circulator operation

I'm a bit confused about circulators and especially dual junction circulators.

1) I was operating under the impression that I need a good match to have good isolation. If so, how does a circulator keep isolation if the antenna is disconnected from a transceiver?

2) Is a dual junction circulator a single junction circulator in series with an isolator?

tnx all.

All reflected power goes to the resistor that terminates the third port.

Yes, see here:
http://www.mpdigest.com/issue/Articl...ce/Default.asp

Good link. Unfortunately that answered my questions, lol.

tnx

nice article, thanks ... took a copy of that for future reference :)

Dave