CN114400427B - Four-frequency power divider based on stepped impedance coupling line - Google Patents

Abstract

The present invention is a four-frequency power divider based on a stepped impedance coupled line, comprising a dielectric substrate, and two double-segment stepped impedance coupled lines arranged on the surface thereof, wherein the double-segmented stepped impedance coupled line includes two connected and uncoupled steps Impedance coupling line, two sections of ladder impedance coupling lines are arranged at an angle, two double section ladder impedance coupling lines are symmetrically arranged and connected through isolation resistors, and the included angles of the two double section ladder impedance coupling lines are close to each other; The input end of the impedance coupling line is connected to the input port feeder, and the input end of the double-segment stepped impedance coupling line is respectively connected to the first output port feeder and the second output port feeder; The advantages of wide bandwidth, large frequency span, as well as good port isolation characteristics and power distribution characteristics are very suitable for modern mobile communication systems and millimeter wave radar systems.

Description

Four-band Power Divider Based on Step Impedance Coupling Line

technical field

The invention relates to the technical field of multi-frequency power divider design, in particular to a four-frequency power divider based on a stepped impedance coupled line.

Background technique

With the rapid development of economy and technology, diversified information services are required, so a variety of mobile communication standards have been proposed, such as GSM, CDMA, WIMAX, WLAN and so on. The limited spectrum resources impose stricter requirements on the division of communication frequency bands, which also makes the communication system develop in the direction of small size and high integration. The power divider has the function of distributing and synthesizing power, and is widely used in various microwave circuits. As an important component in the communication system, the power divider is also developing towards the direction of miniaturization and high integration, so the research on the multi-band power divider has become more and more important. At the same time, the power divider is also of great significance in the field of millimeter-wave radar systems.

The quad-frequency power divider is realized based on the two-section transmission line structure of the coupled microstrip line, which has a complex structure and a small span of operating frequency points; the quad-frequency power divider is realized by using the coupled line section of the stepped impedance changer type, which also has a complex structure. and low isolation.

SUMMARY OF THE INVENTION

Aiming at the problems in the prior art, the present invention provides a four-frequency power divider based on a stepped impedance coupled line, which solves the technical problems of insufficient miniaturization requirements, complex design structure and low isolation in the prior art.

The present invention is achieved through the following technical solutions:

A four-frequency power divider based on a stepped impedance coupled line, comprising a dielectric substrate, and two double-segment stepped impedance coupled lines arranged on its surface, the two-segment stepped impedance coupled line comprising two connected and uncoupled stepped impedance coupled lines The two-segment ladder impedance coupling lines are arranged at an included angle, the two double-segment ladder impedance coupling lines are symmetrically arranged and connected through isolation resistors, and the included angles of the two double-segment ladder impedance coupling lines are close to each other;

The input ends of the two double-segment stepped impedance coupling lines are connected to the input port feeders, and the output ends of the two-segment stepped impedance coupled lines are respectively connected to the first output port feeder and the second output port feeder.

Preferably, the stepped impedance coupling line includes two parallel and spaced-apart coupling lines, and one end of the two coupling lines is connected.

Preferably, the coupling line includes a first section of the coupling line and a second section of the coupling line that are coaxial and connected. A section of the coupling line is connected to each other.

Preferably, the two-segment stepped impedance coupling line includes a first stepped impedance coupling line and a second stepped impedance coupling line that are connected in sequence;

The second stepped impedance coupled lines of the two double-segment stepped impedance coupled lines are coaxially arranged, the two first stepped impedance coupled lines are arranged at an included angle, and one end of the input port feeder is connected to the connection ends of the two first stepped impedance coupled lines.

Preferably, the other end of the input port feeder extends to the first side of the dielectric substrate, the first output port feeder and the second output port feeder extend to the second side of the dielectric substrate, the first side and the second side Side-parallel settings.

Preferably, the isolation resistance includes a first isolation impedance and a second isolation impedance;

Two ends of the first isolation impedance are respectively connected to the intersection points of the two-stage stepped impedance coupled lines of the two double-stage stepped impedance coupled lines.

The second isolation impedances are respectively connected to the output ends of the two double-segment ladder impedance coupling lines.

Preferably, the input port feeder and the output port feeder are both microstrip conductor strips.

Preferably, the bottom surface of the dielectric substrate is provided with a metal ground plate.

Compared with the prior art, the present invention has the following beneficial technical effects:

A four-frequency power divider based on a stepped impedance coupled line of the present invention utilizes the double-resonance characteristics of the coupled line to combine the two-segment coupled lines to form a multi-resonance structure equivalent to four resonance units, and the input signal from the power divider The input port input of the power divider is divided into equal parts, and four frequency points are generated through the double-segment ladder impedance coupling line and the two isolation resistors respectively. Finally, the two output ports of the power divider output the ladder impedance coupling line as the coupling line. It effectively solves the problem that the frequency range is limited due to the uneven phase velocity of the odd and even modes in the microstrip line area, and also simplifies the structure of the four-frequency power divider. Using the stepped impedance coupling line structure, it has good port isolation characteristics, Power distribution characteristics, very suitable for modern mobile communication systems and millimeter wave radar systems.

Further, the two sections of the stepped impedance coupling line of the double section stepped impedance coupling line are arranged at an angle, and the isolation resistor is connected to the intersection of the two double section stepped impedance coupling lines. The use of this arrangement reduces the size of the four-band power divider. Realized on a single-chip PCB board, which is conducive to processing integration, and has low production cost.

Description of drawings

FIG. 1 is a circuit schematic diagram of a four-frequency power divider based on a stepped impedance coupled line according to the present invention.

FIG. 2 is a schematic three-dimensional structure diagram of a four-frequency power divider based on a stepped impedance coupled line according to the present invention.

FIG. 3 is a schematic diagram of the circuit structure size of Embodiment 1. FIG.

FIG. 4 is an S-parameter simulation and test chart of Example 1. FIG.

FIG. 5 is an S-parameter simulation and test diagram of the isolation characteristics of two power output ports in Embodiment 1. FIG.

FIG. 6 is an S-parameter simulation and test diagram of the matching characteristics of two power output ports in Embodiment 1. FIG.

FIG. 7 is a processing actual view of Example 1. FIG.

FIG. 8 is an S-parameter simulation and test chart of Example 2. FIG.

FIG. 9 is an S-parameter simulation and test diagram of the isolation characteristics of two power output ports in Embodiment 2. FIG.

In the figure, 1, input port feeder; 2, first output port feeder; 3, second output port feeder; 4, first stepped impedance coupling line; 5, second stepped impedance coupling line; 6, third stepped impedance coupling line; 7. fourth ladder impedance coupling line; 8. first isolation resistance; 9. second isolation resistance; coupling line (41, 42, 51, 52, 61, 62, 71, 72); 101, dielectric substrate; 102, the metal ground plate; 103, the first side; 104, the second side.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings, which are to explain rather than limit the present invention.

Referring to Figures 1-9, a four-band power divider based on a ladder impedance coupled line includes an input port, a first output port, a second output port, two double-segment ladder impedance coupling lines and two isolation resistors, the two-segment ladder The impedance coupling line includes two connected and uncoupled stepped impedance coupling lines.

One end of the two double-segment ladder impedance coupling lines is connected to the input port, the other ends of the two double-segment ladder impedance coupling lines are respectively connected to the first output port and the second output port, and two ends of the first isolation resistor 8 are respectively connected to two double The connecting ends of the two sections of the section ladder impedance coupling line, and the two ends of the second isolation resistor are respectively connected to the first output port and the second output port.

The two double-segment ladder impedance coupling lines are respectively a first two-segment ladder impedance coupling line and a second two-segment ladder impedance coupling line with the same structure.

The first double-segment stepped impedance coupled line includes a first stepped impedance coupled line 4 and a second stepped impedance coupled line 5 connected in sequence, forming a multi-resonance structure equivalent to four resonance units.

The second two-stage stepped impedance coupling line includes a third stepped impedance coupling line 6 and a fourth stepped impedance coupling line 7 connected in sequence, and forms a multi-resonance structure equivalent to four resonance units.

The first stepped impedance coupled line 4 includes a coupled line 41 and a coupled line 42, and one end of the coupled line 41 and the coupled line 42 is connected by a wire 43; the second stepped impedance coupled line 5 includes a coupled line 51 and a coupled line 52, and the coupled line 51 One end of the coupling line 52 is connected by a wire 53 .

The third stepped impedance coupled line 6 includes a coupled line 61 and a coupled line 62, and one end of the coupled line 61 and the coupled line 62 is connected by a wire 63; the fourth stepped impedance coupled line 7 includes a coupled line 71 and a coupled line 72, and the coupled line 71 and One end of the coupling line 72 is connected by a wire 73 .

The input port is connected with the other end of the coupling line 41 and the coupling line 61; the first output port is connected with the other end of the coupling line 52 and the second isolation resistor 9; the second output port is connected with the other end of the coupling line 72 and the second The isolation resistor 9 is connected, one end of the first isolation resistor 8 is connected to the connection end of the coupling line 42 and the coupling line 51 , and the other end of the first isolation resistor 8 is connected to the connection end of the coupling line 62 and the coupling line 71 .

The coupling lines (41, 42, 51, 52, 61, 62, 71, 72) have the same structure, and all include a first section of the coupling line and a second section of the coupling line that are coaxial and connected, and the first section of the coupling line has a section. The width and length of the second coupling line are different from those of the second coupling line. In the stepped impedance coupling line, the first coupling line section of the two coupling lines is connected by a wire.

Example 1

Referring to FIG. 2 , this embodiment provides a four-frequency power divider based on stepped impedance coupled lines, including a dielectric substrate 101 , a metal ground plate 102 is provided on the bottom surface of the dielectric substrate 101 , and an input port feeder is provided on the top surface of the dielectric substrate 101 1. Feeder line 2 of the first output port, feeder line 3 of the second output port, and two symmetrically arranged double-segment stepped impedance coupled lines, the two double-segment stepped impedance coupled lines are connected by isolation resistors, and the two-segment stepped impedance coupled line is The input end is connected to the input port feeder 1 , and the input ends of the double-segment stepped impedance coupling line are respectively connected to the first output port feeder 2 and the second output port feeder 3 .

The first two-stage stepped impedance coupling line includes a first stepped impedance coupling line 4 and a second stepped impedance coupling line 5 that are connected and uncoupled, and the first stepped impedance coupling line 4 and the second stepped impedance coupling line 5 are arranged at an included angle, They are connected through the intersection of the included angles. In the embodiment, the first stepped impedance coupling line is arranged obliquely, and the second stepped impedance coupling line is vertically arranged.

The second two-stage stepped impedance coupled line includes a third stepped impedance coupled line 6 and a fourth stepped impedance coupled line 7 that are connected and uncoupled. The third stepped impedance coupled line 6 and the fourth stepped impedance coupled line 7 are arranged at an angle. and connected by the intersection of the included angles.

The first two-stage ladder impedance coupling line and the second two-stage ladder impedance coupling line are symmetrically arranged, the intersections of the first two-stage ladder impedance coupling line and the second two-stage ladder impedance coupling line are close to each other, and the isolation resistance is located between the two intersection points. .

Since the structures of the first two-segment ladder impedance coupling line and the second two-segment ladder impedance coupling line are the same, the structure of the two-segment ladder impedance coupling line is described in detail below by taking the first two-segment ladder impedance coupling line as an example. .

The first stepped impedance coupling line 4 includes two parallel and spaced coupling lines 41 and 42, and one end of the coupling line 41 and the coupling line 42 is connected by a wire 43; the second stepped impedance coupling line 5 includes parallel and spaced apart. The provided two coupling lines 51 and 52 are formed. One end of the coupling line 51 and the coupling line 52 is connected by a wire 53, and the first stepped impedance coupling line 4 and the second stepped impedance coupling line 5 are arranged at an angle. In this implementation, , the angle between the first stepped impedance coupling line 4 and the second stepped impedance coupling line 5 is 45°.

The coupling line includes a coaxial first section coupling line section and a second section coupling line, and the width of the first section coupling line section is smaller than that of the second section coupling line. In the stepped impedance coupling line, the first section of the two coupling lines is The coupled line segments are connected by a short circuit.

In the first double-segment stepped impedance coupling line, the second section of the coupling line 41 is connected to the input port feeder 1, the first section of the coupling line 41 is connected to the first section of the coupling line 42, and the coupling line 42 The second section of the coupling line is connected to the second section of the coupling line 51, the first section of the coupling line 51 is connected to the first section of the coupling line 52, and the second section of the coupling line 52 is connected to the first section of the coupling line 52. An output port feeder 2 is connected.

The third stepped impedance coupling line 6 includes two coupling lines 61 and 62 arranged in parallel and spaced apart, and one end of the coupling line 61 and the coupling line 62 is connected by a wire 63; the fourth stepped impedance coupling line 7 includes parallel and spaced apart. Two coupling lines 71 and 72 are provided, and one end of the coupling line 71 and the coupling line 52 is connected by a wire 73 .

In the second double-segment stepped impedance coupling line, the second section of the coupling line 61 is connected to the input port feeder 1, the first section of the coupling line 61 is connected to the first section of the coupling line 62, and the coupling line 62 The second section of the coupling line is connected to the second section of the coupling line 71, the first section of the coupling line 71 is connected to the first section of the coupling line 72, and the second section of the coupling line 72 is connected to the first section of the coupling line. The two output ports are connected to feeder 3.

The above-mentioned isolation resistance includes a first isolation resistance 8 and a second isolation resistance 9. One end of the first isolation resistance 8 is connected to the connection end of the second section of the coupling line of the coupling line 42 and the second section of the coupling line of the coupling line 51. The first isolation resistance The other end of the resistor 8 is connected to the connection end of the second section of the coupling line 62 and the second section of the coupling line 71, and one end of the second isolation resistor 9 is connected to the second section of the coupling line 52. The coupling line and the first output The connection end of the port feeder 2 and the other end of the second isolation resistor 9 is connected to the connection end of the second section of the coupling line 72 and the connection end of the second output port feeder 3 .

In this embodiment, the input port feeder 1 is a first 50 ohm microstrip line conducting strip 10 , one end of the first 50 ohm microstrip line conducting strip 10 extends to the first side 103 of the dielectric substrate 101 , and the other One end is connected to one end of the coupling line 41 and one end of the coupling line 61 respectively; the connection between the first 50 ohm microstrip line conducting strip 10 and the first side 103 of the dielectric substrate is the input end;

In this embodiment, the output port feeder 2 is a second 50-ohm microstrip line conducting strip 11, and one end of the second 50-ohm microstrip line conducting strip 11 extends to the second side 104 of the dielectric substrate 101, and the first The connection between the conductive strip 11 of the 50-ohm microstrip line and the second side 104 of the dielectric substrate 101 is the first output port Port 2 .

The output port feeder 3 is a third 50-ohm microstrip line conducting strip 12, one end of the third 50-ohm microstrip line conducting strip 12 extends to the second side 104 of the dielectric substrate 101, and the second side 104 and The first sides 103 are parallel to each other, and the connection between the conduction strip 12 of the third 50-ohm microstrip line and the second side 104 of the dielectric substrate 101 is the second output port Port3.

In this embodiment, the metal surface on the front side of the circuit substrate is processed and corroded by the manufacturing process of the printed circuit board, thereby forming the required metal pattern. At the same time, the present application utilizes a stepped impedance coupled line structure, which has good port isolation characteristics and power distribution characteristics. On the other hand, the application is small in size, easy to process and low in production cost, and very suitable for modern mobile communication systems. The present invention will be described in further detail below.

Referring to FIG. 3 , in the two coupled lines of the first stepped impedance coupling line, the width of the first section of the coupling line is W _{1 and the} length is L ₁ , the width of the second section of the coupling line is W ₂ , and the length is both L ₂ .

In the two coupled lines of the second stepped impedance coupling line, the width of the first section of the coupling line is W ₃ and the length is L ₃ , the width of the second section of the coupling line is W ₄ , and the length is L ₄ .

The dielectric substrate used has a relative permittivity of 2.2, a thickness of 0.7874mm, and a loss tangent of 0.0009. With reference to Figure 2, the size parameters of the four-band power divider based on the stepped impedance coupled line are as follows: L ₁ =10.45, L ₂ =10.50, L ₃ =10.6, L ₄ =10.5, W ₁ =0.72, W ₂ =1.25, W ₃ =1.2, W ₄ =1.8, S ₁ =0.52, S ₂ =0.38, S ₃ =0.45, S ₄ =0.45 (unit: mm), R ₁ =111Ω, R ₂ =201Ω. The total area of the entire design is 5.6cm x 3.5cm. In this example, the four-frequency power divider based on the stepped impedance coupled line is modeled and simulated in the electromagnetic simulation software HFSS 13.0. Figure 4 is the S-parameter simulation and test diagram of the four-frequency power divider in this example. It can be seen from the figure that the four frequency points of the four-frequency power divider based on the stepped impedance coupled line are 0.9GHz, 1.8GHz, 3.5GHz, respectively. GHz, 4.4GHz, the corresponding insertion loss is -3.09dB, -3.17dB, -3.58dB, -3.85dB, which are relatively close to the ideal value of -3dB. Figure 5 is the S-parameter simulation and test chart of the isolation characteristics of the two power output ports of the quad-frequency power divider in this example. It can be seen from the figure that the isolation at these four frequency points is all less than -18dB, and Figure 6 is the example. The S-parameter simulation and test chart of the matching characteristics of the two power output ports of the mid-quad-band power divider shows that the callback loss of the output ports is less than -17dB. The invention utilizes the stepped impedance coupling line structure, and has good port isolation characteristics and power distribution characteristics. The actual processing map is shown in Figure 6.

Example 2

The four-frequency power divider based on the stepped impedance coupled line of the present invention is applied to the millimeter-wave radar system, and the simulation test results are as follows:

Referring to Figure 8-9, Figure 8 is the S-parameter simulation and test diagram of the quad-band power divider in this example. It can be seen from the figure that the four frequency points of the quad-band power divider based on the stepped impedance coupled line are 21.5 GHz, 26.8GHz, 75.8GHz, 81.1GHz, these four frequency points respectively correspond to the two most commonly used frequency bands of 24G and 77G in the field of millimeter wave radar. Figure 9 is the S-parameter simulation and test chart of the isolation characteristics of the two power output ports of the quad-frequency power divider in this example. It can be seen from the figure that the isolation is less than -35dB at these four frequency points. The return loss of the two power output ports of the quad-band power divider is less than -25dB.

To sum up, a four-frequency power divider based on a stepped impedance coupled line in this embodiment uses a stepped impedance coupled line structure, which has the advantages of small size, wide bandwidth, large frequency span, etc., as well as good port isolation characteristics, power Assign properties. A quad-band power divider with small size and easy processing is realized, which is very suitable for modern mobile communication systems and millimeter-wave radar systems.

The above content is only to illustrate the technical idea of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention all fall within the scope of the claims of the present invention. within the scope of protection.

Claims (8)

1. A four-frequency power divider based on a stepped impedance coupling line is characterized by comprising a dielectric substrate (101) and two double-section stepped impedance coupling lines arranged on the surface of the dielectric substrate, wherein the double-section stepped impedance coupling lines comprise two connected and uncoupled stepped impedance coupling lines which are arranged at an included angle, the two double-section stepped impedance coupling lines are symmetrically arranged and connected through an isolation resistor, and the included angles of the two double-section stepped impedance coupling lines are arranged close to each other;

the input ends of the two double-section stepped impedance coupling lines are connected with the input port feeder line (1), and the output ends of the double-section stepped impedance coupling lines are respectively connected with the first output port feeder line (2) and the second output port feeder line (3).

2. The four-frequency power divider according to claim 1, wherein the stepped impedance coupling line comprises two parallel coupling lines spaced apart from each other, and one end of each of the two coupling lines is connected to each other.

3. The four-frequency power divider based on the stepped impedance coupling line as claimed in claim 2, wherein the coupling line comprises a first coupling line and a second coupling line which are coaxial and connected, the width and length of the first coupling line and the second coupling line are different, and the first coupling lines of the two coupling lines are connected with each other.

4. The four-frequency power divider based on the stepped impedance coupling line according to claim 1, wherein the two-stage stepped impedance coupling line comprises a first stepped impedance coupling line and a second stepped impedance coupling line which are connected in sequence;

the second stepped impedance coupling lines of the two double-section stepped impedance coupling lines are coaxially arranged, the two first stepped impedance coupling lines are arranged at an included angle, and one end of the input port feeder line (1) is connected with the connecting ends of the two first stepped impedance coupling lines.

5. The four-frequency power divider based on the stepped impedance coupling line according to claim 4, wherein the other end of the input port feed line (1) extends to a first side of the dielectric substrate (101), the first output port feed line (2) and the second output port feed line (3) extend to a second side of the dielectric substrate (101), and the first side and the second side are parallel.

6. The four-frequency power divider based on the stepped impedance coupling line as claimed in claim 1, wherein the isolation resistor comprises a first isolation impedance (8) and a second isolation impedance (9);

two ends of the first isolation impedance (8) are respectively connected with the intersection points of two sections of stepped impedance coupling lines of the two double-section stepped impedance coupling lines;

and the second isolation impedance (9) is respectively connected with the output ends of the two double-section stepped impedance coupling lines.

7. The four-frequency power divider based on the stepped impedance coupling line of claim 1, wherein the input port feeder line and the output port feeder line are microstrip line conduction bands.

8. The four-frequency power divider based on the stepped impedance coupling line as claimed in claim 1, wherein the bottom surface of the dielectric substrate (101) is provided with a metal ground plate (102).

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