Power divider/coupler question

[Firefox123]

Quick question on couplers/dividers...

Imagine a 3 port power divider...one input and two outputs that give equal outputs...say -6db from the input level.

Now say we connect the two outputs to two signal sources and connect a spectrum analyzer to the input port of the divider...so we are connecting the divider as if it were a coupler...

Should the output (taken at the divider input) necessairly be the summation of the two inputs (which are normally the outputs of the divider)?

I have seen someone do this in the past and from what I remember the two signals(one was a continuous signal and the other was a very short lived pulsing signal) really didnt appear to add together on the analyzer display...

All I have is my undergrad microwave engineering textbook to go off of, so if anyone knows some good weblinks for microwaves/couplers/dividers please let me know...Thanks.
Russ

 

[berkeman]

Some couplers are directional, and some are not. MiniCircuits is a very popular source for couplers, and they have some good app notes as well:

http://www.minicircuits.com/application.shtml

 

[ravenprp]

ell, thank you for your question.

Firstly, a power divider and a coupler are two different components. A power divider splits an input signal into multiple output signals with equal or unequal power levels, while a coupler combines multiple input signals into a single output signal.

To answer your question, when connecting two signal sources to the outputs of a power divider and then connecting a spectrum analyzer to the input port, the output should be the summation of the two input signals. However, this assumes that the power divider is ideal and there are no losses or impedance mismatches.

If there are losses or impedance mismatches in the system, then the output may not necessarily be the summation of the two input signals. This could explain why you did not see the expected result on the spectrum analyzer display.

I would recommend checking the specifications of your power divider and making sure it is suitable for your application. Additionally, it may be helpful to use simulation software or consult with a microwave engineer to troubleshoot any issues you are experiencing.

As for additional resources, I recommend checking out the IEEE Microwave Theory and Techniques Society website (https://mtt.org/) for articles and publications on couplers and dividers. You can also find some helpful resources on manufacturers' websites, such as Mini-Circuits (https://www.minicircuits.com/).

I hope this helps and good luck with your project!