Abstract: A transmission-line network includes first, second, third, and fourth transmission lines. Signal conductors of the first and third transmission lines are connected in series and the signal conductors of the second and fourth transmission lines are connected in series. Signal-return conductors of the first and fourth transmission lines are connected in series. The signal-return conductors of the second and third transmission lines are connected in series. A first resistor may be connected between a junction between the signal conductors of the first and third transmission lines and a junction between the signal conductors of the second and fourth transmission lines. A second resistor may be connected between a junction between the signal-return conductors of the first and fourth transmission lines and a junction between the signal-return conductors of the second and third transmission lines.

Abstract: In a four-port transmission-line network, a first transmission line is connected to a first port, second and third transmission lines are connected to a first component port, fourth and fifth transmission lines are connected to a second component port, and a sixth transmission line is connected to a fourth port. The transmission lines are connected as baluns to the ports with the unbalanced signal on the port side and the balanced signals interconnecting with others of the transmission lines. In another example, two or more baluns are connected serially. Each balun includes two transmission lines having signal-return conductors connected together at the ends. One end of a signal conductor on the first balun forms a sum port. One end of the signal-return conductors of the second balun forms a difference port, and a capacitor connects the other end of the signal-return conductors to circuit ground.

Abstract: First ends of a plurality of sub-networks of an exemplary transmission-line network are connected together electrically in series. First ends of a plurality of transmission lines of one subnetwork are connected together in parallel and second ends are connected together in series. The one sub-network has a first-end impedance value that is different than a second-end impedance value. The second-end impedance value of the one sub-network is different than a second-end impedance value of another sub-network. A respective transmission line connects each sub-network to a common circuit node and a respective resistor interconnects each adjacent pair of the second ends of the sub-networks.

Abstract: In a four-port transmission-line network, a first transmission line is connected to a first port, second and third transmission lines are connected to a first component port, fourth and fifth transmission lines are connected to a second component port, and a sixth transmission line is connected to a fourth port. The transmission lines are connected as baluns to the ports with the unbalanced signal on the port side and the balanced signals interconnecting with others of the transmission lines. In another example, two or more baluns are connected serially. Each balun includes two transmission lines having signal-return conductors connected together at the ends. One end of a signal conductor on the first balun forms a sum port. One end of the signal-return conductors of the second balun forms a difference port, and a capacitor connects the other end of the signal-return conductors to circuit ground.

Abstract: A transmission-line-based impedance transformer including first and second couplers, with each coupler including respective pairs of coupled signal conductors. The signal conductors are connected sequentially in series between an input port and an output port and may form a single spiral configuration. A signal conductor of one coupler may be connected in series between the two signal conductors of another coupler. The couplers have characteristic impedances between an input impedance and an output impedance. A signal conductor of a coupler may include first and second conductor portions disposed in respective spaced-apart parallel planes, with the other signal conductor of the coupler disposed physically directly between the conductor portions. A signal conductor in the spiral may be shielded from coupled signal conductors by ground conductors disposed in respective spaced-apart parallel planes on opposite sides of the shielded signal conductor.

Abstract: A transmission-line-based impedance transformer including first and second couplers, with each coupler including respective pairs of coupled signal conductors. The signal conductors are connected sequentially in series between an input port and an output port and may form a single spiral configuration. A signal conductor of one coupler may be connected in series between the two signal conductors of another coupler. The couplers have characteristic impedances between an input impedance and an output impedance. A signal conductor of a coupler may include first and second conductor portions disposed in respective spaced-apart parallel planes, with the other signal conductor of the coupler disposed physically directly between the first and second conductor portions. A transmission-line signal conductor in the spiral may be shielded from coupled signal conductors by ground conductors disposed in respective spaced-apart parallel planes on opposite sides of the shielded signal conductor.