All Questions
Tagged with impedance-matching smith-chart
16
questions
1
vote
1
answer
159
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 ...
1
vote
0
answers
47
views
Matching network for two-port with internally matched inputs/outputs
Background
I had a lab in school where we were given an LNA with inputs/outputs matched to 50Ω, that will be connected to a 50Ω system:
The task was to design the input and output matching networks:
...
- 111
0
votes
1
answer
183
views
Impedance matching on VNA does not match calculation (with detail steps included)
I have a PCB with a pi-matching network, and I want to calculate the component values for the matching network.
I use LiteVNA and a WE-MCA Multilayer Chip Antenna for this project.
Here is the basic ...
- 1
6
votes
2
answers
262
views
Smith Chart is giving me an answer I didn't expect - Am I using it right?
I'm trying to track down a VSWR issue with a RF power amplifier (25 W, 150 MHz). The radio we're using to drive it has a VSWR alarm, which triggers during transmit. Older manufacture runs of the PA ...
- 596
2
votes
0
answers
636
views
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 ...
- 412
4
votes
2
answers
3k
views
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 ...
- 59
0
votes
1
answer
373
views
RF Matching Problem
I am having some fundamental issues trying to create an impedance matching network for an 868MHz antenna, I have a PI network between the antenna's connector and the antenna feed point
I have measured ...
0
votes
1
answer
215
views
How is a transmission line with a different characterisitc impedance shown on the smith chart?
A transmission line can be shown on the smith chart as a clockwise rotation, each 180 degrees corresponding to a quarter wavelength. But this is when the characteristic impedance (Z0) of the ...
- 302
0
votes
2
answers
974
views
Find impedance matching in a quarter wave transformer
I would like to know if there is a way you can find the impedance that has to be set between the load \$Z_L\$ when it is complex and the characteristic impedance \$Z_0\$ to have impedance matching ...
- 137
1
vote
1
answer
1k
views
Stub matching at smith chart
I'd like to clarify some concepts about microwaves that I still can't understand it at all. I'm reading Pozar's Microwave Engineering, more specifically stub adaptation in the Smith Chart. The circuit ...
- 47
1
vote
5
answers
978
views
Impedance matching a capacitive source
I am trying to work out how to match a current source coupled with a capacitor to a 50 Ω load for maximum power transfer. Specifically, I have a 6 pF PIN photodiode which driven by a 2.5 GHz optical ...
- 111
11
votes
1
answer
2k
views
Balun/matching network question
I am having problem to verify what an app note (AN068) explains to calculate Balun values. I would appreciate if someone could tell me what/where am I doing wrong?
The summary of the RF part:
Blue ...
- 3,305
3
votes
2
answers
1k
views
Use of Smith charts
There are Smith charts with impedance and admittance coordinates and Smith charts with only impedance coordinates.
I believe I learned how to use the first one. Is there any sense in studying how to ...
- 179
4
votes
1
answer
719
views
RF amplifier load matching
I want to match RF power amp to aerial. There is no 50 ohm or 75 ohm transmission line inbetween.
So, I consider my aim to be matching certain load-reflection coefficient (Γload) to a short circuit (...
- 179
6
votes
1
answer
503
views
Help with Matching circuit
I'm using a SAW filter which has balanced input and output.
In the datasheet there is shown a matching application for 50ohms balanced output.
But plotting the S22 parameters into a Smith Chart and ...
- 2,310