Questions tagged [impedance-matching]
Impedance matching is a process of making one impedance equal to another another.
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What is the purpose of a shunt element in a balun?
I'm working on a balun for a differential front-end receiver and see that they quite often use a shunt element (inductor) across the differential pair.
From what I could gather is that when you insert ...
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Balun converting 100ohm single-ended trace to 50ohm single ended for spectrum analyzer
On my board, I have 100ohm differential pair traces connected to a 1:1 balun, so the signal impedance becomes 100ohm single ended. I would like to measure the signal spectrum with spectrum analyzer. ...
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Coax cables and input impedances
I'm doing a voltage measurement with the help of an Active Differential Probe (TESTEC TT-SI 9010) with an output voltage of +-7V. This voltages have rise times of the order 500ns.
The set up looks ...
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Incorrect Output of RF Mixer
I've designed a RF mixer (Gilbert Cell) which takes a RF frequency between 88-108MHz and a LO of 77.3-97.3MHz, I want to take the difference between the two so the IF is 10.7MHz. Currently, the output ...
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Is it possible to implement shunt stubs to replace shunt capacitors for differential matching?
I am reviewing the subject of stub matching. For example, consider Network D:
Example photo screen-shot from TI documentation: https://e2e.ti.com/cfs-file.ashx/__key/communityserver-discussions-...
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Can I add a resistors to add speakers?
I have a 2 channel stereo output from my laptop connected to a surround sound amp: all 5 speakers with an impedance of 4 ohms (front, rear and sub) play the stereo sound. The speaker connectors on the ...
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Chip antenna matching of a custom board equipped with a STM32WB55
I am planning on designing a custom board using a STM32WB55. I have followed the "How to develop RF hardware using STM32WB microcontrollers" (AN5165) Figure 9 design for the RF part, which ...
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Challenges in Bandwidth in Common mode Choke Modeling
I'm currently working on characterizing a common mode choke (CMC). However, I'm encountering difficulties aligning the bandwidth of my model with the measured results. Specifically, when I attempt to ...
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Why don't people always use 50 ohm resistors when matching impedances?
Impedance matching when designing the RF receiver circuit and antenna design takes a lot of time and effort for VNA. People often use capacitors and inductors to match the impedance of the antenna ...
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Which antenna trace design is better?
I need to design an antenna trace (WiFi and Bluetooth) that connects an ESP32-S3 chip to an IPEX connector with an impedance matching circuit.
I have some constraints that I need to work around:
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Where do I place my matching network for an antenna?
Let's say I have a microcontroller with an antenna output. The characteristic impedance of the pin for the antenna output is x+jy. I want to then connect it to a 50-ohm antenna.
This is the part that ...
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Slight difference in equations for the design of resistive matching network
I'm currently reading trough an application note from Analog Devices 2, in particular the "A NARROW-BAND LC MATCHING EXAMPLE AT 100 MHz" section. I re-did the calculations by hand and got ...
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Impedance matching and termination resistor
I’m a little confused regarding impedance matching with resistors.
As far as I know, the impedance of a trace is a part of its characteristics and it can’t be measured with an ohmmeter. For example, ...
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Confusion About Impedance Matching For Single-Ended and Differential Lines
I understand that for single ended RF signals I must ensure that the characteristic impedance of the transmission line matches the load impedance (say 50 ohm). I am a bit confused for differential RF ...
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how can I calculate impedance matching for STM32WLE5 RF network?
I am attempting to compute an impedance matching network by following the guidelines outlined in the ST Application Note - AN5457. However, on page 24, the formula and calculations appear perplexing ...
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