ULTRA-SMALL SIZE BROADBAND COUPLER

Abstract

There is provided an ultra-small size broadband coupler. A Lange coupler according to an embodiment includes: first lines which are formed in a spiral shape, and have a first port and a second port formed at one end thereof and have connection ends formed at the other end thereof; and second lines which are formed in a spiral shape, and have connection ends formed at one end thereof to be connected to the connection ends of the first lines, and have a third port and a fourth port formed at the other end thereof. Accordingly, the Lange coupler maintains broadband characteristics while minimizing its area, so that it is possible to design a small component for mobile communication and to noticeably reduce an insertion loss.

Claims

1. A Lange coupler comprising: first lines which are formed in a spiral shape, and have a first port and a second port formed at one end thereof and have connection ends formed at the other end thereof; and second lines which are formed in a spiral shape, and have connection ends formed at one end thereof to be connected to the connection ends of the first lines, and have a third port and a fourth port formed at the other end thereof.

2. The Lange coupler of claim 1, wherein the connection ends of the first lines are positioned inside the spiral shape formed by the first lines, and wherein the connection ends of the second lines are positioned inside the spiral shape formed by the second lines.

3. The Lange coupler of claim 2, further comprising inter-connection lines which connect the connection ends of the first lines and the connection ends of the second lines through vias.

4. The Lange coupler of claim 3, wherein the inter-connection lines are positioned on upper portions of the first lines and the second lines.

5. The Lange coupler of claim 4, wherein the first lines comprise a 11 line, a 12 line, a 13 line, a 14 line, wherein the second lines comprise a 21 line, a 22 line, a 23 line, a 24 line, and wherein the inter-connection lines comprise: an inter-connection line for connecting a connection end of the 11 line and a connection end of the 13 line; an inter-connection line for connecting a connection end of the 12 line and a connection end of the 21 line; an inter-connection line for connecting the connection line of the 13 line and a connection end of the 22 line; an inter-connection line for connecting a connection end of the 14 line and a connection end of the 23 line; and an inter-connection line for connecting the connection end of the 22 line and a connection end of the 24 line.

6. The Lange coupler of claim 1, wherein the first port is a port that is configured by coupling an input end of a 11 line and an input end of a 13 line, wherein the second port is a port that is configured by coupling an input end of a 12 line and an input end of a 14 line, wherein the third port is a port that is configured by coupling an input end of a 21 line and an input end of a 23 line, and wherein the fourth port is a port that is configured by coupling an input end of a 22 line and an input end of a 24 line.

7. The Lange coupler of claim 1, wherein respective lengths of the first lines and the second lines are λ/8.

8. A Lange coupling method comprising: receiving a signal through a first port and a second port formed at one end of first lines; and outputting a signal through a third port and a fourth port which are formed at the other end of second lines which have one end connected to the first lines, wherein the first lines are formed in a spiral shape, and have the first port and the second port formed at one end thereof and have connection ends formed at the other end thereof, wherein the second lines are formed in a spiral shape, and have connection ends formed at one end thereof to be connected to the connection ends of the first lines, and have the third port and the fourth port formed at the other end thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:

[0022] FIG. 1 is a view illustrating a polyphase filter structure;

[0023] FIGS. 2 and 3 are views illustrating a structure which has a Wilkinson divider and a transmission line coupled to each other;

[0024] FIG. 4 is a view illustrating an insertion loss of the structure having the Wilkinson divider and the transmission line coupled to each other;

[0025] FIG. 5 is a view illustrating a hybrid coupler structure;

[0026] FIG. 6 is a view illustrating an insertion loss of the hybrid coupler;

[0027] FIG. 7 is a view illustrating a structure of a Lange coupler;

[0028] FIG. 8 is a view illustrating a structure of a Lange coupler according to an embodiment of the disclosure;

[0029] FIG. 9 is a view illustrating a result of simulating amplitude characteristics of the broadband Lange coupler according to an embodiment of the disclosure;

[0030] FIG. 10 is a view illustrating a result of simulating phase characteristics of the broadband Lange coupler according to an embodiment of the disclosure; and

[0031] FIG. 11 is a view illustrating a structure of a Doherty amplifier to which the broadband Lange coupler according to an embodiment of the disclosure is applied.

DETAILED DESCRIPTION

[0032] Hereinafter, the disclosure will be described in detail with reference to the accompanying drawings.

[0033] Embodiments of the disclosure propose a structure of an ultra-small size broadband Lange coupler. Compared to related-art couplers which have a large volume to implement broadband and cause an insertion loss to increase, the Lange coupler according to an embodiment may reduce a volume by dividing lines and implementing in a spiral shape, and may minimize an insertion loss by connecting the divided lines through via-connection.

[0034] FIG. 8 is a view illustrating a structure of a Lange coupler according to an embodiment. The Lange coupler according to an embodiment may include input lines 100, output lines 200, and inter-connection lines 300 as shown in the drawing.

[0035] The input lines 100 and the output line 200 are formed in a spiral shape, and are symmetric to each other. Lengths of the input lines 100 and the output lines 200 are λ/8, respectively.

[0036] That is, a line of λ/4 of the Lange coupler according to an embodiment may be divided into two lines of λ/8, and may be implemented in a spiral shape in order to reduce a size. Accordingly, the Lange coupler according to an embodiment may be implemented to have an ultra-small size of 1.2 mm×0.9 mm.

[0037] The input lines 100 may be configured with four lines 110, 120, 130, 140, and the output lines 200 may be configured with four lines 210, 220, 230, 240.

[0038] An input port and a coupled port may be formed at one end of the input lines 100. Although not shown in FIG. 8, the input port may be configured by coupling an input end 111 of the line-1 110 and an input end 131 of the line-3 130, and the coupled port may be configured by coupling an input end 121 of the line-2 120 and an input end 141 of the line-4 140.

[0039] Connection ends 112, 122, 132, 142 may be formed at the other end of the input lines 100 to be connected with the output lines 200. The connection ends 112, 122, 132, 142 may be positioned inside the spiral shape formed by the input lines 100.

[0040] Connection ends 212, 222, 232, 242 may be formed at one of the output lines 200 to be connected with the connection ends 112, 122, 132 142 of the input lines 100. The connection ends 212, 222, 232, 242 may be positioned inside the spiral shape formed by the output lines 200.

[0041] An isolated port and a direct port may be formed at the other end of the output lines 200. Although not shown in FIG. 8, the isolated port may be configured by coupling an input end 211 of the line-1 210 and an input end 231 of the line-3 230, and the direct port may be configured by coupling an input end 221 of the line-2 220 and an input end 241 of the line-4 240.

[0042] The inter-connection lines 300 may be lines for connecting the connection ends 112, 122, 132, 142 of the input lines 100 and the connection lines 212, 222, 232 242 of the output lines 200.

[0043] Since the connection ends 112, 122, 132, 142 of the input lines 100 are positioned inside the spiral shape and the connection ends 212, 222, 232, 242 of the output lines 200 are positioned inside the spiral shape, the inter-connection lines 300 may couple the connection ends 112, 122, 132, 142 of the input lines 200 and the connection ends 212, 222, 232, 242 of the output lines 200 through vias. That is, the inter-connection lines 300 may be formed on upper layers of the input lines 100 and the output lines 200 to connect the connection ends 112, 122, 132, 142 of the input lines 100 and the connection ends 212, 222, 232, 242 of the output lines 200.

[0044] The inter-connection lines 300 may include five (5) inter-connection lines although they are not illustrated in FIG. 8.

[0045] The inter-connection line-1 may be a line for connecting the connection end 112 of the input line-1 110 and the connection end 132 of the input line-3 130.

[0046] The inter-connection line-2 may be a line for connecting the connection end 122 of the input line-2 120 and the connection end 212 of the output line-1 210.

[0047] The inter-connection line-3 may be a line for connecting the connection end 132 of the input line-3 130 and the connection end 222 of the output line-2 220.

[0048] The inter-connection line-4 may be a line for connecting the connection end 142 of the input line-4 140 and the connection end 232 of the output line-3 230.

[0049] The inter-connection line-5 may be a line for connecting the connection end 222 of the output line-2 220 and the connection end 242 of the output line-4 240.

[0050] The inter-connection lines 300 do not greatly influence the size of the broadband Lange coupler according to an embodiment. That is, a horizontal length or a vertical length of the broadband Lange coupler according to an embodiment does not increase due to the inter-connection lines 300.

[0051] A result of simulating amplitude characteristics of the broadband Lange coupler according to an embodiment is illustrated in FIG. 9. Referring to a bandwidth reduced by 0.3 dB, a bandwidth characteristic of 40% is shown, and therefore, it can be seen that the broadband Langer coupler has a broader bandwidth than a related-art Lange coupler.

[0052] A result of simulating phase characteristics of the broadband Lange coupler according to an embodiment is illustrated in FIG. 10. If a bandwidth is defined with reference to phase distortion of 3 degrees, the broadband Lange coupler according to an embodiment has a bandwidth of 26% and shows a characteristic appropriate to 90-degree coupling of a broadband signal as in a 5G system.

[0053] FIG. 11 illustrates a structure of a Doherty amplifier to which the broadband Lange coupler according to an embodiment is applied. A hybrid coupler which includes a Wilinson divider and a transmission line of λ/4 among configurations of the illustrated Doherty amplifier may be substituted with the broadband Lange coupler according to an embodiment.

[0054] Up to now, the ultra-small size broadband coupler has been described in detail with reference to preferred embodiments.

[0055] In the above-descried embodiments, there is proposed an ultra-small size broadband coupler which divides RF broadband power in next-generation mobile communication, and maintains broadband characteristics while reducing its area, so that an insertion loss and a cost can be reduced when the ultra-small size broadband coupler is employed in a system.

[0056] The ultra-small size Lange coupler according to an embodiment may be utilized in designing an RF circuit, and particularly, may be used for an MMIC circuit like a Doherty power amplifier, and also, may be applied to an active phase shifter using a 90-degree phase difference in a recent beamforming component.

[0057] In addition, while preferred embodiments of the present disclosure have been illustrated and described, the present disclosure is not limited to the above-described specific embodiments. Various changes can be made by a person skilled in the art without departing from the scope of the present disclosure claimed in claims, and also, changed embodiments should not be understood as being separate from the technical idea or prospect of the present disclosure.