Showing papers on "Coplanar waveguide published in 1987"

Microstrip to dielectric waveguide transition

Abstract: A microstrip to dielectric waveguide transition is provided comprising a gth of rectangular dielectric waveguide which has one end tapered in such a manner that the height of the waveguide top surface above the waveguide bottom surface decreases linearly from full height to zero height at the tapered end of the length of waveguide. The bottom surface of the waveguide length is mounted on the top surface of a planar microstrip dielectric substrate having an electrically conductive metallic ground plane on the bottom substrate surface and a length of microstrip conductor on the top substrate surface aligned with the waveguide length and abutting the tapered end of the waveguide length. A second length of microstrip conductor is mounted on the tapered portion and part of the untapered portion of the top surface of the waveguide length and is electrically connected to the first microstrip conductor at the tapered end of the waveguide length. The dielectric constant of the microstrip substrate should be no greater than the dielectric constant of the dielectric waveguide length and preferably should be much less.

Surface-to-Surface Transition via Electromagnetic Coupling of Coplanar Waveguides

Abstract: A transition is investigated which couples coplanar waveguide on one substrate surface (a motherboard) to coplanar waveguide on another substrate surface (a semiconductor chip or subarray) placed above the first. No wire bonds are necessary. A full-wave analysis using coupled line theory is presented and verified experimentally. The use of this transition for coupling to millimeter-wave integrated circuits is discussed.

Single-mode operation of coplanar waveguides

Abstract: A grounded coplanar waveguide structure with finite-size ground planes is analysed as three coupled microstrip lines. The three normal propagation modes of this structure are examined for various geometries, and some physical layout guidelines are established.

Microstrip to coplanar waveguide transitional device

Abstract: A novel transition device is disclosed capable of being used in an integrated circuit comprising a substrate having a first planar surface upon which at least one circuit element is formed and a second planar surface upon which a ground metallization is formed, said first planar surface being spaced from and parallel to the second planar surface, said at least one circuit element being connected to a metal strip and having an open end terminating on said first planar surface, a coplanar grounding station disposed on the first planar surface and situated adjacent to and spaced from said open end, said coplanar grounding station being free of any electrically conducting path between said metal strip and said coplanar grounding station and between said ground metallization and said copolanar grounding station. The expression grounding station as used herein may be defined as a planar structure comprising of at least one metallized patch situated to and spaced from a strip transmission line, said patch lying parallel to and separated from a ground plane of said line, said patch not being electrically connected to said transmission line.

Transmission line mode converter

Abstract: PURPOSE:To attain excellent coplanar microstrip conversion over a wide band from a low frequency till an ultrahigh frequency by utilizing the change in the electric field distribution depending on a grounded type coplanar line. CONSTITUTION:The width of a center conductor strip 8 of the grounded type coplanar line B and a gap (G) between surface ground conductors 6a, 6b arranged at both sides are being expanded while keeping a single characteristic impedance and the size of the gap G is selected at least the thickness of a dielectric base 2 at a connecting point with a microstrip line A. That is, in applying coplanar microstrip conversion, the gap G is widened gradually from the structure shown in figure (a) to form the electric field distribution shown in figure (c). Thus, the mode conversion from the coplanar line transmission mode into the microstrip line transmission mode is performed easily without any characteristic deterioration.

Bias-variable characteristics of coupled coplanar waveguide on GaAs substrate

Abstract: An original structure, an active coupled coplanar waveguide on GaAs substrate, is proposed, where a quasi-TEM analysis using Green's functions leads to the determination of the slow-wave characteristics in this structure. It is shown that the nonreciprocal characteristics can be controlled through the DC-biasing of the different device elements.

Electro‐optic measurement of standing waves in a GaAs coplanar waveguide

Abstract: We have successfully measured, for the first time, standing waves in a GaAs coplanar waveguide at frequencies of 8.2107 and 12.310 GHz by using harmonic‐mixing electro‐optic probing. The technique is nondestructive and has great potential in expanding the measuring frequency band to millimeter wave. This letter describes the principle of the technique, the experimental setup, and the measurement results.

Variational method for coplanar waveguide with anisotropic substrates

Abstract: Lower- and Upper- bound stationary expressions are derived for the line capacitance of the general structure of a coplanar waveguide (CPW) with layered anisotropic media for the first time. Numerical examples show the efficiency of the method, and how the margins of error can be contained within a very small range by the lowerand upper-bound calculations.

High-accuracy tuning of planar millimeter-wave circuits by laser photochemical etching

Abstract: A new laser photochemical reaction for etching of molybdenum has been applied to the in situ tuning of coplanar waveguide (CPW) structures used in millimeter wave integrated circuits. Tests on structures operating at 33 GHz have confirmed low insertion losses and demonstrated an improvement in set accuracy by a factor of 10-30 relative to previously developed strip or solder tuners.

Electro-optic sampling measurement of coplanar waveguide (coupled slot line) modes

Abstract: The application of the electro-optic sampling technique for the characterisation of propagating modes of planar guiding structures on GaAs is described. The characteristics of even and odd modes of coplanar waveguide on semi-insulating GaAs substrate are investigated. The guide wavelength for each mode is directly obtained from standing wave measurements by electro-optic sampling, and compared to the theoretical values.

Distributed diode limitter

Abstract: Monolithic gallium arsenide limiters (30) formed of p-i-n diodes (32, 34) that are distributed devices between conductors of coplanar waveguide sections (40, 42, 44) are disclosed. The diode doped regions underlie the coplanar conductors and the diode intrinsic region underlies the coplanar waveguide gap. The grounded coplanar segments connect to a backside ground through vias (74).

Coplanar waveguide phase shifter controlled by a spatially periodic optical illumination

Abstract: The characteristics of a periodically-illuminated CPW phase shifter are investigated by the spectral domain approach combined with the cascaded transmission line matrix method. It is found that the phase shifter characteristics can be improved by appropriate use of periodic illumination instead of uniform illumination.

Calibrating microwave integrated circuit test systems

Abstract: Apparatus for calibrating an integrated circuit test system comprises a substrate having a substantially planar array of thin film components (1-9) formed thereon The components are provided with contact pads which, for each component, have a spacing which enable the components to be engaged by the tip of a coplanar waveguide probe of the test system Such apparatus permits error correction to be achieved under computer control, resulting in scatter parameter measurements to be made with reference planes at the tips of the probe, obviating the need for sophisticated but error prone de-embedding techniques

Screened coplanar strip line arrangement

Abstract: The screened coplanar strip line arrangement makes it possible to supply two loads with radio-frequency power in the same phase. The strip lines K1 and K2 respectively are coupled to the loads V1 and V2, are in each case short-circuited at a distance A APPROX N lambda/4 from the loads, and are coupled to the strip lines K3 or K4 respectively at a distance a from the respective short circuit. The earthing strips of the strip lines K3 and K4 and the centre conductor of the strip lines K1 and K2 project into a waveguide and thus produce an E-field probe, the behaviour of the earthing strips in the waveguide approximating to the equipotential lines of the electromagnetic wave being passed in the waveguide. The screening housing of the arrangement between the loads V1 and V2 and the E-field probe is designed such that the path length L from one earthing edge MK of the coplanar arrangement to the other is approximately L = lambda/4.

Coplanar‐waveguide excitation of magnetostatic surface waves

Abstract: The theory of excitation of magnetostatic surface waves with a coplanar‐waveguide (CPW) transmission line has been developed. An expression for an equivalent radiation admittance relating the energy carried away by magnetostatic surface waves to electromagnetic energy propagating along the CPW line has been obtained. The input admittance of an open‐circuited yttrium iron garnet (YIG)‐loaded CPW transmission line has been computed with gap width of CPW and YIG film thickness as parameters.

Push-pull radio frequency circuit with integral transistion to waveguide output

Abstract: A radio frequency circuit for ICRF heating includes a resonant push-pull circuit, a double ridged rectangular waveguide, and a coupling transition which joins the waveguide to the resonant circuit. The resonant circuit includes two cylindrical conductors mounted side by side and two power vacuum tubes attached to respective ends of a cylindrical conductor. A conductive yoke is located at the other end of the cylindrical conductors to short circuit the two cylindrical conductors. The coupling transition includes two relatively flat rectangular conductors extending perpendicular to the longitudinal axes of a respective cylindrical conductor to which the flat conductor is attached intermediate the ends thereof. Conductive side covers and end covers are also provided for forming pockets in the waveguide into which the flat conductors extend when the waveguide is attached to a shielding enclosure surrounding the resonant circuit.

Enhanced Performance Ultrabroadband Distributed Amplifiers

Abstract: Distributed amplifiers have been used in recent years to achieve amplification over multioctave bandwidths extending to millimeter-wave frequencies [1].The distributed (or traveling wave) amplifier topology is especially suitable for monolithic integration using GaAs technology due to low sensitivity to component parameter variations and a relatively high active/passive component ratio.A major drawback of the approach has been the relatively low gain per stage (4–7 dB) and high current consumption.This paper describes the application of novel circuit approaches (such as cascode-connected FETs and coplanar waveguide transmission lines) and advanced devices such as high electron mobility transistors (HEMTs) to improve performance, simplify fabrication and achieve greater than 10 dB of single-stage gain over the 2–20 GHz band.

Full Wave Analysis of Slot Line and Coplanar Waveguide on a Magnetic Substrate

Abstract: An analysis is presented for slot line and coplanar waveguide (CPW) on magnetized substrate. The moment method procedure is used to solve for nonreciprocal phase shift of these structures. Plots of calculated and measured phase shift for CPW on ferrite are presented.

Picosecond response of an optically controlled millimeter wave phase shifter

Abstract: The dispersion of a picosecond pulse propagating along a coplanar waveguide on a semiconductor substrate is studied Numerical calculations are used to predict the pulse shape for varying carrier concentrations in a multilayer AlGaAs/GaAs/AlGaAs structure

Monolithic phase shifter study

Abstract: : Modeling and testing of monolithic coplanar waveguide (CPW) phase shifters using both optical and Schottky-contact control techniques have been performed. Simulation work on a periodically illuminated structure has been completed, showing that some improvement in performance may be possible, although with a reduction in frequency bandwidth. CPW transmission lines have been fabricated on semi-insulating GaAs, on lightly and heavily doped epi GaAs, and on AlGaAs/GaAs heterostructure, and electrical characterization has been performed. Both Schottky-bias controlled mechanism, using constant D.C. bias while using optical control has also been developed, which has yielded the best experimental performance to date for a distributed CPW phase shifter.

Experimental performance of an optically controlled coplanar waveguide phase shifter

Abstract: Preliminary measurements on an optically controlled coplanar waveguide phase-shifter are presented. The device is based on the interaction between the wave propagating on the transmission line and an optically induced plasma in the CPW semiconductor substrate. A prototype device consisting of a Schottky contacted CPW on a heterostructure AlGaAs/GaAs/AlGaAs/ S.I. GaAs substrate was tested. The preliminary measurements show that optical control of the phase is possible, even at low illumination intensities.

ning of Planar Millimeter-Wave hotochernica tchin

Abstract: A new laser photochemical reaction for etching of molybde- num has been applied to the in sifu tuning of coplanar waveguide (CPW) structures used in millimeter wave integrated circuits. Tests on structures operating at 33.GWz have confirmed low insertion losses and demon- strated an improvement in set accuracy by a factor of 10-30 relative to previously developed strip or solder tuners. ASER direct-writing techniques based on rapidly scanned microscopic etching and deposition reactions have been recently developed ( 11. By avoiding multistep lithography and conventional pattern transfer, these techniques provide impor- tant leverage via final-step microfabrication operations such as logic personalization, fault avoidance, and defect repair on integrated circuits. In addition, this technology presents new capabilities for trimming and tuning of analog devices. For these applications, advantages of direct-write etching over previous physical-probe and laser ablation methods are low induced temperature, greater spatial resolution, and elimina- tion of debris and nonselective substrate damage. Here we describe the use of a recently developed laser direct-write etching reaction (2), (3) to achieve high-accuracy tuning of planar millimeter-wave circuits. With the recent improvements of these circuits, adjustable elements are becoming important as a means to control limiting parasitics. We find that, in comparison to other methods currently under development, laser etching permits tuner settabilities of one- to-two decades greater accuracy. The new method could be useful as an automated post-fabrication trimming operation to

Technical memorandum: Quasistatic and hybrid-mode analysis of shielded coplanar waveguide with thick metal coating

Abstract: A unified approach is presented to give the quasistatic and hybrid-mode solutions of the shielded coplanar waveguide (CPW) with a uniaxially anisotropic substrate. The quasistatic formulation is based on the variational method and the stationary expression of the line capacitance of the shielded CPW is derived for the first time. The present method takes the metallisation thickness into consideration and it presents accurate numerical values both for the quasistatic and frequency-dependent hybrid-mode solutions. The frequency-dependent characteristic impedances based on various definitions are investigated.

A three-port Ferrite resonator circuit using coplanar waveguide

Abstract: A three-port magnetically-tunable ferrite resonator circuit is proposed, which uses a ferrite resonator and coplanar waveguide on a dielectric substrate. This circuit has both resonator and isolator properties, and is applicable to a magnetically-tunable oscillator using with an active component. It is not necessary to use an additional isolator for reducing the influence of the reflected power on the oscillation. Experiments are done with YIG and CaVG ferrite. The existence of an optimum position for placing ferrite to obtaining the maximum non-reciprocity, is ascertained by the theoretical and experimental results. This circuit is simple in construction , and suitable for wide-band operation.

Towards an Unified Efficient Algorithm for Characterizing the Planar Periodic Waveguides

Abstract: A new efficient algorithm (modified three dimensional spectral domain solution with "modal spectrum" in propagation direction) applied to a variety of planar waveguides with periodic stubs is achieved. In this paper, slow-wave propagation characteristics of both symmetrically and unsymmetrically loaded periodic structures with Iossy dielectric layer such as finline and coplanar waveguide (CPW) are investigated. Many important features like pass-band and stop-band related to cut-off and resonant frequencies are discussed in detail based on numerical computations which are compared with measured results obtained by transmission line experimental procedure.