Wide-band microwave hybrid coupler with arbitrary phase shifts and power splits

A method for coupling microwave signals, the method comprising:

• coupling an input signal to an input port of a first branch, the first branch comprising a cascade of first stripline sections conductively coupled to one another;
• deriving a transmit signal from a transmit port of the first branch;
• and
• deriving a coupled signal from a coupled port of a second branch, the second branch comprising a cascade of second stripline sections conductively coupled to one another,
• wherein a desired phase shift between the transmit port and the coupled port is determined by a monotonically changing horizontal offset, and wherein a power splitting ratio between the transmit port and the coupled port is determined by a value of a uniform vertical distance between the first and the second branches.

A hybrid coupler comprising:

• a first branch comprising a first cascade of first stripline sections conductively coupled to one another, an input port at one end of the first cascade, and a transmit port at the other end of the first cascade;
• and
• a second branch comprising a second cascade of second stripline sections conductively coupled to one another, an isolated port at one end of the second cascade, and a coupled port at the other end of the second cascade,
• wherein the first stripline sections of the first branch and the second stripline sections of the second branch are arranged to have a monotonically changing horizontal offset and a uniform vertical distance.