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# Coaxial Transmission Line

49 Threads found on edaboard.com: Coaxial Transmission Line

## Microstrip Transmission lines .. need some Clarifications

Microstrip lines are same as other transmission lines like waveguide and coaxial cables. So transmission line theory is the pre-request before starting design process. In Microstrip lines it is the length of line which defines your components like inductor (...)

## Point Excitation in HFSS

I doubt a point source will couple well to a transmission line mode, but that being said, your best bet is probably to couple it to a coaxial mode -- since I lack knowledge of any literature on the subject, I'd guess that a parametric sweep on the placement of the excitation is an adequate start. Good Luck!

## Defining a Voltage source using a Probe

when there is a probe it come with coaxial transmission line too. and its clear how to excite coaxial line with voltage source

## reflection of electromagnetic wave

I understood you have to calculate the length L of a coaxial transmission line at wich the input impedance is a short circuit when it's left open at the other side. at a length equal to a quarter wavelength (and it repeats every rotation of pi) an open circuit at a side of a line will be seen as a short to the other side (...)

## 2 GHz 180 degrees phase shifter circuit

Same length of various transmission lines like: stripline, microstrip, coaxial, waveguide, twisted-pair, etc, would give totally different phase shift. On top of this, the same length transmission line made on the same approach (stripline, microstrip, (...)

## What dose this result mean?S12?

You are looking at the insertion loss through the sample length of coaxial line as a function of frequency. These graphs simply show that the loss per unit length of this transmission line increases as the frequency is increased.

## Litz wire at VHF frequencies and best core type?

No, litz wire won't provide any real advantage at VHF. coaxial transmission line transformers are probably your best bet, and 61 ferrite is a good starting material. Low permeability powdered iron mixes like 17 are more suitable for high-Q inductors, and wouldn't make for a very efficient transformer. Plus I don't think anyone makes powdered (...)

## S parameter in RF cable

a power of 0dbm is fed to a coaxial cable . this coaxial cable is connected to an antenna. so the power will be sent through the antenna. i know that in RF we could not speak about the voltage. But could someone tell me what is the Voltage and current in the coaxial cable?

## Coaxial Transmission Line with Discontinuities - Overall S-Matrix?

Hi, I'm working on the following problem but I'm getting stuck, I wouldn't mind some ideas on how to proceed: "A coaxial transmission line having two identical discontinuities as shown below. Calculate the overall scattering matrix seen at the reference plane shown at 4 GHz assuming that the scattering matrix of the discontinuity is: (...)

## Broadband VHF/UHF Amplifier Design Using Coaxial Transformers

Hi all. 1. In given figure 2, the inductors suppose to simulate ferrite? 2. Additional question: for what exactly we need ferrite here? 3. Do somebody have some detailed tutorials/bo

## Calculation of reflection coefficient using FFT in FDTD code (matlab)

I want to obtain the reflection coefficient using FFT in a transmission line, the source was excited with a Gaussian pulse. Τhis is an abstract from a paper that I have as guide: "In order to obtain the reflection coefficient, the coaxial cable was excited with a Gaussian pulse of the form Vs (t) = exp(-(t − 3Ts)/Ts) Ts (...)

## What is a double terminated coaxial cable?

Hi All: While reading the datasheet of EL8108, In page 11, it says, " The EL8108 was designed with driving multiple coaxial cables in mind. With 450mA of output drive and low output impedance, driving six, 75Ω double terminated coaxial cables[/

## coxial pitails for up to 6GHz

I think, the question makes no sense. You are talking about a PCB to coaxial transmission line transition. This means, the "pigtail" has to be soldered exactly to the end segment of a 50 ohm microstrip or similar transmission line. It can't be connected e.g. to the middle of a transmission (...)

## How bandwidth depends on transmission line or channel?

Hi; Consider a coaxial cable, there are two conductors, outside shielding and inside dataline. Between them there is isolator. This is a simple capacitor. And any capacitor filters/distorts after a certain frequency range (consider reactance of a capacitor 1/wC). This parasitic capasitor determines your channel bandwidth. Above those frequencies yo

## FDTD problem:coax feeding and transmission line feed model

hi. I have a question in FDTD and antenna feeding. I want to feed my DRA with coaxial cable and transmission line feed model.I wrote a code in matlab. do I have to use from thin-wire modeling,to model inner conductor of coaxial cable? how model outer conductor of coax? I'm confused really!!! please help me...

## transmission line feeding in FDTD matlab code

hi. I have a problem in feeding of my monopole antenna.I have a monopole antenna above ground palen.I want to simulate an coaxial line feeding for my antenna.for this purpose I want to use from a virtual 1D-transmission line for coaxial line modeling.but I have a question: in addition to (...)

## Questions regarding delay in wire

As in most cases, the question suffers from an incomplete problem specification. Wire capacitance and inductance are unknown without defining the full geometry. To refer to a well-defined case with known electrical properties, you can assume that the wire is part of a transmission line, either coaxial or parallel wires. Then increasing (...)

## 1:25 transmission line transformer

Z0 =√(Zin * Zout) applies to λ/4 transmission lines used as (small band) impedance converter. Wide band transmission line transformers with magnetic core a different thing. The characteristic impedance of the coaxial cable is still an important parameter in TL transformer design. Basically a (...)

## CST-Dipole Antenna-Coaxial feed transmission

Hello , I have create a dipole antenna using cst MWS but with a antenna wire template , i have put the port but i want to put a coaxial cable as feed transmissin line because i want to see the real result for the simulation. Anyone can help in creating the coaxial cable ? It's truly urgent !! Hope that this post will help

## AC current and Electromagnetic wave propergation

transmission lines fall into the wired transmission category. transmissions lines can "leak" energy into space, although this isn't considered in the basic transmission line description. By using a coaxial or other closed transmission (...)

## skin depth clarity required.

you seem to be confusing 2 concepts. If you have a symmetrical transmission line cross-section, such as coaxial cable, then you skin depth understanding applies. The RF currents on the center conductor, for instance, are mostly on the surface, with just a small portion going deeper. So if you are fabrcating your own (...)

## A simple question about antennas and lines

Hello, Normally spoken a transmission line is to transport "energy" from one place to another (for example from the antenna to the receiver). So it normally does not radiate nor receive. This means the center conductor current equals the current at the inside of the screen, but with opposite phase. Outside the coaxial cable, the field of (...)

## microstrip line at frequency below 100MHz

coaxial cables and microstrip lines are operating in TEM mode, which involves no cut-off frequency. Z0 exists for all frequencies, but as cmontoya mentioned, you possibly don't see much transmission line specfic effects.

## Power combiner 200MHz, coaxial type

Hi all, I have to design a power combiner narrow band (f0=200MHz ; Δf=10MHz ) capable of about 6kW output and 6 input ports. The idea is to have a central coaxial feeder a radial transmission line and n (6 in this case) N type 50Ω connectors. I have got some problems in simulating the radial transmission (...)

## Length Of coaxial fed line of Microstrip antenna

I want to implement a coaxial fed microstrip antenna. What should be the length of the conductor from microstrip to BMA Connector? Anyone, help me...

## Why is Electrical length greater than physical length?

The clue is in the propagation speed. In free space a line with le = 1m would introduce a delay of td = 1/c0 = 3.333ns. When, due to dielectric material (as in a coaxial transmission line), the propagation speed is less (about 0.66*c0), this line (with physical length of 1m) would show a delay of. Td (...)

## Anybody have some idea about 'coaxial ceramic resonator'?

These are ordinary coaxiala transmission lines with ceramic materials for dielectrics. These have a very high dielectric constant and thus make the wavelength in the line much smaller compared to regular cables. They are made by first molding the material in a hollow cylinder form and then plating metal on the inside hole (...)

## How do i feed a slot antenna with a coax transmission line in hfss?

Hey peeps, Trying to do this has consumed so much of my time. Can anyone explain to me how best to feed a slot antenna with a coaxial transmission line, and how to investigate the correctness of the design. Thanks in advance

## Symmetric Stripline vs Asymmetric Stripline

There is more than one case for each. A case where I would use a smmetrical stack for impedance control would be when I want signals to evenly propagate to reference planes. Lets say I have a transmission line that needs to route on an internal layer. This TRL is coming onto board through a coaxial cable. If I were to maintain (...)

## Coaxial cable for power transmission

Hi. I'm using coaxial cables to transfer power from the power supply to the device (IC under test). Since there is danger from resonance peaks in the supply's output impedance, I'm trying to model the whole system and find the solution (in form of additional damping). For e.q, my coax is 50 ohms with 101pF/m. Let's say I'm using 1m of it. From

## Design of manual double stub tuner

The basic mechanical design is simple, but you need at least a model to copy it. Basically is a horizontally 50 ohms coaxial cavity transmission line (with air dielectric), having a cut slot along its length. A shunt-connected vertical stub (which is shorted at one end) is moving alongside the initial horizontal (...)

## Electric permittivity measurement

Hi everybody, I would like to measure electric permittivity of a FR4 similar material. Having no time and equipement for transmission/reflection line technique, open ended coaxial probe technique and other more or less time consuming methods I thought of doing I little bit of reverse engineering. I thought of constructing a simple, (...)

## Unbalanced transmission line

Hi all, I'm aware that a coaxial cable is an unbalanced transmission line. It should then imply that an SMA connector is unbalanced too.. Right? I just wanted to make sure. Thanks

depends on the frequency range..., on PCB? with transmission line (possible with coaxial cable)? therefore you should share more details...

## about the measurement of cable

I want to test the loss of transmission line (coaxial cable or twisted pair cable), any advice? thanks.

## transmission line model (coaxial cable and Twisted pair)

I want to model the transmission line with resistor, cap and inductor, so I can simulate the E1 /T1 transeiver system, the bit rate is 2.048M/1.544Mbps. Do you have any simple models about the coaxial cable and Twisted pair line, relative papers and books are also good. thanks.

## transmission line model (coaxial cable and Twisted pair)

I want to model the transmission line with resistor, cap and inductor, so I can simulate the E1 /T1 transeiver system, the bit rate is 2.048M/1.544Mbps. Do you have any simple models about the coaxial cable and Twisted pair line, relative papers and books are also good. thanks.

## where to buy a flexible coaxial cable of 25 ohm

I want to constuct a transmission line transformer with coaxial, but it seem that the coaxial of 25ohm is hard to buy. Can anyone tell me where to buy? regards

## RENORM with CST, HFSS

this actually depend on what you can measure :) you can measure the reflection the 50ohm coaxial line sees, which corresponds to the renormalized s parameters. You cannot measure the generalized s parameters. A very simple example for this is a dispersive infinite transmission line, the return loss should be zero, but (...)

## The correspondance of a coaxial line to a transmission line

Hi everybody: Just now I create a very simple coaxial line model in both CST and HFSS to study the correspondence of real waveguide to transmission line model. But the result seems confusing. My coaxial line is a inner PEC cylinder pin with the radius of a=1mm, and an cylinder PEC (...)

## why impedance tx line always 50 & 60 ohms

i think this value came from coaxial Cable, we mostly use coaxial cable for transmission and as you know the specific coax cables is 50 ohm ampedance, maybe ...

## Material Characterization, permittivity

Do you guys have any application note explaining how to measure permittivity of materials using coaxial transmission line (air line) method. As far as I know, it will be enough to have a coaxial airline and network analyzer to figure out the dielectric constant. Any application note will be (...)

## Transmission line effect

bfkwan, You might try a twisted pair of wires, using signal ground on one of the wires. The characteristic impedance will be around 100 Ohms. Use a 100 Ohm source resistance, and a 100 Ohm termination resistance. This will minimize ringing. You will get a 6dB loss with this scheme. . Another alternatize is to use a coaxial cable. Use aource

## quarter wave transformer

With parallel wire line you can construct any impedance you want for the section. With coaxial feed you are restricted to a few commercially available impedances, none of which may be the value you need in your situation.

## How does signal propagate in a coaxial cable ?

The EM wave is actually generated due to the voltage and current applied to the transmission line (coaxial cable in this case). So when you apply a voltage to the TL the current passes through it and an EM wave is generated. I hope this was helpful :)

## another txline calculate tools.

include microstrip, stripline, CPW, CPW ground, round coaxial......

## About the reflection of two coaxial transmission line

How to estimate the reflection of two segments of coaxial transmission line with same characteristics impedance but different size?

## A question about the 50 OHM connector to the SA

A 50 ohm connector, such as an SMA or N, is simply a short length of coaxial transmission line with convenient threads for attaching a cable. The connector has a characteristic impedance of 50 ohms, but that's not something you can measure on an ohm meter. The 50 ohm resistance you measure is a termination resistor located further inside the (...)

## Transmission line ( coaxial transformers)

Hello Egemini Im not sure about the coaxial part, but Transformers are used basically as an impedance transformer. Most output of PA have very low impedance's. So a transformer (V/I = Z) that's 10:1 can make 5Ohms to 50Ohms . Look at Toko or Coilcraft website for better infomation. Hope this helps