Tagged Questions

0
votes
2answers
153 views

Antenna analyzer

I want to measure the impedance of an antenna (at 434MHz) and for learning/fun try to build a circuit to do so. I found the return loss bridge http://www.vk2zay.net/article/179 Can I measure a ...
0
votes
1answer
96 views

What is a good tolerance for impedance matching or how to calculate losses?

If you build a microstrip on a silcon wafer, connected by picoprobes via SMA connector and cables to a VNA, what is actually a good match of the impedances of the cables and the waveguide. Is there a ...
5
votes
2answers
1k views

Impedance Matching Differential Signals

I'm designing a circuit with RFICs using differential signaling. I'd like to keep noise to an absolute minimum. Let's use the mixer (LT5560) as an example. All of the reference schematics match to 50 ...
3
votes
4answers
705 views

How to terminate 50 ohm transmission line without drawing DC

I am sending a 10 MB/sec digital data stream by amplitude moduating a infrared quantum cascade laser. The laser requires a hefty bias of about half an amp (which drops about 8.5 volts across the ...
8
votes
5answers
869 views

Impedance Matching and Large Trace Widths

I am currently working on a design in which one of my ICs specifies the use of a 50 ohm trace. The answer to this question, Characteristic impedance of a trace, shows that a 120 mil trace is required ...
3
votes
3answers
1k views

Measuring output impedance

Given I have designed and produced an RF circuit with an output for connecting an antenna. I know this antenna has an input impedance of 50Ω. I now wish to measure the actual output impedance of my ...
37
votes
5answers
2k views

What is impedance?

This is presented as both a resource for the community and a learning experience for myself. I have just enough knowledge of the subject to get myself into trouble, but I don't have the best grasp of ...