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A conventional differential line (DL), commonly used on typical digital circuit boards for transmitting high-speed digital data, has fundamental limitations on the maximum signal bandwidth (~10 GHz), mainly due to signal skew, multiple line coupling, and EM interference. Therefore, to support super-high-speed digital data transmission, especially for beyond 5G communications, a practical high-performance transmission structure for digital signals is required. Balanced lines (BLs) can transmit the differential signals with multiple advantages of ultra-wide bandwidth, common-mode rejection, reduced crosstalk, phase recovery, and skew reduction, which enable super-high-speed transmission. In order to utilize the BLs in the DL-based digital circuit, connecting structures between a DL and BLs are required, but the DL-to-BL transition structures dominate the operating bandwidth and signal properties. Therefore, in this paper, properties, and design methods for two ultra-wideband DL-to-BL transitions, i.e., DL-to-CPS (coplanar stripline) and DL-to-PSL (parallel stripline) transitions, are presented. Both implemented DL-to-CPS and DL-to-PSL transitions provide high-quality performance up to 40 GHz or higher, significantly enhancing the frequency bandwidth for the transmission of digital signals while providing compatibility with the DL-based PCBs. The fabricated DL-to-CPS transition performs well from DC to 40 GHz with an insertion loss of less than 0.86 dB and a return loss of more than 10 dB, and the fabricated DL-to-PSL transition also provides good performance from DC to 40 GHz, with an insertion loss of less than 1.34 dB and a return loss of more than 10 dB. Therefore, the proposed DL-to-BL transitions can be applied to achieve super-high-speed digital data transmission with over 40 GHz bandwidth, which is more than four times the bandwidth of the DL, supporting over 200 Gbps of digital data transmission on PCBs for the next generation of advanced communications. [ABSTRACT FROM AUTHOR]

A conventional differential line (DL), commonly used on typical digital circuit boards for transmitting high-speed digital data, has fundamental limitations on the maximum signal bandwidth (~10 GHz), mainly due to signal skew, multiple line coupling, and EM interference. Therefore, to support super-high-speed digital data transmission, especially for beyond 5G communications, a practical high-performance transmission structure for digital signals is required. Balanced lines (BLs) can transmit the differential signals with multiple advantages of ultra-wide bandwidth, common-mode rejection, reduced crosstalk, phase recovery, and skew reduction, which enable super-high-speed transmission. In order to utilize the BLs in the DL-based digital circuit, connecting structures between a DL and BLs are required, but the DL-to-BL transition structures dominate the operating bandwidth and signal properties. Therefore, in this paper, properties, and design methods for two ultra-wideband DL-to-BL transitions, i.e., DL-to-CPS (coplanar stripline) and DL-to-PSL (parallel stripline) transitions, are presented. Both implemented DL-to-CPS and DL-to-PSL transitions provide high-quality performance up to 40 GHz or higher, significantly enhancing the frequency bandwidth for the transmission of digital signals while providing compatibility with the DL-based PCBs. The fabricated DL-to-CPS transition performs well from DC to 40 GHz with an insertion loss of less than 0.86 dB and a return loss of more than 10 dB, and the fabricated DL-to-PSL transition also provides good performance from DC to 40 GHz, with an insertion loss of less than 1.34 dB and a return loss of more than 10 dB. Therefore, the proposed DL-to-BL transitions can be applied to achieve super-high-speed digital data transmission with over 40 GHz bandwidth, which is more than four times the bandwidth of the DL, supporting over 200 Gbps of digital data transmission on PCBs for the next generation of advanced communications.

A new two-standard calibration procedure is outlined for determining the complex permittivity of materials from the propagation constant measured with planar transmission lines. Once calibrated, a closed-form expression for the material permittivity is obtained. The effects of radiation and conductor losses are accounted for in the calibration. The multiline technique, combined with a recently proposed planar transmission-line configuration, is used to determine the line propagation constant. An uncertainty analysis is presented for the proposed calibration procedure that includes the uncertainties associated with the multiline technique. This allows line dimensions and calibration standards to be selected that minimize the total measurement uncertainty. The use of air and distilled water as calibration standards gives relatively small measurement uncertainty. Permittivity measurement results for five liquids, covering a wide permittivity range, agree very closely with expected values from 0.5-5 GHz. [ABSTRACT FROM AUTHOR]

This paper explores the characterization of dielectric and conductive properties of carbon nanotube (CNT) networks. This is carried out by building planar transmission lines where conventional metallic traces are replaced by CNT networks. The proposed transmission lines with CNT networks are presented. Experimental realization and repeated two-port microwave measurements of proposed transmission lines enable the accurate extractions of their fundamental parameters showing percolation effects due to presence of CNT networks. The frequency-dependent phase velocity characteristics show a dramatic reduction compared to the speed of light in vacuum. The large magnitude of extracted complex permittivity for CNT networks also exhibits its percolation performance. The effects of CNTs' bulk density on measured and calculated parameters are explained. The results presented in this paper demonstrate the feasibility and the potential of building transmission lines and radio-frequency (RF) circuits elements using CNT networks. [ABSTRACT FROM PUBLISHER]

Microstrip transmission lines with ferromagnetic Co-Ta-Zr cores are investigated in this paper. Compared to nonmagnetic devices, an increase in both inductance (x 11) and quality factor (x 6) is achieved in the transmission lines. The role of the magnetic material's electrical resistivity and the effect of the shape-induced anisotropy field (created by patterning the magnetic film into narrow stripes) are discussed. It is shown that the nonuniform distribution of the shape anisotropy inside the Co-Ta-Zr pattern can be used to advantage by proper placement of the signal line, thereby increasing the ferromagnetic resonance (FMR) frequency of the magnetic core. Inductance enhancement is achieved at frequencies up to ∼-10 GHz. [ABSTRACT FROM AUTHOR]

The increasing number of biomedical applications for electronic systems have led to the need for stretchable electronics in order to significantly enhance the comfort of the user. This paper describes the design and manufacturing process of new stretchable high-frequency interconnects with meander-shaped conductors in a coplanar waveguide topology. The novel interconnects are produced based on laser-ablation of a copper foil, which is then embedded in a highly stretchable bio-compatible silicone material. Measurements on prototypes of the designed stretchable high-frequency interconnects revealed a maximal magnitude of -14 dB for the reflection coefficient and a minimal magnitude of -4 dB for the transmission coefficient in the frequency band up to 3 GHz. The influence of stretch on the performance of the high-frequency interconnects was analyzed using a stretch testing machine. The results showed that nor the magnitude, neither the phase of the transmission coefficient was influenced by elongations up to 20%. [ABSTRACT FROM AUTHOR]

In this article, we report on simulation results at 10 GHz of planar transmission lines printed on a ferroelectric thin film deposited on sapphire and lanthanum aluminate substrates. The ferroelectric film permittivity is supposed to vary from 700 to 500. First, the main properties of microstrip (MS), coplanar waveguide (CPW) and coplanar strips (CS) namely their effective permittivity, characteristic impedance, and insertion loss are computed as a function of the physical and electrical parameters. Then their tunability and figure of merit are defined and compared. CPW and CS lines present a tunability (Δεeff/εeff_max) of about 16% for a gap value g = 30 μm. The MS lines show a much less tenability of 2%. Moreover, the figure of merit of CPW and CS configurations are of 6.3 and 12.2%/dB for a gap value of 30 μm, respectively. By increasing the gap, these figures of merit can be improved up to the limiting values of 8.7% and 15.4%/dB, respectively. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 280–285, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22106 [ABSTRACT FROM AUTHOR]

This paper presents a new toroidal inductor topology that can be realized in microstrip or stripline configuration. The toroidal structure comprises two sets of mutually isolated multiple-coupled lines that are connected by vias through a ground plane. This geometry facilitates a simple equivalent-circuit model for accurate analysis or synthesis of the component. A comparison between the new toroidal structure and the conventional spiral inductor topology shows good improvement in quality factor and a footprint reduction over 300%. The toroidal designs are validated by full-wave electromagnetic simulation, as well as by measurement for a two-turn toroidal inductor in microstrip configuration. [ABSTRACT FROM AUTHOR]

If a passive asymmetrical reciprocal device is used in addition to short open load thru standards in a two-port vector network analyzer calibration, systematic errors in the calibration kit parameters can be reduced dramatically through numerical optimization to minimize asymmetry after correction. The method is described and the quality of correction assessed using simulated data. Measured results are then presented for calibration on a printed circuit board. Encouraging results and practical limitations are discussed. [ABSTRACT FROM AUTHOR]

In this paper, a new type of planar Goubau line (PGL) for millimeter- and submillimeter-wave applications is proposed for use in wideband integrated circuits. The configurations of these modified Goubau lines are examined and the parameters are provided. The performances of these lines are studied in detail. Characteristics of lines with different dimensions are calculated and displayed. Comparisons with other types of transmission lines are also performed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 290–293, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). [ABSTRACT FROM AUTHOR]

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A full-wave electromagnetic technique is developed for the rapid and accurate calculation of dispersion characteristics in multiconductor and multilayer planar transmission lines. The proposed method is based on the Mrozowski and Przybyszewski algorithms. This powerful method calculates an approximate value of propagation constant at a desired frequency based on more accurate computations of the field distribution and propagation constant at a few selected frequency points. Comparison with previously accurate published data and numerical tests are first performed to confirm the accuracy of our procedure. Numerical results for several configurations are presented [ABSTRACT FROM PUBLISHER]

This paper presents an efficient solution for solving the generalized eigenvalue equation arising in the finite-element (FE) formulation of propagation characterization of planar transmission-line structures. A two-dimensional (2-D) finite-element method (FEM) is used for analyzing the uniform planar transmission lines. The Arnoldi algorithm is used in conjunction with the multifrontal decomposition of the system matrix for solving the eigensystem. Convergence is typically obtained within a few iterations of the Arnoldi process, and the formulation has proven to be robust, even when dealing with a significantly large number of unknowns. Numerical results are presented for the case of a uniform microstrip line, which clearly show the computational savings resulting from the use of the present approach. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 194–197, 2001. [ABSTRACT FROM AUTHOR]

It is expected that the superior high-frequency characteristics, such as Low Loss and low dispersion, of superconducting oxides are applied to microwave circuits. However, low-loss superconducting oxide films can only be fabricated on limited types of substrate materials using present technologies. Therefore, the dielectric constant, dielectric loss, and thickness of substrata materials place severe limitations on the circuit design and the propagation characteristics. This paper discusses the attenuation constants, characteristic impedances, and wiring density of three fundamental planar transmission lines, namely, stripline, microstrip line, and coplanar waveguide fabricated on substrate materials MgO and LaAlO3. This discussion is based on the TEM and quasi-TEM analysis procedures The thin films with low surface resistances have been fabricated on MgO and LaA1O3. It is concluded that the microstrip line is suitable for fabricating a low-loss transmission line and the coplanar waveguide on a low dielectric constant substrate is suitable for high-density wirings. Also measured were the characteristics of the half-wave transmission Line resonators of these three transmission Line configurations, which are made of EuSa2Cu3Ox thin films on an MgO substrate. The attenuation constant of 50 ω, 50, μm wide coplanar waveguid is 9.7 × 10-3 Np/m (8.4 × 10-2 dB/m) at 3.9 6Hz and 28 K. This value is two orders of magnitude lower than that of the copper transmission line. [ABSTRACT FROM AUTHOR]

A new eigenmode algorithm, based on the method of lines, is presented for full-wave analysis of real three-dimensional (3-D) MMIC elements. Finite conductor thickness, finite substrate, dielectric or ohmic losses are rigorously modeled. The analytical calculation In the direction of propagation enables the analysis of structures with very short or long interconnections between the single discontinuities. To demonstrate the generality of the proposed algorithm several completely different structures were analyzed. Examinations of the convergence were performed. Scattering parameters of filters and planar transmission line interconnects like air bridges, via holes and bead transitions were investigated. The calculated results agree very well with computed and measured results published in literature. [ABSTRACT FROM AUTHOR]

The eigenmode transformation technique is formulated for the analysis of inhomogeneously filled shielded waveguides containing metal inserts. The permittivity of the filling medium may be an arbitrary function of the transverse coordinates. The method is based on expanding the electromagnetic field in terms of the eigenmodes of the corresponding empty shielding waveguide. The metal inserts have first the effect of linearly transforming the eigenmodes of the empty guide into those of the shielded waveguide containing the metal inserts (including the TEM-modes). Next the inhomogeneity of the filling medium is taken into account which leads to a proper matrix eigenvalue problem. In addition an alternative formulation is derived from a variational approach. Results of both formulations are compared for a shielded circular dielectric waveguide. The eigenmode transformation technique is applied to various types of planar transmission lines, i.e., coupled microstrip lines, finlines, and coplanar lines. The results are compared with those of other methods. [ABSTRACT FROM AUTHOR]

In this letter, we propose a lossy three-pole Chebyshev filter centered at 5.15 GHz, based on the substrate integrated waveguide (SIW) with scattering characteristics shifted down by 5.68 dB. The filter is composed of three directly coupled SIW cavities with three lossy couplings between nonadjacent resonators. These additional couplings are realized using mixed coupled slot and microstrip lines connected with metal electrode leadless face (MELF) resistors. The filter was fabricated using a standard printed circuit board (PCB) process, and good agreement between the simulated and measured results has been achieved. [ABSTRACT FROM PUBLISHER]

A method to design planar and compact phase shifters with broadband characteristics is presented. It utilizes broadside-coupled microstrip-coplanar waveguide, and thus the proposed devices can be fabricated using the simple and cheap double-side printed circuit boards. The method is used to design 60^\circ and 90^\circ phase shifters. The simulated and measured results show that the developed phase shifters achieve 3 to 11 GHz bandwidth with low phase instability (\pm 2^\circ), very low insertion loss (0.4 dB), high return loss (15 dB), and a compact size (1.5~cm\times 2~cm). [ABSTRACT FROM PUBLISHER]

Microstrip transmission lines fabricated on standard silicon wafers are shown to benefit from the incorporation of thin ferromagnetic Ni-Fe films when compared to control devices without Ni-Fe. At 1 GHz, inductance and quality factor of the microstrip lines are enhanced by factors of 6 and 3, respectively, while the characteristic impedance of a 20 µm wide line is increased by 85%. For constant characteristic impedance, a 200 nm thick Ni-Fe film reduces attenuation from 1.6 to 0.7 dB/cm at 500 MHz. [ABSTRACT FROM AUTHOR]

A dual-band (DB) composite right/left-handed (CRLH) branch-line coupler implemented in metal–insulator–metal technology is presented. A simple and accurate circuit-model design procedure for DB CRLH transmission lines is described and applied to the coupler. A prototype operating at 4.2 and 5.2 GHz is demonstrated in excellent agreement with both circuit and full-wave simulations. © 2006 Wiley Periodicals,Inc. Microwave Opt Technol Lett 48:2331–2333, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21948 [ABSTRACT FROM AUTHOR]

In this letter, a method to obtain the electrical characteristics of complementary split ring resonators (CSRRs) coupled to planar transmission lines is presented. CSRRs have been recently proposed by some of the authors as new constitutive elements for the synthesis of metamaterials with negative effective permittivity, and they have been applied to the fabrication of metamaterial-based circuits in planar technology. The method provides the electrical characteristics of CSRRs (including the intrinsic resonant frequency and the unloaded Q-factor), as well as the coupling capacitance between line and CSRRs, and the parameters of the host line. Parameter extraction from the proposed method is applied to two different structures corresponding to the basic cells of left handed (LH) and negative permittivity lines. The method is of actual interest for the design of microwave circuits and metamaterials based on these complementary resonant particles [ABSTRACT FROM PUBLISHER]

This paper presents a general circuit model for planar transmission line defected ground structures (DGS) that exhibits multi electromagnetic band gaps or stop bands in frequency responses. The proposed equivalent circuit consists of lumped elements that can be easily extracted from full-wave EM simulations. It is simple and accurate for modeling a wide range of DGS in microstrip and coplanar waveguide over a broad bandwidth. Excellent agreement with EM simulations/measurements is demonstrated. [ABSTRACT FROM PUBLISHER]

An improced singular integral equation (SIE) technique is proposed which can be used for the analysis of finlines, microstrip lines, coplanar transmission lines, etc. The concepts of regular solution of the SIE and generalized characteristic equation are introduced. Numerical results show that it is an efficient and accurate method. [ABSTRACT FROM AUTHOR]