Abstract: The present invention is directed to a balun that includes a first coupler structure having a first port of a balanced port pair and an unbalanced port. A second coupler structure includes a second port of the balanced port pair. The second coupler port structure being connected to the first coupler structure such that the second port of the balanced port pair is DC isolated from the first port of the balanced port pair without decoupling components.

Abstract: The present invention is directed to a coupler structure that includes a first port, a second port, a third port, and a fourth port. L first transmission line layers are disposed in the structure. Each first transmission line layer includes a first transmission line conforming to a predetermined geometric configuration. The first transmission line is disposed on a first dielectric material between the first port and the second port. L is an integer. M second transmission line layers are disposed in alternating layers with the L first transmission line layers to form a total of N transmission line layers within the structure. M and N are integers and N is greater than or equal to three. Each second transmission line layer includes a second transmission line substantially conforming to the predetermined geometric configuration. The second transmission line is disposed on a second dielectric material between the third port and the fourth port.

Abstract: The present invention is directed to a coupler that includes a coupler structure including at least one first transmission line disposed on a first major surface of a coupler dielectric substrate and at least one second transmission line disposed on a second major surface of the coupler dielectric substrate. The coupler structure includes four symmetric ports such that each port of the four symmetric ports is characterized by substantially identical impedance characteristics. A first ground plane structure is coupled to the coupler structure and including a first outer dielectric material and a first conductive exterior layer disposed substantially parallel to the first major surface. A second ground plane structure is coupled to the coupler structure and including a second outer dielectric material and a second conductive exterior layer disposed substantially parallel to the second major surface.