Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [reflection-coefficient]

14 questions
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Will the reflection from the load end of a transmission line affect the behaviour of an ideal voltage source?

Consider a transmission line with characteristic impedance of Z₀ and electrical length of λ/4. One end of the transmission line is terminated in a load of impedance (lets assume) 2Z₀. The other end is connected to an ideal voltage source Vsrc. Will…
athul.shaji
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Time domain reflectometer transmission line

I'm quite new to transmission line theory, so I decided to follow an introduction course online. I am struggling with understanding the solution to this question. Here is what the course is giving as an example: Here we see that the source has a…
Dimitar Zhekov
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Can VSWR be complex-valued or is it always real?

This question is related to this one, but about VSWR instead of return loss: Can VSWR be complex since it is based on a complex-valued \$\Gamma\$? If VSWR is complex then it is worth noting that: \$\Gamma =…
KJ7LNW
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What are the reasons to use SWR instead of the reflection coefficient?

It seems that using SWR is a tradition (historical legacy). But even in the history of electronics I can't find why SWR was considered more useful compared with the reflection coefficient. What are/were the reasons to use SWR?
Arseniy
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Protect PCB from RF reflection

I am designing a system on megahertz frequency bands (~ 400-1000MHz.) This device is connected to a variable antenna which does not necessarily stay in match with the circuit so there will be some reflection of the power back to the circuit. The…
Anonymous
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Opposite of reflection coefficient

The reflection coefficient (in circuits, for example) is generally given the symbol Gamma (\$\Gamma\$). What is the symbol given for the pass or transmission coefficient \$1-\Gamma\$? I've usually just seen it written out in terms of \$\Gamma\$ but…
nate
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Transmission line max power transfer

I'm studying transmission lines and came up with the question why (voltage) reflection coefficient being zero is not equal to maximum power transfer (conjugate matching). I did some search and found out people invented power waves and reflection…
jleng
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Reflection coefficient on Smith chart moves in clockwise direction with frequency

If I plot the reflection coefficienct of an active network on the smith chart it moves in a clockwise direction with increase in frequency. How can we intuitively explain this? I've noticed people saying that it becomes anti-clockwise for non-causal…
Keshav Ram
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Output reflection coefficient of a power amplifier

I'm struggling to understand the implication of a poor large signal reflection coefficient at the output of a power amplifier. I designed a power amplifier and checked the large signal S22 (for the optimum load impedance for maximum power) as the…
Vysakh K
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What is the difference of meaning between the phase angle of S11 and the phase angle of Γ (Gamma)?

I realized recently that the Touchstone "DB" S-parameter format (.s1p, etc) uses the phase angle of \$\angle \Gamma\$ instead of \$\angle S_{11}\$ and wondered why it didn't use the phase angle of the complex S11 measurement. . Given the complex…
KJ7LNW
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Can \$\Gamma\$ remain complex while calculating return loss?

I'm working on adding .s1p touchstone export support to the xnec2c NEC2 antenna simulator for Linux. I would like the S11 dB values in the .s1p to have both real and imaginary values. NEC2 calculates Gamma by breaking it into real-valued components…
KJ7LNW
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Calculate phase of impedance

I've seen this question and thought I understood the basic concepts. When I attempt to solve for phase given \$Z = 60 + j10\$ I end up with 9.46. However, my professor has given the answer as 39.81. I am told that the phase angle of 39.81 is derived…
amitchone
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How to interpret VNA data?

I'm looking at the raw data from a VNA (HP 8720A) and I want to understand how to interpret it, and how to do after-the-fact calibration (ie: read raw data, then apply to it whatever corrections a calibration would apply, but outside the VNA). To…
Alex I
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Can reflection take place at the source in transmission lines?

I have read about the reflection of voltage and current, when passed through a transmission line through a load if the load is mismatched with the characteristic impedance. According to my understanding, the reflection happens because the voltage…
Shanmukh Akunuri
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