Patent ID: 6111465
Filing Date: 2000-08-29
Classification: H01F,H03F,H03H

Abstract:
An amplifying unit comprising:an input transformer: anda balanced broadband amplifier; wherein:said input transformer comprises a transmission-line transformer, said transmission-line transformer having a ground terminal serving as a fixed potential reference for determining a middle point output of said input transformer, whereby a characteristic impedance of said input transformer can be maintained;said transmission-line transformer comprises a forced-balun type transmission-line transformer; andwherein said forced-balun type transmission-line transformer has two input ports and first and second output ports, a first impedance between said input ports, a second impedance between said first output port and said ground terminal, and a third impedance between said second output port and said ground terminal, said first, second and third impedances being represented by Zin, Zout1, and Zout2. respectively, an impedance ratio of Zin:Zout1 :Zout2 being about equal to 1:(1/2):(1/2).