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Reflection Losses

17 Threads found on edaboard.com: Reflection Losses

A question in smith chart with s11 parameter

Hi, If the question is whether the magnitude of the reflection(S11) is constant with frequency, the answer is no. I do not understand your last question: "Why this should be done?"

Measurement of S21 (transmission) of glass

I would expect frequency independent Er of glass in a first order, so the microwave value would be around 1.5 as for visilible light. Other than for visible light, reflection losses depend strongly on window thickness and wavelength.

Help with Switched Line Phase Shifters

Your thought is right. Most probably there is a reflection and mismatch between lines and switches. Into the simulator, try to separate the stages and check what input/output impedance see each stage separate. One important thing is that in microstrip design, a smaller strip width leads to higher losses.

Reflection coefficient and a transmission line taper

Hello all. I am working on designing a transmission line which involves the use of a taper. One of the issues I am struggling to understand conceptually is this reflection coefficient often shown for your standard exponential, Klopfenstein, hyperbolic tapers like the one attached to this post. So what does not make sense to me here is the l

Some fundamental question on ANALOG/RF design.

Hey there! I just have a little fundamental question - why should we work in impedance mismatches in low frequencies (voltage/current gain) and not just trying to match to get the maximum power , like we do in RF? Don't we care about power losses that the reflection causes? It's very easy: the concept of matched

coupled microstrip lines measurements

I have built a coupled microstrip circuit which is measured with the 4-ports single ended technique. I am trying to obtain 3 parameters: insertion losses for common and differential modes, and reflection loss for differential mode. So far, I have good results with insertion losses, but reflection loss is quite wrong. I (...)

How does inductor filters (if it's reactive and has no losses)?

Attenuation doesn't necessarily involve losses respectively absorption of energy. It can be achieved by reflecting a signal back to the source. You get perfect attenuation by just unplugging the cable - without any losses. A reactive filter performs frequency dependent reflection.

S-parametrs definition

Hi, Scattering-parameters are used in high speed signal analysis to find out the reflection(S11) and insertion(S12 OR S21) losses. It depends on the no of ports we are using. lets take an example that we have 2-port network 1- input 2-output. In s-parameter Sxy x = output y = input. if S21 then it tells input is at 1-port and output is at 2-port

Water-filled waveguide from PCB laminate, Cu layer on the outside

A dielectric layer d << λ can't cause total reflection. But surely changes the E-field distribution. Did you estimate the losses due to the water RF absorption at 200 MHz? I fear, it's huge (possibly in a several 10 db/m order of magnitude).

frequency range of an ordinary wire

Wire has no frequency limitations up to a reasonable frequency, (many GHz.), the property you should be concerned with is impedance, a bare wire in air has a dielectric constant slightly above 1 and would offer a high impedance as would a PVC covered wire, if your source is a low impedance you could expect losses due to the reflection from the impe

Reflection losses for normal incidence in HFSS

I am new in HFSS and I have a project in which I have to study the performance of a small cage lined with ferrite in the walls. The dimension of the cage are 55x55x52cm. This cage is used to make EMC measurements. The first step is analyze the reflection losses of the ferrites at normal incidence an compare the results of the simulation with those

Gain and Realized Gain has any difference?

there is clear difference between the two gains the realized gain is the gain taking into account the reflection losses at the input of the antenna. in other words it is the ratio of power radiated to the power input to the antenna whereas gain doesnt take into account the reflection losses at the antenna input. (...)

Ideal dipole antenna close to metal ground plane

HFSS has two gains, gain and real gain. Gain is based on the energy that radiates by the antenna while real gain is based on the energy supplied to the antenna, or in other words includes the "losses" due to reflection or low S11. Try to plot realized gain to see if you get any difference.

The relation between cable losses and cable length in coaxial cables

Yes, there is a relation between reflection Coefficient Γ and Loss reflection coefficient Γ = (VSWR ? 1) / (VSWR + 1) Missmatch Loss (dB) = ? 10*LOG (1 ? Γ?)

Losses Incurred by Actual Fabricated Microstrip Circuit

Hi, your filter is mismatched meaning that resonators are not on the right frequencies. You can tell this by examining the reflections - you don't have distinct dips in response. Regarding this, even your simulation doesn't look 100% OK - reflection dips for this class of filter should be symmetric in the passband. One reason for discrepacy betw

Using the body of the car as a receiving antenna !!!

I'm not sure that this is physically duable. The Receiving antena MUST have an impedance matched to the transmitting Source. Think about it as a transmission line - with reflection and losses for non-matched.....

EM simulator for multiple dielectric layer losses

This question goes to all EM wizards. Lets say we want to simulate and find out what should be the transmission/reflection loss of one or multiple dielectric layers. Which EM simulator do you think will easily do the job and how would you set the following generic (with most simulators) conditions: 1. Boundary conditions should be set to per