Ultra-wideband microstrip coupler with small size and low insertion loss

Abstract

The utility model relates to an ultra-wideband microstrip coupler with small volume and low insertion loss. The ultra-wideband microstrip coupler comprises a microstrip layer, a rectangular dielectric substrate and a metal floor in sequence from top to bottom. Compared with a traditional microstrip coupling line coupler, the isolation port of the coupler provided by the utility model is directly grounded and is not connected with the load, so that the flatness of the coupler can be greatly improved under the condition that the size of the original coupler is basically unchanged.

Description

Technical Field

[0001] This utility model belongs to the field of microstrip device technology, specifically relating to an ultra-wideband, small-volume, low-insertion-loss microstrip coupler. Background Technology

[0002] A major problem with microstrip line couplers is their narrow bandwidth and large gain fluctuations. Due to the use of quarter-wavelength coupling lines, the fluctuation amplitude is significant when operating across octaves and in ultra-wideband applications. Various methods have been employed to improve the flatness of microstrip couplers, primarily through multi-stage cascading of coupling lines, stripline coupling, and the addition of cross-toe capacitors. Cascading multiple coupling lines to achieve ultra-wideband performance is a common and effective method, using coupling lines of varying lengths and spacings. However, its biggest drawback is its large size; often four or more stages are needed to achieve satisfactory results, especially at low frequencies. Therefore, this method sacrifices size for ultra-wideband performance. Stripline couplers essentially achieve ultra-wideband performance through multi-stage cascading of coupling lines. However, due to their multi-layer substrate construction, they offer little advantage in terms of cost and size. Adding cross-toe capacitors can improve the flatness of all microstrip or stripline couplers. This is achieved by designing cross-toe capacitors on both sides of the coupling line to enhance coupling and improve flatness. However, this method has limited effectiveness compared to the previous two methods and is generally used as an auxiliary improvement to other methods. In other words, existing microstrip coupled antennas cannot meet the requirements of small size and low differential loss.

[0003] Therefore, there is an urgent need for an ultrawideband, small-volume, low-insertion-loss microstrip coupler. Utility Model Content

[0004] To address the aforementioned problems in the existing technology, this utility model proposes an ultra-wideband, small-volume, low-insertion-loss microstrip coupler. The specific technical solution is as follows:

[0005] This invention provides an ultrawideband, small-volume, low-insertion-loss microstrip coupler, which includes a microstrip layer, a dielectric substrate, and a metal ground plane.

[0006] The microstrip layer includes an input port microstrip, a through-output port microstrip, an upper coupling microstrip, a lower coupling microstrip, a ground via, a ground microstrip, and a coupled output port microstrip;

[0007] The left end of the upper coupling microstrip is connected to the input port microstrip, and the right end of the upper coupling microstrip is connected to the through output port microstrip; the upper end of the ground microstrip is connected to the left end of the lower coupling microstrip, and the right end of the lower coupling microstrip is connected to the upper end of the coupling output port microstrip; the ground via penetrates the rectangular dielectric substrate, the upper end of the ground via is connected to the lower end of the ground microstrip, and the lower end of the ground via is connected to the metal ground plane.

[0008] In another embodiment of this utility model, the grounding microstrip and the lower coupling microstrip are arranged at a 90-degree angle; the lower coupling microstrip and the coupling output port microstrip are arranged at a 90-degree angle.

[0009] In another embodiment of this utility model, the dielectric plate is a single-layer dielectric plate or a multi-layer dielectric plate.

[0010] In another embodiment of this utility model, the dielectric substrate is a Rogress 5880 substrate with a thickness of 0.254 mm and a dielectric constant of 2.2.

[0011] In another embodiment of this invention, the spacing between the upper coupling microstrip and the lower coupling microstrip is determined based on the required coupling degree.

[0012] In another embodiment of this utility model, the dielectric substrate has the same shape and area as the metal floor.

[0013] In another embodiment of this invention, the microstrip layer is made of copper.

[0014] In another embodiment of this utility model, the material of the metal floor is copper.

[0015] The beneficial effects of this utility model are as follows:

[0016] This invention discloses an ultra-wideband, small-volume, low-insertion-loss microstrip coupler, whose structure comprises three layers from top to bottom: a microstrip layer, a rectangular dielectric substrate, and a metal ground plane. Compared to traditional microstrip coupled-line couplers, the isolation port of this invention is directly grounded and not connected to the load, thus significantly improving the flatness of the coupler while maintaining essentially the same coupler size. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the microstrip coupler in an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the simulation results of the microstrip coupler in the embodiments of this utility model;

[0019] Among them, 1. Microstrip layer; 2. Rectangular dielectric substrate; 3. Metal ground plane; 10. Input port microstrip; 11. Upper coupling microstrip; 12. Through output port microstrip; 13. Ground via; 14. Ground microstrip; 15. Lower coupling microstrip; 16. Coupled output port microstrip. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this specification clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments in this specification, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this document.

[0021] The following combination Figure 1-2 This specification provides a detailed description of the technical solutions provided in each embodiment. Specific Implementation Example 1:

[0023] To address the aforementioned problems in the existing technology, this utility model proposes an ultra-wideband, small-volume, low-insertion-loss microstrip coupler. The specific technical solution is as follows:

[0024] This invention provides an ultrawideband, small-volume, low-insertion-loss microstrip coupler, which includes a microstrip layer, a dielectric substrate, and a metal ground plane.

[0025] The microstrip layer includes an input port microstrip, a through-output port microstrip, an upper coupling microstrip, a lower coupling microstrip, a ground via, a ground microstrip, and a coupled output port microstrip;

[0026] The left end of the upper coupling microstrip is connected to the input port microstrip, and the right end of the upper coupling microstrip is connected to the through output port microstrip; the upper end of the ground microstrip is connected to the left end of the lower coupling microstrip, and the right end of the lower coupling microstrip is connected to the upper end of the coupling output port microstrip; the ground via penetrates the rectangular dielectric substrate, the upper end of the ground via is connected to the lower end of the ground microstrip, and the lower end of the ground via is connected to the metal ground plane.

[0027] In another embodiment of this utility model, the grounding microstrip and the lower coupling microstrip are arranged at a 90-degree angle; the lower coupling microstrip and the coupling output port microstrip are arranged at a 90-degree angle.

[0028] In another embodiment of this utility model, the dielectric plate is a single-layer dielectric plate or a multi-layer dielectric plate.

[0029] In another embodiment of this utility model, the dielectric substrate is a Rogress 5880 substrate with a thickness of 0.254 mm and a dielectric constant of 2.2.

[0030] In another embodiment of this invention, the spacing between the upper coupling microstrip and the lower coupling microstrip is determined based on the required coupling degree.

[0031] In another embodiment of this utility model, the dielectric substrate has the same shape and area as the metal floor.

[0032] In another embodiment of this invention, the microstrip layer is made of copper.

[0033] In another embodiment of this utility model, the material of the metal floor is copper. Specific Implementation Example 2:

[0035] This embodiment provides an ultrawideband, small-volume, low-insertion-loss microstrip coupler, the schematic diagram of which is shown below. Figure 1 As shown, the microstrip layer 1, the rectangular dielectric substrate 2, and the metal ground plane 3 are tightly stacked from top to bottom; specifically, they include:

[0036] Microstrip layer 1 includes an input port microstrip 10, a through-output port microstrip 12, an upper coupling microstrip 11, a lower coupling microstrip 15, a ground via 13, a ground microstrip 14, and a coupled output port microstrip 16; wherein,

[0037] The left and right ends of the upper coupling microstrip 11 are connected to the input port microstrip 10 and the through output port microstrip 12, respectively; the upper end of the ground microstrip 14 is connected to the left end of the lower coupling microstrip 15, and the two are arranged at a 90-degree angle; the right end of the lower coupling microstrip 15 is connected to the upper end of the coupling output port microstrip 16, and the two are arranged at a 90-degree angle; the ground via 13 penetrates the rectangular dielectric substrate 2, and its upper end is connected to the lower end of the ground microstrip 14, and its lower end is connected to the metal ground plane 3.

[0038] In this embodiment, the metal floor 3 is rectangular and has the same size as the rectangular dielectric substrate 2;

[0039] In this embodiment, during operation, the radio frequency signal flows in from the input port microstrip 10. After passing through the upper coupling microstrip 11, most of the signal is output through the direct output port microstrip 12. A small portion of the signal is coupled and then split into two parts, which flow to the left and right ends of the lower coupling microstrip 15 respectively. The signal flowing to the left end flows through the ground microstrip 14 and is then reflected by the ground via 13 before flowing back to the ground microstrip 14 and the lower coupling microstrip 15. It is then superimposed with another part of the signal that flows to the coupling output port microstrip 16 after coupling. The superimposed signal is finally output from the coupling output port microstrip 16.

[0040] The equalizer described in this embodiment operates in the 6–18 GHz range. The substrate used in the simulation is a Rogress 5880 substrate with a thickness of 0.254 mm and a dielectric constant of 2.2. The simulation results are as follows: Figure 2 As shown, the insertion loss of this microstrip coupler is less than 0.2dB, the maximum insertion loss at the coupling end is 21.18dB, the minimum insertion loss is 19.97dB, its gain ripple is only 1.21dB, and its return loss is better than 21.9dB. Compared with traditional single-section coupled-line microstrip couplers, its flatness is improved by about 3dB. The isolation port of the microstrip coupler described in this embodiment is directly grounded and not connected to the load, which greatly improves the flatness of the coupler while keeping the original coupler size basically unchanged, and also has the advantages of low insertion loss and good return.

[0041] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of this invention, and should be understood that the scope of protection of this invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on these technical teachings disclosed in this invention without departing from the essence of this invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. An ultra-wideband small size low insertion loss microstrip coupler characterized in that, The microstrip coupler comprises a microstrip layer, a dielectric substrate and a metal ground plate. The microstrip layer comprises an input port microstrip, a straight-through output port microstrip, an upper coupling microstrip, a lower coupling microstrip, a grounding via, a grounding microstrip and a coupling output port microstrip. The left end of the upper coupling microstrip is connected with the input port microstrip, and the right end of the upper coupling microstrip is connected with the straight-through output port microstrip; the upper end of the grounding microstrip is connected with the left end of the lower coupling microstrip, and the right end of the lower coupling microstrip is connected with the upper end of the coupling output port microstrip; the grounding via penetrates through the dielectric substrate, the upper end of the grounding via is connected with the lower end of the grounding microstrip, and the lower end of the grounding via is connected with the metal ground plate.

2. An ultra-wideband microstrip coupler of small size and low insertion loss as claimed in claim 1, characterized in that, The grounding microstrip and the lower coupling microstrip are arranged at a 90-degree angle, and the lower coupling microstrip and the coupling output port microstrip are arranged at a 90-degree angle.

3. An ultra-wideband microstrip coupler of small size and low insertion loss as recited in claim 1, characterized in that, The dielectric substrate is a single-layer dielectric plate or a multi-layer dielectric plate.

4. An ultra-wideband, small size, low insertion loss microstrip coupler as recited in claim 1, wherein, The dielectric substrate adopts a Rogress 5880 substrate with a thickness of 0.254 mm and a dielectric constant of 2.

2.

5. An ultra-wideband, small size, low insertion loss microstrip coupler as recited in claim 1, wherein, The interval between the upper coupling microstrip and the lower coupling microstrip is determined based on the required coupling degree.

6. An ultra-wideband, small size, low insertion loss microstrip coupler as recited in claim 1, wherein, The dielectric substrate and the metal ground plate have the same shape and area size.

7. An ultra-wideband microstrip coupler of small size and low insertion loss as defined in claim 1, wherein, The microstrip layer is made of copper.

8. An ultra-wideband small size low insertion loss microstrip coupler as recited in claim 1, wherein, The metal ground plate is made of copper.

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