Showing papers on "Coplanar waveguide published in 1993"
TL;DR: In this article, an uniplanar crossover hybrid-ring coupler using a coplanar waveguide (CPW) and slotline provides substantially improved amplitude and phase characteristics over a broad bandwidth compared to conventional microstrip hybrid ring couplers.
Abstract: Novel uniplanar 180 degrees and 190 degrees hybrids suitable for MIC and MMIC applications are described. The uniplanar crossover hybrid-ring coupler using a coplanar waveguide (CPW) and slotline provides substantially improved amplitude and phase characteristics over a broad bandwidth compared to conventional microstrip hybrid-ring couplers. Experimental results show that the new coupler has a bandwidth of more than one octave from 2 GHz to 4 GHz with a +or-0.4-dB power dividing balance and a +or-1 degrees phase balance. A uniplanar two-branch directional coupler using a coupled rectangular slotline ring has also been developed. CPW-to-slotline transitions using uniform and nonuniform CPWs or slotlines are also discussed. These transitions are uniplanar and simple to fabricate. No via-holes are needed for ground connections, and integration with solid-state devices is easy. A pair of broadband transitions using CPW shorts and slotline radial stubs is demonstrated with a 1-dB bandwidth of more than 5.2:1. >
142 citations
TL;DR: In this article, a method for the characterization of transmission lines fabricated on lossy or dispersive dielectrics is introduced, which is more accurate than conventional techniques, and is used to examine the resistance, inductance, capacitance, and conductance per unit length of coplanar waveguide transmission lines.
Abstract: A method for the characterization of transmission lines fabricated on lossy or dispersive dielectrics is introduced. The method, which is more accurate than conventional techniques, is used to examine the resistance, inductance, capacitance, and conductance per unit length of coplanar waveguide transmission lines fabricated on lossy silicon substrates. >
134 citations
TL;DR: In this paper, the authors describe the design and performance of shunt inductively coupled bandpass filters implemented on an open coplanar waveguide, which exhibits low radiation loss due to the removal of the capacitively coupled gaps encountered in end or edge coupled filters.
Abstract: This paper describes the design and performance of shunt inductively coupled bandpass filters implemented on an open coplanar waveguide. This new structure exhibits low radiation loss due to the removal of the capacitively coupled gaps encountered in end or edge coupled filters. Unloaded Qs greater than 540 have been achieved in unshielded single section resonators at 4 GHz on very thin substrates. These high Qs enable the design of filters with low insertion loss and good stopband rejection. Applications include low insertion loss, high and printed filters where no screening is required, low noise oscillators and superconducting filters. >
118 citations
TL;DR: In this paper, a finite-width conductor-backed coplanar waveguide (FW-CBCPW) through line is placed within a test fixture commonly used in laboratories, and the scattering parameters of the through line are obtained theoretically by approximating the FW- CBCPW as a simple system of coupled transmission lines.
Abstract: This paper presents theoretical and experimental results for a finite-width conductor-backed coplanar waveguide (FW-CBCPW). The guiding characteristics of FW-CBCPW are investigated first by the rigorous method of mode matching. An FW-CBCPW through line is then placed within a test fixture commonly used in laboratories, and the scattering parameters of the through line are obtained theoretically by approximating the FW-CBCPW as a simple system of coupled transmission lines. Experimental results are shown to agree very well with the theoretical ones. In particular, the anomalous behavior observed in the transmission characteristic of the through line is related to the resonant phenomenon of the terminated side planes which are short-circuited at both input and output ends due to the test fixture. Finally, a technique of mode suppression in the side-plane regions is suggested for the improvement of signal transmission over a broad band of frequency spectrum. The effects of extra higher order modes on the transmission characteristics at high frequencies are also discussed. >
100 citations
Patent•
26 Mar 1993TL;DR: In this paper, a passive semiconductor structure for reduction of the mutual capacitance between parallel conductors is proposed, with two parallel conductor separated from a substrate by a first dielectric layer and covered by a second dielectoric layer.
Abstract: A passive semiconductor structure for reduction of the mutual capacitance between parallel conductors, with two parallel conductors separated from a substrate by a first dielectric layer and covered by a second dielectric layer. The second dielectric layer having a cavity formed between these conductors, whereby the effective relative dielectric constant of the medium between these conductors is reduced.
76 citations
01 Oct 1993
TL;DR: In this article, the effects of parasitic dielectric resonators on the HE (sub 11 sigma) and HE (high efficiency) (sub 13 sigma), modes of a cylindrical DRA have been studied.
Abstract: The effects of parasitic dielectric resonators on the HE (sub 11 sigma) and HE (High Efficiency) (sub 13 sigma) modes of a cylindrical dielectric resonator antenna (DRA) have been studied. The DRA was excited electromagnetically with a grounded coplanar waveguide through an aperture in the common ground plane. Strong couplings were observed for the HE (sub 11 sigma) mode with the parasitic element superimposed on the driven DRA, and for the HE (sub 13 sigma) mode with parasitic elements placed on both sides of the driven DRA. Results indicate significant enhancement in bandwidth for both modes, and good radiation patterns for the HE (sub 11 sigma) mode.
73 citations
Patent•
27 Apr 1993TL;DR: In this article, a transition between a waveguide and transmission line is disclosed in which a probe portion (12) of the transmission line extends into the waveguide to electrically field couple signals.
Abstract: A transition between a waveguide (1) and transmission line (2) is disclosed in which a probe portion (12) of the transmission line extends into the waveguide to electrically field couple signals between the waveguide and transmission line. The transmission line is preferably a coplanar type and includes a substrate (8) having conductors (14) disposed therein which prevent energy from propagating into the substrate from the waveguide. Propagation of energy into the desired transmission line mode is therefore facilitated. Because the probe is formed as an integral part of the transmission line, direct coupling to the waveguide is possible without the use of intervening sections, transitions or transmission lines. The transition may be scaled in order to couple a wide range of frequencies.
70 citations
14 Jun 1993
TL;DR: In this paper, eight novel coplanar waveguide (CPW) to slotline transitions using uniform and non-uniform CPWs or slotlines are discussed, and a pair of broadband transitions using CPW shorts and slotline radial stubs is demonstrated with a 1-dB bandwidth of more than 5.2:1.
Abstract: Eight novel coplanar waveguide (CPW) to slotline transitions using uniform and nonuniform CPWs or slotlines are discussed. These transitions are uniplanar and simple to fabricate. No via-holes are needed for ground connections, and integration with solid-state devices is easy. A pair of broadband transitions using CPW shorts and slotline radial stubs is demonstrated with a 1-dB bandwidth of more than 5.2:1. >
54 citations
TL;DR: In this paper, a general technique to characterize asymmetric coplanar waveguide (CPW) discontinuities with airbridges is presented, where both the fundamental coplanars and slotline modes may be excited together.
Abstract: A general technique to characterize asymmetric coplanar waveguide (CPW) discontinuities with airbridges where both the fundamental coplanar and slotline modes may be excited together is presented. First, the CPW discontinuity without airbridges is analyzed using the space-domain integral equation (SDIE) approach. Second, the parameters (phase, amplitude, and wavelength) of the coplanar and slotline modes are extracted from an amplitude modulated-like standing wave existing in the CPW feeding lines. Then a 2n*2n generalized scattering matrix of the n-port discontinuity without airbridges is derived which includes the occurring mode conversion. Finally, this generalized scattering matrix is reduced to an n*n matrix by enforcing suitable conditions at the ports which correspond to the excited slotline mode. For the purpose of illustration, the method is applied to a shielded asymmetric short-end CPW shunt stub, the scattering parameters of which are compared with those of a symmetric one. Experiments are performed on both discontinuities and the results are in good agreement with theoretical data. The advantages of using airbridges in CPW circuits as opposed to bond wires are also discussed. >
52 citations
14 Jun 1993
TL;DR: In this paper, a new leaky, dominant mode may be present on conductor-backed coplanar strips at the same time as the conventional bound dominant mode, and the frequency range over which both modes can propagate simultaneously increases as the strips become wider, and can be quite large even for fairly narrow strips.
Abstract: Contrary to expectations, the authors recently found that a new leaky, dominant mode may be present on conductor-backed coplanar strips at the same time as the conventional bound dominant mode. The frequency range over which both of these modes can propagate simultaneously increases as the strips become wider, and can be quite large even for fairly narrow strips. These new features, which could affect circuit performance significantly, have been derived theoretically and verified by measurements. >
43 citations
14 Jun 1993
TL;DR: An experimental comparison of coax launchers versus wafer probe excitation of a 10-mil conductor backed CPW (coplanar waveguide) is presented in this article, where the transition effect from the coax launcher onto the CPW was modeled numerically, and good agreement with measured data was found.
Abstract: An experimental comparison of coax launchers versus wafer probe excitation of a 10-mil conductor backed CPW (coplanar waveguide) is presented. It was found that conductor backing of a CPW can cause a serious moding problem when a coax launcher is used. Introducing via holes can eliminate this problem to some degree. In comparison, wafer probe excitation generally shows a better response but the back metallization causes some moding problems. The transition effect from the coax launcher onto the CPW was modeled numerically, and good agreement with measured data was found. >
TL;DR: In this paper, the effects of coplanar feed lines and of E-plane cavity walls on the performance of infinite arrays of dipoles printed on protruding dielectric substrates are investigated.
Abstract: The effects of coplanar feed lines and of E-plane cavity walls on the performance of infinite arrays of dipoles printed on protruding dielectric substrates are investigated. In order to do so, two unit cell configurations are studied: (1) the dipole element fed by coplanar transmission lines and (2) the dipole element fed by coplanar transmission lines with finite-height metallic walls added parallel to the H-plane of the array. The element active impedances are calculated for these configurations, and they are compared with those obtained from arrays of dipoles without coplanar feed lines. Effects of the dielectric substrate permittivity and of its thickness on the array element active impedance are included. The results show that the arrays of dipoles with the coplanar feed lines exhibit feed-line-induced blindnesses which reduce considerably the scan volume of the array. It is also shown that these feed line effects are reduced for thicker or higher permittivity substrates, and that the insertion of electric walls is one possible avenue for eliminating these anomalies. >
TL;DR: In this article, three types of coplanar waveguide/slotline baluns, suitable for monolithic integrated circuits, are designed and characterized to 40 GHz, using microwave wafer probes.
Abstract: Three types of coplanar waveguide/slotline baluns, suitable for monolithic integrated circuits, are designed and characterized to 40 GHz, using microwave wafer probes. The results from each are compared, and methods of biasing the slotline discussed. >
TL;DR: In this article, a finite-length two-wire transmission line is analyzed and closed-form expressions for inductive endfringing and interaction between ends are derived for microwave configurations.
Abstract: Magnetostatic analysis of a finite-length two-wire transmission line yields simple closed-form expressions for inductive end-fringing and interaction between ends. A further argument relates the results to capacitive end effects. Application to microstrip-like lines, twin-strip line and coplanar waveguide is outlined. It is demonstrated by explanation and comparison with the literature that these effects are the dominant discontinuity elements in short lengths of line, vias, resonators, bends, and other basic microwave configurations. >
14 Jun 1993
TL;DR: In this article, experimental results on microshield stepped-impedance filters and transitions to grounded coplanar waveguide are presented, showing potential for improved performance relative to current planar transmission line geometries.
Abstract: Experimental results on microshield stepped-impedance filters and transitions to grounded coplanar waveguide are presented. Microshield shows potential for improved performance relative to current planar transmission line geometries. The filter response compared very well with ideal transmission line theory when effective line length corrections for impedance steps were used. The best transition performance demonstrates an S/sub 11/ below -15 dB from 20 to 40 GHz. The fabrication and design of the transitions and filters are also discussed. >
TL;DR: In this article, a new direct method of computing the electromagnetic field patterns surrounding the conductor-backed coplanar waveguide (CPW) structure is proposed, based on a new technique which employs a series of inverse conformal mappings to transform a known field pattern from a rectangular structure back into the CPW structure in order to obtain its unknown field pattern directly.
Abstract: A new direct method of computing the electromagnetic field patterns surrounding the conductor-backed coplanar waveguide (CPW) structure is proposed. Analytical closed-form expressions describing the quasi-TEM field pattern in both the air and the dielectric substrate for conductor-backed CPW's are presented. This approach is based on a new technique which employs a series of inverse conformal mappings to transform a known field pattern from a rectangular structure back into the CPW structure in order to obtain its unknown field pattern directly. A computer program based on this method has demonstrated the speed at which the fields can be plotted compared to existing methods which require repetitive application. Graphical results of these field patterns are presented as a function of the CPW's geometry and dielectric substrate thickness. These held maps which have been directly drawn with true curvilinear squares enable the determination of power flow density, since the same power flows through each square. This direct method of characterizing the power flow density throughout the CPW structure could become an important design tool for the modeling of coplanar monolithic microwave integrated circuits (CMMIC's). >
Patent•
14 Apr 1993TL;DR: In this paper, a broadband electrooptic modulator is described, which consists of a substrate having substrate modes, having electro-optic effects, and having a first optical waveguide adapted to receive and transmit light therethrough in a first direction and with a first phase velocity.
Abstract: A broadband, electrooptic modulator is disclosed which, in a first embodiment, comprises: a substrate having substrate modes, having electrooptic effects, and having a first optical waveguide adapted to receive and transmit light therethrough in a first direction and with a first phase velocity; a buffer layer disposed on the substrate; and a coplanar waveguide electrode structure having a coplanar mode and being disposed on the buffer layer for receiving an electrical signal propagating therethrough in the first direction with a second phase velocity to phase modulate the light in the optical waveguide at a frequency in the range from 0 Hz up to substantially 40 GHz. The substrate has a sufficiently small thickness so that coupling between the coplanar mode of the coplanar waveguide electrode structure and any one of the substrate modes of the substrate substantially does not occur over a desired frequency bandwidth of operation, and the coplanar waveguide electrode structure has a sufficiently large thickness so that the second phase velocity of the electrical signal is substantially equal to the first phase velocity. In a second embodiment of the invention an intensity modulator is produced by adding a second optical waveguide which, in combination with the first optical waveguide, forms an interferometer.
Patent•
23 Feb 1993TL;DR: In this article, a waveguide is formed by evacuating a path through one or more dielectric layers of the printed wiring board and joining the layers, after which the waveguide cavity is electroless copper plated by providing an electroless plating solution in the cavity.
Abstract: A waveguide able to operate at frequencies above 20 GHz is embedded in a printed wiring board. The waveguide is formed by evacuating a waveguide path through one or more dielectric layers of the board and joining the layers. After the layers are joined, the waveguide cavity is electroless copper plated by providing an electroless plating solution in the cavity. Thereafter, the cavity walls are electroplated to form seamless electrically conductive walls for the waveguide. A dielectric may also be provided in the cavity if desired. Electronic components may be formed in the waveguide by evacuating one or more layers of a printed wiring board in a similar manner, interconnected to the waveguide. In one embodiment, the components may convert the frequency of the signal carried in the waveguide so that higher frequency signals are processed within the RFI EMI protection of the layers of the wiring board.
14 Jun 1993
TL;DR: In this article, the effects of mitres and air-bridge dimensions and locations on coplanar waveguide (CPW) 90 degrees bends were investigated using the moment method, and it was shown that the CPW bends are mainly affected by the airbridge height and location, not the mitering.
Abstract: The effects of mitres and air-bridge dimensions and locations on coplanar waveguide (CPW) 90 degrees bends are investigated using the moment method. An experiment was conducted to verify the accuracy of the calculations. These show that the CPW bends are mainly affected by the air-bridge height and location, not the mitering. >
TL;DR: In this paper, the spectral domain method for the analysis of conductor backed coplanar waveguide structures is used to estimate the potential distribution at the air-dielectric interface.
Abstract: Numerically efficient and accurate formulae based on the spectral domain method for the analysis of conductor backed coplanar waveguide structures are presented. Quasi-TEM parameters are obtained for these waveguide structures by using piecewise linear functions to approximate the potential distribution at the air-dielectric interface. Techniques such as nonuniform discretization and bound estimation are described which demonstrate shorter computational times. Results on the characteristic impedance calculation of standard coplanar waveguide are given to demonstrate the numerical accuracy and efficiency of the method presented here. >
01 Aug 1993
TL;DR: In this article, a comparative study between open and shielded coplanar wavegnide (CPW) discontinuities is presented, and the results of such a simulation are compared to the actual radiation loss obtained rigorously.
Abstract: Received January 17, 1992; revised April 14, 1992.ABSTRACTA comparative study between open and shielded coplanar wavegnide (CPW) discontinuitiesis presented. In this study, the space domain integral equation method is used to characterizeseveral discontinuities such as the open-end CPW and CPW series stubs. Two differentgeometries of CPW series stubs (straight and bent stubs) are compared with respect toresonant frequeney and radiation loss. In addition, the encountered radiation loss due todifferent CPW shunt stubs is evaluated experimentally. The notion of forced radiationsimulation is presented, and the results of such a simulation are compared to the actualradiation loss obtained rigorously. It is shown that such a simulation cannot give reliableresults concerning radiation loss from printed circuits. © 1992 John Wiley & Sons, inc.
14 Jun 1993
TL;DR: In this paper, a simple method which reduces the corresponding error without increasing the numerical efforts is presented, which is tested by calculating the line parameters and the field pattern of a homogeneous MMIC (monolithic microwave integrated circuit) coplanar waveguide.
Abstract: Due to the discretization of space, the finite-difference method cannot exactly resolve singularities of the electric and magnetic fields at metallic edges. A simple method which reduces the corresponding error without increasing the numerical efforts is presented. The novel edge formulation is tested by calculating the line parameters and the field pattern of a homogeneous MMIC (monolithic microwave integrated circuit) coplanar waveguide. This improved formulation, developed by incorporating a correction factor depending on the field singularity at the edge, reduces the errors by a factor of about one half. >
TL;DR: In this paper, a shielded velocity-matched Ti:LiNbO/sub 3/ optical modulator is investigated, focusing on the characteristics of the traveling-wave (TW) electrode and the optical waveguide.
Abstract: A shielded velocity-matched Ti:LiNbO/sub 3/ optical modulator is investigated, focusing on the characteristics of the traveling-wave (TW) electrode and the optical waveguide. The optical waveguide is analyzed and its parameters are determined using the newly developed modified-step-segment method (MSSM). The TW electrode is analyzed using the second-order triangular element quasi-TEM finite element method (FEM). By taking the thickness of the coplanar waveguide (CPW) traveling-wave (TW) electrode into consideration, it is confirmed that there is an optimum overlaid layer thickness for a given electrode thickness. It is also shown that very wide modulation bandwidth can be attained by using the optimum CPW TW electrode thickness and overlaid layer thickness. >
Patent•
29 Jan 1993TL;DR: In this paper, a plastic package for microwave applications up to 14 Ghz is described, which includes a plastic platform, a lead frame embedded on the surface of the platform, and, in one embodiment, a plastic cap (75) mounted on the platform so as to seal the chip within the package.
Abstract: A plastic package for microwave applications up to 14 Ghz is disclosed. The plastic package includes a plastic platform (65), a lead frame embedded on the surface of the platform (65) and, in one embodiment, a plastic cap (75) mounted on the platform (65) so as to seal the chip (70) within the package. The lead frame includes a baseplate (71) for mounting at least one semiconductor chip (70), at least one ground lead attached to the baseplate (71) and extending outwardly therefrom, and at least one signal lead for conducting signals to or from such semiconductor chip (70). The signal lead and at least one ground lead are configured as a microwave transmission line such as microwave coplanar strips, or microwave coplanar waveguide for transmitting microwave frequency signals. The package offers a low inductance ground path, good thermal characteristics, and low parasitic inductance and capacitance. It can be applied for high speed and high frequency applications.
01 Jan 1993
TL;DR: In this paper, a general technique to characterize asymmetric coplanar waveguide (CPW) discontinuities with air bridges where both the fundamental coplanars and slotline modes may be excited together is presented.
Abstract: Abstruct- A general technique to characterize asymmetric coplanar waveguide (CPW) discontinuities with air bridges where both the fundamental coplanar and slotline modes may be excited together is presented. First, the CPW discontinuity without air bridges is analyzed using the space-domain integral equation (SDIE) approach. Second, the parameters (phase, amplitude, and wavelength) of the coplanar and slotline modes are extracted from an amplitude modulated-like standing wave existing in the CPW feeding lines. Then a 2n x 2n generalized scattering matrix of the n-port discontinuity without air bridges is derived which includes the occurring mode conversion. Finally, this generalized scattering matrix is reduced to an n x n matrix by enforcing suitable conditions at the ports which correspond to the excited slotline mode. For the purpose of illustration, the method is applied to a shielded asymmetric short-end CPW shunt stub, the scattering parameters of which are compared with those of a symmetric one. Experiments are performed on both discontinuities and the results are in good agreement with theoretical data. The advantages of using air bridges in CPW circuits as opposed to bond wires are also discussed.
TL;DR: In this paper, LiTaO/sub 3/ and GaAs electrooptic probes were compared in terms of the magnitude of S/sub 11/ and optical probing wavelength.
Abstract: Disturbances of signals on a coplanar waveguide (CPW) induced by the presence of LiTaO/sub 3/ and GaAs electrooptic probes in external electrooptic (EO) sampling have been simulated and compared quantitatively. The finite-difference-time-domain method is used to simulate the full wave field around a coplanar waveguide on a GaAs substrate in an external EO sampling configuration. The results indicate that the induced signal disturbance, or invasiveness, of a LiTaO/sub 3/ probe is almost ten times that of a GaAs probe in terms of the magnitude of S/sub 11/, but that LiTaO/sub 3/ yields about two times the EO response for a given S/sub 11/ and optical probing wavelength. The transparency of LiTaO/sub 3/ to shorter wavelengths, however, allows an even higher sensitivity for this material relative to GaAs. The results suggest that these probes do not exhibit significant invasiveness (magnitude of S/sub 11/ smaller than -40 dB), if they are removed from contact by the distance of CPWs center conductor width. >
14 Jun 1993
TL;DR: In this paper, various types of air bridges within bends and T-junctions are innvestigated using an extension of the spectral domain analysis method for analyzing three-dimensional metallization structures.
Abstract: Various types of air bridges within bends and T-junctions are innvestigated using an extension of the spectral domain analysis method for analyzing three-dimensional metallization structures. Generalized scattering parameters are calculated to compare the different bridge layouts. In order to check the accuracy of the algorithm, four coplanar T-junctions on a GaAs substrate containing three standard air bridges and one modified air bridge have been built and measured. For the even mode scattering parameters, a very good agreement over the whole frequency range, compared to the calculated results, is obtained. Various data for conversion from the even mode to the odd mode within these structures are also given. As a result of the investigations, some design ideas for coplanar waveguide (CPW) circuit designers are determined. Problems in coplanar measurements using probe tips are discussed. >
14 Jun 1993
TL;DR: In this paper, a low-loss coplanar waveguide (CPW) transmission line with ultralow characteristic impedance on multilayer monolithic microwave integrated circuits (MMICs) is presented.
Abstract: A novel technique for realizing low-loss coplanar waveguide (CPW) transmission lines with ultralow characteristic impedance on multilayer monolithic microwave integrated circuits (MMICs) is presented. The performance of these CPW lines is investigated experimentally with either ground planes extended under the signal conductor or the center conductor extended under the ground planes. Using this technique, characteristic impedances as low as 7 Omega have been realized. The technique has been compared extensively with the proven standard thin-film microstrip (TFMS) transmission line technique. The TFMS technique can be used for lines with characteristic impedance as low as 3.6 Omega , but is found here to be significantly more lossy. A CPW line with Z/sub 0/=10 Omega gave a loss figure of 0.2 dB per millimeter at 10 GHz, compared to approximately 0.75 dB/mm for the same Z/sub 0/ in a TFMS. These CPW structures are thus expected to find use particularly in uniplanar MMIC power amplifiers. >
TL;DR: In this paper, the authors report on the design, simulation, fabrication, and measurement of very long superconducting coplanar delay lines on 3-in-diameter LaAlO/sub 3/ substrates.
Abstract: The authors report on the design, simulation, fabrication, and measurement of very long superconducting coplanar waveguide delay lines on 3-in-diameter LaAlO/sub 3/ substrates. Variations of the design involving the addition of a ground plane on the backside of the substrate and for the use of gold wire-bond bridges to electrically connect the in-plane ground planes were investigated. A delay of 45 ns was measured for a line length of 4.3 m. The best response was obtained with wire-bond connections and no backside ground plane. A resonance-free insertion loss of less than 0.01 dB/ns was obtained with a 1.7-GHz bandwidth for NbN at 4.2 K. This is to be compared with a loss of 0.1 dB/ns for a 50-ns 0.141-in OD. (outer diameter) copper coaxial delay line that weighs 1.5 lb and 0.02 dB/ns for a 60-ns 1-in OD copper coaxial delay line that weighs 45 lb. >
14 Jun 1993
TL;DR: An overview of current European coplanar waveguide (CPW) work can be found in this paper, where the authors present an overview of CPW filters, mixers, couplers, and wideband electrooptic modulators.
Abstract: An overview of current European coplanar waveguide (CPW) work is presented. Although early work in Europe was directed at developing closed-form analytic expressions for Z/sub 0/ and in /sub eff/ of a number of variants of CPW, much of the current work is application-oriented. Among the topics examined are CPW filters, mixers, couplers, and wideband electrooptic modulators. Work is also in progress on developing CAD (computer-aided design) data for CPW discontinuities, while theoretical work continues. >