阅读说明：本技术 双频转换电路结构 (Double-frequency conversion circuit structure ) 是由 谢子皓 王至诘 于 2019-08-22 设计创作，主要内容包括：本发明涉及一种双频转换电路结构,其适用于至少两个频率。所述双频转换电路结构包括金属层、第一传输线、第二传输线以及第三传输线。所述第一传输线与所述第二传输线设置于所述金属层上。所述第二传输线的第一端耦接于所述第一传输线的第二端。所述第二传输线的第二端对齐所述金属层的边缘。所述第三传输线的第一端耦接于所述第二传输线的第二端。所述第三传输线远离边缘地延伸。(The invention relates to a double-frequency conversion circuit structure which is suitable for at least two frequencies. The double-frequency conversion circuit structure comprises a metal layer, a first transmission line, a second transmission line and a third transmission line. The first transmission line and the second transmission line are arranged on the metal layer. The first end of the second transmission line is coupled to the second end of the first transmission line. The second end of the second transmission line is aligned with the edge of the metal layer. The first end of the third transmission line is coupled to the second end of the second transmission line. The third transmission line extends away from the edge.)

1. A dual-frequency conversion circuit structure suitable for at least two frequencies, wherein the dual-frequency conversion circuit structure comprises:

a metal layer;

the first transmission line is arranged on the metal layer;

a second transmission line disposed on the metal layer, wherein a first end of the second transmission line is coupled to a first end of the first transmission line, and a second end of the second transmission line is aligned with an edge of the metal layer; and

a third transmission line having a first end coupled to the second end of the second transmission line, wherein the third transmission line extends away from the edge of the metal layer.

2. The dual-band switching circuit structure of claim 1, wherein the second end of the first transmission line comprises a first port, the second end of the third transmission line comprises a second port and a third port, wherein the second end of the third transmission line is away from the edge of the metal layer, the first port is configured to receive an input signal, the second port is configured to output a first output signal, and the third port is configured to output a second output signal.

3. The dual-frequency conversion circuit structure according to claim 2, wherein a phase difference between the first output signal and the second output signal is 180 degrees.

4. The dual-band switching circuit structure of claim 1, wherein the plane of the third transmission line is parallel to the plane of the metal layer.

5. The dual-band switching circuit structure of claim 1, wherein the first transmission line comprises a first segment and a second segment, and a first end of the first segment and a first end of the second segment are coupled to the first port through a node;

the first transmission line further comprises a third line segment, and a first end of the third line segment is coupled to a second end of the second line segment.

6. The dual-band switching circuit structure of claim 5, wherein the first transmission line further comprises a fourth segment, and a first end of the fourth segment is coupled to a second end of the first segment.

7. The dual-band switching circuit structure of claim 6, wherein the first transmission line further comprises a fifth line segment, wherein a first end of the fifth line segment is coupled to the first port, and a second end of the fifth line segment, the second line segment and the first line segment are coupled to the node, wherein the fifth line segment comprises a predetermined impedance.

8. The dual-band switching circuit structure of claim 6, wherein the first transmission line further comprises a sixth segment, wherein a first end of the sixth segment is coupled to the second end of the second segment and the first end of the third segment, and wherein the sixth segment comprises a predetermined impedance.

9. The dual-band conversion circuit structure of claim 2, wherein there is at least one bend between the first end of the second transmission line and the second end of the second transmission line, such that the input signal is transmitted to the third transmission line via the at least one bend of the second transmission line.

10. The dual-band switching circuit structure of claim 1, wherein at least one bend portion is disposed between the first end of the second transmission line and the second end of the second transmission line, and edges of the at least one bend portion form an angle of 45 degrees with a first side of the second transmission line and a second side of the second transmission line, respectively.

Technical Field

The present invention relates to a circuit structure, and more particularly, to a dual-frequency conversion circuit structure.

Background

In the field of wireless communications, there is a general need for dual-band or multi-band applications in a system to save on component requirements and reduce circuit size. In circuit design, a balun (balun) is often employed as a component for converting a signal between balanced and unbalanced. Therefore, how to implement a circuit design applicable to both dual-frequency and balun converters is a matter of concern in the art.

Disclosure of Invention

The invention provides a double-frequency conversion circuit structure which is suitable for at least two frequencies. The double-frequency conversion circuit structure comprises a metal layer, a first transmission line, a second transmission line and a third transmission line. The first transmission line and the second transmission line are arranged on the metal layer. The first end of the second transmission line is coupled to the second end of the first transmission line. The second end of the second transmission line is aligned with the edge of the metal layer. The first end of the third transmission line is coupled to the second end of the second transmission line. The third transmission line extends away from the edge.

Preferably, the second end of the first transmission line includes a first port, the second end of the third transmission line includes a second port and a third port, wherein the second end of the third transmission line is far away from the edge of the metal layer, the first port is used for receiving an input signal, the second port is used for outputting a first output signal, and the third port is used for outputting a second output signal.

Preferably, the phase difference between the first output signal and the second output signal is 180 degrees.

Preferably, the plane in which the third transmission line is located is a plane parallel to the metal layer.

Preferably, the first transmission line comprises a first line segment and a second line segment, and a first end of the first line segment and a first end of the second line segment are coupled to the first port through a node;

preferably, the first transmission line further comprises a third line segment, and a first end of the third line segment is coupled to a second end of the second line segment.

Preferably, the first transmission line further comprises a fourth line segment, and a first end of the fourth line segment is coupled to a second end of the first line segment.

Preferably, the first transmission line further comprises a fifth line segment, wherein a first end of the fifth line segment is coupled to the first port, and a second end of the fifth line segment, the second line segment and the first line segment are coupled to the node, wherein the fifth line segment comprises a predetermined impedance.

Preferably, the first transmission line further comprises a sixth line segment, wherein a first end of the sixth line segment is coupled to the second end of the second line segment and the first end of the third line segment, and the sixth line segment comprises a predetermined impedance.

Preferably, the first end of the second transmission line and the second end of the second transmission line have at least one bend portion therebetween, such that the input signal is transmitted to the third transmission line via the at least one bend portion of the second transmission line.

Preferably, at least one bending portion is disposed between the first end of the second transmission line and the second end of the second transmission line, and an edge of the at least one bending portion forms an angle of 45 degrees with a first side of the second transmission line and a second side of the second transmission line, respectively.

Drawings

In order to make the aforementioned and other objects, features, and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. The figures are not necessarily to scale, and may be correspondingly increased or decreased in size, depending on the purpose, wherein:

fig. 1 is a schematic diagram of a dual frequency conversion circuit configuration according to some embodiments of the invention.

Fig. 2 is a schematic diagram of a plurality of line segments of a dual frequency conversion circuit structure according to some embodiments of the invention.

Fig. 3 is a schematic diagram of a plurality of line segments of a dual-frequency conversion circuit structure according to other embodiments of the invention.

Fig. 4 is a schematic diagram of a dual frequency conversion circuit configuration according to some embodiments of the invention.

FIG. 5 is a schematic diagram of performing even-mode half-circuit analysis on a half-circuit structure according to some embodiments of the invention.

FIG. 6 is a schematic diagram of performing odd-mode half-circuit analysis on a half-circuit structure according to some embodiments of the invention.

Detailed Description

Referring to fig. 1, fig. 1 is a schematic diagram of a dual-frequency conversion circuit architecture 100 according to some embodiments of the invention. As shown in fig. 1, the dual-band conversion circuit structure 100 includes a first circuit 110 and a second circuit 120. The first circuit 110 includes a metal layer 131 and a transmission line 150. The transmission line 150 is disposed on the metal layer 131. One end 151a of the transmission line 150 includes a port 190a so that the first circuit 110 is connected to a test apparatus (not shown) through the connection portion 190 a.

The second circuit 120 includes a metal layer 133, a transmission line 160, and a transmission line 170. The transmission line 160 is disposed on the metal layer 133. Metal layer 133 is adjacent to and juxtaposed to metal layer 131. In some embodiments, the metal layer 131 and the metal layer 133 may be the same metal layer, and thus the transmission line 150 and the transmission line 160 are disposed on the same metal layer.

One end 161a of the transmission line 160 is coupled to one end 151b of the transmission line 150. One end 161b of the transmission line 160 is aligned with the edge 135 of the metal layer 133. In some embodiments, the components (i.e., metal layer 131, metal layer 133, transmission line 150, and transmission line 160) within the range surrounded by the endpoints a, B, C, and D shown in fig. 1 constitute a balun (balun).

In some embodiments, the transmission line 170 is not disposed on the metal layer 133. An end 171a of the transmission line 170 is coupled to an end 161b of the transmission line 160, and the transmission line 170 is configured to extend away from the edge 135 of the metal layer 133. An end 171b of transmission line 170 distal from edge 135 includes ports 190b and 190 c. Second circuit 120 may be coupled to an integrated circuit chip (not shown) or an antenna (not shown) through port 190b and port 190 c. In some embodiments, the transmission line 170 is in a plane parallel to the planes of the metal layers 131 and 133.

As shown in fig. 1, in some embodiments, the transmission lines 150 and 160 are dual-band Microstrip (Microstrip) structures, and the transmission line 170 is a Coplanar stripline (Coplanar strip) structure. The metal layer 133 under the transmission line 160 (microstrip line) may serve as a ground layer, and no metal layer that may serve as a ground layer is disposed under the transmission line 170 (coplanar stripline). In this way, the port 190a of the first circuit 110 is fed with the microwave signal, so that the microwave signal is output through the microstrip line in a balanced-unbalanced output conversion manner, and then the signal is output through the port 190b and the port 190c of the coplanar stripline, thereby achieving the signal conversion of single-ended input and double-ended output, or the signal conversion of double-ended input and single-ended output.

Referring to fig. 2, fig. 2 is a schematic diagram of a plurality of line segments of a dual-frequency conversion circuit architecture 100 according to some embodiments of the invention. As shown in fig. 2, the transmission line 150 includes a plurality of line segments, each line segment including a respective impedance, width and length. In some embodiments, the line segments include line segment 210, line segment 220, line segment 230, and line segment 240. Segment 210 has a width W1 and an impedance z 1. Segment 220 has a width W2 and an impedance z 2. Segment 230 has a width W3 and an impedance z 3. Segment 240 has a width W4 and an impedance z 4.

Referring to fig. 3, fig. 3 is a schematic diagram of a plurality of line segments of a dual-frequency conversion circuit structure 100 according to further embodiments of the invention. As shown in fig. 3, the transmission line 150 includes a line segment 250 and a line segment 260. Segment 250 and segment 260 have a width W0 and an impedance z 0. Transmission line 160 includes line segment 270. Segment 270 has a width W0 and an impedance z 0. In some embodiments, the impedances of the line segment 250, the line segment 260, and the line segment 270 are preset impedances.

The transmission line 160 has at least one bend 165 between its two ends (e.g., one end 161a and one end 161 b). In some embodiments, the transmission line 160 includes 4 bends 165. After the input signal is received at the port 190a, the input signal is transmitted to the transmission line 170 through the bending portion 165 of the transmission line 160. The bend 165 includes a truncated corner such that the area of the bend 165 is reduced. In another embodiment, as shown in fig. 3, the line segment 270 has a width W0, and the extension lines of the side 167 and the side 168 of the transmission line 160 are perpendicular to each other and the bending portion 165. Edge 169 of bend 165 forms a 45 degree angle with side 167 and side 168, respectively (i.e., an isosceles triangle with side length W0 and two angles of 45 degrees is formed at bend 165). As a result, the impedance discontinuity effect of the transmission line 160 can be reduced. In other embodiments, the curved portion 165 has a quarter-circle arc with a radius W0, or other cut-back shape.

The electrical lengths of these line segments (i.e., microstrip lines) of fig. 2 and 3 are related to the input signal frequency. In the circuit layout and structure of the dual-band switching circuit structure 100, the impedances of the segments of the microstrip line can be adjusted in relation to each other, so that the target impedance matching can be achieved at two frequencies (e.g., 2.4GHz and 5.5GHz), and the effect of signal transmission is achieved.

Referring to fig. 4, fig. 4 is a schematic diagram of a dual-band conversion circuit architecture 400 according to some embodiments of the invention. The dual-band converting circuit structure 400 is similar to the dual-band converting circuit structure 100 of fig. 1-3, and has the same operation function. Only the line segments that can be adjusted in relation to one another, such as line segment 210, line segment 220, line segment 230, and line segment 240, are shown in fig. 4. The thin line portions represent line segments (e.g., line segment 250, line segment 260, and line segment 270 of fig. 3) having a predetermined impedance. It should be noted that the dual-band conversion circuit structure 400 of the present invention and the dual-band conversion circuit structure 100 of fig. 1 are symmetrical structures. For example, the line segment 210, the line segment 220, the line segment 230, and the line segment 240 form a half circuit structure (e.g., the half circuit structure 115 of fig. 5) that is symmetrical with another half circuit structure (e.g., the line segment 210 ', the line segment 220', the line segment 230 ', and the line segment 240') based on the symmetry axis 180. As shown in fig. 4, the dual frequency conversion circuit structure 400 has a symmetry axis 180 extending along a certain direction (e.g., a horizontal direction parallel to the line segment 220). On the mirror side of axis of symmetry 180 are line segment 210 'symmetrical to line segment 210, line segment 220' symmetrical to line segment 220, line segment 230 'symmetrical to line segment 230, and line segment 240' symmetrical to line segment 240. In other words, the overall structure of the transmission line 150 of the dual-band switching circuit structure 100 of fig. 1 is an approximately symmetrical structure. In the following description, the half circuit structure 115 is used as an illustration, and one skilled in the art can deduce or simulate the contents of the other half circuit structure through the half circuit structure 115.

As shown in FIG. 4, one end of line segment 210 and one end of line segment 220 are coupled to port 190a via node 310. One end of line segment 230 and the other end of line segment 220 are coupled to port 190b via node 320. One end of line segment 240 is coupled to the other end of line segment 210.

To illustrate that the impedances of the segments of the microstrip lines can be adjusted in relation to each other, please refer to fig. 5 and 6.

FIG. 5 is a diagram of performing even mode half circuit splitting for half circuit structure 115 according to some embodiments of the inventionSchematic of the assay (even-mode analysis). As shown in FIG. 5, the electrical length L1 of line segment 210 is θ₁/2. The electrical length L2 of the line segment 220 is θ₂. The electrical length L3 of the line segment 230 is θ₃. The electrical length L4 of line segment 240 is θ₁/2. Wherein theta is₁、θ₂And theta₃To be associated with two different frequencies f₁And f₂(e.g., 2.4GHz and 5.5 GHz). For example, θ₁、θ₂And theta₃While satisfying the following relational expression.

In even-mode half-circuit analysis, node 310 will assert a predetermined f₁、f₂The signal reaches a short circuit such that in even mode, a predetermined f is let at port 190a₁、f₂The even mode signal in the signal cannot reach the port 190 b. Meanwhile, the end point 241 of the line segment 240 at the axis of symmetry 180 (fig. 4) is considered to be an open circuit (open). Incidentally, the end 231 of the line segment 230 at the axis of symmetry 180 (fig. 4) is also considered to be an open circuit (open). Therefore, the input impedance Zin _ even of the port 190a can be obtained by even-mode half-circuit analysis as shown in equation (1).

In formula (1), j is an imaginary number. Since node 310 is considered a short, the value of Zin _ even is zero. When the value Zin _ even is zero, a relation between the impedance z1 of the line segment 210 and the impedance z4 of the line segment 240 can be obtained as shown in formula (2).

Referring to fig. 6, fig. 6 is a schematic diagram of performing odd-mode analysis (odd-mode analysis) on half-circuit structure 115, according to some embodiments of the invention. As shown in fig. 6, the half-circuit structure 115 includes a circuit portion Pb and a circuit portion Pc, wherein the circuit portion Pb includes a circuit portion Pa. Circuit portion Pa includes segment 230 and segment 260. The circuit portion Pb includes a line segment 220 and a line segment 230. Circuit portion Pc includes segment 210 and segment 240.

In the odd-mode half-circuit analysis, one end of the line segment 240 at the axis of symmetry 180 (fig. 4) is considered a virtual short. Incidentally, one end of the line segment 230 at the axis of symmetry 180 (fig. 4) is also considered as a virtual short.

In the odd-mode half-circuit analysis, the circuit impedance za of the circuit portion Pa is correlated to the impedance z3, the electrical length L3, and the preset impedance z0 of the line segment 230, as shown in equation (3).

The impedance zb of circuit portion Pb is related to the circuit impedance za of circuit portion Pa, the impedance z2 of line segment 220, and the electrical length L2, as shown in equation (4).

Impedance z of the circuit_bCan be obtained by substituting za calculated by the formula (3) into the formula (4).

The impedance zc of circuit portion Pc is related to the impedance z1 of segment 210, the impedance z4 of segment 240, and the electrical length L1 of segment 210 (e.g., θ [ ])₁And/2) as shown in formula (5). In some embodiments, the electrical length L1 of segment 210 is equal to the electrical length L4 of segment 240.

It is worth mentioning that the circuit impedance zc has two variables, so that substituting equation (2) for the even-mode half-circuit analysis into equation (5) yields an impedance z1 relationship with zc.

In other words, the present invention can achieve impedance matching by adjusting the impedances z1, z2, z3, and z4 in the formulas (2) to (5).

As shown in fig. 6, the circuit portion Pc is connected in parallel to the circuit portion Pb. Thus, the circuit portion Pc and the circuit portion Pb form a parallel resistance. Therefore, the input impedance Zin _ odd of the port 190a can be obtained by the parallel resistors, as shown in equation (6).

The values of Zin _ odd in the formula (6) can be obtained from the circuit impedances zb and zc of the formulas (3) - (5) (i.e. the impedances z1-z4 of the line segment 210 and 240).

In the odd-mode half-circuit analysis, when the input impedance Zin _ odd of the port 190a is equal to twice the predetermined impedance, the half-circuit structure 115 can achieve impedance matching, as shown in equation (7).

Z_{in_odd}＝2z₀… formula (7)

Where z0 is a preset impedance.

In some embodiments, when the circuit design is executed on a computing device (not shown), electromagnetic simulation may be performed by associated software tools to calculate the impedance z1-z4 that conforms to equation (7). For example, when the preset impedance z0 is 50 ohms, the operation device (not shown) performs a series of iterative operations. When the impedances z1-z4 are judged to be substituted into equations (2) - (6) and the input impedance Zin _ odd of equation (7) is judged to be equal to 100 ohms, the values of the impedances z1-z4 are recorded. The impedances z1-z4 and the electrical lengths L1-L4 (e.g., according to the frequency f)₁And f₂Compute equation (0)) may be further used to complete the circuit design of the dual-frequency conversion circuit structure 100.

Therefore, when the values of the impedances z1-z4 are applied to the dual-band transforming circuit structure 100, the port 190b and the port 190c of the dual-band transforming circuit structure 100 have a phase difference of 180 degrees, and the dual-band signal can be applied to the dual-band transforming circuit structure 100. In addition, the dual frequency conversion circuit structure 100 is suitable for signals of at least two frequencies. For example, after the port 190a receives a signal having a frequency of 2.4GHz or a signal having a frequency of 5.5GHz, signals having a phase difference of 180 degrees may be output at both ports 190b and 190 c.

In some embodiments, referring to fig. 1, the dual-band transforming circuit structure 100 can be bent to reduce the area of the microstrip line on the circuit layout, thereby reducing the size of the whole circuit structure.

In some embodiments, the dual-band transforming circuit structure 100 has a dual-layer structure (e.g., a microstrip line of the first circuit 110) and a single-layer structure (e.g., a coplanar strip line of the second circuit 120). The dual layer structure allows a test device (not shown) to be connected directly to the first circuit 110 through the port 190 a. Thus, after the microstrip line is fed with the signal from the port 190a, the signal is outputted from the ports 190b and 190c through the coplanar stripline, so as to complete the signal conversion, and vice versa.

In summary, the dual-band switching circuit structure 100 of the present invention improves convenience in use. Moreover, the return loss (return loss) of the circuit layout can be reduced to below-10 dB when the circuit layout is operated at the frequencies of 2.4GHz and 5.5 GHz. In terms of insertion loss (insertion loss), the insertion loss at the frequency of 2.4GHz is about 1.3dB, and the insertion loss at the frequency of 5.5GHz is about 2.5 dB. Therefore, the dual-band transforming circuit structure 100 of the present invention can be operated for signal transformation of two frequencies, so that the two frequencies can be supported on the same circuit to reduce the usage of circuit components, and at the same time, the effect of maintaining good impedance matching can be achieved.