Preface Introduction Conventional Coplanar Waveguide Conductor-Backed Coplanar Waveguide Coplanar Waveguide with Finite-Width Ground Planes Coplanar Waveguide Suspended Inside A Conducting Enclosure Coplanar Striplines Microshield Lines and Coupled Coplanar Waveguide Attenuation Characteristics of Conventional, Micromachined, and Superconducting Coplanar Waveguides Coplanar Waveguide Discontinuities and Circuit Elements Coplanar Waveguide Transitions Directional Couplers, Hybrids, and Magic-Ts Coplanar Waveguide Applications References Index

Coplanar waveguide circuits, components, and systems

A new type of monolithic planar transmission line, the microshield line, is proposed. This line can operate without the need for via-holes or the use of air-bridges for ground equalization. Furthermore, it has shown the tendency to radiate less than the conventional microstrip or coplanar waveguide (CPW) and can provide a wide range of impedances due to the many available parameters for design. The space domain integral equation method is used to analyze four different discontinuities of the proposed type. A comparison to conventional CPW with respect to radiation shows very good performance. >

Study of a novel planar transmission line

A two-dimensional finite-difference-time-domain (FDTD) method is proposed for the full-wave analysis of arbitrarily shaped guided wave structures. By using a phase shift beta Delta z along the z-direction (propagation direction), and assuming the limiting case of Delta z approaching zero, the propagation constant of hybrid modes is calculated using a two-dimensional mesh with a truly two-dimensional grid. When the field equation is multiplied by an additional factor j, only real variables are needed in the computation, leading to a very fast algorithm. >

An efficient 2-D FDTD algorithm using real variables (guided wave structure analysis)

A significantly improved two-dimensional finite-difference time-domain (FDTD) method is proposed for the full-wave analysis of guided wave structures. By using a phase shift beta Delta z along the z-direction (propagation direction) and assuming the limiting case of Delta z, the propagation constant of hybrid modes can be calculated by using a two-dimensional mesh with a truly two-dimensional grid size. By appropriately arranging variables, only a real impulse response is involved. A novel grading scheme allowing a gradually nonequidistant mesh in three dimensions is introduced. >

An improved 2D-FDTD algorithm for hybrid mode analysis of quasi-planar transmission lines

The authors present a novel full-wave mode-matching approach to accurately analyze the dispersion characteristics of millimeter-wave and microwave transmission lines with finite conductivity, metallization thickness, and holding grooves. The approach is quite general, but only the results for a unilateral finline are presented. The accuracy of the solution depends primarily on the correct and complete description of eigenfunction expansions in each of the uniform (stratified) or nonuniform layer regions. The latter consists of metallized strips of finite conductivity, which in turn produce the so-called metal modes (eigenmodes). The metal mode exists in the metallized region with high conductivity for the most part and decays sharply in the air region. Without incorporating the metal modes, the convergence studies will fail and the accuracy of the field theory solution deteriorates. Since the accuracy of the proposed approach is established, the composite effects of the finite conductivity and metallization thickness can be studied rigorously. >

https://ir.nctu.edu.tw:443/bitstream/11536/3953/1/A1990EQ45600002.pdf

Full-wave analysis of lossy quasi-planar transmission line incorporating the metal modes

A quasi-planar structure, the nonsymmetrically shielded coplanar waveguide (NSCPW), is proposed as a quasi-TEM transmission line with advantageous characteristics for millimeter-wave circuit applications. Advantages in terms of broadband behavior and ease of machining, as well as device mounting and substrate mounting, are pointed out. An experimental method is developed which allows the evaluation of the transmission line spectrum in a very wide frequency band (15:1) with a single transmission measurement. The experimentally evaluated propagation characteristics of the dominant and higher order modes are shown to be in excellent agreement with the theoretical predictions based on the generalized transverse resonance technique. This method is also used for an extensive characterization of the structure in terms of characteristic impedance and useful frequency band. >

Theoretical and experimental characterization of nonsymmetrically shielded coplanar waveguides for millimeter-wave circuits

The nonsymmetrically shielded coplanar waveguide (NSCPW) is proposed as a quasi-TEM (transverse electromagnetic) transmission line with advantageous characteristics for millimeter-wave circuit applications. The structure combines properties of the finline and the suspended stripline. In addition to a full-wave theoretical analysis, an experimental technique has been developed which enables the transmission line spectrum to be evaluated in a wide frequency band (15:1) with a single transmission measurement. Results are shown to be in excellent agreement with theoretical predictions. Design curves are also presented. >

Theoretical and experimental characterization of nonsymmetrically shielded coplanar waveguides for millimeter wave circuits

A rigorous theoretical approach is used to characterize quasi-planar transmission lines for millimeter-wave applications. The method takes into account the finite metallization thickness and the presence of grooves for holding the substrate into the housing. An experimental method that allows the characterization of the structures in terms of dominant and higher order modes by a single broadband transmission measurement is considered. Experiments performed on an experimental transmission line consisting of a coplanar waveguide inserted into a nonsymmetrical housing are discussed. This structure offers some advantages over finlines and suspended striplines. Experiments have been performed in the 0.5-15.0 GHz range and are in excellent agreement with theoretical predictions. >

http://ieeexplore.ieee.org/iel2/806/1835/00050141.pdf

U. Goebel

Papers

Theoretical and experimental characterization of nonsymmetrically shielded coplanar waveguides for millimeter-wave circuits

Theoretical and experimental characterization of nonsymmetrically shielded coplanar waveguides for millimeter wave circuits

Theoretical and experimental characterization of integrated millimeter wave structures