Patent ID: 6150896
Filing Date: 2000-11-21
Classification: H03H,H04N

Abstract:
A coupling device for connection between an unbalanced signal line having a first characteristic impedance and a balanced signal line having a second characteristic impedance, the unbalanced signal line including a grounded conductor, the coupling device comprising:a) an input for connection to the unbalanced signal line and an output port for connection to the balanced signal line;b) a balun comprised of a pair of balun input leads at the input port, a pair of balun output leads, a tri-bifilar winding, and a core, the input leads electrically connected to the unbalanced signal line, the balun configured for matching the first characteristic impedance to the second characteristic impedance and for providing a substantially balanced signal at the output leads;c) a first common mode choke and a common mode shunt connected between the balun output leads and the second port, the common mode choke comprised of a core, a pair of windings, a pair of input ends, and a pair of output ends, and the common mode shunt comprised of a core, a first winding with a first winding lead and an opposite first winding grounded lead, and a second winding with a second winding lead and an opposite second winding grounded lead, the first winding grounded lead and the second winding grounded lead electrically connected to the grounded conductor.