Skip to main content

Questions tagged [impedance-matching]

Impedance matching is a process of making one impedance equal to another another.

Filter by
Sorted by
Tagged with
0 votes
1 answer
24 views

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. ...
ololo ololo's user avatar
4 votes
2 answers
990 views

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 ...
euraad's user avatar
  • 1,310
1 vote
3 answers
80 views

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 ...
euraad's user avatar
  • 1,310
0 votes
2 answers
71 views

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'...
KaruF's user avatar
  • 11
1 vote
3 answers
98 views

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 &...
Robert's user avatar
  • 15
1 vote
1 answer
42 views

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 ...
euraad's user avatar
  • 1,310
0 votes
1 answer
70 views

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 ...
Malum Phobos's user avatar
0 votes
1 answer
64 views

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 ...
Tremax's user avatar
  • 65
0 votes
0 answers
43 views

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 ...
Andromeda's user avatar
  • 399
1 vote
1 answer
71 views

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 (...
Andromeda's user avatar
  • 399
1 vote
1 answer
137 views

Calculating output impedance of amplifier to match to 50 Ω

Below is a schematic of an amplifier. The inductor used is a 1 μH inductor, emitter resistor is 2.2 kΩ. The bias resistors are both 200 kΩ. The capacitors are both 1 μF. I am planning to design a ...
xcaliber99's user avatar
2 votes
1 answer
53 views

understanding the recommended impedance match for a SAW filter

I'm trying to understand the recommended impedance match for a TA0168A SAW filter input. The datasheet is https://www.rfmw.com/datasheets/taisaw/ta0168a%20_rev.2.0_.pdf In my first circuit I'm trying ...
TvE's user avatar
  • 288
0 votes
1 answer
156 views

Wideband Impedance Matching for Inductive Source/Load

I'm designing the frontend of a receiver and I want the output impedance to be 50Ω so that I can get as much power into the mixer. I tried placing a bandpass filter (image filter for 88-108MHz) in ...
TheButterMineCutter's user avatar
2 votes
1 answer
95 views

Optimal thin absorber of electromagnetic energy

I am a material engineer and have a question about a formula derivation regarding microwave absorption properties. I really cannot figure it out after days of trying. This should be simple for a ...
temperature's user avatar
1 vote
1 answer
126 views

Matching circuit for piezo transducer

I am at the stage of designing a system that match impedance of the power output (half-bridge) to a piezo transducer operating at 1MHz (Max 60W of power). I calculated the piezo parameters from the ...
piotr's user avatar
  • 292
1 vote
2 answers
72 views

Is the reason for guitar "tone suck", i.e. loss of high end frequencies with impedance mismatching, actually due to high reactance?

When connecting a guitar's output to an input with insufficiently high input impedance, the signal is undesirably filtered, which is referred to as "tone suck". To deal with this, it is ...
interoception's user avatar
2 votes
0 answers
42 views

How to create schematic of common mode choke that reflect on Common mode, differential mode and mixed mode? [closed]

I aim to create a schematic that can replicate the results exactly as seen in the measured S4P file. I have conducted the measurement using a VNA and am attempting the schematic simulation in CST. ...
Alaska's user avatar
  • 101
0 votes
0 answers
33 views

How to reduce on-resistance and parasitic capacitance effects of my MUX setup?

I am designing a mux board to mux a flashing setup. Both UART and SPI lines are on 1.8V logic. The Mux chips have ~4-8ohms on-resistance and 1.7pF on-capacitance. Few questions: Would I need buffers ...
Zed Lepplin's user avatar
0 votes
1 answer
42 views

Coax cables, impedance matching and BNC extensions

I'm trying to understand how to do proper measurements with a Voltage Differential Probe ( TT-SI 9010. This probe has an output impedance of 50ohm and has a BNC (It doesn't specify it in the data ...
Santi Ospina's user avatar
2 votes
1 answer
99 views

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 ...
bluscape's user avatar
  • 175
0 votes
2 answers
42 views

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. ...
jsmith's user avatar
  • 669
1 vote
1 answer
50 views

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 ...
Santi Ospina's user avatar
2 votes
1 answer
147 views

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 ...
TheButterMineCutter's user avatar
0 votes
0 answers
31 views

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-...
j c's user avatar
  • 45
0 votes
3 answers
113 views

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 ...
Gerard's user avatar
  • 51
0 votes
0 answers
60 views

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 ...
Andreiul's user avatar
2 votes
0 answers
48 views

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 ...
Alaska's user avatar
  • 101
0 votes
2 answers
138 views

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 ...
Nguyễn Tiến Sang's user avatar
3 votes
1 answer
87 views

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: ...
Spatz's user avatar
  • 169
1 vote
1 answer
71 views

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 ...
JoeyB's user avatar
  • 2,371
1 vote
1 answer
35 views

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 ...
squeakyclean's user avatar
8 votes
4 answers
1k views

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, ...
mehrad aghaei's user avatar
1 vote
1 answer
55 views

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 ...
Cole Fehr's user avatar
1 vote
0 answers
78 views

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 ...
Atrahasis's user avatar
  • 185
0 votes
2 answers
140 views

How to design an RF frontend for an FM receiver

I'm designing a RF receiver for FM Radio. I simulated the circuit in LTspice and got an output as shown below: This is OK, but I would like the gain to be 24 dB across the range of 88-108 MHz. The ...
TheButterMineCutter's user avatar
1 vote
1 answer
50 views

Connecting multiple loads in self-balancing parallel [closed]

I have three (or 'n', where n=3 at the moment) large LED panels that I want to run in parallel. As we know (or should have known before the 'royal we' actually tried it!), just wiring them together in ...
jackisquizzical's user avatar
1 vote
1 answer
43 views

How can I calculate filter parameters between RF switch and antenna?

In the schematics en.MB1389-WL55JC-highband-E02_Schematic, there's a Pi filter following the RF switch before it links to the SMA connector for the antenna. Upon calculation, I found that the cutoff ...
Atrahasis's user avatar
  • 185
1 vote
1 answer
136 views

Intuitive explanation of shorted stub behaviour

Can someone please give me an intuitive explanation of shorted stub behaviour? NOTE: This is not a duplicate of Intuitive explanation of open stub behaviour which has been narrowed to focus on open ...
Curious Cosmopolitan's user avatar
0 votes
2 answers
189 views

Intuitive explanation of open stub behaviour

Can someone please give me an intuitive explanation of open stubs? I have the length-based mathematical derivation and explanation from my textbook, but I am looking for an intuitive one. For example,...
Curious Cosmopolitan's user avatar
1 vote
1 answer
61 views

External circuit to increase the series capacitance of a resonant circuit

I am working with a long-range reader and antenna coil for a low frequency (135 kHz) RFID application (please see the basic representation below.) The reader features some unknown source impedance, as ...
tomhebe's user avatar
  • 21
4 votes
1 answer
547 views

Why can domestic induction stoves heat aluminium tape, but not aluminium pans?

Domestic induction stoves can't be used with thick aluminium or copper pans, but when I try to heat aluminium tape it does get hot. Can someone explain why this is the case?
Kresna Wahyu's user avatar
2 votes
2 answers
210 views

75 ohm cable in an otherwise 50 ohm antenna system: Can I impedance match it?

I have an marine radio antenna installation as shown in the diagram. Can I place baluns (or similar devices) at either end of the 75 Ω cable to solve the impedance mismatch problem? Background In ...
ealanm's user avatar
  • 21
1 vote
2 answers
217 views

Half Bridge Impedance Matching

I’m currently building a half bridge induction heater and can’t understand impedance matching for the life of me. Here’s an example of a basic half bridge induction heater. How and why was 45uH ...
ElectronicsNoob's user avatar
1 vote
2 answers
102 views

Via process when implementing GCPW in RO4003 + FR-4 multilayer structure

I am currently developing an RF board that receives up to 8GHz. The board consists of a multi-layer structure combining Ro4003C (8mil) and FR-4. The connector I will be using for the RF board is a ...
hyerim's user avatar
  • 13
0 votes
0 answers
52 views

Signal Generator Output Impedance Matching and Floating Ground

I am attempting to recreate a signal generator circuit based on the XR2206, as seen in this video. The schematic uses op-amps for offset cancellation and output amplitude matching. To avoid the need ...
Fatihy's user avatar
  • 45
0 votes
2 answers
93 views

Antenna tuning and L/C matching

I see there are already a few questions asked wether it is better to physcally tune the antenna for said frequency and impedance or use a matching network. It seems the conscenus is often the physical ...
George kirby's user avatar
0 votes
3 answers
236 views

How best to match and ground antenna?

An example of RF AM modulation: https://www.ee-diary.com/2021/12/am-modulator-using-bjt-transistor.html It is clear that the output is on point C4 and the circuit has a RF function, so I need an ...
user avatar
0 votes
2 answers
73 views

How to calculate output impedance of switching regulator?

If I consider a buck converter where in 24 volts, L =100 μH, capacitor 47 μF. Then converter will operate at 400 kHz. How do I calculate the output impedance of the converter?
Laxmidhar Senapati's user avatar
0 votes
1 answer
145 views

LTspice - auto-transformer impedance ratio

Can you please clarify what formula is used by LTspice to calculate the auto-transformer impedance transfer ratio for the equivalent circuits below? Both circuits resonate on the same frequency. I ...
andrzej's user avatar
  • 13
1 vote
1 answer
106 views

Why is the current angle negative?

I don't understand why the current angle is negative.
Noting's user avatar
  • 57

1
2 3 4 5
15