"Roy Lewallen" wrote in message
...
Steve N. wrote:
. . .
Side bar:
For some situations, the resistive part of this new impedance can even
go
negative. ...

Negative feedpoint resistances in phased arrays have of course been
known for a very long time.

Roy,
I didn't mean to imply it wasn't known previously, only wanted to give a
real life example (as a preemptive attempt at heading off a potential "but
that's all theory" response -- perhaps a little gun-shy on this news group
(:-)). I also have no direct knowledge of this type of the network design,
but it has to be designed and the antenna with the neg real part is part of
the system that gets hooked to the network.


You can't "match to" a negative resistance, because matching
requirements are determined by the load, not source, impedance,

OOPS ! I *know* what you mean, but it takes knowledte of both ends -
We, me included, can eaily forget that we have an arbitrarily defined (50
ohm) system that we easily take for granted. ya gotta know you're in a 50
ohm (or whatever) system to "do" the match.

73, Steve, K9DCI