）阅读器射频电路中,取得了较为理想的效果。结果表明：45°外斜切直角拐角和圆弧拐角均能对传输线的不连续性进行补偿,其中,45°外斜切直角拐角存在最佳斜切率M,使拐角处信号的传输特性（即回波损耗和插入损耗）最优。该研究对降低微带线不连续性对信号传输质量的影响具有一定的指导意义。     

带状线组件与射频连接器的键合过渡结构

提出了一种带状线组件与射频连接器的键合过渡结构,采用地-信号-地（ground signal ground,GSG）键合方式以及板内垂直互连成功实现了带状线与射频连接器的过渡,同时对此过渡结构尤其是射频连接器键合台面的特性阻抗进行了理论研究,并采用类比法给出了其特性阻抗公式.为了验证研究结论,对此过渡结构的背靠背形式以及射频连接器进行了加工、测试.测试结果表明,在0.5～40 GHz频带内,该过渡结构具有良好的驻波以及传输特性.     

基于RO4350B的微带线拐角不连续性分析

随着射频/微波/毫米波电路产品尺寸不断朝着小型化和集成化发展，产品检测电路越来越小，检测电路PCB中微带线不得不进行拐角设计。针对业内主流的C波段微带线拐角设计，结合业内广泛应用的罗杰斯RO4350B板材进行仿真分析，对90°直角拐角、 3W规则拐角和45°外斜切拐角3种常见的微带线拐角方案进行了仿真比对分析。同时研究了在特定情况下45°外斜切拐角的最佳斜切率，该研究对指导业内射频工程师设计PCB检测电路降低微带线拐角不连续性具有一定的参考意义。     

一种微带线幅度均衡网络的实现

随着射频系统带宽的增加,如何达到良好的幅频特性成为研究的课题之一。介绍了一种用微带线均衡网络改善雷达发射机射频放大器幅频特性的方法,分析了该均衡网络的工作原理。通过仿真分析,对电路模型进行了改进并在某L频段放大器上对结果进行了验证。由于结构简单易调整,此均衡网络可方便地应用于功放组件内部。     

周期性缺陷接地结构的微带线

基于单元缺陷接地结构(DGS)等效电路模型,研究了周期性缺陷接地结构微带线的色散关系,并给出其阻带的快速估算方法.为提高微波电路的集成度和灵活性,提出了基于周期性DGS结构弯折型微带线,分析其带阻特性、色散特性和阻抗特性.实验证明,该结构在4～7GHz之间具有良好的宽阻带特性.     

一种应用于射频识别阅读器的微带移相电路设计

根据微带线的基本理论,利用高频结构仿真软件HFSS,考虑到微带电路结构参数的影响,对微带线的信号传输系数及相位延迟进行了详细的分析.分析了RFID阅读器射频电路单元中四通道解调技术.设计制作了工作频率为915 MHz、应用于RFID阅读器的射频移相电路,电路的性能指标符合设计的要求.     

The Compensation of Step Discontinuities in TEM-Mode Transmission Lines

A method for the compensation of the effects due to discontinuities that arise when transmission lines of different characteristic impedance are joined is presented. The proposed method is not based calculating the equivalent circuit of the discontinuity but makes use of simple taper on the wider line at an impedance step to remove the effects of the discontinuity.     

Equivalent transformations for the mixed lumped Brune-type sectionand uniform transmission line

As an analytical method for nonuniform transmission lines (NTLs) equivalent transformations are extended to a more general case, namely a mixed lumped Brune-type section and a uniform transmission line (unit element, UE). Circuits consisting of a cascade connection of a lumped Brune section and a UE are equivalent to one consisting of a cascade connection of a nonuniform transmission line whose characteristic impedance distribution is expressed with a trigonometric function and a lumped Brune section. This equivalent transformation method is easily applied to a circuit consisting of a lumped C section and a UE. The equivalent circuit is a circuit consisting of an NTL and a lumped C section. In this case, the characteristic impedance distribution of the NTL may be expressed in terms of a hyperbolic function. Exact network functions of the NTLs are easily obtained from the equivalent circuits without solving the telegrapher's equation. By considering the limiting case of these equivalent transformations, equivalent transformations for circuits consisting of a cascade connection of a lumped resonance circuit and a circuit and a uniform transmission line are derived     

无线无源声表面波传感器的天线匹配方法

针对无源无线声表面波传感器无线信号的有效传输,提出了一种无线无源声表面波传感器的天线阻抗匹配方法。该方法根据声表面波传感器的阻抗特性,可直接进行天线设计,并使天线的输入阻抗与声表面波传感器的输出阻抗共轭匹配。实践中,利用声表面波传感器的梅森(Mason)等效电路模型,及由微带传输线和分布式电容构成的匹配网络,在传感器谐振点附近频率段内,对传感器和天线进行共轭匹配及性能优化。对比共轭匹配前、后的仿真结果可知,声表面波传感器得到了最大的功率传输。     

一种新型复合左右手结构四频微带天线

在传统互补开环谐振(CSSRR)结构上添加T型枝节,形成一种新型复合左右手传输线(CRLH TL)。采用理论分析、电磁仿真和电路仿真研究其电磁特性,给出了单元结构的等效电路,计算了色散曲线,证明该结构是一种具有双频特性的CRLH结构。利用该结构设计、制作并测试了一种C波段四频微带天线,测试结果表明该天线具有较宽的阻抗带宽和很好的辐射特性。     

射频同轴传输线的设计仿真与加工工艺

基于SU-8和BPN紫外负性感光胶,结合微电镀工艺加工制作射频同轴传输线,以实现射频器件信号的传输与耦合。首先确定在阻抗匹配情况下同轴传输线特性阻抗为50Ω的同轴传输线的具体尺寸,然后通过HFSS仿真软件对设计的结构进行模拟仿真。通过仿真结果验证设计的可行性,采用紫外光刻技术利用SU-8光刻胶做出内导体支柱,并用BPN光刻胶做出结构,对结构进行电镀。最后将BPN光刻胶剥离,即可得到射频同轴传输线。此方法制得的同轴传输线具有介质损耗小、辐射损耗小、无色散、带宽大和抗干扰强的优点,适用于高性能射频和微波电路。另外,它的制作工艺能与其他射频和微波器件及集成电路工艺兼容,便于与射频和微波电路集成。     

An Analysis of Gap in Microstrip Transmission Lines

Although microstrip transmission lines have been widely used in microwave integrated circuits, the discontinuity structures in the microstrip transmission lines such as a gap, an abruptly ended strip conductor, and so on, have hardly been analyzed. An analytical method and numerical results for a gap capacitance in the microstrip transmission line are described. The equivalent circuit parameters are formulated with three-dimensional Green's functions, based on a variational principle. The numerical results are in good agreement with the published experimental data. The fringing effect of an abruptly ended strip conductor is also investigated.     

Characteristic Impedance of the Shielded-Strip Transmission Line

Simple formulas are given for the characteristic impedance of a transmission line consisting of a conducting strip of rectangular cross section centered between parallel conducting plates at ground potential. The formulas agree to within 1.2 per cent with an exact formula for a zero thickness strip. In the case of finite thickness up to a quarter of the plate spacing, the formulas are expected to be at least that accurate. A family of characteristic impedance curves given in this paper should prove useful to the design engineer.     

Analysis of dielectric E-plane waveguides and design of filters

A small-size waveguide made of high-permittivity ceramic is analyzed. The propagation constants are calculated approximately by an approach where the electromagnetic fields outside the waveguide are fully taken into consideration. The analysis values agree well with the experimental values. The constants of equivalent circuit for the metallic strip section are obtained by using a separate model for the analysis of the structure. Based on these results, bandpass filters (BPF's) are designed and fabricated. The fabricated BPF's have better transmission and reflection characteristics than those designed on the basis of a trough-guide model     

Broad-band microstrip-to-CPW transition via frequency-dependent electromagnetic coupling

An improved broad-band microstrip-to-coplanar-waveguide (CPW) transition is developed on a basis of the frequency-dependence characteristic of an electromagnetic surface-to-surface coupling. A self-calibrated method of moments is extended to model this unbounded two-port discontinuity with the two dissimilar microstrip/CPW feeding lines. Numerical results are provided to demonstrate its frequency response of transmission under varied strip/slot dimensions and further exhibit its attractive ultra-broad-band transmission with low radiation loss. Next, the back-to-back transition circuits with the two different lengths are fabricated and measured to deembed in experiment the S-parameters of two single-transition structures. Predicted and measured results show good agreement with the return loss less than -10dB over the frequency of 3.2-11.2 GHz.