CN110518323A - The not equal function of four frequency bands based on π type minor matters divide Gysel power splitter - Google Patents

Abstract

The present invention proposes a four-band unequal power divider Gysel power divider based on π-shaped branches, aiming to increase the number of working frequency bands of the unequal power divider Gysel power divider to adapt to the working requirements of multi-band communication systems; including medium Substrate, a metal base plate printed on the lower surface of the dielectric substrate, an input feeder printed on the upper surface, two output feeders and two π-shaped branches that are mirror-symmetrical and connected at one end, and the other ends of the two π-shaped branches are connected There are isolation elements, the connection between the input feeder and each output feeder, and between an output feeder and an isolation element are respectively connected by a quarter-wavelength impedance converter, and a quarter of the connection between an output feeder and the input feeder The width of a wavelength impedance converter is equal to the width of the quarter-wavelength impedance converter connected between the other output feeder and the isolation element, and the quarter-wavelength impedance converter connected between the two output feeders and the input feeder The width of the device varies.

Description

Four-band unequal power divider Gysel power divider based on π-shaped stubs

technical field

The invention belongs to the field of microwave and radio frequency technology, and relates to a four-band unequal power divider Gysel power divider, in particular to a four-band unequal power divider Gysel power divider based on π-shaped branches, which can be applied to wireless communication system radio frequency front end.

Background technique

The Gysel power divider is an important passive device in microwave radio frequency circuits, which has the function of power distribution or combination. It is an improved structure based on the Wilkinson power divider. It can not only achieve all port matching, but also , ground the isolated load to overcome the defect that the Wilkinson structure cannot sufficiently dissipate heat, so it is widely used in radio frequency circuits such as high-power amplifiers, mixers and antenna arrays.

According to the ratio of energy distribution, Gysel power divider has two types: equal power division and unequal power division. Equal Power Splitter Gysel power splitter achieves equal power output at each output port. However, in many communication system applications, Gysel power splitters are urgently required to output unequal power, especially in antenna arrays, unequal power split feeding can effectively suppress the excessive side lobe level of the antenna and save the power supply An attenuator in a network that can greatly reduce loss and cost. On the other hand, with the rapid development of wireless communication, in order to make full use of spectrum resources, increase signal transmission rate, and enhance system reliability, the application of dual-frequency and multi-frequency communication circuits is becoming more and more common. And above multiple frequency bands work at the same time. Introducing the multi-band structure into the unequal power divider Gysel power divider can not only meet the multiple functions of the multi-band terminal equipment, but also simplify the circuit structure, reduce the volume, and realize the miniaturization of the system. Therefore, the design of unequal power divider with multiple working frequency bands has attracted the attention of more and more researchers, and many scholars have devoted themselves to the research and promotion of multi-band unequal power divider Gysel power dividers. However, the current research on the multi-band unequal power divider mainly focuses on the dual-band unequal power divider Gysel power divider. There are no other research reports on the design of Gysel power splitters with unequal power division over two frequency bands, which greatly limits the use and promotion of Gysel power splitters in wireless communications.

For example, an article titled "Dual band gysel power divider with high powerdividing ratio" published by Gai C et al. in Microwave and Optical Technology Letters (VOL.59, NO.10, March 2017) proposed a dual-frequency unequal Power divider Gysel power divider, the dual-frequency unequal power divider Gysel power divider includes three ports, six branch transmission lines, three open-circuit stubs and two grounding isolation resistors, using three open-circuit stubs to replace the two load ports The half-wavelength transmission line between them realizes the design of the dual-band Gysel power splitter. However, its disadvantage is that the unequal Gysel power divider can only work in two frequency bands at the same time, and cannot adapt to the working requirements of multi-frequency terminal equipment with three or more frequencies. The integrity of the metal ground, the structure is relatively complex, so it will be limited in practical application.

Contents of the invention

The purpose of the present invention is to overcome the defects in the above-mentioned prior art, and propose a four-band unequal power divider Gysel power divider based on π-shaped branches, aiming at increasing the number of working frequency bands of the unequal power divider Gysel power divider, In order to adapt to the working requirements of the multi-band communication system.

In order to achieve the above object, the technical solution adopted by the present invention includes a dielectric substrate 1, the lower surface of the dielectric substrate 1 is printed with a metal base plate 2, and the upper surface is printed with an input feeder 3, two output feeders 4 and two mirrored Symmetrical π-shaped branches 5 connected at one end, each of the other ends of the two π-shaped branches 5 is connected with an isolation element 6, between the input feeder 3 and each output feeder 4, and between one output feeder 4 and one isolation The elements 6 are respectively connected by a quarter-wavelength impedance converter 7, and the width of the quarter-wavelength impedance converter 7 connected between one output feeder 4 and the input feeder 3 is isolated from the other output feeder 4 and The widths of the quarter-wavelength impedance converters 7 connected between the elements 6 are equal, and the widths of the quarter-wavelength impedance converters 7 connected between the two output feeders 4 and the input feeder 3 are not equal, wherein:

The π-shaped branch 5 includes the first transmission line 51, the second transmission line 52 and the third transmission line 53 connected in sequence, at the connection position between the first transmission line 51 and the second transmission line 52, and the second transmission line 52 and the third transmission line 53 The connection positions of the two parallel branches 54 are respectively connected to each other, and the other ends of the two parallel branches 54 are connected through a short-circuit microstrip line 55;

The short-circuit microstrip line 55 and the isolation element 6 are respectively connected to the metal base plate 2 through metallized via holes 8 .

The above-mentioned four-band unequal power divider Gysel power divider based on π-shaped stubs, the first transmission line 51, the second transmission line 52 and the parallel stubs 54 all adopt a quasi-U-shaped structure composed of five straight line microstrips. The third transmission line 53 adopts a Z-shaped structure composed of three straight line microstrips, and the width of each straight line microstrip in the first transmission line 51 is equal to that of each straight line microstrip in the third transmission line 53, the first transmission line 51, the second In the transmission line 52 , the third transmission line 53 and the parallel branch 54 , a cut corner is provided at the junction of every two linear microstrips.

In the aforementioned four-band unequal power divider Gysel power divider based on π-shaped branches, the symmetry axis of the two π-shaped branches 5 coincides with the midline of one side of the dielectric substrate 1 .

In the above-mentioned four-band unequal power divider Gysel power divider based on π-shaped stubs, the input feeder 3 is located on the midline of one side of the dielectric substrate 1; the two output feeders 4 are respectively located on both sides of the input feeder 3, and Symmetrical about input feeder 3.

Compared with the prior art, the present invention has the following advantages:

The present invention adopts two π-shaped branches that are mirror-image symmetrical and connected at one end, and each π-shaped branch has a phase difference of 90 degrees in the four frequency bands, and one end of the two π-shaped branches is connected to form a section with an electrical length of The 180-degree transmission line can realize the impedance transformation function in four frequency bands at the same time. The simulation results show that the return loss of the input and output ports, the insertion loss of the output port and the isolation indicators of the present invention can meet the engineering requirements in the four frequency bands. Compared with the existing technology, it can well adapt to the working requirements of multi-frequency terminal equipment.

Description of drawings

Fig. 1 is the overall structural representation of the present invention;

Fig. 2 is a schematic diagram of the π-type branch structure in Fig. 1;

Fig. 3 is the S parameter simulation figure of output port insertion loss of the present invention;

Fig. 4 is the S parameter simulation figure of input and output port return loss of the present invention;

Fig. 5 is an S-parameter simulation diagram of the output port isolation of the present invention.

Detailed ways

The purpose, technical solution and technical effect of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Referring to Fig. 1, a four-band unequal power divider Gysel power divider based on π-shaped stubs includes a dielectric substrate 1, a metal base plate 2 is printed on the lower surface of the dielectric substrate 1, and an input feeder 3 is printed on the upper surface. Two output feeders 4 and two mirror-symmetric π-shaped branches 5 connected at one end, the other ends of the two π-shaped branches 5 are respectively connected with isolation elements 6, and the connection between the input feeder 3 and each output feeder 4 between, and an output feeder 4 and an isolation element 6 are respectively connected by a quarter-wavelength impedance converter 7, and a quarter-wavelength impedance converter 7 connected between an output feeder 4 and an input feeder 3 The width is equal to the width of the quarter-wavelength impedance converter 7 connected between the other output feeder 4 and the isolation element 6, and the quarter-wavelength impedance converter connected between the two output feeder 4 and the input feeder 3 7 varies in width, where:

The dielectric substrate 1 is a rectangular F4B material with a relative permittivity of 2.65, a loss tangent of 0.03, a size of 56mm×51mm, and a thickness of 0.43mm.

The input feeder 3 is a rectangular microstrip structure, the optimal length of its long side is 6 mm, and the optimal value of its short side is 1.12 mm, and the midline of its short side coincides with the midline of the short side AA' of the dielectric substrate 1; the two The output feeder 4 is respectively located on both sides of the input feeder 3, and is symmetrical with respect to the input feeder 3, and its structure and size are the same as the input feeder 3, and the characteristic impedance of the input feeder 3 and the two output feeder 4 are both 50Ω, which is convenient Integrate with other microwave circuits.

The symmetrical axes of the two π-shaped branches 5 coincide with the midline of one side of the dielectric substrate 1 . In this embodiment, the axis of symmetry coincides with the midline of the short side AA' of the dielectric substrate. Its structure is shown in Figure 2, including the first transmission line 51, the second transmission line 52 and the third transmission line 53 connected in sequence, at the connection position of the first transmission line 51 and the second transmission line 52, and the second transmission line 52 and the third transmission line The connection positions of 53 are respectively connected with parallel branches 54, and the other ends of the two parallel branches 54 are connected through a short-circuit microstrip line 55; One end of the stub is connected to construct a transmission line with an electrical length of 180 degrees, which can realize the impedance transformation function in four frequency bands at the same time, and can well adapt to the working requirements of multi-frequency terminal equipment.

The first transmission line 51, the second transmission line 52 and the parallel branch 54 all adopt a quasi-U-shaped structure composed of five straight line microstrips, wherein the first transmission line 51 has a length b1 of its microstrip arm=14mm, and the microstrip The length a1=2mm at the bottom, the length a1=2mm of the two straight microstrips at the junction of the microstrip arms, a3=2.08mm; the second transmission line 52, the length b2=28mm of its microstrip arms, the length a1 at the bottom of the microstrip =2mm, the length a2=1mm of the two linear microstrips at the junction of the microstrip arms, a4=2.69mm; the parallel branch 54, the length a2=1mm of its microstrip arms, the length b5=1.84mm at the bottom of the microstrip, the microstrip The lengths of the two straight microstrips at the junction of the band arms are b4 = 2.57 mm, and b6 = 4 mm.

The third transmission line 53 adopts a Z-shaped structure composed of three straight microstrips, the length a5=2.08mm of the upper and lower two microstrips, a2=1mm, and the length b3=28mm of the middle microstrip; and the first transmission line 51 The width of each straight microstrip in the third transmission line 53 is equal to that of each straight microstrip, and the optimal width value is 1.43mm. The optimal width value of the second transmission line 52 is 0.82mm, and the optimal width value of the parallel branch 54 is 1.08mm.

In the first transmission line 51, the second transmission line 52, the third transmission line 53 and the parallel branch 54, a cut angle is provided at the junction of every two straight line microstrips to reduce the reflection of electromagnetic waves during transmission, preferably a 45-degree cut. horn.

The short-circuit microstrip line 55 and the isolation element 6 are respectively connected to the metal base plate 2 through the metallized via hole 8, wherein the short-circuit microstrip line 55 is a rectangular microstrip structure, and the metallized via hole 8 is set in the middle of the rectangular microstrip, and the rectangular microstrip Both ends of the strip are provided with a 45-degree cut angle, and the optimal length of the long side of the rectangular microstrip is 5.6mm, and the length of the short side is equal to the width of the parallel branch 54.

The isolation element 6 can be in the form of a parallel connection of capacitors and inductors, a series connection of inductance and resistance, or a single resistor. In this embodiment, chip resistors are used as the isolation element, and the optimal resistance value is 100 ohms, so as to ensure the two outputs of the unequal power divider Gysel power divider There is good isolation between ports. The metallized via holes 8 all have a diameter of 0.4mm, which meets the processing requirements and achieves good grounding performance.

The quarter-wavelength impedance converter 7 has the same length, and the optimized value is 20.78mm. The optimized width of the quarter-wavelength impedance converter 7 connected between the two output feeders 4 and the input feeder 3 is respectively 1.3mm and 0.2mm, the quarter-wavelength impedance converter 7 with different line widths is used to change the distribution ratio of energy, so as to realize unequal power output.

Below in conjunction with simulation experiment, technical effect of the present invention is further illustrated:

1. Simulation experiment and content

1.1 Using the commercial simulation software HFSS_19.2, the S parameter of the insertion loss of the output port in the embodiment of the present invention is simulated and calculated in the range of 1-4 GHz, and the result is shown in FIG. 3 .

1.2 Using the commercial simulation software HFSS_19.2, the S-parameters of the return loss of the input and output ports in the embodiment of the present invention are simulated and calculated in the range of 1-4GHz, and the results are shown in FIG. 4 .

1.3 Using the commercial simulation software HFSS_19.2, the S-parameters of the output port isolation in the embodiment of the present invention are simulated and calculated in the range of 1-4 GHz, and the results are shown in FIG. 5 .

2. Simulation results

With reference to Fig. 3, the center frequencies of four operating frequency bands of embodiment 1 are respectively 1.45GHz, 2.17GHz, 2.86GHz and 3.60GHz, and the absolute bandwidth (relative bandwidth) is respectively 150/120/240/130MHZ (10.3%/5.52%/ 8.39%/3.61%); in the first frequency band, the insertion losses S21 and S31 of the two output ports are -1.5±0.9dB and -8.48±0.1dB respectively, realizing a power ratio of 5:1; in the second frequency band , the insertion losses S21 and S31 of the two output ports are -0.92±0.3dB and -8.21±0.4dB respectively, realizing a power ratio of 5:1; in the third frequency band, the insertion losses S21 and S31 of the two output ports They are -1.3±0.34dB and -9.43±0.41dB respectively, achieving a power ratio of 6:1; in the fourth frequency band, the insertion losses S21 and S31 of the two output ports are -0.86±0.1dB and -10.59± 1.2dB, achieving a power division ratio of 9:1; it shows that the power splitter has achieved unequal power division in the four frequency bands.

Referring to Figure 4, at the first center frequency point, the return loss S11 of the input port is -24.74dB, and the return losses S22 and S33 of the two output ports are -25.68dB and -23.95dB respectively; at the second center frequency point , the return loss S11 of the input port is -15.46dB, the return loss S22 and S33 of the two output ports are -15.87dB and -16.97dB respectively; at the third center frequency point, the return loss S11 of the input port is - 15.68dB, the return loss S22 and S33 of the two output ports are -15.15dB and -12.93dB respectively; at the fourth center frequency point, the return loss S11 of the input port is -20.1dB, the echo loss of the two output ports The losses S22 and S33 are -22.8dB and -21.72dB respectively; it shows that the input and output return loss of the power splitter in the four frequency bands is good, which can well meet the engineering requirements.

Referring to Figure 5, at the first center frequency, the isolation S32 of the two output ports is -30.93dB; at the second center frequency, the isolation S32 of the two output ports is -24.1dB; at the third center frequency, the two The isolation S32 of the two output ports is -29.93dB; at the fourth center frequency point, the isolation S32 of the two output ports is -29.19dB; it shows that the isolation effect of the two output ports of the power divider on the four frequency bands is good, and it can be very well meet the engineering requirements.

The above are specific embodiments of the present invention, and do not constitute any limitation to the present invention. Obviously, for professionals in the field, after understanding the content and principles of the present invention, it is possible to do so without departing from the principles and structures of the present invention. , making various modifications and changes in form and details, but these modifications and changes based on the idea of the present invention are still within the claims and protection scope of the present invention.

Claims (4)

1. a kind of not equal function of four frequency bands based on π type minor matters divide Gysel power splitter, which is characterized in that including medium substrate (1), The lower surface of the medium substrate (1) is printed with metal base plate (2), and upper surface is printed with incoming feeder (3), two output feeders (4) it is connected with two π type minor matters (5) to connect in mirror symmetry and one end, two respective other ends of π type minor matters (5) Isolation element (6), between the incoming feeder (3) and each output feeder (4) and output feeder (4) with one every It is connected from quarter wavelength impedance transducer (7) are passed through between element (6) respectively, and an output feeder (4) and input are presented The width of the quarter wavelength impedance transducer (7) connected between line (3), with another output feeder (4) and isolation element (6) width of the quarter wavelength impedance transducer (7) connected between is equal, two output feeders (4) and incoming feeder (3) Between the width of quarter wavelength impedance transducer (7) that connects differ, in which:

The π type minor matters (5), including sequentially connected first transmission line (51), second transmission line (52) and third transmission line (53), the link position and second transmission line (52) and third in first transmission line (51) and second transmission line (52) transmit The link position of line (53) is connected separately with minor matters in parallel (54), and the other end of two minor matters (54) in parallel passes through short-circuit micro-band Line (55) is connected；

The short-circuit micro-band line (55) and isolation element (6) are connect by metallization VIA (8) with metal base plate (2) respectively.

2. the not equal function of four frequency bands according to claim 1 based on π type minor matters divide Gysel power splitter, which is characterized in that institute First transmission line (51), second transmission line (52) and minor matters (54) in parallel are stated, the quasi- U-shaped being made of five straight line micro-strips is all made of Type structure, the third transmission line (53) use the Z-shaped structure being made of three straight line micro-strips, and in first transmission line (51) Each straight line micro-strip is equal with the width of each straight line micro-strip in third transmission line (53), the first transmission line (51), the second transmission In line (52), third transmission line (53) and minor matters (54) in parallel, the junction of every two straight line micro-strip is provided with corner cut.

3. the not equal function of four frequency bands according to claim 1 based on π type minor matters divide Gysel power splitter, which is characterized in that institute Two π type minor matters (5) are stated, symmetry axis is overlapped with medium substrate (1) one side middle line.

4. the not equal function of four frequency bands according to claim 1 based on π type minor matters divide Gysel power splitter, which is characterized in that institute Incoming feeder (3) are stated, are located on the middle line on medium substrate (1) one side；Described two output feeders (4) are located at input feedback The two sides of line (3), and it is symmetrical about incoming feeder (3).