# Questions tagged [reflection]

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### How to plot the reflection coefficent at the load against frequency in ADS

The reflection coefficeint at the load is defined as how do I plot the load reflection coefficent against frequency in ADS? it is easy to plot the source reflection coefficient since it is just ...
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### What to do when studying "travelling wave" in a coaxial cable?

Propagation of travelling waves on cables may sometimes be difficult to apply and understand. There is a method called in french "abaque de Bewley" or "diagramme de Bergeron" (in ...
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### Is there any relation between distance from source to reflector and standing waves?

When two electromagnetic waves (not considering mechanical waves) having the same amplitude and wavelength, moving in opposite directions are superimposed on each other and create standing waves. One ...
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### Thevenin equivalent of open ended transmission line Clarifications required

I am going through the below link for understanding about transmission line reflections. The below figure is an equivalent circuit of an open-ended transmission line. For finding the the voltage at V+ ...
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### Questions about RF ground plane and low frequency reflections

Why do RF signals on a microstrip/stripline require a ground plane to propagate within a circuit? When studying DC and low frequency AC circuits in school, it appears that ground is a particular point ...
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### Are multiple reflections accounted for in S-parameters?

When the S-parameters of a 2-port device whose input and output impedance are different from 50 Ohm are calculated/measured in a 50-Ohm system, multiple reflections occur at port 1 and port 2. Let's ...
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### Parallel transmision lines reflection at the source

Question: There's a 9 V battery with output resistance of 50 Ω, at time t = 0 it is connected to two lossless transmission lines connected in parallel: LTx1 and LTx2. Both lines are identical, with ...
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### How to find Z impedance if I have only S11 (db) and phase

I need to measure Z line impedance. Using VNA I measured S11 it is -53.8785 dB and phase at this point is 175.6706. Could you explain using these numbers how to find R and jR S11 = (Zx-Z0)/(Zx+z0) = -...
1 vote
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### Reflection coefficient in a microwave amplifier

I have a question about the reflection coefficient in a microwave amplifier (two-port network), what is it and what is it based on?
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### How reflection occuring in antenna fed by transmission line affects performance?

Transmission line considered is lossless. Basically the configuration is simple. For transmitter side : a non ideal source (can be voltage current or power) feeding a transmission line (TL1) with ...
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1 vote
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### Could a time-domain reflectometer, with no access to earth-ground, indicate if a long-wire is attached to the end of a long steel beam?

Without using any other wiring, optics, RF, sound, or vibration, I need to know if a 100 meter length of electrical wire is attached to the end of a 50 meter long steel beam. I only have physical ...
1 vote
55 views

### Typical power reflected off wall/window/wooden shelves etc

For interference purposes, I would like to quantify how much signal power I would receive back when my transmitted signal is reflected off an object (a wall, glass window, wooden shelf) at a distance ...
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### Do surface charges exist when EM wave gets reflected by dielectric boundary?

If both the materials on a boundary are dielectric then do surface charge exists. I was solving using pillbox it showed that there should be surface charge on boundary to satisfy change in normal ...
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### Pads reflecting in controlled impedance strip?

Background I'm designing a controlled impedance line for a 1900MHz signal travelling between SIM7000A cellular chip and an antenna. Question Tuning circuits are recommended for antennas with series ...
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### Time Domain Analysis with Vector Network Analyzer

I have done some measurements with a VNA in time domain (by using the transform operation of the instrument). Precisely, I have selected the measurement of S11 (reflection coefficient at port 1 of the ...
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### Impedance matching to minimize VSWR

I was trying to determine what the impact of impedance mismatching would be to an RF output and I came across this. About half way down the page, the author makes this claim. In general, if the ...
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1 vote
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### Input impedance of High - Frequency Amplifiers

I have a question about the choice of the input impedance of a high frequency amplifier. In general I know from elementary analog electronics courses that it is good for an amplifier (for instance an ...
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### Reflect IR beam off reflector instead of emitting straight to TSOP receiver

I have a working set-up to detect beam breaks using an IR LED, modulated at 36kHz, and a TSOP receiver connected to a comparator. It outputs the count via Arduino. The range is about the width of a ...
1 vote
177 views

### Refraction vs Reflection in Ultrasonic sensor for water level detection

I want to use ultrasonic module JSN-SR04 for detection of water level inside tank. The US module has single sensor for Transmission and Reception of US signals as shown below. I wonder if US sensor ...
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### How do wireless receivers reject noise created by the original signal reflecting off walls?

When a transmitter emits an RF signal it reflects and bounces around all over. If a receiver is line-of-sight with that transmitter then the original signal will hit it first but signals bouncing off ...
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1 vote
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### How does risetime affect transmissionline effects?

How do rise and fall times affect reflection in a transmission line? Reflection will occur with shorter lengths as rise times becomes shorter, does this mean risetime effects the wavelength of a ...
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### Calculate the voltage across a load resistor for complex transmission lines

The following parameters are given: 500m homogeneous transmission line. ...
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1 vote
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### Unitary property of scattering matrix

From s-parameter lossless network definition , The sum of the incident powers at all ports is equal to the sum of the reflected powers at all ports. But how do we derive the above unitary property ...
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### relation between reflexion coefficient and power ratio

Assume you have an intermediate input/outpout device connected to a coaxial line. For example, the device may be a DC-bloc, a bias tee, or simply a PCB microstrip transmission line. Using a signal ...
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