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	Standing wave ratio - Wikipedia, the free encyclopedia
		In telecommunications, standing wave ratio (SWR) is the ratio of the amplitude of a partial standing wave at an antinode (maximum) to the amplitude at an adjacent node (minimum).
		The SWR is usually defined as a voltage ratio called the VSWR, for voltage standing wave ratio.
		SWR is an indicator of reflected waves bouncing back and forth within the transmission line, and as such, an increase in SWR corresponds to an increase in power in the line beyond the actual transmitted power.
	en.wikipedia.org /wiki/Standing_wave_ratio (893 words)

	Standing Waves
		In each case we represent the wave amplitude by a complex phasor whose length is proportional to the size of the wave and whose phase angle tells us the relative phase with respect to the origin or zero of the time variable.
		In the case of positive travelling waves, the phase decreases as (-j beta x) with increasing distance x from the generator; whereas for negative travelling waves the phase advances as (+ j beta x) with increasing distance x from the generator.
		In the case of a complex reflection coefficient gamma, the phase angle of gamma determines where along the line the first standing wave minimum lies, in terms of the wavelength and the position of the load.
	www.ee.surrey.ac.uk /Personal/D.Jefferies/standingwaves.html (530 words)

	Standing wave Summary
		A standing wave, also known as a stationary wave, is a wave that remains in a constant position.
		As an example of the second type, a standing wave in a transmission line is a wave in which the distribution of current, voltage, or field strength is formed by the superposition of two waves propagating in opposite directions.
		The degree to which the wave resembles either a pure standing wave or a pure travelling wave is measured by the standing wave ratio (SWR).
	www.bookrags.com /Standing_wave (1742 words)

	Standing Wave Ratio
		The lower the number ratio is, the better the match between the antenna and the transmitter for transmitting RF signals.
		Where a 3:1 SWR is satisfactory with a 500-watt transmitter, a 2:1 SWR may be considered satisfactory with a 10-kilowatt transmitter.
		To achieve a perfect standing wave ratio of 1:1 would mean that we have succeeded in tuning out all other impedances and that the antenna is matched perfectly to the transmitted frequency.
	www.tpub.com /inch/26.htm (1006 words)

	Problems Two
		It is a dimensionless number, equal to the ratio of voltage at a standing wave pattern maximum to the voltage at a standing wave pattern minimum, 1/4 of a transmission line wavelength away along the line.
		The position of the first standing wave minimum is measured from the position of the load, and it is where a probe measuring the total voltage on the line would pick up the smallest signal, as the probe was run back along the line from the load.
		Here, the voltage and currents at the standing wave minimum are those that would be measured if we could include a current meter in one of the wires of the transmission line, and measure the voltage between the wires of the transmission line, both measurements being taken at the standing wave minimum.
	www.ee.surrey.ac.uk /Personal/D.Jefferies/probs2.html (1155 words)

	VSWR - Microwave Encyclopedia - Microwaves101.com
		Without the breakwater wall (which absorbs energy) huge standing waves are possible due to constructive interference, and all those boats would bob up and down like crazy corks and eventually everything would get smashed to tiny bits.
		It this point, 70% of the wave continues on (blue trace) and 30% of the wave is reflected backwards (purple trace).
		Note that the minimum voltage of the standing wave in each case is zero, which means the standing wave ratio is infinite.
	www.microwaves101.com /encyclopedia/vswr.cfm (1479 words)

	Acoustic Lecture Notes
		When a wave is incident on a boundary, the complete acoustic field will result from the superposition of the incident and reflected waves.
		Standing wave formed by incident and partially reflected wave with r as a fraction of the incident wave amplitude in the reflected wave
		The pressures at the nodes and antinodes are measured using probe microphone and the standing wave ratio, S.W.R., in the tube determined.
	www.phys.unsw.edu.au /~kryw/clectures/acoustic/Acoustic1279.html (1589 words)

	Twelfth-wave feedback
		On both sides of the transformer the ratio of the power in the forward wave to the power in the reflected wave will be the same; this is exactly equivalent to saying that the SWR will be the same on both sides of the transformer.
		The relative phases of the forward and reflected wave will be changed after passing through the transformer, but the relative amplitude of each wave will be unchanged; so, the SWR is the same.
		The phase of the standing wave on the transmitter side of the transformer will also depend on the phase of the standing wave on the antenna side - i.e.
	ourworld.compuserve.com /homepages/demerson/12thfdbk.htm (1224 words)

	SWR-INTRO
		"SWR" is the common abbreviation for "Standing Wave Ratio".
		The SWR difference between these two channels will tell you if the antenna is electrically short (channel 19 resonant frequency too high) or electrically long (channel 19 resonant frequency too low).
		With that in mind, the SWR meter is placed in-line between the radio and the coaxial cable that feeds the antenna.
	www.firestik.com /Tech_Docs/swr-intro.htm (967 words)

	G4NSJ SWR VSWR ISWR STANDING WAVE RATIO WAVES VOLTAGE CURRENT
		The standing wave ratio compares the maximum amount of voltage or current pumped into the feeder and aerial to the voltage or current reflected back along the line to the transmitter.
		The two wires in the cheaper SWR meters are usually in the form copper strips on a printed circuit board.
		If the SWR is high, then some of the RF is being reflected back down the feeder to the transmitter rather than leaving the aerial.
	www.g4nsj.co.uk /swr.shtml (514 words)

	Agilent Technologies \| Educator's Corner - Resource Guide for Engineering Educators \| Wave Propagation along a ...
		But the amplitude of the resultant waveform, indicated by the standing wave (green), is not constant along the entire line because the transmitted and reflected signals (yellow and blue) combine.
		The sine wave at point z4 would also be of constant amplitude, but its amplitude would differ from that of the signal at point z6.
		The VSWR, or Voltage Standing Wave Ratio, is the ratio of the highest amplitude signal to the lowest amplitude signal, as measured along the transmission line.
	www.educatorscorner.com /index.cgi?CONTENT_ID=2483 (601 words)

	CBShop intro to standing wave ratio SWR
		SWR (standing wave ratio) is a term every CB'er should know.
		SWR (measured with an SWR meter) shows you how well your coax, antenna mount, ground plane and antenna match the output capability of your CB radio.
		It is a ratio of maximum voltage or current to minimum voltage or current.
	www.cbshop.com /intro_swr.asp (664 words)

	ECE357: Standing Wave Ratio
		The first part will combine with the reflected wave to give a standing wave on the line, while the second part can be thought of as a travelling wave which is just a scaled down version of the original incident wave (see picture).
		Note that the standing wave and the travelling wave will be in phase whenever the standing wave reaches its biggest amplitudes.
		The Standing Wave Ratio is just a way to describe how much variation there is between the different amplitudes of the superposition waveform: S = Vmin/Vmax = (1 + Γ) / (1 - Γ).
	lobe.ibme.utoronto.ca /ECE357/SWR.html (677 words)

	Part 1 - Design, Calibration and Performance of Standing-Wave-Ratio Meters
		An SWR meter is a fixed-ratio resistance bridge.
		It is located in a coaxial line between the transmitter and the antenna where, subject to certain conditions, it indicates SWR on the section of line between transmitter and meter.
		SWR = (1+RC)/(1-RC) may be indicated on the same meter face, the scale being graduated non-linearly, 1 to Infinity.
	www.smeter.net /feeding/swrmeter.php (482 words)

	Wideband SWR meter
		The fact is that the impedance transformations along a transmission line lead to sections with higher and lower voltage, and higher and lower current, called standing waves because the highs and lows are spaced in wavelengths at the operating frequency, and do not move along the cable.
		This ratio happens to be equal to the ratio between the highest and lowest current, and also is equal to the ratio between the cable impedance and the load impedance!
		SWR = (1+p) / (1-p) where p is the position on the meter scale, ranging from 0 to 1.
	ludens.cl /Electron/swr/swr.html (3255 words)

	Where There Is No Telephone
		VSWR stands for Voltage Standing Wave Ratio and is often abbreviated to SWR.
		SWR is a measure of how suitable an aerial is for a particular transmitter at a particular frequency i.e.
		This is done by measuring the SWR at the transceiver output socket and by reducing or increasing the length of the coaxial cable until an acceptable SWR is achieved e.g.
	www.reliefweb.int /library/wtint/chap2.html (1888 words)

	What is standing-wave ratio? - a definition from Whatis.com - see also: SWR, VWSR, IWSR
		Usually, SWR is defined as the ratio of the maximum radio-frequency (RF) voltage to the minimum RF voltage along the line.
		When the line and load impedances are identical and the SWR is 1, all of the RF power that reaches a load from a transmission line is utilized by that load.
		The SWR is the ratio of the RF voltage at a loop to the RF voltage at a node, or the ratio of the RF current at a loop to the RF current at a node.
	searchsmb.techtarget.com /sDefinition/0,,sid44_gci852555,00.html (840 words)

	Understanding Standing Wave Ratios
		The term Standing Wave Ratio, SWR, relates to the variation in the voltage (or current) along the length of the transmission line from the transceiver to the antenna.
		The total loss in power due to a high SWR is the sum of the db power reduction imposed by the transceiver’s protective circuitry and the loss resulting from reflection at the antenna.
		For an SWR less than 1.5:1, power loss is negligible since the transceiver operates at full output power and the mismatch reflection loss at the antenna is less than 0.18 db.
	www.cvarc.org /tech/standwave.html (2118 words)

	Standing wave ratio Information - standing wave ratio
		In telecommunication, standing wave ratio (SWR) is the ratio of the amplitude of a partial standing wave at an antinode (maximum) to the amplitude at an adjacent node (minimum).
		As standing wave ratio ρ, the magnitude of Γ, is always >= 0, the VSWR is always >= +1.
		The study of new semiconductor devices and their technology is sometimes considered as a branch of physics.
	www.inanot.com /Ina-Electronics_Topics_Sk_-_Sy-/Standing_wave_ratio.html (853 words)

	Transmission Line Concepts
		Part of the power is reflected back so that phase addition and subtraction of the incident and reflected waves creates a voltage standing wave pattern on the transmission line.
		Return loss is a measure in dB of the ratio of power in the incident wave to that in the reflected wave, and as defined above always has a positive value.
		From the ratio of the maximum to minimum voltage, the reflection coefficient and terminating impedance could be calculated.
	www.ab4oj.com /atu/vswr.html (632 words)

	Unit 1 - Transmission Line Theory
		For either wave component, the ratio of the voltage to current is a constant, known as the characteristic impedance.
		On moving away from the load to a plane along the transmission line, the voltage reflection coefficient may be expressed as the ratio of the reverse wave voltage to the forward wave voltage at that plane.
		The voltage standing wave ratio (V.S.W.R.) is the ratio of the maximum to minimum voltage on the line.
	members.tripod.com /eva_shinji_ikari_7/Elec2015/03s2/High/all_1.htm (1010 words)

	Sudeep Audio : Radio Terminology
		This is called Standing Wave Ratio (or more correctly V.S.W.R.) and is much beloved by many who like to become paranoid over something.
		If some of the transmitted power is reflected back along the transmission line toward the transmitter then we have a situation where voltage standing wave patterns exist.
		S-meters are as accurate as a group of people standing by the road and individually estimating the speed of passing vehicles.
	www.sudeepaudio.com /fm/term2.htm (1684 words)

	Definition: standing wave ratio (Site not responding. Last check: 2007-11-03)
		standing wave ratio (SWR): The ratio of the amplitude of a standing wave at an anti-node (minimum) to the amplitude at an adjacent node (maximum).
		Note 1: The standing wave ratio (SWR) in a uniform transmission line is given by
		Note 2: Reflections occur as a result of discontinuities, such as an imperfection in an otherwise uniform transmission line, or when a transmission line is terminated with other than its characteristic impedance.
	www.atis.org /tg2k/_standing_wave_ratio.html (89 words)

	Standing Wave Animations
		In each case the fundamental waves are in fl and the superposition is shown in blue.
		The superposition of two continuous sinusoids of identical wavelength and velocity, but with amplitudes in the ratio of 2 to 1 combining to yield a "Standing Wave Ratio" of 3 to 1.
		Energy is transported from each side toward the center of the pattern where the two amplitudes are equal and the wave becomes stationary.
	www.csupomona.edu /~ajm/materials/animations/stwaves.html (247 words)

	Microwave Theory
		The amplitude of the reflected voltage wave normalized to the amplitude of the incident voltage wave is known as the voltage reflection coefficient,
		The standing waves cause the impedance to fluctuate as a function of distance from the load.
		To launch a wave, on the microstrip transmission line the microwave signal is brought from the generator on a coaxial cable which connects to an on-board PCB mounted jack which is soldered directly to the groundplane and feedlines.
	www.madmadscientist.com /html/Theory.htm (1720 words)

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