Dielectric Waveguide Microwave Integrated Circuits---An Overview

An integrated circuit technique for microwave and millimeter wavelengths which uses refractive-type waveguides and signal processing coupled with planar integration techniques characteristic of microstrip microwave integrated circuits (MIC's) is described. Following a comparison of the optical and millimeter approaches to this circuit technique, a discussion of transmission lines and components for millimeter wavelengths is presented. System applications are also described.     

A compact manufacturable 76-77-GHz radar module for commercial ACCapplications

The design and measured results of a single-substrate transceiver module suitable for 76-77-GHz pulsed-Doppler radar applications are presented. Emphasis on ease of manufacture and cost reduction of commercial millimeter-wave systems is employed throughout as a design parameter. The importance of using predictive modeling techniques in understanding the robustness of the circuit design is stressed. Manufacturing techniques that conform to standard high-volume assembly constraints have been used. The packaged transceiver module, including three waveguide ports and intermediate-frequency output, measures 20 mm×22 mm×8 mm. The circuit is implemented using discrete GaAs/AlGaAs pseudomorphic high electron mobility transistors (pHEMTs), GaAs Schottky diodes, and varactor diodes, as well as GaAs p-i-n and pHEMT monolithic microwave integrated circuits mounted on a low-cost 127-μm-thick glass substrate. A novel microstrip-to-waveguide transition is described to transform the planar microstrip signal into the waveguide launch. The module is integrated with a quasi-optical antenna. The measured performance of both the component parts and the complete radar transceiver module is described     

A uniplanar compact photonic-bandgap (UC-PBG) structure and itsapplications for microwave circuit

This paper presents a novel photonic bandgap (PBG) structure for microwave integrated circuits. This new PBG structure is a two-dimensional square lattice with each element consisting of a metal pad and four connecting branches. Experimental results of a microstrip on a substrate with the PEG ground plane displays a broad stopband, as predicted by finite-difference time-domain simulations. Due to the slow-wave effect generated by this unique structure, the period of the PBG lattice is only 0.1λ₀ at the cutoff frequency, resulting in the most compact PEG lattice ever achieved. In the passband, the measured slow-wave factor (β/k₀) is 1.2-2.4 times higher and insertion loss is at the same level compared to a conventional 50-Ω line. This uniplanar compact PBG (UC-PBG) structure can be built using standard planar fabrication techniques without any modification. Several application examples have also been demonstrated, including a nonleaky conductor-backed coplanar waveguide and a compact spurious-free bandpass filter. This UC-PBG structure should find wide applications for high-performance and compact circuit components in microwave and millimeter-wave integrated circuits     

X波段基片集成波导带通滤波器的设计

基片集成波导是一种具有低差损、低辐射、高品质因数的新型平面导波结构.文中利用基片集成波导结构设计并制作了一种x波段的带通滤波器,该滤波器易与其它微波平面电路集成.实测结果表明,该滤波器的中心频率是9.58 GHz,相对带宽是8.35%,通带内的插入损耗是3.8 dB,回波损耗＜-15 dB.     

Equivalent circuit modeling of losses and dispersion in single andcoupled lines for microwave and millimeter-wave integrated circuits

Losses and dispersion in open inhomogeneous guided-wave structures such as microstrips and other planar structures at microwave and millimeter-wave frequencies and in MMICs (monolithic microwave integrated circuits) have been modeled with circuits consisting of ideal lumped elements and lossless TEM (transverse electromagnetic) lines. It is shown that, given a propagation structure for which numerical techniques to compute the propagation characteristics are available, an equivalent circuit whose terminal frequency and time-domain properties are the same as the structure can be synthesized. This is accomplished by equating the network functions of the given single or coupled line multiport with that of the model and extracting all the parameters of the equivalent circuit model by using standard parameters identification procedures. This model is valid over a desired frequency range and can be used to help design both analog and digital circuits consisting of these structures and other active and passive elements utilizing standard CAD (computer-aided design) programs. To validate the accuracy and usefulness of the models, results for a mismatched 50-Ω line in alumina and a high-impedance MMIC line stub are included     

A Broadband Substrate Integrated Waveguide (SIW) Planar Balun

A broadband planar balun is presented in this work that makes use of a substrate integrated waveguide (SIW) technique using a printed circuit board process. The proposed balun structure is able to operate at millimeter wave frequencies and it does not require any tight line coupling sections as frequently used in monolithic microwave integrated circuit balun design. In addition, this balun can be integrated with other planar topologies including nonplanar circuits made of the same substrate for achieving high efficiency. This balun structure consists of a 3 dB SIW power divider and microstrip lines that are placed on both sides of the substrate at balanced ports to obtain an 180deg phase shift. The concept is validated by simulations and measurements. Our measured results suggest that a 10 dB return loss at unbalanced port can easily be achieved across a 42% bandwidth from 19 to 29 GHz. Measured amplitude and phase imbalance between two balanced ports are within 1 dB and plusmn5deg, respectively.     

24-GHz Frequency-Modulation Continuous-Wave Radar Front-End System-on-Substrate

Design and implementation of a 24-GHz frequency-modulation continuous-wave radar front-end system is presented and discussed, and its hybrid planar and waveguide building blocks are fully integrated on one single substrate. A flexible and compact integration methodology on the basis of the substrate-integrated-circuits concept is deployed to design such a microwave front-end system-on-substrate. In this study, it is found that this surface-volume hybrid integration scheme not only enables the complete system integration of planar and nonplanar microwave circuits, but also combines respective advantages of such structures in connection with microstrip lines (planar) and waveguides (nonplanar). Design strategies of the system building blocks including mixers, power dividers, and antenna arrays are discussed together along with the measured results. To verify the developed radar prototype, laboratory-based target-range measurements are conducted.     

Newly Proposed Vertically Installed Planar Circuit and its Application

In this paper, a newly proposed vertically installed planar circuits are described. This circuits were developed for the purpose to make low cost microwave circuit in mass production. As examples, 3 dB-directional coupler and filters are described together with their applications.     

Theoretical analysis of integrated collimating waveguide lens

An integrated collimating waveguide lens is analyzed for applications which require the focusing of an optical beam onto the waveguide of a planar lightwave circuit. The lens has a refractive index profile which is parabolically graded as a function of height to focus light in the vertical plane, and has a convex front face to focus light in the horizontal plane. Analysis based on the propagation of a Gaussian field is used to design a lens pair which minimizes the optical loss for a given propagation length. The beam propagation method is used to identify fabrication tolerances which may have impact on the performance of the lens pair. The lens pair has application in micro-optoelectromechanical (MOEM) switches based on planar optical waveguide circuits.     

Hybrid integration technology of planar circuits and NRD-guide forcost-effective microwave and millimeter-wave applications

An architecture called the hybrid planar/non-radiative-dielectric (NRD) waveguide integrated technology is proposed as a building block for constructing microwave and millimeter-wave circuits. This hybrid approach of integration offers a unique possibility of exploiting inherent complementary advantages of planar structures and NRD waveguides for low-cost wireless applications while eliminating the potential drawbacks associated with both dissimilar structures. Compared to the existing NRD-guide related technology, the proposed framework consists of relocated planar structures on the top and/or the bottom plates of an NRD-guide, sharing the common ground planes. Such a hybrid scheme is particularly suitable for millimeter-wave systems in which active devices can be made with the planar-line technique while passive components can be made with the NRD-guide technique. The two subsets of a complete functional system are interconnected through a class of aperture-based transitions which can be designed to have wide-band performance. In addition, the multichip module (MCM) technique is readily achieved under this proposed scheme. Experimental prototypes, including passive-component and active-device, based on the new hybrid technology presented in this paper, show that the novel hybrid technology promises to be useful in the design of future microwave and millimeter-wave circuits and systems     

Adjustable microstrip transformer for use with Josephson devices in mm-wave ICs

A simple remotely adjustable cryogenic impedance transformer employing superconducting inverted microstrip circuits is described. The scheme is particularly suitable for efficiently coupling low impedance (0.1?5 ?) thin-film devices (e.g. Josephson junctions) in planar microwave integrated circuits to waveguide or other superconducting and semiconducting devices at millimetre wavelengths. Preliminary results obtained at 8 mm are presented.     

Uniplanar techniques for monolithic microwave integrated circuits

`Uniplanar' techniques have recently been introduced for the design of monolithic microwave integrated circuits (MMICs). The aim of these techniques is to achieve a higher level of integration of circuitry and to overcome the need for through-substrate via holes and the related back-face processing steps. This is achieved by using coplanar waveguide (CPW), slotline, and miniature `thin-film microstrip' transmission-line media as opposed to conventional microstrip. The design and performance of a number of uniplanar MMIC couplers, amplifiers, and other test circuits fabricated using the GEC-Marconi (Caswell) foundry are described     

Application of the FD-TD method to the analysis of circuitsdescribed by the two-dimensional vector wave equation

A class of microwave circuits described by a two-dimensional vector wave equation is defined. It is proposed to refer to them as vector two-dimensional or 2-DV circuits to distinguish them from circuits described by a two-dimensional scalar wave equation (typically referred to as 2-D circuits). It is shown that the 2-DV class contains some planar circuits filled with anisotropic media, two-dimensional waveguide discontinuities, and circular waveguide discontinuities. Calculation of dispersion characteristics of inhomogeneously filled hollow waveguides is an eigenvalue problem belonging to the 2-DV class. Application to the finite-difference-time-domain (FDTD) method to the analysis of 2-DV circuits is described. Examples show the efficiency of the method for several types of circuit     

E-Plane Integrated Circuit Filters with Improved Stopband Attenuation (Short Papers)

Improved stopband attenuation is achieved by thick strips, by reduced waveguide sidewall dimensions, and by double planar integrated circuits. In contrast to thick strips which may cause high passband insertion losses and filters with reduced waveguide dimensions which require additional tapers, double planar E-plane integrated circuit filters combine the advantages of low costs, high stopband, and low passband insertion losses. Computer-aided design of a four-resonator Ka -band double metal insert filter achieves a calculated stopband attenuation between 40 and 60 GHz of more than 50 dB, the calculated minimum passband insertion loss is 0.43 dB (measured 1.8 dB). Higher order mode excitation and finite thicknesses of the inserts are included in the calculations.     

共面紧凑型微波光子晶体在共面波导中的应用

提出一种地平面刻蚀共面紧凑型微波光子晶体(PBG)的共面波导结构,介绍了微波光子晶体的基本单元结构,并设计出具有90°弯折的共面波导样品.使用矢量网络分析仪测试该结构的散射参数,测量结果显示,其传输特性比普通的共面波导在高频部分具有较大的提高.同时,相比于传统的三维微波光子晶体,该结构具有导体损耗小,加工工艺简单,便于应用于光电封装和单片微波集成电路的特点.

Abstract：

A novel coplanar waveguide using coplanar compact microwave photonic-handgap (PBG) structure is proposed. The basic unit of microwave PBG structure is introduced and a waveguide sample with a 90 degree break is designed. Testing results obtained through vector network analyzer display an obvious promotion in transmission parameter, especially in the high frequency part. Meanwhile, compared with the common 3-dimension microwave PBG structure, this structure with a low conductor loss can be processed with standard planar fabrication technology, which makes it applicable in opto-electronic package and monolithic microwave integrated circuit (MMIC).     

Spectral domain analysis of eigenmodes in a shielded multilayer coplanar waveguide for microwave and millimeter-wave integrated circuits

Coplanar waveguide has found increasing use in microwave and millimeter-wave integrated circuits, and a knowledge of its eigenmodes is very useful for circuit design. In this paper, we determine the dispersion properties of the eigenmodes in a shielded multilayer coplanar waveguide using the spectral domain approach. Numerical results of the propagation constants for different combinations of dielectric materials are presented to illustrate the behaviors of the eigenmodes.     

The Design of Planar Circulators for Wide-Band Operation

The stripline circulator used in microwave integrated circuits (MIC) is considered one of ferrite planar circuits (two-dimesional circuits). We investigated the optimum shape of a planar circulator for wide-band operation, perceiving the wider freedom of the planar structure in circuit design. The wide-band planar circulator, designed using the powerful contour-integral method is triangular shaped with slightly concave sides. The 20-dB isolation fractional bandwidth of the designed circulator is about 52 percent.     

An improved GaAs MESFET equivalent circuit model for analog integrated circuit applications

An improved equivalent circuit model of a gallium-arsenide (GaAs) MESFET that is optimized for the design and analysis of precision analog integrated circuits is described. These circuits entail different modeling requirements from digital or microwave circuits, for which existing equivalent circuit models are optimized. Improved techniques are presented to model the drain-to-source conductance, device capacitance, and the functional dependence of drain-to-source current.     

Application of MIC Formulas to a Class of Integrated-Optics Modulator Analyses: A Simple Transformation (Short Papers)

Modulation electric fields in a class of planar, lumped-parameter circuit or traveling-wave-type electrooptic modulators in integrated optics are analyzed by applying a simple transformation of variables to presently available formulas on microwave integrated circuits (MIC's). Example calculations are shown.     

Planim: a new concept in the design of MIC filters

The planar circuit approach for the characterisation of microstrip circuits is combined with the image parameter method to give a new powerful technique for integrated circuit filter design (planim). The inclusion of two-dimensional effects in the synthesis procedure makes the planim approach particularly suited for monolithic microwave circuits. The design of microstrip filters with extremely wide stopbands is shown as an example.