Coplanar Gap Research Articles

High-Order Resonating Cavity-Backed Slot Antenna Array Based on Contactless Air-Filled Substrate Integrated Waveguide and Transition to Inverted Grounded Coplanar Gap Waveguide

High-Order Resonating Cavity-Backed Slot Antenna Array Based on Contactless Air-Filled Substrate Integrated Waveguide and Transition to Inverted Grounded Coplanar Gap Waveguide

Design of Coplanar Proximity Coupled Feed Hexagonal Shaped Circular Polarized Microstrip Patch Antenna

This paper presents a broadband-multiband circularly polarized hexagonal patch antenna. The structure is fed by a unique coplanar hexagonal gap coupled proximity coupled feed with parasitic elements. The antenna is designed using a 14.2×14.2 mm2 FR4 substrate. By introducing hexagonal slot and I slot in the patch, the structure behaves as a multiband antenna with resonating frequencies at 2.76, 5.66 and 11.52 GHz. with 0.2837, 0.4525 and 0.3356 GHz respective bandwidths. By inserting I-shaped slots and rectangular slots in patch and also, I-shaped slots in the ground, the circular polarization is achieved in the L band and C band. The proposed structure was fabricated and tested. The simulated results of the magnitude of S11, radiation patterns and realized gains show good agreement with tested results.
 HIGHLIGHTS
 
 Proposed antenna is single layer broadband multiband circularly polarized hexagonal patch antenna
 A unique feed technique coplanar hexagonal gap coupled proximity coupled feed with parasitic elements is used
 The size of the antenna is compact 14.2×14.2 mm2 and resonating frequencies at 2.76, 5.66 and 11. 52 GHz. with 0.2837GHz/28.37%, 0.4525GHz/ 45.23% and 0.3356GHz/33.56%, respective bandwidths and efficiency
 The antenna is used for WiFi/WiMax application as well as terrestrial communication applications near the costal region or a high humidity environment
 
 GRAPHICAL ABSTRACT

Nanoscale lift-off process using field emission scanning probe lithography

Nanoelectronics manufacturing requires an ongoing development of lithography and also encompasses some “unconventional” methods. In this context, the authors use field emission scanning probe lithography (FE-SPL) to generate nanoscaled electronic devices. For the generation of future novel quantum devices, such as single-electron transistors or plasmonic resonators, patterning of features in the sub-10 nm regime as well as a defined metallization is necessary. In terms of metallization, the authors take advantage of the well-known lift-off process for creating narrow gap junctions. Narrow gap electrodes have found wide approval in the formation of narrow gap junctions and can be employed for the investigation of the electrical properties of molecules. In the lift-off process presented here, two sacrificial layers (50 nm polymethylglutarimide and 10 nm calixarene) have been deposited and patterned by FE-SPL. Subsequently, the sample was treated with tetraethyl-ammonium hydroxide in order to ensure an undercut. Afterward, a layer of 10 nm thick Cr has been deposited on top and finally the sacrificial films have been removed, leaving behind only the chromium film deposited directly on the substrate. In this work, the authors will present the utilization of novel active cantilevers with diamond coated silicon tips for FE-SPL purposes in order to generate chromium metal features by lift-off for the generation of future quantum devices. In this context, they will present the integration of an ultrananocrystalline diamond (UNCD) layer deposited on the tip of an active silicon cantilever. Electron emission and FE-SPL capabilities of UNCD coated silicon tips are evaluated. The authors demonstrate a reliable fabrication scheme of sub-15 nm coplanar narrow gap metal electrodes.

Gas breakdown and plasma impedance in split-ring resonators

The appearance of resonant structures in metamaterials coupled to plasmas motivates the systematic investigation of gas breakdown and plasma impedance in split-ring resonators over a frequency range of 0.5−9 GHz. In co-planar electrode gaps of 100 μm, the breakdown voltage amplitude decreases from 280 V to 225 V over this frequency range in atmospheric argon. At the highest frequency, a microplasma can be sustained using only 2 mW of power. At 20 mW, we measure a central electron density of 2 × 1020 m-3. The plasma-electrode overlap plays a key role in the microplasma impedance and causes the sheath impedance to dominate the plasma resistance at very low power levels.

Inductively coupled superconducting half wavelength resonators as persistent current traps for ultracold atoms

A crucial point in the experimental implementation of hybrid quantum systems consisting of superconducting circuits and atomic ensembles is bringing the two partners close enough to each other that a strong quantum coherent coupling can be established. Here, we propose to use the metallization structures of a half wavelength superconducting coplanar waveguide resonator as a persistent current trap for ultracold paramagnetic atoms. Trapping atoms with the resonator structure itself is provided by using short-ended and inductively coupled resonators instead of capacitively coupled ones as customary in circuit quantum electrodynamics. We analyze the external quality factor of short-ended coplanar waveguide resonators and show that it can be easily designed for the desired regime of quantum circuits. The magnetic field configuration at the resonator is calculated by means of numerical three-dimensional simulations of the London equations. We present a way to transport an atomic ensemble into the coplanar resonator gap where the magnetic field of the cavity mode is maximum. The configuration allows stable trapping by persistent currents and paves the route toward strong coupling between atomic clouds and the cavity mode which is required for cooperative effects and gives the interface between atoms and circuit quantum electrodynamics.

Ultra Wideband Co-planer Microstrip Patch Antenna for Wireless Applications

In this paper, a comparative study of co-planar gap coupled rectangular and elliptical microstrip patch antenna is presented. It is analyzed by using circuit theory concept. The proposed antennas show ultra wideband operations which depend on dimensions of the patches, gap between them as well as air gap thickness. It is observed that the performance of gap coupled elliptical patch antenna is better than that of rectangular patch antenna while the area of rectangular and elliptical patches is same. The bandwidth of proposed rectangular patch antenna is found to be 50.7 % with average gain of 6.5 dBi while for elliptical patch antenna the bandwidth and gain further improves up to 57.6 % and 9.5 dBi respectively. The theoretical results are in good agreement with the simulated results obtained from IE3D simulation software.

Alignment-free fabrication of a hybrid electro-optic polymer/ion-exchange glass coplanar modulator

A hybrid electro-optic (EO) polymer phase modulator with a 6 μm coplanar electrode gap was realized on ion exchange glass substrates. The critical alignment steps which may be required for hybrid optoelectronic devices were eliminated with a simple alignment-free fabrication technique. The low loss adiabatic transition from glass to EO polymer waveguide was enabled by gray scale patterning of novel EO polymer, AJLY. Total insertion loss of 5 dB and electrode gap of 8 μm was obtained for an optimized device design. EO polymer poling at 135 °C and 75 V/μm was demonstrated for the first time on a phosphate glass substrate and was enabled by the sol-gel buffer layer.

Study on the Discharge Modes of the Microplasma Generated in a Plasma Display With an Auxiliary Electrode

The characteristics of the discharge modes in the microplasma generated in a plasma display with a coplanar gap and an auxiliary electrode were investigated in accordance with various plate gaps and coplanar gaps. The measurement results of the discharge current peak time, discharge current, and luminous efficacy showed that modes 2 and 3 appeared in the microplasma in the cases of various plate gaps and coplanar gaps and that the luminous efficacy increased in mode 2 and decreased in mode 3. In addition, a stabilized microplasma in a plasma display with an auxiliary electrode was obtained when the plate gap was longer than the coplanar gap, and the maximum luminous efficacy was obtained when the plate gap was similar to the coplanar gap. According to the measurement results, the discharge modes and the parametric studies are attractive to obtain and design for high luminous efficacy in a plasma display with a coplanar gap and an auxiliary electrode.

Wall Charges and Transition Voltage of Microplasma Modes in Plasma Devices With an Auxiliary Electrode

In this paper, the characteristics of microdischarge phenomena in a plasma device with an auxiliary electrode located on the center of the coplanar gap were investigated. The microdischarge showed three discharge modes in accordance with the auxiliary pulse voltages, and its luminous efficacy was improved when it operated in the efficient mode. To understand the mechanisms of that improvement of efficiency, a wall-charge measurement system was proposed and applied to measure the wall-charge behavior, which is a key for the diagnosis of discharge characteristics. For the efficient mode, measurement of wall-charge behavior indicated the presence of the three high efficiency factors, namely, long-gap discharge, current reduction, and priming effect. For the inefficient mode, however, the measured wall-charge behavior indicated that strong short-gap discharges were generated between sustain and auxiliary electrodes, and then, the high efficient factors were not observed. Additionally, in order to operate the device in the efficient mode, the tendency of the mode transition was investigated in terms of panel specifications, such as barrier rib height and coplanar gap. The results indicate that the transition voltage between the efficient and inefficient modes increased when the barrier rib height increased, and it showed the tendency resembling the Paschen curve with various coplanar gaps.

Driving Characteristics of a High-Efficacy AC PDP With an Auxiliary Electrode

A new driving waveform was proposed in order to stabilize the driving characteristics of a high-efficacy AC plasma-display panel (PDP) with a coplanar gap of 200 mum and an auxiliary electrode. To stabilize the reset and address discharge, an erase pulse was applied to the auxiliary electrode instead of the sustain electrode after the sustain period. The write pulse was applied to the scan electrode, and a reset discharge was induced between the scan and auxiliary electrodes. As a result, the minimum address voltage could be reduced to a level similar to that achieved with a conventional ac PDP with a coplanar gap of 80 mum. Furthermore, the address-discharge time lag of the ac PDP with a coplanar gap of 200 mum was improved to a level that is comparable with that of the ac PDP with a coplanar gap of 80 mum.

Electroplating silver tetracyanoquinodimethane between gold micro-gap electrodes for the fabrication of coplanar devices, a new way to integrate material synthesis and devices fabrication within one step

In this paper we propose a method for the integration of the synthesis of silver-tetracyanoquinodimethane (AgTCNQ) and the fabrication of its devices within one step. The method was performed by electroplating Ag between gold coplanar micro-gap electrodes in tetracyanoquinodimethane (TCNQ) solution. As soon as silver was electrochemically dissolved in the TCNQ solution, it immediately reacted with TCNQ to form AgTCNQ and then deposited between Au gap electrodes. With the continuing of the reaction, the Au micro-gap electrodes were connected by AgTCNQ to form Au/AgTCNQ/Au coplanar gap devices. With this electroplating technique, series gap devices of AgTCNQ were fabricated, and the devices exhibited switching phenomena with good reproducibility. This method integrated the synthesis of AgTCNQ and the fabrication of its devices within a single step, and should be also inspirable for other charge transfer complexes.

The Effect of the Auxiliary Electrode on the Microplasma Generated in a Plasma Display With a Coplanar Gap

The microplasma modes generated in a plasma display with a coplanar gap and an auxiliary electrode were investigated using the discharge current peak time (discharge delay) and discharge current. Three types of modes were classified as follows: mode 1) showed a decrease in both the discharge current and the discharge delay, mode 2) showed a decrease in the discharge current and an increase in the discharge delay, and mode 3) showed an increase in the discharge current and a decrease in the discharge delay. The infrared efficiency increased in modes 1) and 2) with an increase in the auxiliary pulse voltage. However, in mode 3), the IR efficiency started to decrease. According to the measurement results, modes 1) and 2) are suitable for microplasma generated in a coplanar gap with an auxiliary electrode to obtain high efficacy.

A New AC Plasma Display Panel With Auxiliary Electrode for High Luminous Efficacy

A new ac plasma display panel (PDP) for high luminous efficacy is proposed, and its characteristics are investigated. The new ac PDP has a coplanar gap of 200 mum and an auxiliary electrode located between the scan and common electrodes. The periodic pulses are applied to the auxiliary electrode during the sustain period, which plays the roles of enhancing the infrared emission and reducing the discharge current. The sustain voltage decreases with the increase of the auxiliary pulse voltage until 80 V. When the voltage of the pulse applied to the auxiliary electrode is 50 V, the luminous efficacy reaches its peak value and is approximately 8.7 lm/W obtained from the measurement of Ne + 20% Xe gas-mixture discharges in the green cells. The luminous efficacy of the new proposed test ac PDP with Ne + 13% Xe and Ne + 20% Xe gas mixtures is improved by 190% and 320%, respectively, compared to that of the conventional ac PDP with a Ne + 13% Xe gas mixture

Local discharge and distribution of wall charge in coplanar dielectric barrier discharge

The local discharge and wall charge distribution on dielectric surface in coplanar dielectric barrier discharge have been studied experimentally by employing a segment-electrode system. The results show that the local discharge currents on the segment electrodes are different when the segments act as cathode and/or anode, but the charge transfers during the current pulses are symmetric on the correlative parts of the electrodes. The wall charge distribution and the wall voltage during afterglow are uniform on the dielectric layer above the segments near the coplanar gap, while they decrease outwards in the outer side of the electrode if the voltage supply is not high enough. The segment-electrode configuration provides a possible way to investigate the local processes of the discharge in dielectric barrier discharge.

Study of various coplanar gaps discharges in ac plasma display panel

To achieve a high luminous efficacy in a plasma display panel, the display characteristics, including the luminance, discharge current, and luminous efficacy, were investigated with various coplanar gaps. The temporal behavior of the infrared emission from 80-, 150-, 200-, and 300-/spl mu/m coplanar gap discharges was also studied. The luminance and luminous efficacy increased as the coplanar gap increased until 200 /spl mu/m. However, when the coplanar gap was 300 /spl mu/m with a fixed barrier rib height of 150 /spl mu/m, the luminous and luminous efficacy suddenly decreased. This phenomenon can be explained by the results of the infrared emission observation, as the discharge shape of the 300-/spl mu/m coplanar gap became narrow when the height of barrier rib was fixed at 150 /spl mu/m. The luminous efficacy of the 200-/spl mu/m coplanar gap discharge was about 3.2 lm/W (green cells) when an Ne+4%Xe gas mixture was used as the discharge gas in the alternating current plasma display panel.

Large-gap AC coplanar plasma display cells: macro-cell experiments and 3-D simulations

We present experimental and simulation studies of the plasma in a macroscopic AC plasma display panel discharge cell operating with a large coplanar gap. We find that the xenon excitation efficiency is much larger than that in the conventional, small-gap electrode configuration but with larger sustaining voltage. We discuss the discharge mode and efficiency in such large gap configurations, with the help of time resolved optical diagnostics and simulations.

Modeling gap discontinuity in coplanar waveguide using quasistatic spectral domain method

An efficient computer technique based on the spectral domain method is presented to solve the problem of modeling coplanar gap discontinuity. Comparison with available published data is done to confirm the accuracy of the method.

Improved Dielectric Response in Strontium Titanate Thin Films Grown by Pulsed Laser Ablation

ABSTRACTWe have grown epitaxial strontium titanate films on lanthanum aluminate substrates at a range of oxygen pressures and substrate temperatures. The complex dielectric function was measured versus frequency (10 kHz to 1 MHz) and temperature (room temperature to 4.2 K) on coplanar capacitors patterned on the films. Preliminary data from 1.5 to 2.5 GHz is also presented. The dielectric constant εr was as high as 4600 at 65 K, a factor of two greater than previously reported for strontium titanate thin films and a factor of 1.8 greater than the bulk value at the same temperature. Tuning the capacitor by applying a dc bias of ±15 V across the 3 μm coplanar gap at 4.2 K yielded a ratio of maximum to minimum dielectric constant of 2.8. At 101 K this ratio was 2.2. A bulk capacitor does not show tuning over such a large temperature range.

Radiation hardness of coplanar submicron gap Charge‐Coupled Devices (CCD) with rapid thermal nitrided oxides

Nitrided oxides are used as the CCD's gate oxides in this work. The nitridation process is carried out in NH3 or N2O ambient. After irradiation of Co‐60 with a total dose of 106 rads, we find that ...

Lower-bound algorithms for coplanar line and gap capacitance evaluations

Coplanar line characteristics have been widely investigated. However, calculations of capacitances, both in air and in inhomogeneous dielectric, have often been based on simple yet successful assumptions, which seem to deserve further validation. In this paper, both non conventional conformal mapping techniques and a new variational formulation are used, leading to accurate upper-bound impedance evaluations, and some comparisons with lower-bound results and published data are presented. Moreover, the application of refined variational algorithms to gap capacitance evaluations is discussed: the algorithm proposed by Maeda (1972) for computation of gap capacitances is revisited, and some improvements are described. Results are discussed with reference to values already presented in the literature and excellent agreement with experimental data is shown.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>