SISL-based low-loss broadband one-to-four power divider

Abstract

The invention relates to the technical field of wireless communication, and discloses a low-loss broadband one-to-four power divider based on SISL. According to the technical scheme, the antenna is characterized by comprising a standard coaxial waveguide, a metal inductive impedance matching structure, a quarter impedance conversion strip line, a periodic electromagnetic band gap structure, a thin film dielectric plate, a metal cavity, an inductive matching diaphragm, an input and output transition structure and a metal microstrip line, through a method of placing an FPC printing strip line in a conventional metal cavity, the problems that a conventional cavity and a microstrip are large in power division loss and narrow in bandwidth are solved, and meanwhile the power division in the form is light in weight and large in bearable power; frequency bands above millimeter waves are easy to adapt to different microwave assemblies, a passive circuit and an active circuit can be designed on the structure at the same time, system integration is achieved, and the system integration degree of the microwave assembly is greatly improved; the overall processing has low requirements on precision and assembly, can effectively reduce the cost, and is suitable for different microwave system application scenes.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and more specifically, to a low-loss broadband one-to-four power divider based on SISL. Background Art

[0002] The broadband one-to-four power divider in the prior art has a large internal cavity, high microstrip power division loss, and a narrow bandwidth, which results in a large size and is difficult to integrate with other microwave components in the high-frequency millimeter wave frequency band and above, and cannot be applied to different microwave system application scenarios.

[0003] Therefore, the present invention provides a low-loss broadband one-to-four power divider based on SISL, which improves the above technical problems. Summary of the invention

[0004] The disclosed embodiments aim to address the deficiencies in the prior art and provide a low-loss broadband one-to-four power divider based on SISL. The present invention solves the problems of large loss and narrow bandwidth of conventional cavity and microstrip power dividers by placing FPC printed strip lines inside a conventional metal cavity. At the same time, this form of power divider is light in weight and can withstand large power. It is easy to adapt to different microwave components in frequency bands above millimeter waves, and passive circuits and active circuits can be designed on the structure at the same time to achieve system integration, greatly improving the system integration of microwave components. The overall processing does not have high requirements on precision and assembly, which can effectively reduce costs and is suitable for different microwave system application scenarios.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: a low-loss broadband one-to-four power divider based on SISL, comprising: a standard coaxial waveguide, a metal inductive impedance matching structure, a quarter impedance transformation strip line, a periodic electromagnetic bandgap structure, a thin film dielectric plate, a metal cavity, an inductive matching diaphragm, an input-output transition structure, and a metal microstrip line;

[0006] A quarter impedance transformation strip line is installed at the upper and lower ends of the metal cavity; the quarter impedance transformation strip lines at the upper and lower ends are connected to each other through a metal microstrip line;

[0007] A metal microstrip line with a T-shaped structure is installed on one side of the middle position inside the metal cavity, and the longitudinal ends of the metal microstrip line are located at the center position inside the metal cavity and are respectively connected to the quarter impedance transformation strip lines at the upper and lower ends;

[0008] Both ends of the quarter impedance transformation strip line are connected to standard coaxial waveguides;

[0009] The end of the metal microstrip line away from the metal inductive impedance matching structure is connected to a standard coaxial waveguide;

[0010] A periodic electromagnetic band gap structure is installed in the middle position of the metal cavity, and a metal inductive impedance matching structure is arranged near the center position of the metal cavity;

[0011] Inductive matching diaphragms are installed at the center of the quarter impedance transformation strip line and the longitudinal center of the metal microstrip line;

[0012] An input and output transition structure is installed at the standard coaxial waveguide connection;

[0013] A thin film dielectric plate is arranged between the quarter impedance transformation strip line and the inner wall of the metal cavity.

[0014] As a preferred technical solution of the present invention, the signal is first input through a standard coaxial waveguide, and then transmitted along the metal microstrip line and the inside of the metal cavity in the form of a quasi-TEM mode; the quasi-TEM mode finally generated is transmitted to the output port through a specially designed T-shaped structure, and the four signals with equal amplitude and direction are transmitted through a quarter impedance transformation strip line.

[0015] As a preferred technical solution of the present invention, the thin film dielectric plate is embedded in the metal cavity and suspended in the air cavity formed by the metal cavity. The heights of the upper and lower air cavities are H c、 H b , the thickness of the middle thin film dielectric plate is H s And the dielectric constant is ε r , the width of the cavity is b, the height is a, and the boundary conditions are ideal metal conductor boundary conditions; according to the different ranges of the ratio of the conduction band width to the cavity height ρ0, the narrow conduction band and the wide conduction band are calculated.

[0016] As a preferred technical solution of the present invention, the narrow conduction band calculation formula is:

[0017]

[0018] a=H c +H b +H s

[0019]

[0020] V0=1.7886-0.2035ρ c +0.475ρ r

[0021] R0=1.0835+0.1007ρ s -0.9457ρ r

[0022] E0=0.2077+1.2177ρs -0.08364ρ r

[0023] F0=0.03451-0.1031ρ s +0.01742ρ r

[0024] Where Z0 represents the characteristic impedance of the suspended strip line, ε eff Represents the equivalent dielectric constant.

[0025] As a preferred technical solution of the present invention, the calculation formula of the wide conduction band is:

[0026]

[0027] V0=-0.6301-0.07028ρ c +0.494ρ r

[0028] R0=1.9492+0.1553ρ c -0.5123ρ r

[0029] E0=0.464+0.9647ρ c -0.2063ρ r

[0030] F0=-0.1424-0.3017ρ c -0.02411ρ r

[0031] Comparison of the results calculated using the finite difference method shows that the accuracy of the impedance and dielectric constant of the wide conduction band is within ±3%, while the accuracy of the impedance and dielectric constant of the narrow conduction band is within ±2%.

[0032] In summary, the present invention has the following beneficial effects:

[0033] First, wide bandwidth; it adopts a new low-loss broadband one-to-four power splitter based on SISL technology, which can work normally at three or even five times the frequency.

[0034] Second, the integration is high; passive circuits and active circuits can be designed on this structure at the same time to achieve system integration with a high integration level.

[0035] Third, it has self-packaging characteristics and good electromagnetic compatibility performance; the air cavity is shielded by metallized through holes, and when multiple circuits are integrated together, there is less mutual interference.

[0036] Fourth, it has small size and compact structure. The miniaturization problem is solved by loading, stacking and other measures. When connected and integrated with other electrical systems, part of the circuit can be placed at the bottom or top of the multi-layer substrate, making the overall structure more compact.

[0037] Fifth, low loss; in order to ensure the purity of electromagnetic wave transmission inside the cavity, that is, not introducing other modes of electromagnetic wave transmission, by adding inductive matching diaphragms, it is fully guaranteed that the electromagnetic wave mode remains unchanged during transmission, so no dielectric loss will occur.

[0038] Sixth, the design is highly flexible; the new low-loss broadband one-to-four power splitter based on SISL technology can be used for network topology design, and the two cavities can be used flexibly, which is very effective for the design of multi-layer structures and stacked antennas.

[0039] Seventh, it can withstand large power; electromagnetic waves are transmitted inside the cavity in a quasi-TEM mode, and the energy is confined inside the cavity and transmitted along the metal microstrip line and the cavity in the form of a quasi-TEM mode. The power it can withstand is equivalent to that of a conventional rectangular waveguide. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A three-dimensional exploded diagram of the internal structure of a SISL low-loss broadband one-to-four power divider provided in an embodiment of the present invention;

[0041] Figure 2 A schematic top view of the internal structure of a SISL low-loss broadband one-to-four power divider provided in an embodiment of the present invention;

[0042] Figure 3 A schematic diagram of a thin film dielectric plate provided in an embodiment of the present invention in a metal housing;

[0043] Figure 4 A schematic diagram of a thin film dielectric plate provided in an embodiment of the present invention in a metal waveguide housing;

[0044] Figure 5 and Figure 6 An electric field distribution diagram provided by an embodiment of the present invention;

[0045] Figure 7 A standing wave curve diagram provided by an embodiment of the present invention;

[0046] Figure 8 Insertion loss curve diagram provided for an embodiment of the present invention;

[0047] Fig. 9 An output port phase curve diagram provided by an embodiment of the present invention;

[0048] In the figure: standard coaxial waveguide 1, metal inductive impedance matching structure 2-3, quarter impedance transformation strip line 4, periodic electromagnetic bandgap structure 5, thin film dielectric plate 6, metal cavity 7, inductive matching diaphragm 8-9, input-output transition structure 10, metal microstrip line 11. DETAILED DESCRIPTION

[0049] The present application is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements can also be made without departing from the concept of the present application. These all belong to the protection scope of the present application.

[0050] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] It should be noted that, if there is no conflict, the various features in the embodiments of the present application can be combined with each other, all within the scope of protection of the present application. In addition, although the functional module division is performed in the device schematic diagram and the logical order is shown in the flow chart, in some cases, the steps shown or described can be performed in a sequence different from the module division in the device or the flow chart. In addition, the words "first", "second", "third", etc. used herein do not limit the data and execution order, but only distinguish the same items or similar items with basically the same functions and effects.

[0052] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification and in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0053] In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0054] The disclosed embodiments are intended to solve the problems of large internal cavity, high microstrip power division loss and narrow bandwidth of broadband one-to-four power dividers in the prior art. In view of this, the disclosed embodiments propose a low-loss broadband one-to-four power divider based on SISL, which solves the problems of large loss and narrow bandwidth of conventional cavities and microstrip power dividers by placing FPC printed strip lines inside conventional metal cavities. At the same time, this form of power divider is light in weight and can withstand high power; it is easy to adapt to different microwave components in frequency bands above millimeter waves, and passive circuits and active circuits can be designed on the structure at the same time to achieve system integration, greatly improving the system integration of microwave components; the overall processing does not require high precision and assembly, which can effectively reduce costs and is suitable for different microwave system application scenarios.

[0055] Please refer to Figure 1-2 , Figure 1-2 The schematic diagram of the structure of the SISL low-loss broadband one-to-four power divider according to the embodiment of the present disclosure is shown. The power divider includes: a standard coaxial waveguide 1, a metal inductive impedance matching structure 2-3, a quarter impedance transformation strip line 4, a periodic electromagnetic bandgap structure 5, a thin film dielectric plate 6, a metal cavity 7, an inductive matching diaphragm 8-9, an input-output transition structure 10, and a metal microstrip line 11 in a T-shaped structure.

[0056] A quarter impedance transformation strip line 4 is installed at the upper and lower ends of the metal cavity 7; the quarter impedance transformation strip lines 4 at the upper and lower ends are connected to each other through a metal microstrip line 11;

[0057] A metal microstrip line 11 with a T-shaped structure is installed on one side of the middle position inside the metal cavity 7. The two longitudinal ends of the metal microstrip line 11 are located at the center position inside the metal cavity 7 and are respectively connected to the quarter impedance transformation strip line 4 at the upper and lower ends;

[0058] The two ends of the quarter impedance transformation strip line 4 are connected to a standard coaxial waveguide 1;

[0059] One end of the metal microstrip line 11 away from the metal inductive impedance matching structure 2-3 is connected to a standard coaxial waveguide 1;

[0060] A periodic electromagnetic band gap structure 5 is installed in the middle position inside the metal cavity 7, and a metal inductive impedance matching structure 2-3 is arranged near the center position of the periodic electromagnetic band gap structure 5;

[0061] Inductive matching diaphragms 8-9 are installed at the center of the quarter impedance transformation strip line 4 and the longitudinal center of the metal microstrip line 11;

[0062] An input-output transition structure 10 is installed at the connection of the standard coaxial waveguide 1 .

[0063] A thin film dielectric plate 6 is arranged between the quarter impedance transformation strip line 4 and the inner wall of the metal cavity 7 .

[0064] The electromagnetic wave signal is input through the standard coaxial waveguide 1, and is transmitted inside the cavity along the metal microstrip line 11 in the form of a quasi-TEM mode. The quasi-TEM mode generated at this time transmits four signals of equal amplitude and direction to the output port through a specially designed T-shaped structure through a quarter impedance transformation strip line 4.

[0065] The input and output interfaces are both standard coaxial waveguide 1, which can be directly connected to different types of millimeter-wave modules. If connected to the RF chip, just remove the standard coaxial waveguide 1 and connect directly to the 50Ω pin of the RF chip without the need for additional matching circuits.

[0066] The metal microstrip line 11 realizes broadband or even ultra-broadband impedance matching by means of a multi-stage quarter impedance transformation strip line 4. In order to ensure the purity of electromagnetic waves transmitted inside the cavity, that is, no additional electromagnetic wave transmission forms of other modes are introduced. At this time, by adding the inductive matching diaphragms 8-9, it is ensured that the electromagnetic wave mode remains unchanged during the transmission process, so no dielectric loss will be generated.

[0067] By increasing the order of the quarter impedance transformation strip line to 4, the present invention can be realized to work normally at a frequency multiplied by three to five times or more.

[0068] The signal is input through the main port, and after the mode conversion of the coaxial waveguide TEM mode to the quasi-TEM mode to the coaxial waveguide TEM mode is completed, the signal is output from four equal-amplitude and in-phase output ports, thereby completing the signal distribution.

[0069] During the process of the signal being divided into two and four, the impedance characteristics inside the cavity change accordingly. Improper handling will cause impedance mismatch and other situations, and there is no regularity to summarize the mismatch, which will cause the entire device to be unable to be used normally and cannot be eliminated normally. In order to solve this problem, a metal inductive impedance matching structure 2-3 and an inductive matching diaphragm 8-9 are added in the middle of each one-to-two split to eliminate the mismatch caused by the electromagnetic wave signal in the transmission process inside the cavity and the influence of additional high-order modes on the electrical channel.

[0070] The thin film dielectric plate 6 is embedded in the metal cavity 7 and suspended in the air cavity formed by the metal cavity. Figure 3 As shown. The heights of the upper and lower air cavities are H c、 H b , the thickness of the middle thin film dielectric plate 6 is H s And the dielectric constant is ε r , the width of the cavity is b, the height is a, and the boundary conditions are ideal metal conductor boundary conditions. However, in practical applications, the metal outer surface of the suspension line is generally realized by a metal waveguide shell, such as Figure 4As shown, the metal microstrip line 11 is printed on a very thin FPC, and during the signal transmission process, the current is transmitted along the metal microstrip line 11 in a direction.

[0071] According to the different ranges of the ratio of conduction band width to cavity height ρ0, the narrow conduction band and the wide conduction band are calculated;

[0072] Specifically, a narrow conduction band (0<ρ0<0.5)

[0073]

[0074] a=H c +H b +H s

[0075]

[0076] V0=1.7886-0.2035ρ c +0.475ρ r

[0077] R0=1.0835+0.1007ρ s -0.9457ρ r

[0078] E0=0.2077+1.2177ρ s -0.08364ρ r

[0079] F0=0.03451-0.1031ρ s +0.01742ρ r

[0080] Where Z0 represents the characteristic impedance of the suspended strip line, ε eff Represents the equivalent dielectric constant.

[0081] Specifically, a wide conduction band (0.5<ρ0<1)

[0082]

[0083] V0=-0.6301-0.07028ρ c +0.494ρ r

[0084] R0=1.9492+0.1553ρ c -0.5123ρ r

[0085] E0=0.464+0.9647ρ c -0.2063ρ r

[0086] F0=-0.1424-0.3017ρ c -0.02411ρ r

[0087] Comparison of the results calculated using the finite difference method shows that the accuracy of the impedance and dielectric constant of the wide conduction band is within ±3%, while the accuracy of the impedance and dielectric constant of the narrow conduction band is within ±2%.

[0088] like Figure 5-6 As shown, when the air gap between the upper and lower cover plates is less than a quarter wavelength, the periodic structure can exhibit PMC characteristics, that is, the out-of-band electromagnetic waves will be completely suppressed in this area outside the frequency band. This characteristic meets the requirements of electromagnetic wave propagation for the cutoff frequency. This characteristic allows the electromagnetic waves to be transmitted along the metal microstrip line 11 and the inside of the cavity in the form of a quasi-TEM mode; at the same time, since the structure does not introduce additional electromagnetic wave transmission forms of other modes, it fully ensures that the electromagnetic wave mode remains unchanged during the transmission process, so no dielectric loss will be generated; in addition, the structural feature is the use of a photolithography printing process. Under the same processing accuracy conditions, the power division structure designed in this article has higher tolerance performance and lower loss.

[0089] Examples, such as Figure 7-9 As shown, the simulation results show that the electromagnetic wave has high purity in the signal channel transmission, and will not introduce other modes, so that the electromagnetic wave is transmitted along the metal microstrip line 11 and the inside of the cavity in the form of quasi-TEM mode; at the same time, since the structure does not introduce other modes of electromagnetic wave transmission, it fully ensures that the electromagnetic wave mode remains unchanged during the transmission process, so no dielectric loss will be generated. The output port phase is highly overlapped, indicating that the path from the input port to the output port is completely consistent; the present invention can completely cover the 10-16GHz frequency band, which is of great significance to the Ku-band satellite communication system.

[0090] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A low-loss broadband one-to-four power divider based on SISL, characterized in that: The broadband one-to-four power divider comprises: a standard coaxial waveguide (1), a metal inductive impedance matching structure (2-3), a quarter impedance transformation strip line (4), a periodic electromagnetic bandgap structure (5), a thin film dielectric plate (6), a metal cavity (7), an inductive matching diaphragm (8-9), an input-output transition structure (10), and a metal microstrip line (11); A quarter impedance transformation strip line (4) is installed at the upper and lower ends of the metal cavity (7); the quarter impedance transformation strip lines (4) at the upper and lower ends are connected to each other via a metal microstrip line (11); A metal microstrip line (11) with a T-shaped structure is installed on one side of the middle position inside the metal cavity (7), and the longitudinal ends of the metal microstrip line (11) are located at the center position inside the metal cavity (7) and are respectively connected to the quarter impedance transformation strip lines (4) at the upper and lower ends; Both ends of the quarter impedance transformation strip line (4) are connected to a standard coaxial waveguide (1); One end of the metal microstrip line (11) away from the metal inductive impedance matching structure (2-3) is connected to a standard coaxial waveguide (1); A periodic electromagnetic bandgap structure (5) is installed in the middle position inside the metal cavity (7), and a metal inductive impedance matching structure (2-3) is arranged near the center position of the metal cavity (7) on the periodic electromagnetic bandgap structure (5); Inductive matching diaphragms (8-9) are installed at the center position of the quarter impedance transformation strip line (4) and the longitudinal center position of the metal microstrip line (11); An input-output transition structure (10) is installed at the connection of the standard coaxial waveguide (1); A thin film dielectric plate (6) is provided between the quarter impedance transformation strip line (4) and the inner wall of the metal cavity (7).

2. According to claim 1, a SISL low-loss broadband one-to-four power splitter is characterized in that: The signal is first input through a standard coaxial waveguide (1), and then transmitted through the metal cavity (7) in the form of a quasi-TEM mode along a metal microstrip line (11) and the inside of the metal cavity (7); the quasi-TEM mode generated finally transmits four signals of equal amplitude and direction to an output port through a specially designed T-shaped structure via a quarter impedance transformation strip line (4).

3. The SISL low-loss broadband one-to-four power divider according to claim 1, characterized in that: The thin film dielectric plate (6) is embedded in the metal cavity (7) and suspended in the air cavity formed by the metal cavity. The heights of the upper and lower air cavities are H and H respectively. c、 H b The thickness of the middle thin film dielectric plate (6) is H s And the dielectric constant is ε r , the width of the cavity is b, the height is a, and the boundary conditions are ideal metal conductor boundary conditions; according to the different ranges of the ratio of the conduction band width to the cavity height ρ0, the narrow conduction band and the wide conduction band are calculated.

4. The SISL low-loss broadband one-to-four power divider according to claim 3, characterized in that: The formula for calculating the narrow conduction band is: a=H c +H b +H s V0=1.7886-0.2035ρ c +0.475r r R0=1.0835+0.1007ρ s -0.9457r r E0=0.2077+1.2177ρ s -0.08364r r F0=0.03451-0.1031ρ s +0.01742r r Where Z0 represents the characteristic impedance of the suspended strip line, ε eff Represents the equivalent dielectric constant.

5. The SISL low-loss broadband one-to-four power divider according to claim 3, characterized in that: The calculation formula for the wide conduction band is: V0=-0.6301-0.07028ρ c +0.494r r R0=1.9492+0.1553ρ c -0.5123r r E0=0.464+0.9647ρ c -0.2063r r F0=-0.1424-0.3017ρ c -0.02411r r Comparison of the results calculated using the finite difference method shows that the accuracy of the impedance and dielectric constant of the wide conduction band is within ±3%, while the accuracy of the impedance and dielectric constant of the narrow conduction band is within ±2%.

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