Impedance Matching
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
A Review of Electric Impedance Matching Techniques for Piezoelectric Sensors, Actuators and Transducers
Review A Review of Electric Impedance Matching Techniques for Piezoelectric Sensors, Actuators and Transducers Vivek T. Rathod Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, USA; [email protected]; Tel.: +1-517-249-5207 Received: 29 December 2018; Accepted: 29 January 2019; Published: 1 February 2019 Abstract: Any electric transmission lines involving the transfer of power or electric signal requires the matching of electric parameters with the driver, source, cable, or the receiver electronics. Proceeding with the design of electric impedance matching circuit for piezoelectric sensors, actuators, and transducers require careful consideration of the frequencies of operation, transmitter or receiver impedance, power supply or driver impedance and the impedance of the receiver electronics. This paper reviews the techniques available for matching the electric impedance of piezoelectric sensors, actuators, and transducers with their accessories like amplifiers, cables, power supply, receiver electronics and power storage. The techniques related to the design of power supply, preamplifier, cable, matching circuits for electric impedance matching with sensors, actuators, and transducers have been presented. The paper begins with the common tools, models, and material properties used for the design of electric impedance matching. Common analytical and numerical methods used to develop electric impedance matching networks have been reviewed. The role and importance of electrical impedance matching on the overall performance of the transducer system have been emphasized throughout. The paper reviews the common methods and new methods reported for electrical impedance matching for specific applications. The paper concludes with special applications and future perspectives considering the recent advancements in materials and electronics. -
Impedance Matching
Impedance Matching Advanced Energy Industries, Inc. Introduction The plasma industry uses process power over a wide range of frequencies: from DC to several gigahertz. A variety of methods are used to couple the process power into the plasma load, that is, to transform the impedance of the plasma chamber to meet the requirements of the power supply. A plasma can be electrically represented as a diode, a resistor, Table of Contents and a capacitor in parallel, as shown in Figure 1. Transformers 3 Step Up or Step Down? 3 Forward Power, Reflected Power, Load Power 4 Impedance Matching Networks (Tuners) 4 Series Elements 5 Shunt Elements 5 Conversion Between Elements 5 Smith Charts 6 Using Smith Charts 11 Figure 1. Simplified electrical model of plasma ©2020 Advanced Energy Industries, Inc. IMPEDANCE MATCHING Although this is a very simple model, it represents the basic characteristics of a plasma. The diode effects arise from the fact that the electrons can move much faster than the ions (because the electrons are much lighter). The diode effects can cause a lot of harmonics (multiples of the input frequency) to be generated. These effects are dependent on the process and the chamber, and are of secondary concern when designing a matching network. Most AC generators are designed to operate into a 50 Ω load because that is the standard the industry has settled on for measuring and transferring high-frequency electrical power. The function of an impedance matching network, then, is to transform the resistive and capacitive characteristics of the plasma to 50 Ω, thus matching the load impedance to the AC generator’s impedance. -
Voltage Standing Wave Ratio Measurement and Prediction
International Journal of Physical Sciences Vol. 4 (11), pp. 651-656, November, 2009 Available online at http://www.academicjournals.org/ijps ISSN 1992 - 1950 © 2009 Academic Journals Full Length Research Paper Voltage standing wave ratio measurement and prediction P. O. Otasowie* and E. A. Ogujor Department of Electrical/Electronic Engineering University of Benin, Benin City, Nigeria. Accepted 8 September, 2009 In this work, Voltage Standing Wave Ratio (VSWR) was measured in a Global System for Mobile communication base station (GSM) located in Evbotubu district of Benin City, Edo State, Nigeria. The measurement was carried out with the aid of the Anritsu site master instrument model S332C. This Anritsu site master instrument is capable of determining the voltage standing wave ratio in a transmission line. It was produced by Anritsu company, microwave measurements division 490 Jarvis drive Morgan hill United States of America. This instrument works in the frequency range of 25MHz to 4GHz. The result obtained from this Anritsu site master instrument model S332C shows that the base station have low voltage standing wave ratio meaning that signals were not reflected from the load to the generator. A model equation was developed to predict the VSWR values in the base station. The result of the comparism of the developed and measured values showed a mean deviation of 0.932 which indicates that the model can be used to accurately predict the voltage standing wave ratio in the base station. Key words: Voltage standing wave ratio, GSM base station, impedance matching, losses, reflection coefficient. INTRODUCTION Justification for the work amplitude in a transmission line is called the Voltage Standing Wave Ratio (VSWR). -
RF Matching Network Design Guide for STM32WL Series
AN5457 Application note RF matching network design guide for STM32WL Series Introduction The STM32WL Series microcontrollers are sub-GHz transceivers designed for high-efficiency long-range wireless applications including the LoRa®, (G)FSK, (G)MSK and BPSK modulations. This application note details the typical RF matching and filtering application circuit for STM32WL Series devices, especially the methodology applied in order to extract the maximum RF performance with a matching circuit, and how to become compliant with certification standards by applying filtering circuits. This document contains the output impedance value for certain power/frequency combinations, that can result in a different output impedance value to match. The impedances are given for defined frequency and power specifications. AN5457 - Rev 2 - December 2020 www.st.com For further information contact your local STMicroelectronics sales office. AN5457 General information 1 General information This document applies to the STM32WL Series Arm®-based microcontrollers. Note: Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere. Table 1. Acronyms Acronym Definition BALUN Balanced to unbalanced circuit BOM Bill of materials BPSK Binary phase-shift keying (G)FSK Gaussian frequency-shift keying modulation (G)MSK Gaussian minimum-shift keying modulation GND Ground (circuit voltage reference) LNA Low-noise power amplifier LoRa Long-range proprietary modulation PA Power amplifier PCB Printed-circuit board PWM Pulse-width modulation RFO Radio-frequency output RFO_HP High-power radio-frequency output RFO_LP Low-power radio-frequency output RFI_N Negative radio-frequency input (referenced to GND) RFI_P Positive radio-frequency input (referenced to GND) Rx Receiver SMD Surface-mounted device SRF Self-resonant frequency SPDT Single-pole double-throw switch SP3T Single-pole triple-throw switch Tx Transmitter RSSI Received signal strength indication NF Noise figure ZOPT Optimal impedance AN5457 - Rev 2 page 2/76 AN5457 General information References [1] T. -
Reflection Coefficient Analysis of Chebyshev Impedance Matching Network Using Different Algorithms
ISSN: 2319 – 8753 International Journal of Innovative Research in Science, Engineering and Technology Vol. 1, Issue 2, December 2012 Reflection Coefficient Analysis Of Chebyshev Impedance Matching Network Using Different Algorithms Rashmi Khare1, Prof. Rajesh Nema2 Department of Electronics & Communication, NIIST/ R.G.P.V, Bhopal, M.P., India 1 Department of Electronics & Communication, NIIST/ R.G.P.V, Bhopal, M.P., India 2 Abstract: This paper discuss the design and implementation of broadband impedance matching network using chebyshev polynomial. The realization of 4-section impedance matching network using micro-strip lines each section made up of different materials is carried out. This paper discuss the analysis of reflection in 4-section chebyshev impedance matching network for different cases using MATLAB. Keywords: chebyshev polynomial , reflection, micro-strip line, matlab. I. INTRODUCTION In many cases, loads and termination for transmission lines in practical will not have impedance equal to the characteristic impedance of the transmission line. This result in high reflections of wave transverse in the transmission line and correspondingly a high vswr due to standing wave formations, one method to overcome this is to introduce an arrangement of transmission line section or lumped elements between the mismatched transmission line and its termination/loads to eliminate standing wave reflection. This is called as impedance matching. Matching the source and load to the transmission line or waveguide in a general microwave network is necessary to deliver maximum power from the source to the load. In many cases, it is not possible to choose all impedances such that overall matched conditions result. These situations require that matching networks be used to eliminate reflections. -
Coupled Transmission Lines As Impedance Transformer
Downloaded from orbit.dtu.dk on: Sep 25, 2021 Coupled Transmission Lines as Impedance Transformer Jensen, Thomas; Zhurbenko, Vitaliy; Krozer, Viktor; Meincke, Peter Published in: IEEE Transactions on Microwave Theory and Techniques Link to article, DOI: 10.1109/TMTT.2007.909617 Publication date: 2007 Document Version Peer reviewed version Link back to DTU Orbit Citation (APA): Jensen, T., Zhurbenko, V., Krozer, V., & Meincke, P. (2007). Coupled Transmission Lines as Impedance Transformer. IEEE Transactions on Microwave Theory and Techniques, 55(12), 2957-2965. https://doi.org/10.1109/TMTT.2007.909617 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. 1 Coupled Transmission Lines as Impedance Transformer Thomas Jensen, Vitaliy Zhurbenko, Viktor Krozer, Peter Meincke Technical University of Denmark, Ørsted•DTU, ElectroScience, Ørsteds Plads, Building 348, 2800 Kgs. Lyngby, Denmark, Phone:+45-45253861, Fax: +45-45931634, E-mail: [email protected] Abstract— A theoretical investigation of the use of a coupled line transformer. -
Chapter 25: Impedance Matching
Chapter 25: Impedance Matching Chapter Learning Objectives: After completing this chapter the student will be able to: Determine the input impedance of a transmission line given its length, characteristic impedance, and load impedance. Design a quarter-wave transformer. Use a parallel load to match a load to a line impedance. Design a single-stub tuner. You can watch the video associated with this chapter at the following link: Historical Perspective: Alexander Graham Bell (1847-1922) was a scientist, inventor, engineer, and entrepreneur who is credited with inventing the telephone. Although there is some controversy about who invented it first, Bell was granted the patent, and he founded the Bell Telephone Company, which later became AT&T. Photo credit: https://commons.wikimedia.org/wiki/File:Alexander_Graham_Bell.jpg [Public domain], via Wikimedia Commons. 1 25.1 Transmission Line Impedance In the previous chapter, we analyzed transmission lines terminated in a load impedance. We saw that if the load impedance does not match the characteristic impedance of the transmission line, then there will be reflections on the line. We also saw that the incident wave and the reflected wave combine together to create both a total voltage and total current, and that the ratio between those is the impedance at a particular point along the line. This can be summarized by the following equation: (Equation 25.1) Notice that ZC, the characteristic impedance of the line, provides the ratio between the voltage and current for the incident wave, but the total impedance at each point is the ratio of the total voltage divided by the total current. -
Output Impedance Matching with Fully Differential Operational Amplifiers
Texas Instruments Incorporated Amplifiers: Op Amps Output impedance matching with fully differential operational amplifiers By Jim Karki Member, Technical Staff, High-Performance Analog Introduction synthetic imped ance matching is more complex. So we Impedance matching is widely used in the transmission of will first look at the output impedance using only series signals in many end applications across the industrial, matching resistors, and then use that as a starting point to communications, video, medical, test, measurement, and consider the more complex synthetic impedance matching. military markets. Impedance matching is important to The fundamentals of FDA operation are presented in reduce reflections and preserve signal integrity. Proper Reference 1. Since the principles and terminology present- termination results in greater signal integrity with higher ed there will be used throughout this article, please see throughput of data and fewer errors. Different methods Reference 1 for definitions and derivations. have been employed; the most commonly used are source Standard output impedance termination, load termination, and double termination. An FDA works using negative feedback around the main Double termination is generally recognized as the best method to reduce reflections, while source and load termi- loop of the amplifier, which tends to drive the impedance nation have advantages in increased signal swing. With at the output terminals, VO– and VO+, to zero, depending source and load termination, either the source or the load on the loop gain. An FDA with equal-value resistors in (not both) is terminated with the characteristic imped- each output to provide differential output termination is ance of the transmission line. -
Determining the Proper Jumper Setting
DETERMINING THE PROPER JUMPER SETTING FOR IMPEDANCE MATCHING The jumper must be set in a position that correctly multiplies the impedance of the system to a level that is equal to or greater than the impedance of the amplifier. The jumper setting can be determined using the following simple steps: 1. Determine the amplifier's minimum impedance. The amplifier's minimum impedance is usually found following Wattage and Frequency Response in the amplifier's specification page of the manual. It may also be listed on the back panel of the amplifier near the speaker terminals. AC impedance is measured in ohms. 2. Identify the correct impedance-matching chart according to the amplifier's minimum impedance. There are two impedance matching charts, one for 8 ohm amplifiers and one for 4 ohm amplifiers. Choose the chart that describes your amplifier. If your amplifier is 6 ohm stable, use the 8 ohm chart. 3. Determine the impedance for each pair of speakers by referring to its manual. 4. Determine the total number of 4 ohm pairs of speakers. (rows on charts) 5. Determine the total number of 8 ohm pairs of speakers. (columns on charts) 6. Follow the appropriate row and column to determine jumper settings. IMPEDANCE MATCHING VOLUME CONTROLS Impedance matching volume controls eliminate the need for a speaker selector. By determining the drive capability of the amplifier with a few simple calculations, we can determine the number of speakers the system can safely operate. CONSIDERATIONS 1. Make sure that your amplifier has adequate wattage for the number of speakers. Watts per channel divided by the number of pairs should equal or exceed the individual speaker’s minimum wattage requirements. -
Microwave Impedance Measurements and Standards
NBS MONOGRAPH 82 MICROWAVE IMPEDANCE MEASUREMENTS AND STANDARDS . .5, Y 1 p p R r ' \ Jm*"-^ CCD 'i . y. s. U,BO»WOM t «• U.S. DEPARTMENT OF STANDARDS NATIONAL BUREAU OF STANDARDS THE NATIONAL BUREAU OF STANDARDS The National Bureau of Standards is a principal focal point in the Federal Government for assuring maximum application of the physical and engineering sciences to the advancement of technology in industry and commerce. Its responsibilities include development and main- tenance of the national standards of measurement, and the provisions of means for making measurements consistent with those standards; determination of physical constants and properties of materials; development of methods for testing materials, mechanisms, and struc- tures, and making such tests as may be necessary, particularly for government agencies; cooperation in the establishment of standard practices for incorporation in codes and specifications; advisory service to government agencies on scientific and technical problems; invention and development of devices to serve special needs of the Government; assistance to industry, business, and consumers in the development and acceptance of commercial standards and simplified trade practice recommendations; administration of programs in cooperation with United States business groups and standards organizations for the development of international standards of practice; and maintenance of a clearinghouse for the collection and dissemination of scientific, technical, and engineering information. The scope of the Bureau's activities is suggested in the following listing of its four Institutes and their organizational units. Institute for Basic Standards. Applied Mathematics. Electricity. Metrology. Mechanics. Heat. Atomic Physics. Physical Chem- istry. Laboratory Astrophysics.* Radiation Physics. Radio Stand- ards Laboratory:* Radio Standards Physics; Radio Standards Engineering. -
Vswr-Lecture.Pdf
The Principle V(SWR) The Result Mirror, Mirror, Darkly, Darkly 1 Question time!! • What do you think VSWR (SWR) mean to you? • What does one mean by a transmission line? – Coaxial line – Waveguide – Water pipe – Tunnel (Top Gear, The Grand Tour) • Relative permittivity. – Vacuum = 1.00000 – Air = κair = 1.0006. • Why is the concept of an infinite transmission line of any use? 2 VSWR Schematic The elements in the orange box represents the equivelent circuit of a transmission line. This circuit demonstrates that the characteristics of the line are determined by mechanical effects: Capacitance is proportional to the area divided by the gap. Inductance is proportional to the number turns and area of the loop Resistance is determined by the material it is made up of. 3 Some Definitions • What is meant by an infinite transmission line and what does have to matching and hence, VSWR. – Any line that is perfectly matched, by definition has VSWR of 1:1 – A line which has infinite length (free space=377Ώ). – A large attenuator – A transmission line can have any impedance. 4 VSWR Waveform • Circuit 5 50.9 50.7 6 Power 50.5 50.3 50.1 49.9 49.7 49.5 49.3 49.1 Power 48.9 48.7 48.5 120.00 119.00 118.00 117.00 116.00 115.00 114.00 113.00 112.00 111.00 110.00 Ώ The theorem shows the maximum power transfer with source and resistance resistance and withsource transfer power maximum the shows theorem The 100 to set Maximum power transfer theorem transfer power Maximum • Some more Definitions • What is VSWR? – VSWR is the acronym for Voltage (Standing Wave Ratio). -
Significant Papers from the First 50 Years of the Boulder Labs
B 0 U l 0 I R LABORATORIES u.s. Depan:ment • "'.."'c:omn-..""""....... 1954 - 2004 NISTIR 6618 and NTIA SP-04-416 Significant Papers from the First 50 Years of the Boulder Labs Edited by M.E. DeWeese M.A. Luebs H.L. McCullough u.s. Department of Commerce Boulder Laboratories NotionallnstitlJte of Standards and Technology Notional Oc::eonic and Atmospheric Mministration Notional Telecommunications and Informofion Administration NISTIR 6618 and NTIA SP-04-416 Significant Papers from the First 50 Years of the Boulder Labs Edited by M.E. DeWeese, NIST M.A. Luebs, NTIA H.L. McCullough, NOAA Sponsored by National Institute of Standards and Technology National Telecommunications and Information Administration National Oceanic and Atmospheric Administration Boulder, Colorado August 2004 U.S. Department of Commerce Donald L. Evans, Secretary National Institute of Standards and Technology Arden L. Bement, Jr., Director National Oceanic and Atmospheric Administration Conrad C. Lautenbacher, Jr., Undersecretary of Commerce for Oceans and Atmosphere and NOAA Administrator National Telecommunications and Information Administration Michael D. Gallagher, Assistant Secretary for Communications and Information ii Acronym Definitions CEL Cryogenic Engineering Laboratory CIRES Cooperative Institute for Research in Environmental Sciences CRPL Central Radio Propagation Laboratory CU University of Colorado DOC Department of Commerce EDS Environmental Data Service ERL ESSA Research Laboratory ESSA Environmental Science Services Administration ITS Institute for