[TowerTalk] broadband tranformers and loads with a reactive component

[CP2235@aol.com]

helllo all...

can you help me in the following question

take a unsymmetrical broadband transformer (I think it is also called
autotransformer or UNUN sometimes). Normally such a device consists of a
trifilar winding over a toroid core:

(xxxxx are the windings)

                      
 Ground  ----xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx------- High Z
                          I
                          I  (tap)
                       Low Z

with
n1 = number of windings between ground and low-z tap
n2 = number of all windings

the impedance matching ratio turns out as
(n1/n2)^2  =  LowZ / HighZ     

(^2 stands for squared)


now my question:
what happens if you connect a complex impedance (antenna) which is not purely
resistive but has a (capacitive or inductive) reactive component to the
transformer?
how is this complex impedance transformed?
example: if you connect an impedance of 100 + j50 ohms to a 1:2 transformer
(high z side), what do you see on the low z side, 50 + j25 ohms?? or is just
the vector amount (sorry I dont know the proper word in english) of the
complex impedance transformed?
or do those tranformers only work "properly" with purely resistive loads?
in the case with added reactance the tranforming ratio might depend on
additional parameters like frequency and the way the tranformer has been built
(thus his own impedance..) ??

so the function might only be given in a small range (which range?) of added
reactance?  
 
or what else...?

can somebody enlighten me please??

73 Con DF4SA

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