An example of a transmission-line transformer may include a transmission-line assembly and a balun assembly. The transmission-line assembly may include first and second conductors forming at least first and second transmission-line sections. The transmission-line assembly may provide a signal path through the first conductor and second conductor in series to a circuit ground. Balanced lines of the balun assembly may be connected to respective intermediate points on the first and second conductors between the first and second transmission-line sections. The transmission-line transformer may provide a signal path between a first end of the first conductor of the transmission-line assembly and the unbalanced line of the balun assembly.