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# Impedance Characteristic

349 Threads found on edaboard.com: Impedance Characteristic

## Question on log periodic dipole antenna

I would guess the transmission line Z is around 70ohm like other 1/4 wavelength dipole antennas. According to literature, it's more complicated. As a simplified idea, imagine that the characteristic feed line impedance loaded by the dipole elements equals the antenna input impedance. So it's always higher than the antenna input impe

## Stability of the CSA amplifier

The assumed first order gain characteristic isn't bad as an estimation. There's an additional cascode stage pole, but you can probably ignore it. The other expressions are however only right if C2 >> Cf, otherwise the amplifier output impedance matters. As a short cut, it's rather unlikely to drive an amplifier with a single gm stage into i

## characteristic impedance of suspended stripline

Do you have access to software such as HFSS? I know in HFSS in particular, you can place a waveport over your TL and it will solve for the modal impedance(s). There are probably several other numerical solvers to achieve the same results.

## Reference characteristic impedance in TRL calibration

Yes, a calibration set is referenced to a real Z0 and calibrates the measurement setup to give results referring to this real Z0, although the used cables are lossy and have slightly different (e.g. complex) impedance. Real calibration sets can have deviations from ideal Z0 or need a small amount of port extension. If so, correction data may me

## Scattering parameters complex characteristic impedance and TRL calibration

Scattering parameters once a TRL calibration is performed are referred to the Zc of the micro-strip line. Determining with measurement Zc (that is not an outcome of the calibration process) is a problem ( myabe a next question to ask about). However from the theory we know that Zc is in general complex. Let say nearly real, but with a small imag

## wide band input matching in LNA

impedance matching and filtering are different purposes, although a LC matching network has filter properties and a filter can be designed to provide matching of different source and load impedances. But a matching network that implements a specific filter characteristic will usually need more LC elements than the pure matching function. (...)

## How to measure resistance of coaxial wire?

Coaxial cable characteristic impedance isn't a resistance and can't be only measured with special instruments. To distinguish between 50 and 75 ohm cables, look at the ratio of center conductor to dielectric diameter. It's around 3 for 50 ohms versus 6 for 75 ohms.

## Microstrip Patch Antenna Ansoft Designer

An equivalent-circuit model for the patch antenna can be found in Balanis' "Antenna Theory: Analysis and Design" textbook, and probably elsewhere on the internet. Basically, you want to create a lossy, half-wavelength resonator, the characteristic impedance of which differs significantly from your system impedance.

## imaginary characteristic impedance

I would think that multimode soutions, like waveguides at higher frequency than the fundamental band, would show up as imaginary impedances. the idea that energy can be temporarily stored in these evanescent modes, just like in a capacitor at low frequency, but it is not dissipated there, and eventually returns to the fundamental mode.

## Characteristic Impedance of Differential Transmission Line

Differential Transmission Lines have 2 impedances.Even mode and odd mode.The characteristic impedance of a differential lines is composed of these two mode dependent characteristic impedances.For more information, "RF and Microwave Coupled-Line Circuits", Inder Bahl, Prakash Bhartia,Rajesh Mongia. Artech House

## soldering HDMI over ethernet

When I cut and solder one of the 8 wires What does "cut and solder exactly mean"? The ethernet cable is made of shielded twisted pairs, differential transmission lines with defined characteristic impedance. For HDMI speed, the pairs must not be untwisted or unshielded for more than one or two centimeter length. Also the length of a

## cst studio suite microwave studio

The line impedance (characteristic impedance) of a uniform transmission line, is the ratio of the amplitudes of a single pair of voltage and current waves propagating along the line in the absence of reflections. The wave impedance of an electromagnetic wave is the ratio of the transverse components of the electric and (...)

## Determining Characteristic Impedance with T-line Circuit Model

The input impedance of transmission line is given by Zo*(1 + Γ*exp(-2*γ*l))/(1 - Γ*exp(-2*γ*l)). Where Γ is the reflection coefficient at the load end, l is the length of the line and γ is the propagation constant. For short circuit Γ is -1 and open cicuit Γ is 1. Thus geometric mean of sqrt(Zshort*Zopen) is

## Best connector for high data-rate bus

Hi, look for a high speed data connector with the same characteristic impedance like the LVDS signals. BTW: asking for "the best" isnīt a good idea. For one the best is the cheapest, for the other it is the smallest, for the other it is a water proof one, and so on. What is the best colour? Klaus

## RF PCB - Design Guidline

Microwave engineering is its own field of study. Various PCB features can act as resonators and/or antennas, the choice of dielectric itself can have a large impact on performance, and characteristic impedance becomes a critical concept. So long as you can keep all of your trace lengths electrically short (smaller than one fifth of a wavelength),

## Why "neck up" diff pair when escaping BGA?

I am only confused by the Altium claims that the characteristic impedance of the diff pair can be maintained in the necked down area As far as I see in their docs, Altium allows defining different rules for the pair nets so that you can route under the BGA room without being impeded to to that due to violate spe

## Active Surge Clamp Operation

A clamp is a shunt operation so it depends on source impedance and load.(100R) You are expecting something else? where did this come from?

## Strange group delay at lower frequencies in Momentum

Is the load on the CPW equal to its characteristic impedance?

## transmission line charastristic impedance

I am sure you are confusing characteristic impedance with the characteristic impedance of free space which is constant and is 50 Ohms Surely you mean the impedance of free space, that is ≈377 Ω (not 50 Ω). I don't think this is the confusion of the OP. There are two th

## Effect of metal resistivity on the characteristic impedance of microstrip line

Hi We know that the characteristic impedance of a microstrip line is given as follows: 130174 In general the metal resistivity is so small that Z0 can be taken as sqrt(L/C). But if the metal resisitivity is not that small? Then according to the equation, this resistivity should affect the Z0. Is it true? I did si