一种新型介质谐振器带通滤波器

本文阐述一种能与微波集成电路结合使用的新型介质谐振器带通滤波器。这种滤波器是目前能用于微波集成电路的性能最佳的一种窄带滤波器。本文对这种滤波器作了理论分析;并导出了有关滤波器设计的主要公式;给出了一至四谐振器带通滤波器的实测性能。例如:一个相对带宽为 0.2％的 5cm三谐振器滤波器,其带内插损为 0.8dB左右,带外衰减大于50dB,30dB与 3dB的带宽比约为 3.3。     

Transmission Line Model Based CAD of Multilayer Dielectric Filters

A systematical procedure for multilayer dielectric filter design is introduced here based on the transmission line model (TLMBCAD). By this procedure, low-pass, high-pass, and band-pass filters can be designed in the same way. The transmission line model works well and is time efficient not only for normal incidence of linearly polarized wave but also for oblique incidence wave with circular polarization. Design examples are given for low-pass and band-pass filters. Simulation results show that the method developed in this paper is valuable for the engineering design of multilayer dielectric filters.     

毫米波E面膜片滤波器的加工误差研究

E面膜片滤波器由于结构简单、高Q值、滤波特性好、设计精度高、易于批量生产等优点,在毫米波雷达系统中得到广泛应用.文中对E面膜片滤波器进行了理论分析,利用误差合成法以及数据模拟仿真,研究了Ka波段E面膜片滤波器中,膜片厚度、膜片安装、膜片长度在不同加工误差下,对滤波器系统性能S参数的影响,为其加工制造提供理论指导.     

E面部分填充介质矩形波导的导体损耗

本文推导了E面部分填充介质矩形波导的导体损耗的计算公式,给出了Ka波段标准波导中对称填充结构的衰减常数随填充厚度、介电常数及工作频率的一系列变化曲线,由此得出在一定填充厚度范围内衰减常数小于未填充波导的值等若干有用结论.作为一应用实例,计算了一只Ka波段三节E面带通滤波器的频率响应特性,所得插入损耗的理论值与测量结果符合较好.     

矩形波导中左右手材料光子晶体的色散特性研究

研究了在矩形波导E平面填充的一维周期或准周期左右手材料光子晶体中电磁波的色散特性。采用传输矩阵法推导出一种适用于任意一维光子晶体E面填充矩形波导的2×22×2阶特征矩阵。定量分析了周期光子晶体中单元结构的重复次数、光子晶体的排列方式(周期,斐波那契,Thue-Morse和Octonacci排列)、及左手/右手材料介电常数等变量的改变对纵剖面电模式(LSE)色散特性的影响。结果表明,在矩形波导E面填充一维左右手材料光子晶体可以实现带隙特性,并且带隙的宽度和频谱位置受到左右手材料的介电特性及光子晶体排列方式的影响。该结构支持2个通带,一个是高于基模截止频率的正向波传播频带;另一个是显著低于基模截止频率的后向波传播频带。因此,在矩形波导E面填充左右手材料光子晶体为小型化波导和小型化滤波器的设计提供了新的思路。     

A Frequency-Stabilized Microwave Band-Rejection Filter Using High Dielectric Constant Resonators

The high permittivity dielectric resonator is a low loss microwave filter element whose size is substantiality less than metal waveguide cavities. Temperature stabilizing their resonant frequency increases the applicability of such elements. A temperature compensated 3-section band-rejection filter using dielectric resonators has been fabricated and tested. The measured electrical performance was comparable to metal waveguide filters and the frequency stability for temperature variations was comparable to brass waveguide cavity filters which are not temperature compensated.     

Band-pass nonlinearities

This paper presents a simple method for analyzing the effect of a nonlinearity sandwiched between band-pass filters, applying it to the case of weak signals when both filters pass the same band of frequencies, and obtaining completely general expressions for the output signal and noise when the output filter passes a harmonic of the input band.     

An NRD fed dielectric rod antenna for the short millimeter wave band

A simple E-plane tapered rectangular dielectric rod fed by NRD guide is used as a millimeter wave antenna. This class of aerial features attractive radiation patterns with relatively low sidelobes and moderate gain. The measured results show that such an antenna and mounting structure can be exploited as effective radiating element in the short millimeter wave frequency band.     

Magnetically tunable rectangular waveguide E-plane integratedcircuit filters

A rigorous field theory method is described for the computer-aided design (CAD) of magnetically tunable E-plane metal-insert filters, where the waveguide sections are symmetrically loaded with ferrite slabs, and for large-gap finlines filters on a ferrite substrate. The design method is based on field expansion in suitably normalized eigenmodes which yields directly the modal scattering matrix of all discontinuities. The theory includes both higher-order mode interaction and the finite thickness of the metal inserts. Optimized data are given for magnetically tunable Ku-band metal insert and finline filter examples. The metal-insert type achieves a tuning range of its operating midband from about 14.1 to 15.7 GHz. The theory is verified by measurements     

Computer aided design for new microwave filter topologies for spatial applications in Ka band

This paper presents, in the first part, an original topologie of dielectric resonators for multilayer filter applications in Ka band. The resonant element is defined by a partially metallized dielectric plate enclosed in a parallelepipedic cavity. This topology allows a high integration in a planar environment type and presents high electrical performances too. It is easily manufactured, and suitable for high frequencies filtering and power applications. In order to realize multipole filters without tuning, a direct electromagnetic optimization method developed in our laboratory is applied. This method combines a electromagnetic software based on the finite element method, and a specific one to establish the identified coupling matrix deducted from the filter responses. Some experiments are performed to verify the theoretical design. In the second part, we consider a new global function which combines filtering and radiating characteristics. For the first time, an opened tuning less two-pole filter defined by two superposed resonators coupled by a metallic iris is designed. Its filtering and radiating functions are optimized in the same time to present required electrical performances.     

An NRD-fed dielectric rod antenna for the short millimeter wave band

A simple E-plane tapered rectangular dielectric rod fed by NRD guide is used as a millimeter wave antenna. This class of aerial features attractive radiation patterns with relatively low sidelobes and moderate gain. The measured results show that such an antenna and mounting structure can be exploited as effective radiating element in the short millimeter wave frequency band.     

同址干扰用电调谐带通滤波器设计

介绍了电调谐滤波器设计原理及在同址干扰中的应用,采用伪梳状线思想对传统结构滤波器进行优化,提出两端均为电容调谐的电调滤波器结构。设计微带线实现的变容管电调谐带通滤波器,对改进后的滤波器性能进行仿真。该文设计的滤波器调节范围为580~900 MHz,在体积上具有一定优势。     

Optimized E-plane bandpass filters with improved stopbandperformance

A computer-aided synthesis technique for E-plane bandpass filters with improved stopband performance is developed. An optimization procedure based on equal ripple optimization is adopted. The design of a symmetrical E-plane bandpass filter with improved stopband performance is considered; higher order mode interaction between E-plane discontinuities is included in the design. The predicted filter performance shows improved stopband performance and reduced filter dimensions compared with conventional E-plane bandpass filters. The validity of the method is confirmed by the measurement of a fabricated five resonator E-plane bandpass filter with improved stopband performance     

基于液晶材料的带宽可重构毫米波滤波器

根据液晶材料在毫米波段良好的介电特性和调谐能力,设计了一款基于液晶材料的毫米波带宽可重构宽带带通滤波器。滤波器使用一个高通滤波器和一个低通滤波器级联实现带通效果;在低通部分加载液晶材料,通过调谐液晶材料的等效介电常数改变低通滤波器的响应频率,实现带宽的可重构。仿真结果表明,当调谐液晶介电常数从2.4变化到3.8时,滤波器的高频截止频率从52 GHz下降至48 GHz,相对带宽从84.9%变为78.3%。     

Efficient implementation of tunable ladder filters using multi-output current controlled conveyors

A methodology to realize continuous-time current-mode tunable ladder filters of any order has been presented. This proposed technique individually simulates signal flow graph (SFG) of each branch element from passive filter prototype using only multi-output second generation current controlled conveyors (MCCCIIs) and grounded capacitors. This leads to simple structure, ease of design and suitability for IC fabrication. A third-order Butterworth low-pass filter, a third-order elliptic low-pass filter and a sixth-order Chebyshev band-pass filter are employed to demonstrate the proposed realization scheme. These simulated filters retain minimum requirement of passive and active elements and provide the filter corner frequency tunability. Moreover, the method allows an implementation of the elliptic filters by simply adding floating capacitors to all-pole filter structures.     

Design of waveguide E-plane filters with all-metal inserts by equalripple optimization

An optimization based approach to the design of E-plane filters is described. An optimization procedure based on Cohn's equal ripple optimization is developed. This vector procedure has several advantages over the general purpose optimization routines previously applied to the design of F-plane filters. The problem of local minima does not arise. Optimization is carried out with respect to the Chebyshev (or minimax) criteria. Less frequency sampling and therefore less calculation of the electrical parameters of E-plane discontinuities is required. The design of a symmetrical F-plane filter is considered. Higher order mode interaction between E-plane discontinuities is not included in the design. For the design example considered this is shown not to be significant. A numerically efficient method, requiring only real scalar arithmetic, for calculating the insertion loss of a symmetrical cascade of lossless symmetrical 2-ports is employed. Measurements on a fabricated filter confirm the accuracy of the design procedure     

小型化三维发夹型LTCC宽带带通滤波器

利用低温共烧陶瓷(LTCC)工艺,通过通孔互联实现了三维结构的发夹型宽带带通滤波器。该结构将谐振单元的横向尺寸转移到z轴方向实现,有效减小了滤波器的尺寸并且谐振器间的耦合系数为传统结构的1.6倍。利用五个谐振器结构实现较宽的频带(>30%)和较好的选择特性。设计并实际制作了中心频率10 GHz的LTCC带通滤波器,3 dB带宽为8.8～12.1 GHz,实测指标与设计仿真结果较为吻合。     

Analysis and realization of L-band dielectric resonatormicrowave filters

High power L-band dielectric resonator microwave filters, used in satellite systems because of their good temperature and vibration characteristics, low weight, and size, are discussed. The electromagnetic and electrical parameters of different microwave dielectric resonator structures are computed by means of the two-dimensional and three-dimensional finite element method, which are applied both for free and forced oscillation systems. The design and response evaluation of an elliptic filter using rectangular dielectric resonators excited in their TM₁₁₀ mode are presented     

A Second-Order Dual X-/Ka-Band Frequency Selective Surface

In this letter, a new technique for designing dual-band frequency selective surfaces with arbitrary bands of operation, with second-order band-pass responses at each band of operation, is presented and experimentally verified. The technique is based on utilizing a particular topology of a second-order band-pass microwave filter and synthesizing its constituting elements using periodic structures with inductive, capacitive, or resonant type surface impedances. The result is a low-profile planar structure composed of three metal and two dielectric layers that acts as a spatial version of the dual-band microwave filter.      

遥测射频监视仪中带通滤波器的设计与实现

介绍遥测射频监视仪中的平行耦合线带通滤波器的设计与实现。该遥测射频监视系统的功能是监控2.5GHz载波频率准确性和稳定性。在阐述平行耦合线带通滤波器设计原理基础上,运用ADS综合射频仿真软件对滤波器的各项性能指标进行分析,并插入陷波器用以克服平行耦合线带通滤波器存在寄生通带的弱点。测试结果表明,该滤波器能很好地完成抑制干扰及噪声的功能,确保监视系统的正常工作。