Top Metal Plate Research Articles

High Selectivity, Dual-Mode Substrate Integrated Waveguide Cavity Bandpass Filter Loaded Using CCSRR

In this paper, a third-order, high selectivity Substrate Integrated Waveguide (SIW) bandpass filter (BPF) loaded with Circular Complementary Split-Ring Resonator (CCSRR) is proposed for C band applications. The SIW cavity BPF comprises two stepped resonators ([Formula: see text] and [Formula: see text]) and one CSRR ([Formula: see text]) engraved on the top metal plate. Initially, the cavity loaded with stepped resonators ([Formula: see text] and [Formula: see text]) alone does not make a good selectivity on the lower out of band. Hence, the CCSRR is introduced between the stepped resonators ([Formula: see text] and [Formula: see text]) to improve the filter’s selectivity and enhance the filter’s bandwidth. The introduction of CCSRR enhances the selectivity on the lower out-of-band at 5.5[Formula: see text]GHz, and the extra pole increases the bandwidth. The metamaterial behavior of CCSRR is validated by permittivity extraction. The 3[Formula: see text]dB bandwidth of the third-order SIW filter is 840 MHz with a center frequency of 6.18[Formula: see text]GHz. The designed filter uses RTDuroid 5880 substrate of [Formula: see text] = 2.2 with a size of 28.4 × 28.4 × 0.51[Formula: see text]mm3. The proposed filter measurement and simulated results agree with each other.

Multidomain Negative Capacitance Effect in P(VDF-TrFE) Ferroelectric Capacitor and Passive Voltage Amplification

This article demonstrates low supply voltage ( ${V}_{{\text {DD}}}{)}$ and high-frequency polarization switching in an organic ferroelectric capacitor (OFEC). The Landau–Khalatnikov (LK) equation is used to model the organic ferroelectric (OFE) in the Sentaurus technology computer-aided design (TCAD) environment considering multidomain (MD) dynamics and interaction factor ( ${K}_{{\text {OFE}}}{)}$ , resulting in a strong resemblance with the reported experimental results. The operation of OFEC at gigahertz frequency is examined with the experimentally validated MD-LK model. We study the impact of multiple domains in the OFEC on the transient response considering three separate sizes of the top metal plate (TMP). Our findings show that OFEC with a larger TMP area charges slowly than the other OFEC with smaller and proposed area TMP because of the enormous amount of domains in the larger area TMP. Various effects of ${V}_{{\text {DD}}}$ , external resistor ( ${R}{)}$ , and LK static parameters on negative capacitance signature (NCS) are investigated. We observe the NCS effect at 1 V because the coercive voltage of the OFEC is around 0.56 V, which is 73.33% lower than the conventional ferroelectric (FE) lead zirconate titanate (PZT), resulting in a minimum energy-delay product (EDP) of $2.7\times 10^{-{26}}$ Js. We observe that as the value of ${K}_{{\text {OFE}}}$ increases, the nature of domain wall switches from hard to soft, that is, coercive voltage reduces, resulting in a smaller hysteresis loop. Finally, a passive voltage amplifier (PVA) is implemented which shows voltage amplification of 1.45 at 500 MHz with low viscosity ( $\rho _{{\text {OFE}}} = {4.5}\,\,\Omega $ cm), which is still a challenge for PZT-based NC field-effect transistor (NCFET) reported in the literature.

Zero-Gap Waveguide: A Parallel Plate Waveguide With Flexible Mechanical Assembly for mm-Wave Antenna Applications

A new gap waveguide concept is presented, where the air gap between the perfect electric conductor and artificial magnetic conductor (AMC) parallel plates of a conventional gap waveguide structure has been reduced to almost zero. When the air gap is reduced, the periodic metal pin layer (which emulates the AMC characteristics) may come in contact with the top metal layer. A statistical analysis of a random contact of the pin texture and the top metal plate in this new type of gap technology guiding structure, so-called zero-gap, is elaborated in this paper. The periodic pin texture creates a stopband for parallel plate modes, and it is also used as a mechanical support while assembling the waveguide structure. This presents a significant manufacturing advantage, especially for corporate feed-network of array antennas at millimeter-wave frequencies. A $V$ -band $8\times 8$ slot array fed with this new waveguide is also designed and manufactured to show the potential of this newly proposed zero-gap waveguide structure. The measured results show 20% of relative impedance bandwidth ( $|S_{11}| dB) and an overall antenna efficiency larger than 60% over the 56.5–69-GHz frequency band.

Transition From Surface Cavity Mode to Cavity Mode in Deep-Grooved Parallel Plate Waveguide

The parallel plate waveguide (PPWG) is an excellent device for guiding and controlling at terahertz wave. When a deep groove is integrated into a PPWG, only the surface cavity mode is excited, which limits its applications in filtering and sensing. In this paper, we demonstrated that in a double deep-grooved PPWG, both fundamental and higher-order cavity modes can be observed. Our experimental and simulation results show that the effective groove depth of the fundamental cavity mode in the bottom deep groove can be efficiently increased by cutting another shallow groove in the top metal plate, facing the bottom deep groove. In addition, the transition from the so-called surface cavity mode to traditional cavity mode can be observed with increasing depth of the shallow groove. These results may have applications in the multichannel filtering and sensing field.

Optically pumped subwavelength-scale metallodielectric nanopatch resonators

We discuss subwavelength-scale semiconductor metal-optic resonators placed on the metal substrate with various top metal plate sizes. Albeit with large optical losses, addition of metal layers converts a leaky semiconductor nano-block into a highly-confined optical cavity. Optically pumped lasing action is observed with the extended top metal layer that can significantly suppress the radiation losses. Careful investigation of self-heating effects during the optical carrier injection process shows the importance of temperature-dependent material properties in the laser rate equation model and the overall laser performances.

Compact substrate integrated waveguide filter using dual-plane resonant cells

A dual-plane resonant cell wideband bandpass filter is proposed and designed on substrate integrated waveguide (SIW) cavities using U-shape slots and H-shape fractal defected ground structure (DGS). The U-shape slots etched on the top meta layer of the SIW cavity are used to constitute a multiple-mode resonator and the H-shape fractal DGS etched on the bottom metal layer can greatly improve the filter performance while keeping the overall size of the filter circuit to be much compact. The proposed filter can lead to a size reduction of approximately one-third compared with the traditional SIW filters only using U-shape slots on the top metal plate of the SIW cavity. The filter has been fabricated and experimentally measured. The measured data are in good agreement with the simulated results. The measured 3 dB bandwidth is from 7.15 to 11.25 GHz, representing a fractional bandwidth of 44.6% at a center frequency of 9.2 GHz. Within the passband, the measured return loss performance is quite good (below −22dB), and the insertion loss is measured to be 1.05 dB, including the loss from two SMA connectors. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:111–114, 2016

Signal Power-Insensitive Analog MEMS Tunable Capacitor by Immobilizing the Movable Plates

This paper presents an extremely power-insensitive microelectromechanical systems (MEMS) tunable capacitor equipped with immobilization capability in the moving plates when an radio frequency signal is flowing. The proposed tunable capacitor is similar to the conventional metal–insulator–metal capacitor, but the top metal plate is capable of moving laterally as well as vertically; it moves to the left and right to set the capacitance value by modulating the overlap area between the top and bottom plates (analog tuning and high capacitance tuning ratio are the merits), and then the top plate is pulled down to be immobilized resulting in remarkable robustness to the signal power, as well as high capacitance value. The proposed tunable capacitor, which was fabricated by metal surface micromachining, showed the tuning ratio of 181% at 2 MHz (470–852 fF) and 194% at 1 GHz with lateral and vertical actuation voltages under 50 V. It also exhibited small capacitance change against the radio frequency (RF) signal power; the maximum capacitance variation by the signal power of up to 9 W was <5.5% over the full tuning range, which is the record-high power insensitivity among the analog MEMS tunable capacitors. This excellent power insensitivity is due to the immobilizing capability of the proposed tunable capacitor. The proposed tunable capacitor maintained the set capacitance value with a variation of <8% over 10 million cycles under 1-W signal (cold switching condition). The design, modeling, fabrication, and measurements, including RF characteristics, are all described in this paper. [2014-0345]

RF MEMS Extended Tuning Range Varactor and Varactor Based True Time Delay Line Design

MEMS varactors are one of the important passive MEMS devices. Their applica- tions include use in VCOs, tunable impedance matching networks, tunable fllters, phase shifters, and true time delay lines. The shunt capacitive structure has been employed in most of the conventional MEMS varactor designs because of its simplicity. However, the capacitance ratio of this conventional shunt capacitive MEMS varactor is limited to 1.5 because of the MEMS Pull- In efiect, which happens when the de∞ection between the MEMS top and bottom metal plates increase beyond 1/3 of the airgap between the two metal plates. At that time, the top metal plate will quickly snap down. This efiect is the major limitation in MEMS varactor designs and can cause nonlinearity and mechanically instability. In order to eliminate this Pull-In efiect, the author employed the so-called MEMS extended tuning range structure. This structure utilizes a variable height top metal beam with separate actuation parts. The airgap between the center part of the top beam and the bottom plate has been designed to be less than 1/3 of the airgap between the top beam and the bottom actuation pads. When DC bias is applied to the actuation parts, the entire top beam will move down together. Consequently, before the Pull-In efiect happens at the actuation parts, the center part has already traveled through its entire tuning range, which means that the capacitive ratio of this kind of MEMS varactor can go to inflnity. A fabrication process employing a GaAs substrate has been designed based on surface micro- machining technology. The maximum capacitance ratio of the designed MEMS extended tuning range varactor is 5.39 with a Cmax value of 167fF. Based on this MEMS varactor design, a Ka-band MEMS varactor based distributed true time delay line has been designed. This dis- tributed true time delay line includes a high impedance CPW transmission line with 70› un- loaded impedance at 28GHz and eight MEMS extended tuning range varactors based on the varactor design periodically loaded on the CPW line. The testing results show that a 56 - phase delay variation has been achieved at 28GHz. The measured insertion loss at 28GHz is i1:07dB at the up-state and i2:36dB at the down-state. The measured return losses, S11 and S22, are both below i15dB at 28GHz and below i10dB over the entire tested frequency range of 5GHz to 40GHz.

Etude numérique du transfert thermique métal-fluide dans un conduit rectangulaire en régime instationnaire

On résout numériquement, par une méthode aux différences finies, le profil de température dans un canal à plaques parallèles pour une largeur unité, traversé par un fluide en convection forcée, incompressible, en régime d'écoulement laminaire ou turbulent. Les différents modes de transferts thermiques sont pris en compte ainsi qu'une condition de flux imposée, dépendante du temps, sur la partie supérieure; dans le conduit, le couplage entre le problème conductif de parois et conductif-convectif du fluide est réalisé au niveau des interfaces. Le coefficient de transfert paroi-fluide est déterminé, à tout instant, dans la région d'établissement thermique, à partir d'une équation de bilan thermique établie sur la face soumise à cette condition de flux. Les résultats sont comparés à ceux obtenus à partir d'un modéle simplifié MS “dit quasi-statique” et validés expérimentalement à l'aide de mesures faisant intervenir un dispositif de thermographie infrarouge. Numerical results of the determination, by the finite difference method, of the temperature profile in a parallel plates duct containing an incompressible laminar or turbulent fluid in forced convection is presented. Different heat transfer conditions are considered as well as a time-dependent heat flux condition on the top metal plate. The coupling between conduction and convection is carried by the ‘solid-fluid’ interface. The heat transfer coefficient between plate and fluid is found at each point and time by a heat balance equation on the top plate. The results are compared with those found employing a simplified model MS and proved by the infra-red thermography results. Das Temperaturprofil in einem Kanal aus parallelen Platten wird mit Hilfe der Finite-Differenzen-Methode numerisch untersucht. Für die laminare und turbulente erzwungene Konvektion eines inkompressiblen Mediums werden verschiedene Wärmeübergangsbedingungen und ein zeitabhängiger Wärmestrom an der Deckplatte betrachtet. Die Kopplung zwischen Wärmeleitung und Konvektion wird dabei durch eine “fest-flüssig”-Schnittstelle berücksichtigt. Der Wärmeübergangskoeffizient zwischen Platte und Fluid wird für jeden Ort und jeden Zeitpunkt durch eine Wärmebilanz an der Deckplatte bestimmt. Die Ergebnisse werden mit einem einfacheren Modell verglichen und mit Hilfe der Infrarot-thermographie überprüft. Пpивoдятcя чиcлeнныe peэyльтaты oпpeдeлeния кoнeчнo-paэнocтным мeтoдoм тeмпepaтypнoгo пpoфиля в плocкoпapaллeльнoм кaнaлe, в кoтopoм пpoиcxoдит вынyждeннoкoнвeктивнoe лaминapнoe или тypбyлeнтнoe тeчeниe нecжимaeмoй жидкocти. Paccмaтpивaютcя paэличныe ycлoвия тeплoпepeнoca, в чacтнocти, ycлoвиe эcтaциoнapнoгo тeплoвoгo пoтoкa нa вepxнeй мeтaлличecкoй плacтинe. вэaимocвяэь мeждy тeплoпpoвoднocтью и кoнвeкциeй ocyщecтвляeтcя нa гpaницe paэдeлa тбepдoгo тeлa и жидкocти. C иcпoльэoвaниeм ypaвнeния тeплoвoгo бaлaнca нa вepxнeй плacтинe нaйдeн кoэффициeнт тeплooбмeнa мeждy плacтинoй и жидкocтью в кaждoй тoчкe в paэнoe вpeмя. Peэyльтaы cpaвнивaютcя c дaнными, кoтopыe пoлyчeны c пoмoщью yпpoщeннoй мoдeли MS, и пoдтвepждaютcя дaнными инфpaкpacнoгo тeплoвиэopa.

Alcohol, Task Difficulty, and Incentives in Drill Press Operation

The effects of alcohol, task difficulty, and incentives on a drill press simulation were examined. On four nonconsecutive days the subject received four alcohol levels, one level per day. The levels were: 0.00%, 0.03%, 0.06%, and 0.09% blood alcohol concentration (BAC). The drill press simulation task consisted of placing a drill probe alternatively into two holes in a metal plate. For every level of alcohol, each subject received eight levels of task difficulty which were varied by changing the hole size and distance between holes. Task difficulty was in units of bits of information ranging from two to nine and was derived from a portion of Welford's (1968) version of Fitts' Law. For every level of task difficulty, each subject received two levels of incentive: productivity and accuracy which were enforced by monetary rewards. The subject's response was measured by hits and misses. A hit was defined as fully inserting the metal drill probe in either of two holes in the top metal plate of the workpiece without touching the plate. A miss was defined as a contact of the probe with the top plate. Alcohol had a significant effect on hits ( p = 0.0001) as evidenced by a 12% decrease in hits at the 0.06% BAC, and a 19% decrease at the 0.09% BAC. Task difficulty affected both hits and misses (p = 0.0001). The greatest decrease in hits between any two levels of task difficulty was an 89% decrease from the easiest task difficulty level to the most difficult level. The largest decrease between any two levels of difficulty in misses was 57% and occurred between the eight and five bit task difficutly level. Incentive had a significant effect on hits ( p = 0.0002) and misses ( p = 0.0001). Hits were 27.5% less in the productivity condition than in the accuracy condition. Misses were 74% less in the accuracy condition than in the productivity condition. Although the alcohol by task difficulty interaction was significant for hits ( p = 0.0001), and the incentive by task difficulty interactions were significant for both hits and misses ( p = 0.0001), plots of these effects were not subject to meaningful interpretation.