Patent ID: 9240623
Filing Date: 2016-01-19
CPC Classification: H01P

Claim Text:
1. A device for coupling microwave signals, the device comprising: a first branch comprising a cascade of first stripline sections conductively coupled to one another; a second branch comprising a cascade of second stripline sections conductively coupled to one another; and a single stripline section and a capacitor coupled in series to at least one of the branches, 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, the length of the single stripline section is adjusted to tune the flatness of a phase balance between signals at a transmit port and a coupled port of the first and the second branch, two ends of one of the first or second branches are configured as an input port and the transmit port, and two ends of another one of the first or second branches are configured as an isolated port and the coupled port, the single stripline section is not coupled with any stripline section on an opposite side of a laminate layer, and the flatness of the phase balance is achievable to less than five degrees over a fractional bandwidth of over 150 percent.