Balun

transformer

From a technologist viewpoint, alot of baluns are also based upon 1:1 transformations (in differing configurations.) It seems like 1:1 transformers tend to have wider bandwidth than direct 4:1 (impedance) transformers.

So, using a 4:1 balun configuration with a natural 1:1 impedance transformer as a constituent, it seems to tend to perform better than a 4:1 (impedance) or

John

I have a PDF on this. Just email me and I will send it.

There is always the Guanella 4:1 balun to consider that has a theoretically infinite cut off frequency.

The best reading I have found on these mystical items is by Jerry Sevick. There are a few papers by him, unfortunately they are IEEE and therefore cost an arm and a leg and a good book "Transmission Line Transformers" published by Noble. It's a bit hard to get but worth the effort.

transformers

or

I understand that... Before I 'studied' the subject, I was also confused (like the original poster) about the real difference between a 'transformer' and a special configuration called a 'balun.' When I was a kid, and didn't realize the almost subtile differences, I almost thought that the term was gratuitious (however incorrectly.) The whole area of transmission line transformers, traditional transformers and various configurations can be quite interesting and enlightening !!! :-).

John

transformers

transformer

(impedance) or

There is also a directional coupler that can be formed from two cleverly connected conventional transformers as shown in US Patent 3,426,298 Figure 10.