Questions tagged [vna]
VNA (Vector Network Analyzer) - Device to measure characteristics of electrical networks
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Impedanace matching on VNA does not match calculation (with detail steps included)
I have a PCB with pi-matching network, and I want to calculate the components values for the matching network.
I use LiteVNA and this antenna for this project:
https://www.we-online.com/components/...
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Can you calibrate your VNA to show matching circuit behavior, without the antenna connected?
We need to make a matching circuit for an antenna, but the antenna feed point is in an inconvenient location.
Is there a way to calibrate the VNA at the feed point such that the VNA will show the ...
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S parameters calculation from VNA file
I am trying to validate that our broadband LNA(Low noise amplifier) is working correctly. I wanted to measure the S21 of the LNA, I calibrated the VNA for the specified frequency range and measured ...
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Is my VNA broken or miscalibrated, or are these weird results normal?
My company got a new vector network analyzer recently and I'm using it to try to learn more about microwave circuits, especially the resonant cavities that we use in our measurement systems. I've seen ...
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What's the difference between a vector network analyzer (VNA) and a frequency response analyzer (FRA?)?
I know what a VNA does, but what does an FRA do that's different? From what I can find, an FRA seems to be primarily used in electrochemistry and other physical sciences, where what is being tested ...
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When calibrating a VNA, does the feedline length matter?
We need to measure an antenna feedpoint (to record an .S1P file) that is far away from the VNA. We can calibrate the VNA to the feedline that will ultimately be attached to the antenna before it goes ...
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Signal modulation with VNA
I want to apply a 1 V, 1 MHz signal to my DUT (coaxial waveguide) while sweeping the frequency from 300 kHz to 6 GHz by the VNA.
Right now, I applied the signal by the signal generator to the bias tee ...
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Choosing between diplexer and resistive power divider
I want to use a passive device to apply a 1V and 1MHz signal in a transmission line, While I am sweeping the frequency from 300kHz to 6GHz by Vector Network Analyzer (VNA) in that transmission line ...
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Understanding TRM calibration in network analyzers
I am trying to figure out how TRM calibration in network analyzers works. I have read a couple papers about it, but didn't understand it properly, therefore I tried to develop it myself. I do this by ...
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Bias tee in Vector Network Analyzer
Can I use a bias tee in the back of a VNA (E5080B) as a port 1 and 2, or do I need a mixer for it? I want to measure the network parameters of a device that requires bias.
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Source impedance influence on DC/DC converter input impedance measurement
simulate this circuit – Schematic created using CircuitLab
I have been tasked to verify the input impedance of a medium powered DC/DC converter (<1kW), and no experienced colleagues to ...
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Vector Network Analyser (VNA)
I am trying to achieve impedance matching using load-pull mechanism and I recently found out that on a Smith chart in the VNA, the S21 doesn't make any sense as I have to plot transmission parameters ...
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Need help with signal modulation
To capture a mammalian cell, I need to have a constant 4MHz AC signal (coming from a function generator) while sweeping the frequency from the vector network analyzer (VNA) 9kHz to 9GHz to read the ...
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The meaning between raw and calibrated S parameters
VNA: E5071C
Cal kit: 85033E
DUT: cable end bandpass filter
This figure shows measuring S21 of filter:
Upper figure shows real part of S21 and lower one shows imaginary part of S21.
Blue line is raw ...
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Convert dB to ohms
I did some impedance measurements in high frequencies using a VNA.
I did not pay attention to the format of the measured values that were in dB so it is now to late for me to reperform measurements.
I ...
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Can a BNC through-load be used as the load to SOL-calibrate a VNA?
Related to this question, I'm having a hard time finding a female 50-ohm load to calibrate a reference plane at the end of a male BNC feedline. However, feed-through loads are readily available.
Is ...
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Is there anything particularly special about a "short" and an "open" in a VNA calibration kit?
I would like to calibrate a VNA with the reference plane at the end of a male BNC feedline. Surprisingly, female SOL kits are hard to find. There are many BNC 50-ohm loads available but I'm having ...
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How vector network analyzer measures S-parameters of lumped element?
i've seen video lecture where S-parameters of 50 Ohm resistor placed in series between input and output port of VNA with reference resistance also of 50 Ohm are calculated by hand. S11 was calculated ...
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VNA discovery question
I was playing with my VNA yesterday and noticed in the Smith chart view of a surface mount device that the trace went from an open at 30 KHz, through inductive to some capacitance at 6 GHz. Nothing ...
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Pi matching off-board antenna with module pigtail
I have an Iridium 9603 satellite modem integrated in a project and would like to tune its antenna feed line using a pi matching circuit on my carrier PCB. What's unique about this situation is that ...
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VNA: Why does the IF bandwidth affect the measurement speed?
I believe I understand the role of the IF bandwidth (IFBW) in a VNA measurement:
The signal is mixed down to the intermediate frequency (IF) and the receiver detects the signal in a frequency band ...
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How to connect the VNA to RF transmission line for antenna tuning?
I am working on a 2.45 GHz(Bluetooth) project. the design has a Chip antenna with 50 Ω impedance trace to connect antenna and chip.
I intend to tune the antenna impedance using the Pi network using ...
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How to measure the input impedance of a laser diode/LED using a VNA?
It would be nice to have some advice on an issue I'm having with a laser diode. I have a DFB laser diode that has no kind of series resistor connected to it in the package. I want to make a driver for ...
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"Short" calibration
The following section from ST Micro's AN4974 - 'Antenna Matching' app note is a bit of a mystery.
Is there a VNA / network analyzer guru out there who can tell me what the 4th line there is saying? I ...
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How to choose a sweep range for a known and unknown device with a VNA?
I'm trying to determine best practices for using a VNA to measure say, an antenna.
Let's say I have a known antenna with a spec sheet that says it's frequency range is between x and y. Should I set ...
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How to measure radio wave penetration and reflection through different mediums
I would like to do a few experiments to test how different EM radiation frequencies (915 MHz to 5 GHz) interact with 3D print filament materials (like PLA, PolyCarbonate, TPU, etc...). Specifically I ...
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What is the frequency measurement range of a NanoVNA?
I have tried to measure a fabricated patch antenna which has theoretically multiband ranging from 1 GHz to 8 GHz, but when I tried to measure it through NanoVNA it barely shows the result from 1 GHz ...
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How to protect measurement equipment channels from ESD?
I was wondering what is the best way to protect measurement equipment, when handling like oscilloscopes/spectrum analyzers/Vnas/sensitive circuits (especially when stored in (none esd) foam)?
I was ...
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How to improve measurement results with pocketVNA
I use a pocketVNA to measure the impedance of antennas and I also bought a couple of SMA connectors and a few cables to connect the antennas to the device.
I run a 2-point calibration of the device (...
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Calibrating a VNA
I am using the Siglent SSA3032A-R spectrum analyser which has a Vector Network Analyser (VNA).
Before measuring the impedance of an antenna under test so that I can match this antenna, I have to ...
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VNA Characterization of a non 75Ohm system
I'm trying to characterize a 75ohm cable using a VNA.
As it differs from 50Ohm I need to do some adjustments with how I'm measuring but I'm not sure what is considered best practice for that.
I was ...
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Tuning an antenna using a NanoVNA, Smith chart and impedance readings
I am new to antenna design and teaching myself how to optimize antennas using a VNA.
I have created a monopole antenna on a PCB (i.e. a single length of track.) The antenna can be fed via a PI network ...
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1-port VNA quality factor measurement
I am using an Anritsu VNA (MS2034B) to obtain the LINEAR MAGNITUDE and PHASE of S11 via a calibrated 1-port measurement. The DUT is an inductively coupled RLC resonator (schematic below). However, I ...
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Match SMA antenna input connector to 50ohm
I'm using an "IOT" radio module designed with a 50 ohm single ended antenna output. The working frequency is about 868 MHz, the maximum transmit power is 14dBm. The module antenna output is ...
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Spurious resonance in microstrip transmission line
We were trying to study the broadband response of a microstrip line on a 1.5mm thick Rogers AD1000 substrate whose Dk=10.7 and loss tangent=0.0023 at 10 GHz. The trace width is 1.2 mm. The S21 is ...
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How is the "open" component of the vector analyzer calibration kit made?
I've done some measures of S parameters with a VNA a long time ago. I'm not an expert om this, but I remember the procedure of calibration, which was using, for a single port, the three lumped ...
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Measuring and connecting a parallel LC circuit
I have built an LC circuit at 3.4 MHz and measured it's resonance with a VNA as schown in this picture and described here:
The parallel LC circuit is connected to the output of the VNA and is open, ...
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What does an S21 of 0dB mean?
In a video titled PDN Measurements with a VNA Rolf Ostergaard shows how to transform the magnitude of the insertion loss S21 to an impedance value. This is the formula he uses:
$$
Z = 25\Omega \times ...
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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 ...
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Estimate transmitted ultrasonic power
I want to use ultrasonic (20 kHz to 100 kHz) transducers to couple ultrasound into pipes for cleaning purposes. You can easily buy those transducers with driving circuits on Aliexpress but I want to ...
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Is the VNA incident signal sine or cosine?
I wonder what kind of the input power signal is in the S11 parameter. Is the sine or cosine I know correct?
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What is the significance of a negative imaginary component in a S21 measurement?
What is the significance of a negative imaginary component in a S21 measurement ?
For example, in the following plot of a passive network, the linear magnitude of the S21 parameter decreases with ...
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What is a good loop probe to use for non contact measurements at 13.56MHz?
I have a receiving antenna (9 turn spiral, 1cm in diameter) that I would like to measure (inductance) wirelessly at 13.56MHz. While looking through application notes from ST and NXP semiconductors, I ...
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Antenna matching circuit - weird behaviour
I have a 2.4GHz device with room for a Pi matching circuit. I cut J5 (to disconnect the MCU - brown line in layout picture), soldered the ground of the coaxial cable in the white region and the ...
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How to interpret the S21 phase measured by LCA or VNA?
I have measured the S21 phase of my device, which came as below. I would like to know if this phase is with reference to the input or with reference to the DC?
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How do I see the resonance of a high-impedance coil with a VNA?
When it comes to measurements with VNA, my experience tells me that whenever there is a "dip" in the S11 parameter, your takeaway should be that there is a resonance there (this is how the ...
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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) = -...
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Correct calibration of reflection (S11) measurement
Following situation (apologies for my potential stupidity, I am very new to RF): I am doing a reflection/S11 measurement using a cut-off piece of coaxial cable (no stub, just a straight cut).
The idea ...
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Why is S11 measurement changing on Agilent E5071B Network Analyzer?
Just a note: This is the second time I've ever used a VNA.
I am trying to measure S11 of the 1.88GHz RF Input of this Powercast RF Energy Harvesting board. Link to the datasheet.
Powercast Board ...
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Minimum Viable VNA N-to-N Test Cable for 2480MHZ
Can I get away with a $60 dollar N-to-N 1 meter cable from a reputable vendor for use in the scenario below? I have limited practical experience with a new VNA that just has an N connector output and ...
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