Quadrature hybrid coupler using one-port, linear circuit elements

Claim 2

A quadrature hybrid coupler comprising: two conductors wherein one end of each of said two conductors and a first common junction, and the other ends of said conductors and a second common junction constitute the four ports of said coupler; a first network connected between said two conductors; and a second network, dual to said first network, connected between said common junctions; said networks having multipole impedance characteristics.

Claim 3

The coupler according to claim 1 wherein a pair of baluns are connected in series with one pair of coupler ports that share the same common junction; and wherein one end of the external circuits connected to said baluns and to said other pair of coupler ports, are connected to said second common junction.

Claim 4

The coupler according to claim 1 wherein a balun is connected in series with each of said four coupler ports.

Claim 5

The coupler according to claim 2 wherein the core impedances of said baluns are incorporated into said second network.

Claim 6

The coupler according to claim 3 wherein the core impedances of said baluns are incorporated into said second network.

Claim 7

A quadrature hybrid coupler including: a pair of baluns, each comprising two conductors having a first end and a second end; the first end of one conductor of each balun being connected to a first common junction, defining a ground connection; the second ends of said one conductor being connected together forming a second common junction; a first network being connected between said common junctions; a second network, dual to said first network, being connected between the second ends of the other of said conductors; and wherein the four ends of said other conductors constitute the four ports of said coupler.

Claim 8

A quadrature hybrid coupler including: a pair of baluns, each comprising two conductors having a first end and a second end; the first end of one conductor of each balun being connected to a first common junction, defining a ground connection; the second ends of said one conductor being connected together forming a second common junction; a first network being connected between said common junctions; a second network, dual to said first network, being connected between the second ends of the other of said conductors; and wherein the four ends of said other conductors constitute the four ports of said coupler.

Claim 9

The coupler according to claim 6 wherein each of said networks includes at least two reactive elements to form a multipole impedance characteristic.

Claim 10

The coupler according to claim 6 wherein said first network includes a shunt inductive element.

Claim 11

The coupler according to claim 8 wherein the parallel combination of the core inductances of said baluns constitutes at least a portion of the inductance of said shunt inductive element.

Claim 12

The coupler according to claim 6 wherein said first network includes a shunt capacitive element; and wherein the parallel combination of the spurious capacitances of said baluns constitutes at least a portion of the capacitance of said shunt capacitive element.

Claim 13

The coupler according to claim 6 including a delay line, for compensating for the transit time through said baluns, connected in series with the second end of each of said other conductors.

Claim 14

A quadrature hybrid coupler including: four baluns, each of which comprises two conductors having a first end and a second end; the first end of one of the condUctors of a first balun and of a second balun, and a first end of one of the conductors of a third balun and of a fourth balun being connected to a first common junction, defining a ground connection; the second ends of said one conductor of said first and said second baluns being connected together forming a second common junction; the second ends of said one conductor of said third and said fourth baluns being connected together forming a third common junction; a first network connected between said second and third junctions; the second ends of the other conductors of said first and third baluns being connected together; the second ends of the other conductors of said second and fourth baluns being connected together; a second network, dual to said first network, being connected between the second ends of the other conductors of said first and second baluns, and the second ends of the other conductors of said second and fourth baluns; and wherein the four first ends of said four other conductors in conjunction with said common ground connection constitute the four ports of said coupler.

Claim 15

A quadrature hybrid coupler including: four baluns, each of which comprises two conductors having a first end and a second end; the first end of one of the condUctors of a first balun and of a second balun, and a first end of one of the conductors of a third balun and of a fourth balun being connected to a first common junction, defining a ground connection; the second ends of said one conductor of said first and said second baluns being connected together forming a second common junction; the second ends of said one conductor of said third and said fourth baluns being connected together forming a third common junction; a first network connected between said second and third junctions; the second ends of the other conductors of said first and third baluns being connected together; the second ends of the other conductors of said second and fourth baluns being connected together; a second network, dual to said first network, being connected between the second ends of the other conductors of said first and second baluns, and the second ends of the other conductors of said second and fourth baluns; and wherein the four first ends of said four other conductors in conjunction with said common ground connection constitute the four ports of said coupler.

Claim 16

The coupler according to claim 12 wherein each balun comprises a length of transmission line of characteristic impedance Zo equal to Square Root NN*, where N and N* are the impedances, respectively, of said first and second networks.