Patent ID: 7978021

Claim:
A balanced-to-unbalanced transformer comprising: a power supply terminal; an unbalanced terminal; a pair of balanced terminals including first and second terminals connected to the unbalanced terminal via a branch point; a +90° phase shift circuit including a first-terminal-side series capacitor connected in series to a line between the branch point and the first terminal; and a −90° phase shift circuit including a second-terminal-side series inductor connected in series to a line between the branch point and the second terminal; wherein the +90° phase shift circuit includes: a first inductor having a first end connected to a first terminal side of the first-terminal-side series capacitor and a second end connected to the power supply terminal; and a second inductor having a first end connected to a branch point side of the first-terminal-side series capacitor and a second end connected to the power supply terminal.