Analytical Design and Optimization of a WR-3 Waveguide Diplexer Synthesized Using Direct Coupled Resonator Cavities
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Gold Nanoarray Deposited Using Alternating Current for Emission Rate
Xue et al. Nanoscale Research Letters 2013, 8:295 http://www.nanoscalereslett.com/content/8/1/295 NANO EXPRESS Open Access Gold nanoarray deposited using alternating current for emission rate-manipulating nanoantenna Jiancai Xue1, Qiangzhong Zhu1, Jiaming Liu1, Yinyin Li2, Zhang-Kai Zhou1*, Zhaoyong Lin1, Jiahao Yan1, Juntao Li1 and Xue-Hua Wang1* Abstract We have proposed an easy and controllable method to prepare highly ordered Au nanoarray by pulse alternating current deposition in anodic aluminum oxide template. Using the ultraviolet–visible-near-infrared region spectrophotometer, finite difference time domain, and Green function method, we experimentally and theoretically investigated the surface plasmon resonance, electric field distribution, and local density of states enhancement of the uniform Au nanoarray system. The time-resolved photoluminescence spectra of quantum dots show that the emission rate increased from 0.0429 to 0.5 ns−1 (10.7 times larger) by the existence of the Au nanoarray. Our findings not only suggest a convenient method for ordered nanoarray growth but also prove the utilization of the Au nanoarray for light emission-manipulating antennas, which can help build various functional plasmonic nanodevices. Keywords: Anodic aluminum oxide template, Au nanoarray, Emission rate, Nanoantenna, Surface plasmon PACS: 82.45.Yz, 78.47.jd, 62.23.Pq Background Owing to the self-organized hexagonal arrays of Excited by an incident photon beam and provoking a uniform parallel nanochannels, anodic aluminum oxide collective oscillation of free electron gas, plasmonic (AAO) film has been widely used as the template for materials gain the ability to manipulate electromagnetic nanoarray growth [26-29]. Many distinctive discoveries field at a deep-subwavelength scale, making them play a have been made in the nanosystems fabricated in AAO major role in current nanoscience [1-5]. -
Calculation and Measurement of Bianisotropy in a Split Ring Resonator Metamaterial ͒ David R
JOURNAL OF APPLIED PHYSICS 100, 024507 ͑2006͒ Calculation and measurement of bianisotropy in a split ring resonator metamaterial ͒ David R. Smitha Department of Electrical and Computer Engineering, Duke University, P.O. Box 90291, Durham, North Carolina 27708 and Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 Jonah Gollub Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 Jack J. Mock Department of Electrical and Computer Engineering, Duke University, P.O. Box 90291, Durham, North Carolina 27708 Willie J. Padilla Los Alamos National Laboratory, MS K764, MST-10, Los Alamos, New Mexico 87545 David Schurig Department of Electrical and Computer Engineering, Duke University, P.O. Box 90291, Durham, North Carolina 27708 ͑Received 2 June 2005; accepted 5 June 2006; published online 21 July 2006͒ A medium that exhibits artificial magnetism can be formed by assembling an array of split ring resonators ͑SRRs͒—planar conducting elements that exhibit a resonant response to electromagnetic radiation. The SRR exhibits a large magnetic dipole moment when excited by a magnetic field directed along its axis. However, the SRR also exhibits an electric response that can be quite large depending on the symmetry of the SRR and the orientation of the SRR with respect to the electric component of the field. So, while the SRR medium can be considered as having a predominantly magnetic response for certain orientations with respect to the incident wave, it is generally the case that the SRR exhibits magnetoelectric coupling, and hence a medium of SRRs arranged so as to break mirror symmetry about one of the axes will exhibit bianisotropy. -
Bringing Optical Metamaterials to Reality
UC Berkeley UC Berkeley Electronic Theses and Dissertations Title Bringing Optical Metamaterials to Reality Permalink https://escholarship.org/uc/item/5d37803w Author Valentine, Jason Gage Publication Date 2010 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California Bringing Optical Metamaterials to Reality By Jason Gage Valentine A dissertation in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering – Mechanical Engineering in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Xiang Zhang, Chair Professor Costas Grigoropoulos Professor Liwei Lin Professor Ming Wu Fall 2010 Bringing Optical Metamaterials to Reality © 2010 By Jason Gage Valentine Abstract Bringing Optical Metamaterials to Reality by Jason Gage Valentine Doctor of Philosophy in Mechanical Engineering University of California, Berkeley Professor Xiang Zhang, Chair Metamaterials, which are artificially engineered composites, have been shown to exhibit electromagnetic properties not attainable with naturally occurring materials. The use of such materials has been proposed for numerous applications including sub-diffraction limit imaging and electromagnetic cloaking. While these materials were first developed to work at microwave frequencies, scaling them to optical wavelengths has involved both fundamental and engineering challenges. Among these challenges, optical metamaterials tend to absorb a large amount of the incident light and furthermore, achieving devices with such materials has been difficult due to fabrication constraints associated with their nanoscale architectures. The objective of this dissertation is to describe the progress that I have made in overcoming these challenges in achieving low loss optical metamaterials and associated devices. The first part of the dissertation details the development of the first bulk optical metamaterial with a negative index of refraction. -
Internal Loss of Superconducting Resonators Induced by Interacting
Internal loss of superconducting resonators induced by interacting two level systems Lara Faoro1,2 and Lev B. Ioffe2 1 Laboratoire de Physique Theorique et Hautes Energies, CNRS UMR 7589, Universites Paris 6 et 7, 4 place Jussieu, 75252 Paris, Cedex 05, France and 2 Department of Physics and Astronomy, Rutgers The State University of New Jersey, 136 Frelinghuysen Rd, Piscataway, 08854 New Jersey, USA (Dated: August 6, 2018) In a number of recent experiments with microwave high quality superconducting coplanar waveg- uide (CPW) resonators an anomalously weak power dependence of the quality factor has been observed. We argue that this observation implies that the monochromatic radiation does not sat- urate the Two Level Systems (TLS) located at the interface oxide surfaces of the resonator and suggests the importance of their interactions. We estimate the microwave loss due to interacting TLS and show that the interactions between TLS lead to a drift of their energies that result in a much slower, logarithmic dependence of their absorption on the radiation power in agreement with the data. High quality superconducting CPW resonators are mentally [12, 14–16]. used in a number of diverse fields, ranging from as- The failure of the conventional theory of TLS to predict tronomical photon detection [1, 2] to circuit quantum the power dependence of the quality factor for the high electrodynamics [3–6]. In these applications, the CPW quality resonators is an indication of a serious gap in our resonator is operated in a regime of low temperature understanding of TLS in amorphous insulators. In this ( 10mk) and low excitation power (single photon). -
The Open Resonator
The Open Resonator Sven Arnoldsson Department of Mechanical Engineering Blekinge Institute of Technology Karlskrona, Sweden 2002 Thesis submitted for completion of Master of Science in Mechanical Engineering with emphasis on Structural Mechanics at the Department of Mechanical Engineering, Blekinge Institute of Technology, Karlskrona, Sweden. Abstract: In this work it has been shown experimentally that it is possible to create a high pressure with an open resonator in air. Pressure levels and their positions inside the resonator were studied and documented in order to describe the behaviour of the resonator. Parameters of particular interest are the resonant frequencies of the reflecting plates and their deflection shapes, which depends on their geometric form. Keywords: Non-linear acoustics, modal analysis, open resonator, resonance, Q-factor, even frequencies, conical reflector. Acknowledgements This work was carried out at the Department of Mechanical Engineering, Blekinge Institute of Technology, Karlskrona, Sweden, under the supervision of Dr. Claes M. Hedberg. I wish to express my gratitude to Dr. Claes M. Hedberg for his scientific guidance and support throughout the work. Also I would like to thank my colleagues in the Master of Science programme and all the other members of the Department of Mechanical Engineering for valuable discussions and support. Karlskrona, 2002 Sven Arnoldsson Contents 1 Notation 4 2 Introduction 6 3 Theory 8 3.1 Dimension of an open resonator 14 4 Measurements 15 4.1 Test equipment 16 4.2 The open resonator with two flat plates 17 4.2.1 Tested the glass plates 19 4.2.2 The highest pressure in resonator with two flat plats. -
Tunable Trapped Mode in Symmetric Resonator Designed for Metamaterials
Progress In Electromagnetics Research, PIER 101, 115{123, 2010 TUNABLE TRAPPED MODE IN SYMMETRIC RESONATOR DESIGNED FOR METAMATERIALS A. Ourir, R. Abdeddaim, and J. de Rosny Institut Langevin, ESPCI ParisTech, UMR 7587 CNRS, Laboratoire Ondes et Acoustique (LOA) 10 rue Vauquelin 75231 Paris Cedex 05, France Abstract|The excitation of an antisymmetric trapped mode on a symmetric metamaterial resonator is experimentally demonstrated. We use an active electronic device to break the electrical symmetry and therefore to generate this trapped mode on a symmetric spilt ring resonator. Even more, with such a tunable mode coupling resonator, we can precisely tune the resonant mode frequency. In this way, a shift of up to 15 percent is observed. 1. INTRODUCTION At the beginning of this century, left-handed metamaterials have attracted considerable interest of scientists working in the ¯eld of microwave technology [1{4]. Since then, planar metamaterials realized in microstrip technology have been demonstrated [5, 6]. A compact lefthanded coplanar waveguide (CPW) design based on complementary split ring resonators (SRRs) was proposed afterwards [7]. Due to their inherent magnetic resonance, SRRs can advantageously be employed in microwave ¯lter designs. They deliver a sharp cut-o® at the lower band edge which corresponds to their resonance frequency. Moreover, the SRRs can be tuned using varactor diodes. By this way, tracking ¯lters can be designed for multiband telecommunication systems, radiometers, and wide-band radar systems. Actually, these resonators can be tuned easily using varactor diodes [8]. Recently, a resonant response with a very high quality factor has been achieved in planar SRRs based metamaterials by introducing symmetry breaking in the shape of its structural elements [9, 10]. -
Frequency Response
EE105 – Fall 2015 Microelectronic Devices and Circuits Frequency Response Prof. Ming C. Wu [email protected] 511 Sutardja Dai Hall (SDH) Amplifier Frequency Response: Lower and Upper Cutoff Frequency • Midband gain Amid and upper and lower cutoff frequencies ωH and ω L that define bandwidth of an amplifier are often of more interest than the complete transferfunction • Coupling and bypass capacitors(~ F) determineω L • Transistor (and stray) capacitances(~ pF) determineω H Lower Cutoff Frequency (ωL) Approximation: Short-Circuit Time Constant (SCTC) Method 1. Identify all coupling and bypass capacitors 2. Pick one capacitor ( ) at a time, replace all others with short circuits 3. Replace independent voltage source withshort , and independent current source withopen 4. Calculate the resistance ( ) in parallel with 5. Calculate the time constant, 6. Repeat this for each of n the capacitor 7. The low cut-off frequency can be approximated by n 1 ωL ≅ ∑ i=1 RiSCi Note: this is an approximation. The real low cut-off is slightly lower Lower Cutoff Frequency (ωL) Using SCTC Method for CS Amplifier SCTC Method: 1 n 1 fL ≅ ∑ 2π i=1 RiSCi For the Common-Source Amplifier: 1 # 1 1 1 & fL ≅ % + + ( 2π $ R1SC1 R2SC2 R3SC3 ' Lower Cutoff Frequency (ωL) Using SCTC Method for CS Amplifier Using the SCTC method: For C2 : = + = + 1 " 1 1 1 % R3S R3 (RD RiD ) R3 (RD ro ) fL ≅ $ + + ' 2π # R1SC1 R2SC2 R3SC3 & For C1: R1S = RI +(RG RiG ) = RI + RG For C3 : 1 R2S = RS RiS = RS gm Design: How Do We Choose the Coupling and Bypass Capacitor Values? • Since the impedance of a capacitor increases with decreasing frequency, coupling/bypass capacitors reduce amplifier gain at low frequencies. -
Classic Filters There Are 4 Classic Analogue Filter Types: Butterworth, Chebyshev, Elliptic and Bessel. There Is No Ideal Filter
Classic Filters There are 4 classic analogue filter types: Butterworth, Chebyshev, Elliptic and Bessel. There is no ideal filter; each filter is good in some areas but poor in others. • Butterworth: Flattest pass-band but a poor roll-off rate. • Chebyshev: Some pass-band ripple but a better (steeper) roll-off rate. • Elliptic: Some pass- and stop-band ripple but with the steepest roll-off rate. • Bessel: Worst roll-off rate of all four filters but the best phase response. Filters with a poor phase response will react poorly to a change in signal level. Butterworth The first, and probably best-known filter approximation is the Butterworth or maximally-flat response. It exhibits a nearly flat passband with no ripple. The rolloff is smooth and monotonic, with a low-pass or high- pass rolloff rate of 20 dB/decade (6 dB/octave) for every pole. Thus, a 5th-order Butterworth low-pass filter would have an attenuation rate of 100 dB for every factor of ten increase in frequency beyond the cutoff frequency. It has a reasonably good phase response. Figure 1 Butterworth Filter Chebyshev The Chebyshev response is a mathematical strategy for achieving a faster roll-off by allowing ripple in the frequency response. As the ripple increases (bad), the roll-off becomes sharper (good). The Chebyshev response is an optimal trade-off between these two parameters. Chebyshev filters where the ripple is only allowed in the passband are called type 1 filters. Chebyshev filters that have ripple only in the stopband are called type 2 filters , but are are seldom used. -
Oct. 30, 1923. 1,472,583 W
Oct. 30, 1923. 1,472,583 W. G. CADY . METHOD OF MAINTAINING ELECTRIC CURRENTS OF CONSTANT FREQUENCY Filed May 28. 1921 Patented Oct. 30, 1923. 1,472,583 UNITED STATES PATENT OFFICE, WALTER GUYTON CADY, OF MIDDLETowN, connECTICUT. METHOD OF MAINTAINING ELECTRIC CURRENTS OF CONSTANT FREQUENCY, To all whom it may concern:Application filed May 28, 1921. Serial No. 473,434. REISSUED Be it known that I, WALTER G. CADY, a tric resonator that I take advantage of for citizen of the United States of America, my present purpose are-first: that prop residing at Middletown, in the county of erty by virtue of which such a resonator, 5 Middlesex, State of Connecticut, have in whose vibrations are maintained by im vented certain new and useful Improve pulses; received from one electric circuit, ments in Method of Maintaining Electric may be used to transmit energy in the form B) Currents of Constant Frequency, of which of an alternating current into another cir the following is a full, clear, and exact de cuit; second, that property which it posses 0 scription. ses of modifying by its reactions the alter The invention which forms the subject nating current of a particular frequency or of my present application for Letters Patent frequencies flowing to it; and third, the fact that the effective capacity of the resonator andis an maintainingimprovement alternatingin the art ofcurrents producing of depends, in a manner which will more fully 5 constant frequency. It is well known that hereinafter appear, upon the frequency of heretofore the development of such currents the current in the circuit with which it may to any very high degree of precision has be connected. -
Alternating Current Principles
Basic Electrical Theory Power Principles and Phase Angle PJM State & Member Training Dept. PJM©2014 10/24/2013 Objectives • At the end of this presentation the learner will be able to; • Identify the characteristics of Sine Waves • Discuss the principles of AC Voltage, Current, and Phase Relations • Compute the Energy and Power on AC Systems • Identify Three-Phase Power and its configurations PJM©2014 10/24/2013 Sine Waves PJM©2014 10/24/2013 Sine Waves • Generator operation is based on the principles of electromagnetic induction which states: When a conductor moves, cuts, or passes through a magnetic field, or vice versa, a voltage is induced in the conductor • When a generator shaft rotates, a conductor loop is forced through a magnetic field inducing a voltage PJM©2014 10/24/2013 Sine Waves • The magnitude of the induced voltage is dependant upon: • Strength of the magnetic field • Position of the conductor loop in reference to the magnetic lines of force • As the conductor rotates through the magnetic field, the shape produced by the changing magnitude of the voltage is a sine wave • http://micro.magnet.fsu.edu/electromag/java/generator/ac.html PJM©2014 10/24/2013 Sine Waves PJM©2014 10/24/2013 Sine Waves RMS PJM©2014 10/24/2013 Sine Waves • A cycle is the part of a sine wave that does not repeat or duplicate itself • A period (T) is the time required to complete one cycle • Frequency (f) is the rate at which cycles are produced • Frequency is measured in hertz (Hz), One hertz equals one cycle per second PJM©2014 10/24/2013 Sine Waves -
Feedback Amplifiers
UNIT II FEEDBACK AMPLIFIERS & OSCILLATORS FEEDBACK AMPLIFIERS: Feedback concept, types of feedback, Amplifier models: Voltage amplifier, current amplifier, trans-conductance amplifier and trans-resistance amplifier, feedback amplifier topologies, characteristics of negative feedback amplifiers, Analysis of feedback amplifiers, Performance comparison of feedback amplifiers. OSCILLATORS: Principle of operation, Barkhausen Criterion, types of oscillators, Analysis of RC-phase shift and Wien bridge oscillators using BJT, Generalized analysis of LC Oscillators, Hartley and Colpitts’s oscillators with BJT, Crystal oscillators, Frequency and amplitude stability of oscillators. 1.1 Introduction: Feedback Concept: Feedback: A portion of the output signal is taken from the output of the amplifier and is combined with the input signal is called feedback. Need for Feedback: • Distortion should be avoided as far as possible. • Gain must be independent of external factors. Concept of Feedback: Block diagram of feedback amplifier consist of a basic amplifier, a mixer (or) comparator, a sampler, and a feedback network. Figure 1.1 Block diagram of an amplifier with feedback A – Gain of amplifier without feedback. A = X0 / Xi Af – Gain of amplifier with feedback.Af = X0 / Xs β – Feedback ratio. β = Xf / X0 X is either voltage or current. 1.2 Types of Feedback: 1. Positive feedback 2. Negative feedback 1.2.1 Positive Feedback: If the feedback signal is in phase with the input signal, then the net effect of feedback will increase the input signal given to the amplifier. This type of feedback is said to be positive or regenerative feedback. Xi=Xs+Xf Af = = = Af= Here Loop Gain: The product of open loop gain and the feedback factor is called loop gain. -
Unit I Microwave Transmission Lines
UNIT I MICROWAVE TRANSMISSION LINES INTRODUCTION Microwaves are electromagnetic waves with wavelengths ranging from 1 mm to 1 m, or frequencies between 300 MHz and 300 GHz. Apparatus and techniques may be described qualitatively as "microwave" when the wavelengths of signals are roughly the same as the dimensions of the equipment, so that lumped-element circuit theory is inaccurate. As a consequence, practical microwave technique tends to move away from the discrete resistors, capacitors, and inductors used with lower frequency radio waves. Instead, distributed circuit elements and transmission-line theory are more useful methods for design, analysis. Open-wire and coaxial transmission lines give way to waveguides, and lumped-element tuned circuits are replaced by cavity resonators or resonant lines. Effects of reflection, polarization, scattering, diffraction, and atmospheric absorption usually associated with visible light are of practical significance in the study of microwave propagation. The same equations of electromagnetic theory apply at all frequencies. While the name may suggest a micrometer wavelength, it is better understood as indicating wavelengths very much smaller than those used in radio broadcasting. The boundaries between far infrared light, terahertz radiation, microwaves, and ultra-high-frequency radio waves are fairly arbitrary and are used variously between different fields of study. The term microwave generally refers to "alternating current signals with frequencies between 300 MHz (3×108 Hz) and 300 GHz (3×1011 Hz)."[1] Both IEC standard 60050 and IEEE standard 100 define "microwave" frequencies starting at 1 GHz (30 cm wavelength). Electromagnetic waves longer (lower frequency) than microwaves are called "radio waves". Electromagnetic radiation with shorter wavelengths may be called "millimeter waves", terahertz radiation or even T-rays.