Excitation of Waveguide by Stripline- and Microstrip-Line-Fed Slots

This paper presents investigations on coupling between stripline/microstrip line and a rectangular waveguide coupled through a slot in the ground plane which is fixed in the cross-sectional plane of the waveguide. A closed-form expression for the impedance loading on stripline/microstrip line is evaluated from knowledge of the complex power flowing down the rectangular waveguide supporting the dominant mode and discontinuity in the modal voltage in stripline/microstrip line. The reactance cancellation is obtained by terminating the stripline/microstrip tine exciting the slot in a short-circuited stub. The structure under this condition forms a transition between stripline/microstrip line and a waveguide. The design curves on slot length versus frequency are presented for different values of dielectric constants. The variation of coupling as a function of frequency and also the location of the slot is evaluated. Numerical results for slot coupling useful for the design of waveguide simulators are also presented.     

Perturbation analysis and modeling of curved microstrip bends

The curved microstrip bend consisting of a microstrip ring segment between two microstrip lines is analyzed for its transmission properties. The microstrip lines are modeled by equivalent ideal magnetic wall waveguides for which the electromagnetic field solutions are known. The field solutions in the microstrip ring segment are derived by using a perturbation analysis of a modified (magnetic wall) curved waveguide model. Other techniques have been formulated to evaluate the fields inside curved metallic waveguides. These include the use of an equivalent nonuniformly loaded straight waveguide and rectangular and annular model analysis. The perturbation solution for the fields in the equivalent curved waveguide model presented is readily adaptable to the mode-matching procedure, and is used to calculate the properties of the curved microstrip bend discontinuities. The frequency-dependent reflection and transmission coefficients of curved microstrip bends are determined and compared with those of the right-angle and chamfered right-angle microstrip bends     

一种新型毫米波集成波导微带转换的分析与设计

提出一种新型集成于单层微带基片的毫米波集成波导微带转换 ,由一圆形微带谐振器、微带共面波导探针组成。利用全波分析软件对该转换器进行了分析计算、优化设计。测试了波导微带转换实物 ,结果表明 ,在Ka波段在 1 GHz频带内 ,该波导微带转换具有较低的插入损耗 ( <0 .4d B)和反射损耗 ( <-1 4d B)。可满足相关毫米波微带集成电路系统的应用要求。     

Millimeter-Wave Transition From Waveguide to Two Microstrip Lines Using Rectangular Patch Element

A millimeter-wave transition from a waveguide to two microstrip lines and the design methodology are proposed. A rectangular patch element in a short-terminated waveguide is analyzed by the cavity model of a patch antenna and the dyadic Green's function of the waveguide. The analysis points out that the rectangular patch element has an optimum width for wideband, which only has the function of the broad wall width of the waveguide. The transition also works as a divider. A numerical investigation of a transition having two microstrip lines validates the analytical model in terms of wideband, and indicates that the distance between the two microstrip lines has an optimum length for suppressing higher order modes. A prototype transition exhibits an insertion loss of 0.5 dB from 76 to 77 GHz, and a bandwidth of 6.9% (5.29 GHz) for the reflection coefficient below -15 dB for the waveguide port     

Circular-waveguide-fed microstrip patch antennas

A microstrip patch antenna fed by a circular waveguide is presented. The microstrip patch built on a foam substrate is laid on the flange of the circular waveguide's open mouth. The waveguide feeds the patch by coupling energy to the patch through a narrow slot underneath the patch. Two operating frequency bands were observed and the characteristics of the antenna were measured.     

一种Ku波段波导-微带转换器的研制

本文利用三维高频仿真软件HFSS设计并分析了中心频率为15GHz的波导一微带过渡结构。这种结构的输入输出是直通方向的,与以往的波导-微带过渡结构相比,这种结构体积小、气密性好、更利于小型化。根据测试结果,设计的过渡结构在13GHz-17GHz频率范围内有良好的性能,插入损耗小于0．5dB,端口驻波系数小于1．35。     

基片集成非辐射介质波导激励电路研究

随着直接在印刷电路板(PCB)或金属化的介质板上制作基片集成非辐射介质(SINRD)波导的概念提出,如何用平面电路的方式激励此种SINRD波导是今后广泛应用SINRD波导电路的要解决的关键技术之一,这是因为这一技术的解决可以为平面多层化毫米波系统在更高频率上的使用打下基础.本文提出了一种利用微带线到槽线过渡结构,然后利用槽线准TEM波主模和SINRD波导LSM11主模的场型相似性,用槽线去激励PCB型SINRD波导的新型馈电结构.通过使用多层结构,电路由两层的ArlonTC600的PCB组成,从微带结构到槽线的过渡电路可以直接焊接在稍薄的板子上.接下来可在接近SINRD波导介质条带的中心位置激励所需的工作模式LSM11模,这种槽线到SINRD波导的配置可以获得更宽的带宽和高度的集成.仿真和实验结果证实了上述观点的正确性.     

The phase center position of a microstrip horn radiating in aninfinite parallel-plate waveguide

In this paper the field radiated by a flared microstrip line in an infinite parallel-plate waveguide with separation between plates of less than half a wavelength is studied. The field at any point of the parallel-plate waveguide is expressed as a summation of modal solutions of the Helmholtz equation. The phase center of the microstrip horn is calculated for uniform amplitude distributions along the horn aperture. The theory may be applied to obtain the phase and amplitude distributions along the output ports of microstrip bootlace lenses     

悬置微带线的过渡设计

设计了一种新型微带-悬置微带线和波导-悬置微带线的过渡结构。此过渡模型工艺简单、尺寸紧凑、加工精度不高,在较宽的频带范围内实现了较好的过渡特性。这种过渡设计可以改善悬置微带电路的应用范围,同其它电路或系统可以更好地综合应用。通过仿真设计和样品测试,在整个Ka频段,波导-悬置微带线过渡结构插入损耗小于0.75 dB。     

A novel surface-mountable millimeter-wave bandpass filter

A novel millimeter-wave waveguide bandpass filter structure suitable for surface mounting is introduced. The filter is constructed using a rectangular waveguide formed in MMIC substrate employing recently introduced microstrip-to-waveguide transducer. Input and output of the filter are implemented as microstrip lines. The transitions between the microstrip lines and the rectangular waveguide are implemented by using the microstrip-to-waveguide transition. The waveguide filter structure is surface-mountable as flip-chip and can be manufactured using a MMIC process that makes it extremely accurate. It has potential applications in millimeter-wave systems like local multipoint distribution system (LMDS) and autonomous cruise control (ACC) radar for automobiles     

一种V波段近距探测毫米波功率放大器设计

介绍了一种用于弹上近距探测系统,工作在非大气窗口波段的功率放大器,该功放基于MMIC实现电路设计,采用端口驻波较好的两路电桥,由多级级联实现功率合成,波导到微带采用两路微带探针经波导E面插入,完成波导立体传输线与微带集成传输线间的过渡转换,同时又实现同相宽带功率分配/合成。实际的测试表明,在工作带宽内,指标满足设计要求...     

Full-wave analysis of waveguide-to-microstrip transitions for millimeter wave applications

A “full-wave” solution is presented for the waveguide to microstrip transition. The exact Green's function of the transition is used in a moment method procedure. The behavior of the microstrip transition to a rectangular waveguide is studied with respect to the critical dimensions of the microstrip width, length and backshort location. The convergence characteristics of the full wave analysis method are investigated, along with the current distribution and the input impedance. Results given for the return loss is compared with measurements.     

Millimeter-wave waveguide-based out-of-phase power divider/combiner using microstrip antenna

A millimeter-wave waveguide-based out-of-phase power divider/combiner using microstrip patch antenna has been proposed in this paper. The stepped rectangular waveguide provides smooth impedance matching from standard rectangular waveguide to oversized rectangular waveguide. In order to obtain good amplitude balance, four symmetrical microstrip patch antennas are utilized. A Ka-band four-way passive power combiner is designed and measured. The measured results show a reasonable agreement with the simulated ones.     

一种X 波段磁场耦合式波导-微带转换结构

波导-微带转换器是微波集成电路和天馈线系统中的重要器件。结合具体应用,设计了一款新型、宽带磁耦合式波导-微带转换器。和传统结构相比,本设计用双层的贴片结构代替金属块状阶梯脊,通过在贴片上加载金属过孔来展宽转换的带宽;将阶梯状金属贴片和微带探针一体化设计,从而避免了焊接带来的损耗和结构不稳定,并且减小了加工难度,降低了重量和成本。测试结果表明,波导-微带转换器的两个端口在8.85～11.52GHz 的频带内回波损耗小于-15 dB,插入损耗约为0.8dB,均满足应用需求。     

Space domain analysis of micro-IDG structures

The microstrip loaded inset dielectric waveguide has been proposed as a transmission medium alternative to microstrip, and as a useful antenna medium at X-band and millimetric frequencies. In the present analysis we consider the case where a multi-layer, multi-conductor microstrip circuit may be housed within inset dielectric waveguide. A generalised transverse resonance diffraction method is developed in the space domain for analyzing such structures. Experimental and theoretical results for the propagation characteristics of the fundamental and first higher order mode of a few different configurations are presented showing good agreement     

Curvature effect in microstrip ring resonators

A planar waveguide model for microstrip is used to obtain an improved method of correcting for curvature effects in ring resonators. The extent of the improvement is illustrated by a comparison of experimental measurements and theoretical predictions of microstrip dispersion.     

A Ku-BAND WAVEGUIDE FREQUENCY MULTIPLIER USING HARMONIC-REJECTION MICROSTRIP PATCH TRANSITIONS

A compact frequency multiplier waveguide module is built by placing a planar microstrip section between two rectangular waveguides. The size of the microstrip section is minimized by eliminating all harmonic band-rejection filters. Special feed locations for the input waveguide-to-microstrip transition patches provide the second-harmonic rejection at the input, and a balanced circuit configuration formed with a pair of transistors produces the pump signal cancellation at the output. The measurements on a fully-assembled waveguide module showed a peak frequency conversion gain of-2.3 dB at 16.7 GHz with the associated output power level of 6 dBm.     

Dissipation Loss Effects in Isolated and Coupled Transmission Lines

This paper describes a computer-aided analysis of dissipation losses in uniform isolated or coupled transmission lines for microwave and millimeter-wave integrated-circuit applications. The analysis employs a quasi-TEM model for isolated transmission lines and for the even- and odd-mode transmission lines associated with coupled-line structures. The conductor and dielectric losses are then related to equivalent charge density distributions, which are evaluated using a method-of-moments solution. The transmission lines treated by this analysis may contain any number of Iossy conductors and inhomogeneous dielectrics, consisting of any number of different homogeneous dielectric regions. A development is provided to explicitly relate the four-port terminal-electrical performance of directional couplers to evaluated even- and odd- mode loss coefficients. Examples of evaluated losses are presented in graphical form for isolated lines of inverted microstrip and trapped inverted microstrip and edge-coupled microstrip with a dielectric overlay. The analysis accuracy has been confirmed using microstrip and coplanar waveguide configurations. A comparison is made of the total loss characteristics for microstrip, coplanar waveguide, inverted microstrip, and trapped inverted microstrip. Calculations are compared with measurements for the coupled-line structure. Accuracy of the solution and suggested refinements are discussed. Five computer programs are documented.     

Electromagnetic coupling of coplanar waveguides and microstriplines to highly lossy dielectric media

The spectral-domain technique is utilized to analyze the coupling characteristics of coplanar waveguides and microstrip lines coupled with multilayer lossy dielectric media. Numerical results illustrating the dispersion characteristics of coplanar and microstrip lines, as well as the various electric field components coupled to highly lossy dielectric media, are presented. It is shown that the presence of a superstrate of lossless dielectric between the coplanar waveguide and the lossy medium plays a key role in setting up an axial electric field component that facilitates leaky-wave-type coupling to the lossy medium. The thickness of the superstrate relative to the gap width in the coplanar waveguide is important in controlling the magnitude of this axial electric field component. The coupling characteristics of the microstrip and coplanar lines are compared, and results generally show improved coupling if coplanar waveguides are utilized. Values of the attenuation constant α are higher for coplanar waveguide than for microstrip line, and for both structures α decreases with frequency     

Integrated microstrip and rectangular waveguide in planar form

Usually transitions from microstrip line to rectangular waveguide are made with three-dimensional complex mounting structures. In this paper, a new planar platform is developed in which the microstrip line and rectangular waveguide are fully integrated on the same substrate, and they are interconnected via a simple taper. Our experiments at 28 GHz show that an effective bandwidth of 12% at 20 dB return loss is obtained with an in-band insertion loss better than 0.3 dB. The new transition allows a complete integration of waveguide components on substrate with MICs and MMICs