Showing papers on "Coplanar waveguide published in 1986"

Considerations in the Use of Coplanar Waveguide for Millimeter-Wave Integrated Circuits

Abstract: Using a full-wave analysis, coplanar waveguide (CPW) transmission line is compared to microstrip in terms of conductor loss, dispersion, and radiation into parasitic modes. It is shown that, on a standard 0.1-mm semiconductor at 60 GHz, the dimensions of CPW can be chosen to give better results in terms of conductor loss and dispersion than microstrip. A calculation of parasitic mode generation is presented for CPW on a semiconductor for an open substrate, for a substrate suspended above a ground plane, and for substrates separated from a ground plane by quartz.

Dispersion of Picosecond Pulses in Coplanar Transmission Lines

Abstract: The dispersion of coplanar-type transmission lines has been extended to the terahertz regime to examine the distortion of picosecond electrical pulses. Dispersion of coplanar waveguides is compared to equivalent microstrip lines. Agreement with available experimental data is demonstrated for coplanar strips, An approximate dispersion formula for coplanar waveguides is also reported for CAD applications.

Finite-Element Analysis of Slow-Wave Schottky Contact Printed Lines

Abstract: Extensive finite-element analyses on MMIC slow-wave structures with both Iocalized and layered models are presented Good agreement is achieved between the data presented here and other theoretical results and experiments Higher order elements that improve accuracy are discussed The comparative studies for Schottky contact microstrip and coplanar waveguide with Iocalized and layered models are presented Potential applications of the Iocalized models to more general and practical slow-wave circuits are also discussed

Finite-element analysis of slow-wave Schottky contact printed lines

Abstract: Extensive finite-element analyses on MMIC slow-wave structures with both Iocalized and layered models are presented. Good agreement is achieved between the data presented here and other theoretical results and experiments. Higher order elements that improve accuracy are discussed. The comparative studies for Schottky contact microstrip and coplanar waveguide with Iocalized and layered models are presented. Potential applications of the Iocalized models to more general and practical slow-wave circuits are also discussed.

Coplanar Waveguides Used in 2-18 GHz Distributed Amplifier

Abstract: This paper describes the use of coplanar waveguide as an alternative transmission medium in a monolithic distributed amplifier. The coplanar waveguide layout substantially reduces coupling effects between adjacent lines, and eliminates the need for via holes and substrate thinning, leading to higher fabrication yields. The resulting device reported here is a compact (1.3 x 1.5mm) low noise distributed amplifier on a thick GaAs substrate (15 mil), with a gain of 6.0 +- 0.5dB over the frequency range of 2 - 18GHz.

A coplanar waveguide probe

Abstract: A coplaner waveguide probe (2) comprises a dielectric substrate (8) having a pattern of ground electrodes (4) and signal electrodes (6) arranged on one surface. An electrically conductive layer (12) is provided on a further surface of the substrate (8) in electrical contact with the ground electrodes (4). The electrical contact between the electrically conductive layer (12) and the ground electrodes (4) is provided by a series of via holes (18) containing electrically conductive material, such as gold or conductive epoxy (20), and/or extension portion of the electrically conductive layer (12).

New measurement technique: cw electro-optic probing of electric fields

Abstract: This letter describes a new nondestructive measurement technique—cw electro‐optic probing, and reports results of experiments on GaAs coplanar waveguide sample. The technique is simple in instrumentation and convenient in applications. We believe that it can become a powerful tool for studying the electric field in various devices and integrated circuits.

Quasistatic characteristics of a coplanar waveguide with thick metal coating

Abstract: The variational expression of the line capacitance is derived for the coplanar waveguide (CPW) with thick metal coating for the first time. It is presented in the general form to be applicable to the case with uniaxially anisotropic media. An efficient and accurate numerical method is employed to calculate the line parameters, and it reveals the effect of the metalisation thickness of a CPW.

Coplanar Waveguide Vs. Microstrip for Millimeter Wave Integrated Circuits

Abstract: Using a full wave analysis, coplanar waveguide transmission line is compared to microstrip in terms of conductor loss, dispersion and radiation into parasitic modes. It is shown that, on standard .1 mm semiconductor at 60 GHz, the dimensions of coplanar waveguide can be chosen to give better results in terms of conductor loss and dispersion than microstrip. Curves are presented comparing the microstrip open end and the coplanar waveguide short circuit in terms of parasitic mode generation.

Coplanar microstrap waveguide

Abstract: COPLANAR MICROSTRAP WAVEGUIDE ABSTRACT An electrical connection between two semicon-ductor devices employs a coplanar microstrap waveguide comprising a plurality of thin straps of conductive metal embedded in a polyimide substrate and dimensioned to exhibit the properties of a coplanar waveguide. The waveguide structure provides the proper impedance matching between the two devices and enables them to handle signals having frequencies in the gigahertz range.

Coplanar waveguide crossover

Abstract: The present invention consists of a crossover for coplanar waveguides. A pair of microstrip/strip line conductors are transitioned into coplanar conductors on opposite sides of a substrate. This places the electrical and magnetic fields in an orthogonal relation so as to reduce the possible interference. Once crossed the coplanar conductors are transitioned back to microstrip/strip line conductors.

Calibration apparatus for integrated circuits

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.

Microwave phase shifter with piezoelectric control

Abstract: A microwave phase shifter comprise a dielectric waveguide having a flat side and a moving conductor plane member substantially parallel to the waveguide side. Piezoelectric means are provided to move the plane member with respect to the waveguide side between a portion relatively remote from the waveguide side and an other position substantially in contact with the waveguide side. The piezoelectric means consists preferably of a stack of piezoelectric members supplied by a variable d.c. power source. Owing to the piezoelectric means for moving the conductor plane member, a variable phase shift is continuously adjusted. Such a phase shifter can be as an antenna network when the dielectric waveguide contains groups of radiator perturbations, such as conductor strips, respectively controlled by one or several piezoelectric means carrying conductor plates facing waveguide portions including the perturbations groups.

Monolithic p-i-n diode limiter

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).

Circulators using coplanar waveguide

Abstract: Bosma's method of analysing stripline circulator operation is modified to suit circulators using coplanar waveguide. One of the circulators designed in this way shows a maximum isolation of 19.1 dB, insertion loss 0.8 dB and VSWR 1.3 or less at a centre frequency of 9.56 GHz.

Planar MMIC Hybrid Circuit and Frequency Converter

Abstract: A "planar" circuit configuration for MMIC (Monolithic Microwave Integrated Circuit) has been proposed. It uses coplanar waveguides and slotlines on the upper side of the substrate. Novel hybrid circuits have been fabricated. It has also been shown that small sized, balanced FET circuits can be achieved.

A planar subharmonically-pumped 71 GHz receiver with integral feed antenna

Abstract: A planar, subharmonically-pumped, hybrid millimeter-wave receiver with integral antenna is described. Coplanar waveguide filters are used to isolate the ports and provide image enhancement. The integral planar antenna has 12 dB gain and is suited for use as a feed. The main lobe is normal to the substrate surface. The receiver is designed for an instantaneous bandwidth of 10 GHz. Experiments at 71 GHz indicate single-sideband mixer conversion loss of 6.5 dB. We believe that this represents the highest level of integration yet demonstrated in this frequency range.

Printed dipoles electromagnetically coupled to coplanar waveguide for linear or circular polarisation

Abstract: Two configurations are proposed for feeding printed dipoles with coplanar waveguide transmission lines. The coplanar waveguide feed is printed on a ground plane sandwiched between a high-permittivity substrate and a low-permittivity substrate which supports the antenna. Both linear and circular polarisation can be achieved. Measured results are presented.

Propagation characteristics of some novel coplanar waveguide transmission lines on GaAs at MM-wave frequencies

Abstract: Three new Coplanar Waveguide (CPW) transmission lines, namely, Suspended CPW (SCPW), Stripline-like Suspended CPW (SSCPW) and Inverted CPW (ICPW), are proposed and also analyzed for their propagation characteristics The substrate thickness, permittivity and dimensions of housing are assumed to be arbitrary These structures have the following advantages over conventional CPW Firstly, the ratio of guide wavelength to free space wavelength is closer to unity which results in larger dimensions and hence lower tolerances Secondly, the effective dielectric constant is lower and hence the electromagnetic field energies are concentrated more in the air regions which should reduce attenuation Thirdly, for a prescribed impedance level, the above structures have a wider slot width for identical strip width Thus, low impedance lines can be achieved with reasonable slot dimensions Fourthly, in an inverted CPW shunt mounting of active devices, such as Gunn and IMPATT diodes, between the strip and the metal trough is possible This feature further enhances the attractiveness of the above structures Lastly, an E-plane probe type transition from a rectangular waveguide to suspended CPW can also be easily realized The computed results for GaAs at Ka-band illustrate the variation of normalized guide wavelength, effective dielectric constant and the characteristic impedance as a function of the: (1) frequency; (2) distance of separation between the trough side walls; (3) normalized strip and slot widths; and (4) normalized air gap

Coplanar push-pull-type waveguide mixer

Abstract: The invention relates to a push-pull-type waveguide mixer with a stripline substrate which is inserted transversely into a signal waveguide and to which two diodes are connected which are arranged behind one another and in parallel with the narrow side of the signal waveguide, the LO supply and IF output being effected via the stripline. The push-pull-type waveguide mixer according to the invention is characterised by the following features: - the stripline is constructed as a coplanar line, the narrow outer conductors of which are curved and the shape of which approximates the equipotential lines in the signal waveguide; - the diodes are in each case connected between an outer conductor and the inner conductor of the coplanar line.

Dispersion in shielded coupled coplanar waveguides

Abstract: A full-wave solution is developed to investigate the dispersion in shielded coupled coplanar waveguides. This study shows that the quasi-TEM data available in the literature for the coupled coplanar waveguide cannot accurately predict the performance of this structure at high frequencies.

Finite Element Analysis of Slow Wave Coplanar Waveguide with Localized Depletion Regions

Abstract: A finite element field analysis program is developed to study the effect of localized finite conductivity region in the Schottky-contact CPW in the slow-wave application. Theoretical results obtained for the MIS (layered) CPW structure show good agreements with those in the existing literature. Our analysis indicates the new Schottky-contact slow-wave CPW structure under analysis is viable for low loss and wideband electronically tunable phase shifter application.

Strip line-type microwave modulator using photoconductivity

Abstract: When the strip line containing a semiconductor material is illuminated by light with an energy larger than the band gap, the resistivity of the semiconductor changes and the control of the microwave propagation in the line can be realized. For high-speed control it is necessary to use the semiconductor with short lifetime and to increase the intensity of illuminating light. In this paper, a fundamental study has been performed for the microwave modulator using photoconductivity. Strip lines suitable for this modulator are a coplanar waveguide and a slot line. This paper investigates the coplanar waveguide. An optimum structure is found that provides the strongest microwave attenuation for a given light intensity. The dependence on the frequency of the attenuation constant is also found. The analysis is based on the spectral domain method. To confirm the usefulness of the modulator proposed here, the modulator has been made of Si and tested at 10 GHz. It is found that the modulation up to 100 kHz is possible even with a light source such as a lightemitting diode.

Adjustable tuning for planar millimeter-wave circuits

Abstract: At millimeter wavelengths uncontrollable parasitics are of ten large enough to significantly degrade circuit performance when they are not compensated by adjustable elements. It is difficult to add adjustable elements to planar millimeter-wave circuits without increasing their size, weight, and cost. In this paper we investigate three adjustable elements, all involving movement of a short along a section of coplanar waveguide (CPW). These tuners are incorporated in a planar detector circuit for purposes of demonstration and characterization. Their losses are determined. The precision with which they can be adjusted is also considered. Of the three, a tuner based on the laser-assisted etching of molybdenum is shown to have the highest performance at millimeter wavelengths. This tuner employs laser direct write etching1 with a recently developed photochemical reaction for trimming molybdenum.

Cross-bar quadrature mixer

Abstract: This mixer is particularly intended for the millimetre waveband The waveguides for the RF signal (RF) and the local oscillator signal (LO) extend immediately next to one another in parallel A substrate with a coplanar line is inserted across the line direction into the waveguide for the RF signal (RF) The substrate is continued through an opening in the common wall of the two waveguides To connect the local oscillator signal (LO), the inner conductor of the coplanar line protrudes into the LO waveguide The waveguide for the RF signal (RF) is terminated by a displaceable short-circuit behind the substrate On the coplanar line, two diodes (D1, D2), which are perpendicularly irradiated by the RF signal, are mounted at a distance of lambda /4 from one another with common earth

Analysis and applications of modified coupled coplanar lines

Abstract: Modified coupled coplanar lines, compatible with the classical and conductor-backed coplanar waveguides, are analysed using the quasistatic and full-wave spectral domain methods. Results of the analysis are utilised for designing a 10 dB directional coupler. Measured isolation of the coupler is higher than 33 dB in the bandwidth up to 5 GHz.

Narrowband 10 GHz and 20 GHz GaAs FET Amplifiers in Coplanar Waveguide.

Abstract: : Single-stage, narrowband 10 GHz and 20 GHz GaAs FET amplifiers using Coplanar Waveguide (CPW) distributed matching elements were built and tested. The amplifiers were constructed to closely model monolithic amplifiers on GaAs by mounting GaAs FET chips into an epsilon (r) = 13 substrate material, onto which the CPW matching elements were placed. A CPW test fixture was designed and a routine for de-embedding the s-parameters of FET chips mounted in CPW was developed and successfully used. The 10-GHz amplifiers had an average of 9 dB gain. Due to a de-embedding error none of the 20-GHz amplifiers provided positive gain at 20 GHz. A second de-embedding effort yielded s-parameters that were used to accurately predict the actual performance of the 20-GHz amplifier designs.

Opto-electronic Correlation Measurements on Damaged Si-on-sapphire Using Coplanar Waveguides

Abstract: The use of coplanar waveguide geometries to replace the more conventional microstrip transmission line arrangement used for sampling with photoconductive switches is discussed. It is shown that a significant reduction in the gap capacitance is achieved, improving the sampling time resolution to a point where the chief limitation is the pulse duration of the laser (∼3 ps).

Adjustable tuning for planar

Abstract: At millimeter wavelengths uncontrollable parasitics are often large enough to significantly degrade circuit performance when they are not compensated by adjustable elements. It is difficult to add adjustable elements to planar millimeter-wave circuits without increasing their size, weight, and cost. In this paper we investigate three adjustable elements, all involving movement of a short along a section of coplanar waveguide (CPW). These tuners are incorporated in a planar detector circuit for purposes of demonstration and characterization. Their losses are determined. The precision with which they can be adjusted is also considered. Of the three, a tuner based on the laser-assisted etching of molybdenum is shown to have the highest performance at millimeter wavelengths. This tuner employs laser direct write etching 1 with a recently developed photochemical reaction for trimming molybdenum.

An Integrated DBS Receiver Front-End using a Monolithic Frequency Converter

Abstract: A low-noise 12-GHz receiver front-end consisting of a novel integration of a monolithic frequency converter (two-stage LNA and mixer), MIC bandpass filter, and lumped element IF network on a coplanar waveguide (CPW) mother board is described. The techniques employed for the design and fabrication of the monolithic frequency converter, including a new dual-FET mixer configuration, are described. Measurements of the front-end indicate a noise figure of generally less than 5 dB and an associated gain of 10 dB across the 11.7 GHz to 12.2 GHz input band (0.9- to 1.4-GHz IF band).