Transmission line Definition and 172 Threads

Transmission line equation is of the form- Φ(x, t) = F(x − ct) + G(x + ct) where F(x-ct) is the forward traveling wave and G(x+ct) is the reverse traveling wave 'x' is the distance from the origin. Now my question is where does the origin lie? Usually in Transmission lines we assume...

Homework Statement The Attempt at a Solution I m getting 10V as one side is O.C so the whole voltage come across it...correct me where i m going wrong

I have to thinking about how the skin effect come into play in transmission lines with two conductors and dielectric in the middle. For normal skin effect, we consider a potential across a conductor as shown: Where the tangential E right above and right below the surface at z=0, are...

Hi, I'm kind of struggling on finding information regarding the transfer of 1000MW to a load located 500km away. As far as 400kV transmission line is considered I can't find a design similar to these therefore would anyone be able if the following would be correct: Assumption: (using...

Hi, I'm hoping somebody can help me understand something. I'm studying transmission lines and I'm confused about SWR and standing waves on a transmission line. According to my book the voltage on the transmision line is the super position of an incident and reflected voltage wave given by...

I mean even something tiny, like the seat-adjuster...would that electrocute you to death? Is it possible to touch something plastic and still get electrocuted?

Homework Statement If a transmission line operating at 250 MHz has a characteristic impedance Z0 of 50 Ohm and propagation coefficient γ = 0.4 + j7.5 per meter, calculate its primary coefficients R, L, C and G. Hello, I do not know what formula I can use to solve this problem. If anyone...

Homework Statement I have source with some impedance (say 10 ohms-not shown in fig). since the tx line is 50 ohms, I added a series termination resistor of 40 ohms to match it with the tx line. After the series resistor there is a parallel termination of 50 ohms, which is followed by a tx...

Hi, i just need some help with something, I have been given a question to solve. I need to find a) sending end current, b) sending end power factor c) full load active power losses of a three phase "double Circuit" transmission line...I know how to calculate all of those for a three phase...

Help finding the load impedance of a transmission line? How do you find the load impedance of a transmission line?

So we are told in our class that the characteristic impedance of a coaxial cable is impractical to be at a value like 500Ohms. Why is that? The assumption is that the transmission line is lossless and that the dielectic constant (Er) is 1

Hello, I am looking at the following calculation for the reflection coefficient of a transmission line using the formula ((ZL - ZO) / (ZL +ZO) I can understand it all apart from the last part (0.355e^j). Can someone please tell me how that figure was gained from (-0.354 + 0.030j) (216 + j15...

Can Transmission line be dangerous during rain ?! Suppose you are standing beneath 132KV transmission line. A pretty big water drop drops from the transmission line into your bald head. Is there any chance you get shock? My understanding of physics tells me that, if the drop left the...

Are the R,L,C specifications for a cable to be taken as the lumped circuit model paramters, or can I use the dimensions to actually calculate the cable's total R,L, and C? Say a cable has a specification of "capacitance = 10pF/m", then is it safe to say that if I have 10 meters of the cable...

hi need some direction on this problem please. see attached file, i decided to type more or less my progress,instead of attaching nonsence !. i had had a few more ideas but no luck. any positive direction would be much appreciated, I've looked back at my textbook (electromagnetics by hayt...

How does current flow in a coaxial cable in each of the following cases : 1. When the cable is connected to a DC voltage source. 2. When the cable is connected to an AC voltage source 3. When the outer metallic shield is connected to ground and DC and Ac sources are connected separately I...

An open-ended quarter-wavelength, air-spaced, parallel-wire transmission line is found to be in resonance with an oscillator when its length is 0.25 m. When a capacitance of 1 pF is connected across the open end, it is found that the length of the line must be reduced to 0.125 m to obtain...

Hi all, I am trying to compute the coupling effects or crosstalk in the circuit attached. In MTL (multiconductor transmission line) model of two wire or three wire lines for main lines, how to calculate or simple equation of mutual conductance? which is denoted as g12 in the circuit...

Homework Statement As attached. Homework Equations - The Attempt at a Solution I think P is a step-up transformer while Q is a step-down transformer. Does the current and/or voltage change during XY? I know the answer is either B or C, but I do not the explanation. Can anyone...

Eqn. (2.1) \frac{\partial v}{\partial z} = -L \frac{\partial i}{\partial t} Eqn. (2.2) \frac{\partial i}{\partial z} = -C \frac{\partial v}{\partial t} Eqn. (2.5) v(z,t)=V^+f(t-\frac{z}{v_p})+V^-f(t+\frac{z}{v_p}) From the book I'm reading: "By substituting Equation (2.5) into Equations...

In the case of a complex source impedance ZS and load impedance ZL, maximum power transfer is obtained when ZS = ZL*. For a lossless transmission line terminated on one end with a purely resistive load, zero reflection is obtained when ZS=ZL. What about the case of a lossy transmission...

Homework Statement Calculate the output vo(t) if the input is the signal vin(t) shown in attached figures. The Attempt at a Solution I've calculated that ransfer function transmission line: H(s) = Vo(s)/Vin(s) = exp(-j*gamma*l), where gamma = -j*omega*sqrt(LC). However, tau = sqrt(LC)*l...

Good morning Gentlemen (and Ladies), I'm looking for some help from you HV experts out there. I have had an event where it is believed that a flooded transformer connection box induced a fault on to a 33kV 3phase transmission line, and the fault current was enough for the repulsive forces...

I read on Kraus' "Electromagnetics", 4th edition (p 583), that four-wire transmission lines (in a quadrupole configuration - the conductor with the same polarity are in diagonal) improve shielding. + - - + I tried to find some more information about this sort of transmission lines but...

If you have a two-wire transmission line that is open-ended at the load, and connected to an alternating voltage generator at the source, then the voltage between the open ends can be as high as twice the voltage of the generator. However, if the two ends are shorted, then the voltage would be...

On a coaxial transmission line is there AC current running through the center wire? And this AC current produces EM radiation that bounces down the wave guide. So is the purpose of this transmission line to send the signal via radio waves. And is this how cable tv works, are radio waves being...

Transmission line charateristics measurement?? Dear all, I want to do cable analysis of a 3800m long twisted pair wire to set up a communication system. It is not usual twisted pair wire (telephone), has different impedance, R=194, L=4mH, C=180uF. The things to be analyzed are...

hello forum, has anyone heard before about a Goubou wave and single wire transmission? I always thought that for a circuit to properly work two conductors were needed, the signal conductor and the return conductor, both in DC and AC... Is that true? thanks. fisico30

In high speed digital designs, there is a series terminating resistor to match the output impedance of the driver IC with the transmission line on the PCB. Some think the purpose of this resistor is to decrease the drive of the IC. How do I convince them its not to decrease the (current) drive...

Find the inductance per unit length of parallel plate tx line width = w and space =d between the two plates. w>>d. My question is whether the total inductance is twice the calculate inductance because total inductance is the sum of inductance of the top and the bottom plate. But it seems all...

Say you had a lossless transmission line that consists of an ideal source, a 50 ohm impedance, a 100 ohm impedance, and a 100 ohm terminator. The material is the same. You send a pulse down the line. When the pulse hits the impedance mismatch, you get a smaller reflection back, and a pulse...

I want to confirm that the TEM wave is actually travel inside the dielectric between the two plates of the parallel plate transmission line. So even though surface current and surface charge appeared on the surface of the conductor plates as the consequence of the boundary conditions between the...

I have two questions about Tx lines 1. Can we think of the Tx line in terms of just LC ladder. If yes, why can't this be thought of as a LC filter. In that case, the tx line would be a low pass filter. Increasing C would make the cut off freq even lower. 2. If I don't terminate at the load...

Hi, I'm learning something on circuit QED, which has a part called transmission line resonator (TLR). It plays the role of a cavity. However, I don't get how it works that way. Can anyone give some help ? Thanks in advance !

Homework Statement A 69 kW single-phase load with a power factor of 0.68 lagging is fed by a long cable with an impedance of 0.011+j0.005 Ω per phase. The voltage across the load is 230 V RMS. Calculate the heat loss in the cable in Watt [W]. Homework Equations The Attempt at a...

This is from How Stuff Works: The power company essentially uses the Earth as one of the wires in the power system. The Earth is a pretty good conductor and it is huge, so it makes a good return path for electrons. "Ground" in the power distribution grid is literally "the ground" that's all...

I am at a loss on how to apply transmission line theory when a probe is connected to a high speed bus or for a matched RF line. For example, a signal going from a PCI clock to a bufffer which has a very short trace(so no termination is required). Now, if I connect a logic analyzer probe to this...

Homework Statement If I have a coaxial transmission line, with a resistor halfway through, and another resistor at the end, how do I calculate the reflection coefficient for the spot where the resistor is halfway? Here is a diagram of what I mean. Dashes and dots are are the lines, and }...

Hello all, I'm now working on the 2.45GHz frequency transmission line layout on the PCB. I would like to know whether there is a design guideline for the 1) minimum length of the transmission line. how do I know or calculate? I can calculate the width of the TL to get the 50ohm impedance...

Homework Statement In Fig a line is used to produce a short rectangular pulse of width 12ns and peak value 800V. With S-2 open. S-1 is closed to charge the line to Vdc; after charging, S-1 is opened. Then, at t = 0, S-2 is closed to discharge the line through RR and form the pulse. Find the...

Here's a scenario about which I have doubt. Consider a transmission line which has a length λ/4 and which has open circuit at load end. The source resistance is zero. The source voltage be Vs and the source frequency is sufficiently high to be considered as high frequency application . The line...

Two very large parallel conducting plates of very large length l, and width w are separated by a distance d. A current I=Jw flows to the right in the lower plate and to the left in the upper plate. Each of the two currents produces a magnetic field \frac{B}{2} between the two plates. (a)...

Could it be dangerous to connect an alternator to a long transmission line,if the line has high capacitance?if dangerous then why? please explain...

Hi All, I understand that if you have a lossless transmission line and a lossless antenna and there is a mismatch at the antenna/transmission line junction, no energy is lost. If the transmitter is delivering 100 watts into the line, 100 watts will be radiated from the antenna. I'm...

Homework Statement An annular sheet (i.e. a flattened ring) , of thickness t = 1mm and made of a material of resistivity 0.5 Ohm m connects the inner and outer conductors of an air spaced coaxial transmission line at a point on the line. A low frequency signal is fed into one end of the line...

Homework Statement Prove that for a line having resistance R, and reactance X, and supplying load of P+jQ has an approximate voltage drop of: Vr = [RP+XQ]/Vs Homework Equations none given. The Attempt at a Solution I made a diagram, with R, X, and P+jQ in series. Vr is the...

I was reading about transmission lines. I thought if the line and load are matched, then the voltage on the line will be equal to the voltage on the load. But fig 16.2 (page 1000) in the book here, the voltage at load is half the line voltage. I don't get it! Book link- (click the contents link...

In a transmission line, what makes the current flow? I understand that the line is excited by an AC voltage at one end. This sets up a changing electric field between the conductors and therefore a changing magnetic field. However, there is no voltage along the line, so what makes the current...

Transmission line approximation Homework Statement In the derivation of the approximate formulas of \gamma and Z0 for low loss lines, all terms containing the second and higher order powers of R/wL and G/wC were neglected in comparison with unity. (R/wL<<1 and G/wC<<1)...

Dear All I am hoping for some insight into a transmission line problem I have been experiencing. I am quite inexperienced and unqualified in this area so if I am not clear please let me know. In wiring loom assemblies my employer offers there is a twisted transmission pair. The...