Questions tagged [impedance-matching]
Impedance matching is a process of making one impedance equal to another another.
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Antenna complex input impedance into real impedance
I'm trying to design a loop antenna and make it resonate around 100 MHz.
Using a standard 50 ohms port, the resonating frequency is not at 100 MHz. Since I cannot change the geometry, I'm going to ...
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S-parameters of a matching network
I have the following matching network designed for \$\omega=2\pi\cdot 1GHz\$ and I want to calculate \$S_{11}\$ and \$S_{21}\$. The normal definitions/calculation setup for S11 that I use are in the ...
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Single stub matching of loop antenna at 4.2 GHz
I am trying to match a loop antenna using the single stub matching technique.
Operation frequency: 4.2 GHz
Vacuum wavelength: 7.2 cm
Cable:
Impedance: 50 Ω
Velocity factor: 0.66
The antenna impedance ...
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S21 calculation
In this post
It mentioned that there's a factor 2 in S21 value.
But I'm still don't understand why there's a 2 in it.
My schematic is shown below.
Shouldn't S21 = Vout/Vgen?
My question is: where is ...
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Understanding impedance matching in RF PCB applications (STM32WB55)
I'm just getting into RF design since I inherited a board that uses an STM32WB55C for BLE. For now I want to start getting more familiar with the RF concepts since I don't have a lot of experience.
As ...
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Correct connection of a Wi-Fi board having both printed antennas and U.FL sockets
An RF part of a dual antenna Wi-Fi module from Aliexpress.
We can see coax sockets connected in parallel to printed antennas. Two external antennas and corresponding pigtails are part of the package.
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Which is preferred over differential pairs: trombones or sawtooths?
I have been told that trombones are much better to use than sawtooths, even if sawtooths may be prefered in some certians scenarios.
Here I have added trombones to the differential pairs. If I had ...
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Is it possible to simulate reflections by designing an RLC transfer function?
Assume that you're knowing the PCB stack and the geometry of the conductor.
You're computing the capacitance per mm and inductance per mm and also the total resistance of the conductor.
That means you ...
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Difference between characteristic impedance vs complex impedance
Are there any differences between complex impedance of antenna pcb trace vs characteristic impedance of antenna pcb trace.
This question rised up because of online pcb trace impedance calculator doesn'...
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How to match multiple impedance discontinuities?
I am trying to design a circuit to transmit various digital high frequency signals over cables, connectors and pcb to an oscilloscope. The simplified circuit looks like this:
simulate this circuit &...
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Impedance of different track widths - Should I compute the average width?
Assume that you having one track that goes from 0.11mm in width to 0.09mm in width.
I want to compute the impedance, but I need to select the width. What option should I select?
The largest width of ...
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RC filter cutoff and impedance
I wanted to create RC lowpass filter with cutoff frequency 15 kHz and output impedance 50 ohm. What should be R and C values? I'm a little confused how to interpret 50 ohm output impedance to ...
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Match 50 ohm impedance to LNA input impedance
I have following PCB version of circuit: on SMA input we have antenna strictly matched to 50 ohm, then we have regular RF switch IC, after RF switch impedance matching network and final stage is ...
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Operational amplifier layout- Controlled impedance
In the following picture, we can see a reference layout by Texas instrument for OPA838:
I noticed, in the polygon on the top layer, they have used a specific gap=0.5 mm, I wonder if they used a ...
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Layer stack up and impedance matching- 100 ohm
I have a 14 layer stack up as follows (the stack up is from EURO circuit):
I need to provide 100 Ohm differential impedance for my LVDS on layer 7, currently by the information from the manufacturer (...
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