Abstract: An apparatus includes an input port, an output port, a first bias input, a first shunt PIN diode, a first radio frequency (RF) choke inductor, and a first direct current (DC) blocking capacitor. The input port may be connected to the output port, a first terminal of the first shunt PIN diode, and a first terminal of the first RF choke inductor. A second terminal of the first RF choke inductor is connected to a first terminal of the first DC blocking capacitor and the first bias input. A second terminal of the first shunt PIN diode and a second terminal of the first DC blocking capacitor are connected to a circuit ground potential. A first bias voltage having a magnitude lower than a knee voltage of the first shunt PIN diode is applied at the first bias input.

Abstract: A broadside 90° microwave coupler is composed of three metal layers in a homogeneous dielectric media. The coupler is constructed in a multi-layer configuration with two conductor strips arranged on top of each other so as to be electro-magnetically coupled. A ground plane formed with a third metal layer below the coupled conductor strips is opened so that it is separated from the conductor strips by a gap. The two conductor strips are fully embedded into the dielectric layer. The characteristic physical dimensions of the coupler are determined to achieve the desired coupling coefficient while maintaining low reflection, high isolation and phase balance at the output ports of the coupler.

Abstract: A broadside 90° microwave coupler is composed of three metal layers in a homogeneous dielectric media. The coupler is constructed in a multi-layer configuration with two conductor strips arranged on top of each other so as to be electro-magnetically coupled. A ground plane formed with a third metal layer below the coupled conductor strips is opened so that it is separated from the conductor strips by a gap. The two conductor strips are fully embedded into the dielectric layer. The characteristic physical dimensions of the coupler are determined to achieve the desired coupling coefficient while maintaining low reflection, high isolation and phase balance at the output ports of the coupler.