CN108539349B

CN108539349B - Spiral power divider based on medium integrated suspension line

Info

Publication number: CN108539349B
Application number: CN201810730462.7A
Authority: CN
Inventors: 马凯学; 冯婷; 王勇强
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2018-07-05
Filing date: 2018-07-05
Publication date: 2020-08-11
Anticipated expiration: 2038-07-05
Also published as: CN108539349A

Abstract

The invention discloses a spiral power divider based on a medium integrated suspension line, which is a 2-path power divider formed by mutually winding N regular octagonal coils, wherein N is a positive number greater than or equal to 1, a center tap is led out from the outermost circle of each regular octagonal coil and matched with 50 omega to serve as an input end of the power divider, two output ports are led out from the innermost circle of each regular octagonal coil, and a resistor is bridged between the two output ports for isolation. The wiring bent into the regular octagon spiral shape enables the power divider circuit to be highly integrated, the maximization of circuit board area utilization is achieved, odd-even mode impedance can be adjusted by adjusting the distance between the coils, and therefore the line width of the coils is adjusted, and the circuit is more compact. Excess medium outside the circuit coverage is cut away so that the TEM waves propagate primarily in the air cavity, thereby reducing dielectric losses.

Description

Spiral power divider based on medium integrated suspension line

Technical Field

The invention relates to the technical field of radio frequency microwave circuits, in particular to a spiral power divider based on a dielectric integrated suspension line.

Background

With the rapid development of modern wireless communication technology, the complexity of wireless devices and the requirement for portability are continuously increased, which puts higher requirements on miniaturization, low loss, high efficiency, low cost and the like of wireless communication devices. The power divider distributes the power of the input end to two or more output ports in equal proportion or unequal proportion, which has great significance for designing complex devices and systems such as dual-polarized antennas, power synthesis amplifiers and the like, and the realization of miniaturization, low loss and low cost of the power divider is the problem to be solved at present.

A common power divider includes: t type merit divides the ware, Gysel merit to divide the ware and Wilkinson merit to divide the ware, all designs based on quarter-wavelength transmission line. However, such a quarter wavelength length would occupy a considerable area on a printed circuit board or on a monolithic microwave integrated circuit. Designing a new power divider structure to replace the original quarter-wavelength transmission line is an important step for realizing miniaturization. In addition, for broadband requirements, the multi-section cascade of the power divider can bring large circuit loss.

Disclosure of Invention

The invention provides a regular octagonal spiral power divider based on a dielectric integrated suspension line, which realizes higher isolation, lower circuit loss, wider bandwidth and smaller circuit area while equally distributing power.

The invention is realized by the following technical scheme:

the spiral power divider based on the medium integrated suspension line comprises a spiral power divider and a medium integrated suspension line platform; the spiral power divider is a 2-path power divider and is formed by mutually winding N regular octagonal coils with the line width of W and the line spacing of S, N is a positive number greater than or equal to 1, and the outer radius of the outermost coil is R1; and (3) packaging and fixing the regular octagonal spiral power divider in an air cavity of the medium integrated suspension wire platform.

Specifically, the outermost coil of the spiral power divider is the 1 st turn, and sequentially comprises the 1 st turn, the 2 nd turn and the 3 rd turn … … Mth turn from outside to inside, wherein M is a positive integer which is greater than or equal to 1 and less than or equal to N, and when N is a decimal number, M is a positive integer which is greater than N and less than N + 1; selecting any side of the 1 st circle, and leading out a section of metal conduction band tap at the central point of the side to serve as an input port of the regular octagon spiral power divider and match the input port to 50 omega; cutting an opening with the length of G from the edge opposite to the edge where the input port is located in the 1 st circle, respectively cutting an opening with the length of G from the edge parallel to and adjacent to the edge of the opening of the 1 st circle and the edge opposite to the edge in the 2 nd circle, respectively cutting an opening with the length of G from the edge parallel to and adjacent to the edge of the opening of the 2 nd circle and the edge opposite to the edge in the 3 rd circle, respectively, and so on, respectively cutting an opening with the length of G from the edge parallel to and adjacent to the edge of the opening of the M-1 st circle and the edge opposite to the edge in the M-1 st circle, and bridging and interconnecting the M-1 st circle and the M-1 st circle through a section of metal bridge, so that two paths from the input end of the positive octagon spiral power divider are complete and uninterrupted, are wound from the 1 st circle to the M-th circle all the way, the two paths are respectively led out through two metal conduction bands to serve as two, the two output ports are isolated by a resistor R at the Mth circle.

Specifically, the line width W, the line spacing S, the opening length G, the outer radius R1 of the outermost coil, and the isolation resistance R are determined according to the operating frequency of the regular octagonal spiral power divider.

Specifically, the medium contact suspension line platform comprises 1 st to 5 th double-sided printed circuit boards which are sequentially laminated from top to bottom, metal layers are arranged on the front and the back of each layer of circuit board, and a medium is filled between the two metal layers of each layer of circuit board; the upper surface and the lower surface of the 3 rd layer circuit board are provided with the eight-sided spiral power divider circuit, the 2 nd layer circuit board and the 4 th layer circuit board are hollowed out corresponding to the 3 rd layer circuit part, and an air cavity structure can be formed between the 1 st layer circuit board and the 3 rd layer circuit board and between the 3 rd layer circuit board and the 5 th layer circuit board respectively.

Specifically, the third layer of circuit board is hollowed into a shape identical to the power divider circuit structure, and except for the supporting medium, the redundant medium is cut off.

Specifically, the intermediate mediums filled in the circuit boards of the 1 st layer to the 5 th layer are FR4, FR4, Rogers588Q, FR4 and FR4 in sequence, and the thicknesses are 0.6mm, 0.254mm, 0.6mm and 0.6mm in sequence.

The invention has the following advantages and beneficial effects:

the regular octagonal spiral power divider based on the dielectric integrated suspension line is formed by winding N regular octagonal coils with the line width of W and the line spacing of S, wherein N is a positive number greater than or equal to 1, the spiral mutually wound wires are bent into a regular octagon shape to enable the power divider circuit to be highly integrated, the area utilization of a circuit board is maximized, the coupling between the coils has an important influence on the odd-even mode impedance of the power divider, the purpose of adjusting the odd-even mode impedance can be achieved by adjusting the line spacing and the line width, higher characteristic impedance is obtained, the line width of the wires is reduced, and the whole circuit is more compact. By means of the self-packaging characteristic of the medium integrated suspension line, the regular octagonal spiral power divider circuit is sealed in the cavity surrounded by metal, good electromagnetic shielding is achieved, and radiation loss is effectively reduced. The medium integrated suspension line is used for transmitting a TEM mode, waves are mainly transmitted in the medium, a medium layer where the regular octagonal spiral power divider circuit is located is hollowed into a shape similar to a circuit structure, the redundant medium is cut off except for a supporting medium, and the circuit loss of the power divider is further reduced by a method for reducing the medium loss. Meanwhile, the regular octagonal spiral power divider based on the medium integrated suspension line has the characteristics of wide bandwidth, self-packaging, light weight, integrated integration, low cost and the like, and the cost performance of the regular octagonal spiral power divider is further improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

fig. 1 is a cross-sectional view of a regular octagon spiral power divider based on a dielectric integrated suspension line according to embodiment 1 of the present invention;

fig. 2 is a three-dimensional view of a regular octagonal spiral power divider based on a dielectric integrated suspension line according to embodiment 1 of the present invention;

fig. 3 is a top view of a layer 3 dielectric plate and a layer G5 metal of a regular octagon spiral power divider based on a dielectric integrated suspension line according to embodiment 1 of the present invention;

fig. 4 is a top view of a layer 3 dielectric plate and a layer G6 metal of a regular octagon spiral power divider based on a dielectric integrated suspension line according to embodiment 1 of the present invention;

fig. 5 is a simulation and test graph of a regular octagon spiral power divider based on a dielectric integrated suspension line according to embodiment 1 of the present invention;

fig. 6 is a cross-sectional view of a medium-cut regular octagon spiral power divider based on a medium integrated suspension line according to embodiment 2 of the present invention;

fig. 7 is a three-dimensional view of a medium-cut regular octagon spiral power divider based on a medium integrated suspension line according to embodiment 2 of the present invention;

fig. 8 is a top view of a layer 3 medium of a medium-cut regular octagon spiral power divider based on a medium integrated suspension line according to embodiment 2 of the present invention;

fig. 9 is a simulation and test graph of the dielectric-cut regular octagon spiral power divider based on the dielectric integrated suspension line according to embodiment 2 of the present invention;

fig. 10 is a comparison graph of insertion loss test curves of the octagon spiral power divider based on the dielectric integrated suspension line in embodiment 1 of the present invention and the dielectric-cut octagon spiral power divider based on the dielectric integrated suspension line in embodiment 2 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

Example 1

The embodiment discloses a medium integrated suspension line-based octagonal spiral power divider, as shown in fig. 1 and fig. 2, fig. 1 is a cross-sectional view of the medium integrated suspension line-based octagonal spiral power divider provided in embodiment 1 of the present invention, and fig. 2 is a three-dimensional view of the medium integrated suspension line-based octagonal spiral power divider provided in embodiment 1 of the present invention.

In this embodiment, the eight-sided spiral power divider based on the integrated suspension line of medium includes the integrated suspension line platform of medium, the integrated suspension line platform of medium includes 5 layers of top-down laminated double-sided printed circuit board, including 10 layers of metal layers altogether from G1 to G10, fill the medium between the two-sided metal of every layer of circuit board, the middle medium that the 1 st layer to 5 th layer of circuit board fill is FR4 in proper order, FR4, Rogers5880, FR4, FR4, thickness is 0.6mm in proper order, 0.6mm, 0.254mm, 0.6mm, 0.6 mm. The upper and lower two sides of the 3 rd layer circuit board, that is, the G5 and G6 metal layers, are designed with the regular octagonal spiral power divider circuit described in embodiment 1, and the middle of the 2 nd layer circuit board and the 4 th layer circuit board are respectively hollowed out, so that the 1 st layer circuit board and the 3 rd layer circuit board are ensured, and a cavity structure can be respectively formed between the 3 rd layer circuit board and the 5 th layer circuit board. Metal layers G2 and G9 act as signal ground for the suspension circuit. As shown in fig. 3 and fig. 4, fig. 3 is a top view of the layer 3 medium and the layer G5 of the octagon spiral power divider based on the dielectric integrated suspension line provided in embodiment 1 of the present invention, and fig. 4 is a top view of the layer 3 medium and the layer G6 of the octagon spiral power divider based on the dielectric integrated suspension line provided in embodiment 1 of the present invention. The regular octagonal spiral power divider in embodiment 1 of the present invention is a 2-way power divider, and is formed by winding 1.5 coils with a line width of W and a line spacing of S, from outside to inside, in sequence, the 1 st turn and the 2 nd turn have an outer radius of R1, and the 2 nd turn has an inner radius of R2. And selecting one side of the regular octagon in the 1 st circle, leading out a center tap as an input port of the power divider, and matching the input port to 50 omega. An opening with the length of G is cut at the edge opposite to the edge where the input Port1 is located, an opening with the length of G is cut at the edge which is adjacent to the edge of the opening of the 2 nd turn in parallel, one of two paths separated from the input Port is directly connected to the 2 nd turn through a metal conduction band D1, and the other path is bridged to the 2 nd turn through a metal conduction band D2 and 2 metal through holes V1 and V2. One path through the metal conduction band D1 is bridged and matched to 50 Ω by the metal conduction band D3 and 2 metal vias V5, V6 as an output Port 3. One path through the metal conduction band D2 is bridged and matched to 50 Ω by the metal conduction band D4 and 2 metal vias V3, V4 as an output Port 2. The two output ports Port2 and Port3 are isolated by a resistor with a resistance value R at the center of the regular octagon, so as to improve the isolation of the power divider. In particular, the metal conduction bands D2, D3 and D4 are distributed on the G6 layer.

The wiring bent into the regular octagon and spirally wound mutually enables the circuit of the power divider to be highly integrated, the maximization of circuit board area utilization is achieved, coupling between coils has an important influence on odd-even mode impedance of the power divider, the purpose of adjusting the odd-even mode impedance can be achieved by adjusting the coil distance and the line width, higher characteristic impedance is obtained, the wiring line width is reduced, and the whole circuit is compact. By means of the self-packaging characteristic of the medium integrated suspension line, the regular octagonal spiral power divider circuit is sealed in the cavity surrounded by metal, good electromagnetic shielding is achieved, and radiation loss is effectively reduced.

In this embodiment 1, the eight-sided spiral power divider based on the dielectric integrated suspension line operates at a center frequency of 2.5GHz, and the circuit parameters are as follows: w1.04 mm, S0.38 mm, G0.8 mm, R1 5.83mm, R2 3.17 mmmm, and R is 133 omega. The circuit size achieved is 0.39 lambda_g×0.24λ_g，λ_gThe circuit size is much smaller than in the prior art, being the guided wavelength at the center frequency. As shown in fig. 5, fig. 5 is a simulation and test graph of the eight-sided spiral power divider based on the dielectric integrated suspension line provided in this embodiment 1, and electromagnetic simulation and test results are well matched, where a fractional bandwidth corresponding to 15dB input/output return loss is 58.8%, a fractional bandwidth corresponding to 15dB isolation is 62.63%, and an in-band insertion loss is less than 0.3 dB.

Example 2

In order to further reduce circuit loss, the medium of the 3 rd-layer circuit board described in embodiment 1 is hollowed out to a shape similar to a circuit structure, and except for a supporting medium, an excess medium is cut off, as shown in fig. 6, 7, and 8, fig. 6 is a cross-sectional view of the medium-cut-off eight-sided spiral power divider of the medium-integrated suspension line described in embodiment 2, fig. 7 is a three-dimensional view of the medium-cut-off eight-sided spiral power divider of the medium-integrated suspension line described in embodiment 2, and fig. 8 is a top view of the layer 3 medium of the medium-cut-off eight-sided spiral power divider of the medium-integrated suspension line described in embodiment 2. The TEM mode is propagated in the dielectric integrated suspension line, the wave is mainly propagated in the medium, redundant medium outside the circuit is cut off, the TEM wave is propagated in the air cavity, and the relative dielectric constant of the air is smaller than that of the medium, so that the dielectric loss is reduced, and the overall loss of the circuit is reduced. As shown in fig. 9, fig. 9 is a simulation and test graph of the dielectric integrated suspended line forward octagon spiral power divider with dielectric ablation according to this embodiment 2, and electromagnetic simulation and test results are well matched, where a fractional bandwidth corresponding to 15dB input/output return loss is 62%, a fractional bandwidth corresponding to 15dB isolation is 61.39%, and in-band insertion loss is less than 0.2 dB. As shown in fig. 10, fig. 10 is a comparison graph of insertion loss curves of the regular octagonal spiral power divider described in example 1 and the regular octagonal spiral power divider after the medium is cut off described in example 2, and it can be seen that the circuit loss can be reduced by 0.1dB indeed after the extra medium is cut off in example 2.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The spiral power divider based on the medium integrated suspension line is characterized by comprising a spiral power divider and a medium integrated suspension line platform; the spiral power divider is a 2-path power divider and is formed by mutually winding N regular octagonal coils with the line width of W and the line spacing of S, N is a positive number greater than or equal to 1, and the outer radius of the outermost coil is R1; packaging and fixing the regular octagonal spiral power divider in an air cavity of the medium integrated suspension line platform; the outermost coil of the spiral power divider is a 1 st coil, and sequentially comprises a 1 st coil, a 2 nd coil and a 3 rd coil … … Mth coil from outside to inside, wherein M is a positive integer which is greater than or equal to 1 and less than or equal to N, and when N is a decimal number, M is a positive integer which is greater than N and less than N + 1; selecting any side of the 1 st circle, and leading out a section of metal conduction band tap at the central point of the side to serve as an input port of the regular octagon spiral power divider and match the input port to 50 omega; cutting an opening with the length of G from the edge opposite to the edge where the input port is located in the 1 st circle, respectively cutting an opening with the length of G from the edge parallel to and adjacent to the edge of the opening of the 1 st circle and the edge opposite to the edge in the 2 nd circle, respectively cutting an opening with the length of G from the edge parallel to and adjacent to the edge of the opening of the 2 nd circle and the edge opposite to the edge in the 3 rd circle, respectively, and so on, respectively cutting an opening with the length of G from the edge parallel to and adjacent to the edge of the opening of the M-1 st circle and the edge opposite to the edge in the M-1 st circle, and bridging and interconnecting the M-1 st circle and the M-1 st circle through a section of metal bridge, so that two paths from the input end of the positive octagon spiral power divider are complete and uninterrupted, are wound from the 1 st circle to the M-th circle all the way, the two paths are respectively led out through two metal conduction bands to serve as two, the two output ports are isolated by a resistor R at the Mth circle.

2. The spiral power divider based on the dielectric integrated suspension wire as claimed in claim 1, wherein the values of the line width W, the line spacing S, the opening length G, the outer radius R1 of the outermost coil and the isolation resistance R are determined according to the operating frequency of the regular octagonal spiral power divider.

3. The spiral power divider based on the dielectric integrated suspension wire of claim 1, wherein the dielectric contact suspension wire platform comprises 1 st to 5 th double-sided printed circuit boards which are laminated in sequence from top to bottom, the front and the back of each layer of circuit board are provided with metal layers, and a medium is filled between the metal layers on the two sides of each layer of circuit board; the upper surface and the lower surface of the 3 rd layer circuit board are provided with the eight-sided spiral power divider circuit, the 2 nd layer circuit board and the 4 th layer circuit board are hollowed out corresponding to the 3 rd layer circuit part, and an air cavity structure can be formed between the 1 st layer circuit board and the 3 rd layer circuit board and between the 3 rd layer circuit board and the 5 th layer circuit board respectively.

4. The spiral power divider based on the dielectric integrated suspension wire of claim 3, wherein the layer 3 circuit board is hollowed out to have the same shape as the power divider circuit structure, and the excess dielectric is cut off except for the supporting dielectric.

5. The spiral power divider based on the dielectric integrated suspension wire of claim 3, wherein the intermediate dielectric filled in the circuit boards from the 1 st layer to the 5 th layer is FR4, FR4, Rogers588Q, FR4 and FR4 in sequence, and the thicknesses are 0.6mm, 0.254mm, 0.6mm and 0.6mm in sequence.