Questions tagged [transmission-line]
A transmission line may refer to a cable or assembly that is designed to carry radio frequencies and must consider the wave nature of the signal. Coaxial cable is an example of a transmission line. It may also refer to high-voltage power transmission lines, used to transfer power from generating stations to consumers.
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Can I calculate minimum rise time of a transmission line if I know the length and the loss tangent?
Overview: I am trying to work out if it's possible to transmit my 1.2Gbps MIPI data down a 600mm long flexible PCB strip. Assuming I have the impedance correct, will the signal still be degraded by ...
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Unequal resistive power splitter
I'm looking at a 3-port, unequal resistive power splitter design like the dashed-line box in the diagram.
1 is the source, whereas 2 and 3 are two loads of impedance, say Z0. All 1, 2, and 3 are ...
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Analytical solution for the characteristic impedance along vertical wire over PEC ground plane (at given point h)?
For the purpose of TL transformer simulation I need a solution for the characteristic impedance of vertical wire, with radius a, at the infinitesimally short segment - not point, at the height h above ...
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When should an unmatched antenna be measured with a cable length in even multiples of a half-wavelength?
A few years ago someone told me that if you use a cable which has a length of an even half-wavelength multiple for the frequency being tested, then the impedance measured at the end of that cable will ...
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Time delay in lumped element delay line
I was trying to analyse a lumped element-delay line by changing the frequency and measuring \$ V_{in}\$ , as shown in the graph the goal of my analysis is to find the time-delay and the attenuation ...
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Connecting CMOS sensor to (far away) PCB: understanding cable length
The problem is a bit complex due to the number of unknown parameters and my inexperience. I need a way to determine how far I can put the PCB from the sensor without problems in the transmission of ...
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Parasitic Passbands in distributed filters
it is known that if we realize a filter (for instance a low pass filter) by using distributed elements (transmission lines), there will be some parasitic passbands (which moreover show a behaviour ...
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Transmission Line (shielded dual stripline )
Evaluate and illustrate:
equipotential contours and a vector electric field distribution for .
I got this result: and .
I want to ask that, is the direction of the Electric field lines are correct?
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Parallel transmission lines impedance
I just want to know the correct way to calculate \$Z_{in}\$ in this network. It's very simple but I think I might be doing something wrong. Is it ok to calculate the impedance over one line and get \$...
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Capacitance among N conductors
I would like to have a rough estimate of the capacitance per unit length of a system composed by N parallel identical straight wires.
I tried to sketch the capacitance network but I'm able to solve it ...
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Understanding amplitude-time peaks in one dimensional reflection and transmission of sound waves
There is a one dimensional system of interfaces with a transducer sending and receiving sound wave (Plane wave) normal to the interface boundary. The system consists of two mediums, medium 1 & ...
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How to calculate the earth fault current in a transmission system with no ground wire?
Background information, and my thought on the matter are provided in the end of the question.
I need to calculate the fault current in case a fault occur for instance 10 km away from a transformer ...
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What is happening, physically during a Transmission Line Reflection in a closed and open circuit scenario?
I am having trouble understanding what is happening physically during a transmission line reflection, in particular the short circuit and open circuit case. I understand that when when a transmission ...
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Modelling an RS-485 Bus
I am trying to model an RS-485 bus in LTSpice that consists of two power conductors and two data conductors within a single cable. The power conductors are twisted together and shielded, and the data ...
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How to design for an impedance matching device for non-TEM waveguides?
Let us start from the assumption that we are working with RF waveguides which do not support TEM modes. In such scenario, there is no physical (only formal) meaning to an equivalent voltage and ...
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Validity of RLGC model for QTEM transmission lines with numerically calculated characteristic impedance and propagation constant
My problem
In my understanding, any system that supports a QTEM mode can be represented by an RLGC transmission line model with negligible error. Indeed, when I perform a calculation in CST microwave ...
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Integrated Circuit z-impedance
I have an OBU (On-board Unit) circuit and it has a DSRC (Dedicated Short-Range Comm) IC, but I don't have any information about the IC from S11 and Z etc.
I want to ask how can I find the Z-impedance ...
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How do I correctly calculate the S-parameters of cascaded lines?
Suppose I have two coupled transmission lines cascaded. I know the S parameters of both lines. From these S parameters, I can extra SA and SB
S = [SA SB; SB SA]
Now, I can find S_odd = SA-SB and ...
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How to determine the length of a quarter wave transmission line which would be added to an existing circuit for impedance matching?
Are the values I have calculated accurate? With this setup, there seems to be a 90 degree phase difference across Tx2. I'm not sure if the 90 degree phase shift is supposed to across just Tx1 or ...
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Are transistors on MMICs considered lumped elements?
Are transistors, in practice, always small enough to be considered lumped elements in Monolithic Microwave Integrated Circuits (MMICs)? Similarly for discrete transistors used in hybrid microwave ...
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Phase velocity non-TEM transmission line
Assuming that a transmission line operates in a TEM or quasi-TEM mode, the phase velocity can be determined from the line parameters (R,L,C,G per meter assuming the RLCG model of a transmission line). ...
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How to determine the rise time to treat if the signal as a transmission line?
I know that If the length of the track is between 1/6 or 1/4 of the effective length of a feature like an edge a system can be regarded as lumped.
BUT A a lot of times, the rise time cannot be taken ...
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Why is the relation between voltage ratio and frequency a linear one in a lumped transition line?
In an experiment the cutoff frequency of a lumped transmission line is determined by measuring the ratio of the output/input voltages.
The lumped transmission line is a ladder network of 40 capacitors ...
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Transmission Line Power Flow
Background:
So, I recently watched Veritasium's video, "The Big Misconception About Electricity" and EEVblog's response to it.
Here is the circuit in question:
I think understand why the ...
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Slew rate in a transmission line
Let's say I have a 3km long transmission line with a capacitance of C = 50pF/m, the resistance is 100Ohm. The inductance and the conductance per unit length are negligible.
If I want to receive the ...
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Solutions to wave equations
In the following steps for a solution to the Telegrapher's equations, I don't understand how equation 9.17 follows from 9.16. Substituting in \$\gamma\$ as given, it seems that the result should be \$...
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Double Stub Matching Impedance
I'm trying to understand the double stub matching impedance using Smith Chart.
Here is the diagram for the double stub impedance:
The impedance on the right has to appear purely resistive.
So ...
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Is it beneficial to use a taper for the feed input of a PCB antenna?
What is your opinion on using a taper for the feed input of a PCB antenna? Say the feed is 2mm wide and the transmission line is 0.45 mm. Would a taper just cause more impedance mismatch? Or would it ...
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Transmission lines in paralell for RS485
I have a system with two RS485 transceivers connected by a 300 meters long cable, with 6 wires inside it. In this case, 3 paralell wires of this cable are being used for the "A" signal and ...
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Voltage regulation at full load
The voltage regulation is I(Rcosa -Xsina)/Vr
For leading pf
Here %of regulation=(VRcosa-Vxsina)/Vr ×100 %=((4×0.8)-(6×0.6))/100 ×100% =-0.4
Where I am doing wrong?
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The reason the advantage of Single conductor transmission line be changed to non-singular conductor transmission line
Question:
If Single conductor of EHV(Extra high voltage) transmission line be changed to non-singular conductor of EHV transmission line,there are some advantages about this changing
1.Decrease the ...
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Detecting an electrical connection without a complete circuit
Wired Fencing
In a regular (wired) fencing system (for sabre and foil,) contact is determined simply by applying a current to the weapon through a wire and forming a circuit between a conductive ...
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Deriving admittance matrix for shortened quarter-wavelength transmission line
For Reduced-size branch-line and rat-race hybrids for uniplanar MMIC's , how to derive equation (2) ?
and is the imaginary constant j needed in equation (1) ?
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Can I represent this circuit like this
I want to do even-odd mode analysis, is representation of the circuit as shown below correct? Are these two circuits equivalent. Z is the characteristic impedances and theta are the electrical length ...
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Ringing issue in high-side IGBT connected transmission line
I am trying to charge a transmission line (Z0=4.4 ohms, propagation delay=1.4 ns) by a HV (1-1000 V, 600 mA) power supply through a 1700 V rated IGBT (S1). The charged transmission line gets ...
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Transmission Line 2-Port Parameters
I am checking some Spice models of transmission lines.
I have a Belden 1583A Ethernet Cable, with the following parameters \$R=93.8 \ \Omega\text{/km}\$ and \$Z_0=100 \Omega\$, hence \$C=47.652 \ \...
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Can I use a RF and/or Time-domain reflectometer to find 'wet contact'?
Friends of mine have a circuit where the RCD trips but only after prolonged rain. There are a number of garden and security lights on that circuit so I very much suspect there is a junction box where ...
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Load Impedance Derivation
I'm having some trouble deriving this equation for transmission line theory:
From: http://www.antenna-theory.com/tutorial/txline/transmission3.php
When I sub the Telegrapher's equations into eqn ...
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Use of 3 phase transformers which are ∆-Y connected and Y-∆ connected
Different literatures say different things regarding ∆-Y and Y-∆ 3 phase transformer connection...
Some say that ∆-Y is used for step down and Y-∆ is used for step up while others say just the ...
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Determining the Impedance of the antenna on a known circuit
I am stuck on how to approach the following problem:
I have a graph with both the response of a short-circuit and an unknown impedance antenna.
The only information I have from this graph is the ...
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Some calculations on Transmission Lines
I have to do some (simple) calculations for a transmission line. I was given a power supply of \$11V\$/\$22\Omega\$, \$Z_0 = 50\Omega\$, \$v = 2.2 \times 10^8 m/s\$, a load capacitance of \$1.124nF\$ ...
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Has anyone ever seen this transmission line setup (double series terminated)?
I am designing a custom PCB interface to be used with some off-the-shelf devices. The relevant off-the-shelf interface they provide is cumbersome and doesn't fit my application, so I am designing my ...
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Find the the length x of the transmission line of \$100 \Omega\$ characteristic impedance
Find the the length x of the transmission line of \$100 \Omega\$ characteristic impedance where the load \$Z_L\$=\$100 + j 100 \Omega\$ becomes purely resistive. Also find \$R_x\$. Assume \$VSWR = 2.6 ...
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Transformer impedence-question about problems
I'm given this transmission line problem in which I have a 3-phase transformer and I'm also given its impedence. I usually solve these problems using only one phase. So what should the impedence value ...
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Confusion in parrallel and series of Transmission line
A transmission line terminals in two branches,each of length \$\frac{\lambda}{4}\$,as shown.The branches are terminated by \$50 \Omega\$ loads.The lines are lossless and have the characteristics ...
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Divergence of Et in TEM propagation in transmission lines
I was going through MIT opencourseware https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-013-electromagnetics-and-applications-spring-2009/readings/MIT6_013S09_chap07.pdf and I ...
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RS485 transmission errors
I am trying to get two Atmega328ps to talk to each other over RS485 with MAX485 as transceiver. Below is the scope trace of D+ and D-.
Yellow : 485A line,
Cyan : 485B line,
Blue: A - B (...
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Calculate input impedance of transmission line without knowing L or C
I have the following problem:
A TV antenna lead-in wire 10 cm long has a characteristic impedance of 250 ohms and is open-circuited at its end. If the line operates at 400 MHz, determine its input ...
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Impedance discontinuity problem at transmission line?
I am confused about how the waveform will be to the left of discontinuity. Please help me understand it better.
Here is my understanding:
When the unit step hits the inductive discontinuity, at the ...
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antenna matching with lumped elements
Is there any resources online that describe how to match antenna elements to a TX line with a lumped element matching network? I've got a 50 ohm load and a TX line that i'm trying to match to a 2....
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