Abstract: A branch coupler includes a first branch, comprising an input end, an isolation end, a first transmission line, a first branch line and a second branch line, the input end is electrically connected to the isolation end through the first transmission line, the first branch line is electrically connected to input end, and second branch line is electrically connected to the isolation end; a second branch, comprising a first output end, a second output end, a second transmission line, a third branch line and a fourth branch line, the first output end and the second output end are connected through second transmission line, the third branch line is connected to the first output end, and the fourth branch line is connected to the second output end; the first branch line is connected to the third branch line, and the second branch line is connected to the fourth branch line.

Abstract: A branch-line coupler of reduced size but comparable performance includes a first transmission line, a second transmission line, a first bent transmission line, and a second bent transmission line. The first transmission line includes a first strip transmission line, a first branch transmission line, and a second branch transmission line. The first strip transmission line extends along a predetermined direction, the first and second branch transmission lines being slotted. The first and second branch transmission lines are symmetrical around a first axis and around a second orthogonally-disposed axis. The first bent transmission line is electrically connected to the terminals of the first and second transmission lines on one side, and the second bent transmission line is electrically connected to the terminals of the first and second transmission lines on the other side.

Abstract: A branch-line coupler, adapted to radio frequency circuits, includes an input port, a first output port, a second output port, an isolated port, a first transmission line, a second transmission line, a first bent branch line, and a second bent branch line. The first transmission line is electrically connected between the input port and the first output port, and carries two open branches. The second transmission line is electrically connected between the isolated port and the second output port, and carries two open branches. The first bent branch line is electrically connected between the input port and the isolated port. The second bent branch line is electrically connected between the first output port and the second output port. The open branches of the first transmission line and the second transmission line resemble the bone structure of a fish skeleton.

Abstract: A branch coupler includes a first branch, comprising an input end, an isolation end, a first transmission line, a first branch line and a second branch line, the input end is electrically connected to the isolation end through the first transmission line, the first branch line is electrically connected to input end, and second branch line is electrically connected to the isolation end; a second branch, comprising a first output end, a second output end, a second transmission line, a third branch line and a fourth branch line, the first output end and the second output end are connected through second transmission line, the third branch line is connected to the first output end, and the fourth branch line is connected to the second output end; the first branch line is connected to the third branch line, and the second branch line is connected to the fourth branch line.

Abstract: A branch-line coupler of reduced size but comparable performance includes a first transmission line, a second transmission line, a first bent transmission line, and a second bent transmission line. The first transmission line includes a first strip transmission line, a first branch transmission line, and a second branch transmission line. The first strip transmission line extends along a predetermined direction, the first and second branch transmission lines being slotted. The first and second branch transmission lines are symmetrical around a first axis and around a second orthogonally-disposed axis. The first bent transmission line is electrically connected to the terminals of the first and second transmission lines on one side, and the second bent transmission line is electrically connected to the terminals of the first and second transmission lines on the other side.

Abstract: A branch-line coupler, adapted to radio frequency circuits, includes an input port, a first output port, a second output port, an isolated port, a first transmission line, a second transmission line, a first bent branch line, and a second bent branch line. The first transmission line is electrically connected between the input port and the first output port, and carries two open branches. The second transmission line is electrically connected between the isolated port and the second output port, and carries two open branches. The first bent branch line is electrically connected between the input port and the isolated port. The second bent branch line is electrically connected between the first output port and the second output port. The open branches of the first transmission line and the second transmission line resemble the bone structure of a fish skeleton.

Abstract: A double-frequency antenna structure with a high degree of electrical isolation between long distance and short distance antennas includes a dielectric substrate having at least two corners and a center area. A first set of antenna arrays is positioned at the corners. A second set of antenna arrays is positioned at the center area. At least one first folded isolation plate is mounted on the dielectric substrate, and positioned between the first set of antenna arrays and the second set of antenna arrays. At least one second folded isolation plate each is mounted on one first folded isolation plate.

Abstract: A small scale power divider which is less susceptible to large tolerances in the manufacture includes a substrate and a power dividing circuit thereon. The power dividing circuit includes an input port, a first output port, a second output port, an impedance converter, a first microstrip line, and a second microstrip line. An end of the first microstrip line is connected to the impedance converter, another end of the first microstrip line is connected to the first output port. An end of the second microstrip line is connected to the impedance converter, another end of the second microstrip line is connected the second output port.

Abstract: A small-scale branch-line coupler suitable for use in mobile devices includes a first, second, third, and fourth ports, respectively acting as input, transmission, coupled, and isolated ports. A first, second, third, and fourth connection parts are connected to the ports and transmission lines. First angular transmission lines are between first and second ports, third angular transmission lines are between third and fourth ports. A third long strip transmission line connects the first port and the fourth port. A fourth long strip transmission line connects the second port and the third port. The branch-line coupler occupies a small area and has high performance.

Abstract: A small scale power divider which is less susceptible to large tolerances in the manufacture includes a substrate and a power dividing circuit thereon. The power dividing circuit includes an input port, a first output port, a second output port, an impedance converter, a first microstrip line, and a second microstrip line. An end of the first microstrip line is connected to the impedance converter, another end of the first microstrip line is connected to the first output port. An end of the second microstrip line is connected to the impedance converter, another end of the second microstrip line is connected the second output port.

Abstract: A power distribution circuit includes a first portion, a second portion, a third portion, an isolation element, a first transmission sub-circuit and a second transmission sub-circuit. The first portion, the second portion, and the third portion are coupled to respective external components. The isolation element is coupled between the second portion and the third portion. The first transmission sub-circuit is set on one side of the isolation element, and is coupled between the first portion and the second portion. The second transmission sub-circuit is set on the other side of the isolation element, and is coupled between the first portion and the third portion. The first transmission sub-circuit and the second transmission sub-circuit are symmetrically set on both sides of the isolation element.

Abstract: A small-scale branch-line coupler suitable for use in mobile devices includes a first, second, third, and fourth ports, respectively acting as input, transmission, coupled, and isolated ports. A first, second, third, and fourth connection parts are connected to the ports and transmission lines. First angular transmission lines are between first and second ports, third angular transmission lines are between third and fourth ports. A third long strip transmission line connects the first port and the fourth port. A fourth long strip transmission line connects the second port and the third port. The branch-line coupler occupies a small area and has high performance.

Abstract: A double-frequency antenna structure with a high degree of electrical isolation between long distance and short distance antennas includes a dielectric substrate having at least two corners and a center area. A first set of antenna arrays is positioned at the corners. A second set of antenna arrays is positioned at the center area. At least one first folded isolation plate is mounted on the dielectric substrate, and positioned between the first set of antenna arrays and the second set of antenna arrays. At least one second folded isolation plate each is mounted on one first folded isolation plate.

Abstract: A small-scale branch-line coupler suitable for use in mobile devices includes a first, second, third, and fourth ports, respectively acting as input, transmission, coupled, and isolated ports. A first, second, third, and fourth connection parts are connected to the ports and transmission lines. First angular transmission lines are between first and second ports, third angular transmission lines are between third and fourth ports. A third long strip transmission line connects the first port and the fourth port. A fourth long strip transmission line connects the second port and the third port. The branch-line coupler occupies a small area and has high performance.

Abstract: A double-frequency antenna structure with a high degree of electrical isolation between long distance and short distance antennas includes a dielectric substrate having at least two corners and a center area. A first set of antenna arrays is positioned at the corners. A second set of antenna arrays is positioned at the center area. At least one first folded isolation plate is mounted on the dielectric substrate, and positioned between the first set of antenna arrays and the second set of antenna arrays. At least one second folded isolation plate each is mounted on one first folded isolation plate.

Abstract: A small-scale branch-line coupler suitable for use in mobile devices includes a first, second, third, and fourth ports, respectively acting as input, transmission, coupled, and isolated ports. A first, second, third, and fourth connection parts are connected to the ports and transmission lines. First angular transmission lines are between first and second ports, third angular transmission lines are between third and fourth ports. A third long strip transmission line connects the first port and the fourth port. A fourth long strip transmission line connects the second port and the third port. The branch-line coupler occupies a small area and has high performance.

Abstract: A double-frequency antenna structure with a high degree of electrical isolation between long distance and short distance antennas includes a dielectric substrate having at least two corners and a center area. A first set of antenna arrays is positioned at the corners. A second set of antenna arrays is positioned at the center area. At least one first folded isolation plate is mounted on the dielectric substrate, and positioned between the first set of antenna arrays and the second set of antenna arrays. At least one second folded isolation plate each is mounted on one first folded isolation plate.

Abstract: A miniaturized power distributing device with harmonic suppression function and low cost is set in a substrate, and includes first, second, and third metal levels. The first metal level includes a power divider to divide one signal into multiple output signals, or to combine multiple input signals into one output signal. The second metal level includes a filter structure to filter out harmonics. The third metal level is isolated against electromagnetic wave signal leaking from the second metal level. The second metal level is set between the first and third metal levels, dielectric layers are set between the first and second metal levels and between the second and third metal levels.

Abstract: A power distribution circuit includes a first portion, a second portion, a third portion, an isolation element, a first transmission sub-circuit and a second transmission sub-circuit. The first portion, the second portion, and the third portion are coupled to respective external components. The isolation element is coupled between the second portion and the third portion. The first transmission sub-circuit is set on one side of the isolation element, and is coupled between the first portion and the second portion. The second transmission sub-circuit is set on the other side of the isolation element, and is coupled between the first portion and the third portion. The first transmission sub-circuit and the second transmission sub-circuit are symmetrically set on both sides of the isolation element.

Abstract: A power distribution circuit includes a first portion, a second portion, a third portion, an isolation element, a first transmission sub-circuit and a second transmission sub-circuit. The first portion, the second portion, and the third portion are coupled to respective external components. The isolation element is coupled between the second portion and the third portion. The first transmission sub-circuit is set on one side of the isolation element, and is coupled between the first portion and the second portion. The second transmission sub-circuit is set on the other side of the isolation element, and is coupled between the first portion and the third portion. The first transmission sub-circuit and the second transmission sub-circuit are symmetrically set on both sides of the isolation element.