CN216056997U

CN216056997U - Radio frequency circuit with font routing replacing resistor

Info

Publication number: CN216056997U
Application number: CN202122586082.0U
Authority: CN
Inventors: 刘文硕; 林季民; 林轩颀; 谢育安
Original assignee: Huanxu Shenzhen Electronic Technology Innovation Co ltd
Current assignee: Huanxu Shenzhen Electronic Technology Innovation Co ltd
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2022-03-15
Anticipated expiration: 2031-10-26

Abstract

The utility model provides a radio frequency circuit with a font routing replacing resistor, which is used for replacing the resistor, wherein the resistor has a first equivalent impedance at radio frequency. The radio frequency circuit with the font routing replacing resistor comprises a routing layer and a grounding layer, wherein the routing layer comprises a first welding pad, a second welding pad and a font routing unit. The second bonding pad corresponds to the first bonding pad. The font is walked the line unit and is connected between first bonding pad and second bonding pad and have the linewidth, and the linewidth is less than 50 ohm linewidth. The grounding layer is arranged below the wiring layer and is separated from the wiring layer by a height. The font routing unit has a second equivalent impedance at the radio frequency, the second equivalent impedance is determined according to the line width, the height and the radio frequency, and the second equivalent impedance is the same as or close to the first equivalent impedance. Therefore, the font routing can replace the entity resistance without influencing the high-frequency impedance matching.

Description

Radio frequency circuit with font routing replacing resistor

Technical Field

The present invention relates to radio frequency circuits, and particularly to a radio frequency circuit with a resistor replaced by a font trace.

Background

Since electronic products are smaller and smaller, and have different Radio Frequency (RF) technologies, and many different RF devices interfere with each other in the same system, multiple sets of matching circuits need to be reserved on the RF circuit to solve the interference and mismatch problems. If the reserved circuit is not used, a physical resistor is needed to connect the circuit. Fig. 1 is a perspective view of a conventional rf circuit 100 with a resistor, which includes a first pad 200, a second pad 300, and a resistor 400, wherein the resistor 400 is connected between the first pad 200 and the second pad 300. The physical resistor 400 is an additional cost to the product.

If the physical resistor 400 is removed in response to the cost saving requirement, the conventional method needs to re-adjust the matching circuit before and after the adjustment in order to maintain the original impedance matching and RF signal performance, which is especially serious in the WIFI5G high frequency band, and all RF tests need to be re-measured, thereby increasing the manufacturing cost and time efficiency. Therefore, there is no RF circuit in the market that can avoid re-adjusting the matching circuit and re-measuring the RF test, reduce the manufacturing cost and shorten the time efficiency, and therefore, the relevant practitioners are seeking to solve the above problems.

SUMMERY OF THE UTILITY MODEL

Therefore, an objective of the present invention is to provide a rf circuit with a font trace instead of a resistor, which uses a connection manner of the font trace on two pad (Footprint) structures and a corresponding ground layer to create a high frequency inductance characteristic similar to a physical resistor, thereby improving the high frequency impedance effect of the conventional trace and solving the impedance mismatch problem in the prior art.

According to one aspect of the present invention, a RF circuit with a resistor replaced by a patterned trace is provided to replace the resistor, wherein the resistor has a first equivalent impedance at RF frequencies. The radio frequency circuit with the font routing replacing resistor comprises a routing layer and a grounding layer, wherein the routing layer comprises a first welding pad, a second welding pad and a font routing unit. The second bonding pad corresponds to the first bonding pad. The font is walked the line unit and is connected between first bonding pad and second bonding pad and have the linewidth, and the linewidth is less than 50 ohm linewidth. The grounding layer is arranged below the wiring layer and is separated from the wiring layer by a certain height. The font routing unit has a second equivalent impedance at the radio frequency, the second equivalent impedance is determined according to the line width, the height and the radio frequency, and the second equivalent impedance is the same as or close to the first equivalent impedance.

In an embodiment, the rf circuit with the font trace replacing resistor further includes another ground layer disposed between the trace layer and the ground layer, the another ground layer having a through hole corresponding to the font trace unit of the trace layer.

In one embodiment, the ground layer and the routing layer of the rf circuit of the font routing replacing resistor are separated by a height greater than or equal to 2 mils and less than or equal to 15 mils.

In one embodiment, the ground layer and the routing layer of the RF circuit of the font routing replacement resistor are separated by a height equal to 0.6 to 3.5 times the 50 ohm line width.

In one embodiment, the first pad and the second pad of the rf circuit of the font routing replacing resistor are separated by a distance, and a region is formed between the first pad and the second pad, the size of the region conforming to one of the standard size 0201, the standard size 0402 and the standard size 0603 of the surface mount device; wherein the standard size 0201 has a first length and a first width, the first length and the first width are 0.6mm and 0.3mm respectively; wherein the standard size 0402 has a second length and a second width, which are 1.0mm and 0.5mm, respectively; the standard size 0603 has a third length and a third width, and the third length and the third width are 1.6mm and 0.8mm, respectively.

In one embodiment, the font trace unit of the rf circuit has a trace length equal to 16 mils and a line width equal to 2 mils.

In one embodiment, the resistor of the rf circuit with the font trace replacing resistor is a 0 ohm resistor, and the rf frequency is less than or equal to 10 GHz.

In one embodiment, the shape of the font trace unit of the radio frequency circuit with the font trace replacing the resistor is one of a zigzag shape, an S shape and an inverted U shape.

In one embodiment, the font routing unit of the rf circuit with the font routing replacing resistor has the shape of the zigzag and includes: the first transmission line is connected to the first welding pad; the second transmission line is connected to the first transmission line; and a third transmission line connected between the second transmission line and the second pad; the first transmission line, the second transmission line and the third transmission line are all located between the first welding pad and the second welding pad, a first included angle is formed between the first transmission line and the second transmission line, a second included angle is formed between the second transmission line and the third transmission line, and the first included angle is equal to the second included angle.

In one embodiment, the routing layer and the ground layer of the rf circuit are disposed on a printed circuit board, and the printed circuit board is one of a glass fiber substrate and a ceramic substrate.

Therefore, the radio frequency circuit of the utility model uses the welding pad of the original circuit by the font routing to replace the resistance, and combines the font routing unit and the grounding layer to ensure that the high-frequency impedance characteristic is equivalent to the characteristic of the physical resistance, thereby directly replacing the physical resistance without influencing the impedance matching.

Drawings

FIG. 1 is a schematic perspective view of a prior art RF circuit having a resistor;

FIG. 2 is a schematic diagram of an RF circuit with a first embodiment of the present invention, in which a resistor is replaced by a I-shaped trace;

FIG. 3 shows a cross-sectional view of the RF circuit of FIG. 2, taken along section line 3-3, of the font trace in place of a resistor;

FIG. 4 is a schematic diagram of an RF circuit with a second embodiment of the present invention, in which a word line replaces a resistor;

FIG. 5 is a schematic diagram of an RF circuit with a resistor replaced by a I-shaped trace according to a third embodiment of the present invention;

FIG. 6 is a schematic diagram of an RF circuit with a resistor replaced by a I-shaped trace according to a fourth embodiment of the present invention;

FIG. 7 is a schematic diagram of an RF circuit with a resistor replaced by a I-shaped trace according to a fifth embodiment of the present invention;

FIG. 8 is a schematic diagram of an RF circuit with a resistor replaced by a I-shaped trace according to a sixth embodiment of the present invention; and

fig. 9 is a schematic diagram of an rf circuit with a word trace instead of a resistor according to a seventh embodiment of the present invention.

Description of reference numerals:

100: radio frequency circuit with resistor

100a,100b,100c,100d,100e,100f,100 g: radio frequency circuit with font routing replacing resistor

200: first bonding pad

300: second bonding pad

400: resistance (RC)

500a,500b,500c,500d,500e,500f,500 g: font routing unit

510a,510b,510 e: a first transmission line

520a,520b,520 e: second transmission line

530a,530b,530 e: third transmission line

540 b: a fourth transmission line

550 b: fifth transmission line

600a,600b,600c,600d,600e,600f,600 g: perforation

D: distance between each other

H: height

Layer 1: wiring layer

Layer2, Layer 3: grounding layer

R: region(s)

TW: line width

θ 1: first included angle

θ 2: second included angle

Detailed Description

Referring to fig. 1, fig. 2 and fig. 3 together, wherein fig. 2 shows a schematic diagram of a radio frequency circuit 100a with a word trace instead of a resistor according to a first embodiment of the present invention; and FIG. 3 shows a cross-sectional view of RF circuit 100a of FIG. 2, taken along section line 3-3, of the font trace instead of a resistor. The rf circuit 100a with the font trace replacing resistor is used to replace the resistor 400 shown in fig. 1, and the resistor 400 has a first equivalent impedance at an rf frequency. The rf circuit 100a with zigzag trace instead of resistor includes a trace Layer1 and a ground Layer 3.

The routing Layer1 includes a first pad 200, a second pad 300 and a font routing unit 500 a. The second pad 300 corresponds to the first pad 200. The font trace unit 500a is connected between the first pad 200 and the second pad 300 and has a line width TW smaller than a 50 ohm line width. Ground Layer3 is disposed below routing Layer1 and is separated from routing Layer1 by a height H. The font routing unit 500a has a second equivalent impedance at the rf frequency, the second equivalent impedance is determined according to the line width TW, the height H and the rf frequency, and the second equivalent impedance is the same as or close to the first equivalent impedance. Therefore, the rf circuit 100a of the present invention uses the pad of the original circuit in place of the resistor, and combines the font routing unit 500a and the ground Layer3 to make the high frequency impedance characteristic equivalent to the characteristic of the physical resistor 400, so that the physical resistor 400 can be directly replaced without affecting the impedance matching. In addition, the present invention removes the physical resistor 400 and replaces it with the font routing unit 500a, and the equivalent impedance characteristic of the font routing unit 500a can avoid the readjustment of the matching circuit and the re-measurement of the RF test, thereby greatly reducing the manufacturing cost and shortening the time efficiency.

Specifically, the resistor 400 is a 0 ohm resistor. The radio frequency is less than or equal to 10GHz, that is, all wireless communication systems using less than 10GHz can be covered. In the routing Layer1, the first PAD 200 and the second PAD 300 are both Surface Mount Device (SMD) PADs (PAD). The first bonding pad 200 and the second bonding pad 300 are separated by a distance D, and an area R is formed between the first bonding pad 200 and the second bonding pad 300, and the size of the area R conforms to one of a standard size 0201, a standard size 0402 and a standard size 0603 of the SMD. Wherein standard size 0201 has a first length and a first width, the first length and the first width are 0.6mm and 0.3mm, respectively; standard size 0402 has a second length and a second width, which are 1.0mm and 0.5mm, respectively; the standard size 0603 has a third length and a third width, which are 1.6mm and 0.8mm, respectively.

In the embodiment of fig. 2, the zigzag routing unit 500a is zigzag (i.e. zigzag) and includes a first transmission line 510a, a second transmission line 520a and a third transmission line 530 a. The first transmission line 510a is connected to the first pad 200, and the second transmission line 520a is connected to the first transmission line 510 a. The third transmission line 530a is connected between the second transmission line 520a and the second pad 300. The first transmission line 510a, the second transmission line 520a and the third transmission line 530a are disposed between the first pad 200 and the second pad 300, a first included angle θ 1 is formed between the first transmission line 510a and the second transmission line 520a, a second included angle θ 2 is formed between the second transmission line 520a and the third transmission line 530a, and the first included angle θ 1 is equal to the second included angle θ 2. Furthermore, the font routing unit 500a has a line length equal to the total length of the first transmission line 510a, the second transmission line 520a and the third transmission line 530 a. In one embodiment, the first included angle θ 1 may be 90 degrees, the line length may be equal to 16 mils, and the line width TW may be equal to 2 mils, but the utility model is not limited thereto.

The rf circuit 100a with zigzag trace replacing resistor further includes a ground Layer2, and the ground Layer2 is disposed between the trace Layer1 and the ground Layer 3. The ground Layer2 has a through hole 600a, the through hole 600a corresponds to the font trace unit 500a of the Layer1, the through hole 600a can increase the inductance of the font trace unit 500a at the rf frequency, so that the second equivalent impedance of the font trace unit 500a is the same as or close to the first equivalent impedance of the 0 ohm resistor 400. The ground Layer2 and the ground Layer3 are both grounded and are disposed below the routing Layer 1. The routing Layer1, the ground Layer layers 2 and 3 are disposed on a Printed Circuit Board (PCB), and the PCB may be one of a glass fiber substrate (FR4 PCB) and a Ceramic substrate (Ceramic PCB). In one embodiment, the height H between the routing Layer1 and the ground Layer3 may be equal to 0.6 to 3.5 times the 50 ohm line width. Preferably, the height H is equal to 1.4 times the 50 ohm line width. In another embodiment, the height H may be greater than or equal to 2 mils and less than or equal to 15 mils, but the utility model is not limited thereto.

For example, the first table shows the Impedance (Impedance) of Smith Chart (Smith Chart) of the font trace replacing resistor 100a, 0 ohm resistor and 50 ohm line width under different radio frequency conditions (1GHz, 2.44GHz and 5.85GHz), and the second table shows the error of the imaginary part Impedance of the font trace replacing resistor 100a and 50 ohm line width compared with 0 ohm resistor under different radio frequency conditions. As can be seen from the first and second tables, the first equivalent impedance of the resistor 400(0 ohm resistor) at 5.85GHz is 48.52-j4.59, and the second equivalent impedance of the font routing unit 500a at 5.85GHz is 48.41-j 5.29; in other words, under the condition that the rf frequency is 5.85GHz (WIFI5G), the error of the imaginary impedance of the rf circuit 100a of the present invention with the word trace replacing resistor is only 0.7 ohm (5.29 ohm minus 4.59 ohm) compared to the imaginary impedance of the 0 ohm resistor, while the error of the imaginary impedance of the existing 50 ohm line width (i.e. the existing 50 ohm line width connection between the pads) is 3.72 ohm (8.31 ohm minus 4.59 ohm) compared to the 0 ohm resistor, so the present invention improves the error of 3.02 ohm (3.72 ohm minus 0.7 ohm).

Watch 1

Watch two

Referring to fig. 2, fig. 3 and fig. 4 together, wherein fig. 4 shows a schematic diagram of a radio frequency circuit 100b with a word trace instead of a resistor according to a second embodiment of the present invention. The rf circuit 100b with font trace replacing resistor includes a trace Layer1, a ground Layer2, and a Layer 3. The routing Layer1 includes a first pad 200, a second pad 300 and a font routing unit 500 b. The shape of the zigzag routing unit 500b is zigzag and includes a first transmission line 510b, a second transmission line 520b, a third transmission line 530b, a fourth transmission line 540b and a fifth transmission line 550 b. The first transmission line 510b is connected to the first pad 200, and the fifth transmission line 550b is connected to the second pad 300. The first transmission line 510b, the second transmission line 520b, the third transmission line 530b, the fourth transmission line 540b, and the fifth transmission line 550b are sequentially connected to each other. In addition, the ground Layer2 has a through hole 600b, and the through hole 600b corresponds to the middle portion of the font routing unit 500b of the routing Layer 1.

Referring to fig. 2, fig. 3 and fig. 5, wherein fig. 5 shows a schematic diagram of a radio frequency circuit 100c with a word line instead of a resistor according to a third embodiment of the present invention. The rf circuit 100c with font trace replacing resistor includes a trace Layer1, a ground Layer2, and a Layer 3. The routing Layer1 includes a first pad 200, a second pad 300 and a font routing unit 500 c. The shape of the trace unit 500c is zigzag and similar to the trace unit 500a shown in fig. 2, except that the sharp corners are arc corners. In addition, the ground Layer2 has a through hole 600c, and the through hole 600c is the same as the through hole 600a in fig. 2, and therefore, the description thereof is omitted.

Referring to fig. 2, fig. 3, fig. 4 and fig. 6, wherein fig. 6 shows a schematic diagram of a rf circuit 100d with a word trace instead of a resistor according to a fourth embodiment of the utility model. The rf circuit 100d with font trace replacing resistor includes a trace Layer1, a ground Layer2, and a Layer 3. The routing Layer1 includes a first pad 200, a second pad 300 and a font routing unit 500 d. The shape of the trace unit 500d is zigzag and similar to the trace unit 500b shown in fig. 4, except that the sharp corners are arc corners. In addition, the ground Layer2 has a through hole 600d, and the through hole 600d is the same as the through hole 600b in fig. 4, and therefore, the description thereof is omitted.

Referring to fig. 2, fig. 3 and fig. 7 together, wherein fig. 7 shows a schematic diagram of a rf circuit 100e with a word trace instead of a resistor according to a fifth embodiment of the utility model. The rf circuit 100e with font trace replacing resistor includes a trace Layer1, a ground Layer2, and a Layer 3. The routing Layer1 includes a first pad 200, a second pad 300 and a font routing unit 500 e. The font routing unit 500e is shaped like an inverted U (i.e. inverted U) and includes a first transmission line 510e, a second transmission line 520e and a third transmission line 530 e. The first transmission line 510e is connected between the first pad 200 and the second transmission line 520e, and the third transmission line 530e is connected between the second pad 300 and the second transmission line 520 e. In addition, the ground Layer2 has a through hole 600e, and the through hole 600e corresponds to the font routing unit 500e of the routing Layer1, the upper portion of the first pad 200 and the upper portion of the second pad 300.

Referring to fig. 2, fig. 3, fig. 7 and fig. 8, wherein fig. 8 shows a schematic diagram of a rf circuit 100f with a word trace instead of a resistor according to a sixth embodiment of the utility model. The rf circuit 100f with font trace replacing resistor includes a trace Layer1, a ground Layer2, and a Layer 3. The routing Layer1 includes a first pad 200, a second pad 300 and a font routing unit 500 f. The shape of the font routing unit 500f is an inverted U-shape and is similar to the font routing unit 500e of fig. 7, except that the sharp corners are arc corners. In addition, the ground Layer2 has a through hole 600f, and the through hole 600f is the same as the through hole 600e of fig. 7, and therefore, the description thereof is omitted.

Referring to fig. 2, fig. 3 and fig. 9 together, wherein fig. 9 shows a schematic diagram of a rf circuit 100g with a word trace instead of a resistor according to a seventh embodiment of the utility model. The RF circuit 100g with font trace replacing resistor includes a trace Layer1, a ground Layer2, and a Layer 3. The routing Layer1 includes a first pad 200, a second pad 300 and a font routing unit 500 g. The font routing unit 500g is in an S-shape, i.e. the routing is a curve. In addition, the ground Layer2 has a through hole 600g, and the through hole 600g is the same as the through hole 600a in fig. 2, and therefore, the description thereof is omitted.

The technical effects of the through

holes

600b,600c,600d,600e,600f, and 600g are the same as the through hole 600a in fig. 2, that is, the inductive property of each

font trace unit

500b,500c,500d,500e,500f, and 500g at the rf frequency can be improved, and the second equivalent impedance of each

font trace unit

500b,500c,500d,500e,500f, and 500g is the same as or close to the first equivalent impedance of the resistor 400 of 0 ohm.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the utility model.

Claims

1. A radio frequency circuit with a resistor replaced by a font wire is used for replacing a resistor, the resistor has a first equivalent impedance at a radio frequency, and the radio frequency circuit with the font wire replacing the resistor is characterized by comprising:

a routing layer, comprising:

a first bonding pad;

a second pad corresponding to the first pad; and

the linear routing unit is connected between the first welding pad and the second welding pad and has a line width which is smaller than a 50 ohm line width; and

a grounding layer arranged below the wiring layer and separated from the wiring layer by a certain height;

the font routing unit has a second equivalent impedance at the radio frequency, the second equivalent impedance is determined according to the line width, the height and the radio frequency, and the second equivalent impedance is the same as or close to the first equivalent impedance.

2. The rf circuit of claim 1, further comprising:

and the other grounding layer is arranged between the wiring layer and the grounding layer and is provided with a through hole, and the through hole corresponds to the font wiring unit of the wiring layer.

3. The RF circuit of claim 1, wherein the height is greater than or equal to 2 mils and less than or equal to 15 mils.

4. The RF circuit of claim 1, wherein the height is equal to 0.6 to 3.5 times the 50 ohm line width.

5. The RF circuit of claim 1, wherein the first pad and the second pad are separated by a distance, and an area is formed between the first pad and the second pad, the size of the area conforming to one of a standard size 0201, a standard size 0402 and a standard size 0603 of a surface mount device;

wherein the standard size 0201 has a first length and a first width, and the first length and the first width are 0.6mm and 0.3mm, respectively;

wherein the standard size 0402 has a second length and a second width, which are 1.0mm and 0.5mm, respectively;

the standard size 0603 has a third length and a third width, and the third length and the third width are 1.6mm and 0.8mm, respectively.

6. The RF circuit of claim 1, wherein the font routing unit further has a line length, the line length is equal to 16 mils, and the line width is equal to 2 mils.

7. The RF circuit of claim 1, wherein the resistor is a 0 ohm resistor and the RF frequency is less than or equal to 10 GHz.

8. The RF circuit of claim 1, wherein the shape of the trace unit is one of a Z-shape, an S-shape and an inverted U-shape.

9. The RF circuit of claim 8, wherein the shape of the trace unit is Z-shaped and comprises:

a first transmission line connected to the first pad;

a second transmission line connected to the first transmission line; and

a third transmission line connected between the second transmission line and the second pad;

the first transmission line, the second transmission line and the third transmission line are all located between the first welding pad and the second welding pad, a first included angle is formed between the first transmission line and the second transmission line, a second included angle is formed between the second transmission line and the third transmission line, and the first included angle is equal to the second included angle.

10. The RF circuit of claim 1, wherein the routing layer and the ground layer are disposed on a printed circuit board, and the printed circuit board is one of a glass fiber substrate and a ceramic substrate.