Microstrip directional coupler
Through the microstrip directional coupler designed with a single-layer microstrip circuit, the problems of high flatness and high power capacity in the miniaturized design are solved, and high-efficiency RF signal transmission in the 2.5GHz~6GHz frequency band are achieved, reducing costs and reducing equipment volume.
Patent Information
- Application Number
- CN202422216493.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-10
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-09-10
AI Technical Summary
The prior art is difficult to achieve high flatness and high power capacity directional couplers in the 2.5GHz to 6GHz frequency band in miniaturized design, and the devices on the market are costly and have a long supply cycle, which cannot meet the development needs of RF projects.
The single-layer microstrip circuit design is adopted, including a microstrip directional coupling structure, and the interlaced setting of the first and second toothed structures and the adjustment of the microstrip line width are optimized to optimize the amplitude and directionality of the coupling signal, so as to realize the size of the microstrip directional coupler within the preset size, combining the microstrip coupling method and lumped parameter elements to meet the ultra-wideband working requirements.
It realizes 150 watt continuous wave RF power transmission in the 2.5GHz~6GHz frequency band, with directionality better than -18dBc, in-band flatness ≤±1dB, in-band insertion loss ≤0.3dB, volume smaller than traditional products, and cost lower than similar devices in the market.
Smart Images
Figure CN223066445U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of couplers, in particular to a microstrip directional coupler. Background Art
[0002] In the 21st century, the fields of radio frequency communication and electronic countermeasures have developed rapidly. With the rapid development of ground digital communication and electronic countermeasures in the 2.5GHZ~6GHZ frequency band, more and more radio frequency applications in the 2.5GHZ~6GHZ frequency band have been developed. At the end of the transmitting component part inside the radio frequency application product system, a directional coupler with high output power and high flatness is often required for output signal acquisition and detection circuit. The detection circuit is widely used in important circuits such as closed-loop power control and output standing wave mismatch protection. As the miniaturization requirements of electronic product development become more and more prominent, the requirements for power capacity and working bandwidth are also increasing. In addition, it is difficult to find suitable devices on the market, and their purchase cost and long and uncertain supply cycle will also cause certain risks to project planning control. According to the prediction of current and future markets and product applications, there is a need for a high-flatness radio frequency directional coupler with a working bandwidth covering the entire 2.5GHZ~6GHZ frequency band and a radio frequency power capacity of more than 150 watts.
[0003] At present, the main broadband directional couplers on the market use multi-section coupling to achieve broadband power coupling functions, while ensuring that their performance indicators meet the requirements of customized projects. Due to its structural limitations, this type of coupler often has a larger volume with the ability to pass high power, while a smaller volume cannot pass high power. If the indicators need to meet the requirements of a wider working bandwidth, the circuit volume will also increase accordingly, which runs counter to the direction of miniaturization design. In addition, the broadband high-power directional coupler devices on the market have a certain price cost, which invisibly increases the development cost of related RF projects. Utility Model Content
[0004] The utility model aims to overcome the deficiencies of the prior art and provide a microstrip directional coupler.
[0005] The object of the present utility model is achieved through the following technical solutions: A microstrip directional coupler adopts a single-layer microstrip circuit and includes a microstrip directional coupling structure. The microstrip directional coupling structure includes a microstrip coupling structure. The microstrip coupling structure includes a first toothed structure. Multiple segments of toothed microstrip structures are arranged on the first toothed structure, and the distance between each toothed microstrip structure is a preset distance; a second toothed structure is arranged opposite to the first toothed structure, and multiple segments of toothed microstrip structures with the same number as the first toothed structure are arranged in a staggered manner on the second toothed structure, so as to balance the coupling amplitude; microstrip lines are connected to both ends of the first toothed structure and the second toothed structure. The line widths of the microstrip lines at the four ports decrease after entering the first toothed structure and the second toothed structure, so as to optimize the port standing wave; the cross depth of the toothed microstrip structures on the first toothed structure and the second toothed structure is a preset depth, and the length is a preset length, so that the size of the microstrip directional coupler is within a preset size; the first toothed structure and the second toothed structure are used to balance the coupling signal amplitude and optimize the coupling signal directivity.
[0006] Preferably, the preset size is 12.01 mm * 4.94 mm.
[0007] Preferably, the line widths of the microstrip lines at the four ports of the first toothed structure and the second toothed structure are 1.1 mm before entering the first toothed structure and the second toothed structure, and 1 mm after entering.
[0008] Preferably, the preset depth is 0 mm, the preset length is 0.9 mm, the preset distance is 0.31 mm, and 7 segments of toothed microstrip structures are arranged on both the first toothed structure and the second toothed structure.
[0009] Preferably, it further includes a microstrip directional coupling circuit. The microstrip directional coupling circuit includes a signal input port, a coupler, a radio frequency output load port, a signal attenuation circuit, a radio frequency power signal coupling output port, and a coupler isolation port. The coupler is respectively connected to the signal input port, the radio frequency output load port, the signal attenuation circuit, and the coupler isolation port. The signal attenuation circuit is connected to the radio frequency power signal coupling output port. The signal input port, the radio frequency output load port, the radio frequency power signal coupling output port, and the coupler isolation port are respectively grounded after passing through a load; the microstrip directional coupling circuit operates in a preset frequency band.
[0010] Preferably, the preset frequency band is 2.5 GHz to 6 GHz.
[0011] The beneficial effects of the present utility model are:
[0012] 1) The structure that combines the microstrip coupling method with lumped parameter components reduces the volume of the device. At the same time, it is measured that the maximum continuous wave RF power that can pass through within the operating frequency band of 2.5 GHz - 6 GHz is 150 W. It also has a directivity of more than -18 dBc, the in-band flatness is ≤ ±1 dB, and the in-band insertion loss is ≤ 0.3 dB. The indicators are fully applicable to the development of RF products in this frequency band, and it is superior to most current circuits of the same type in terms of volume, operating bandwidth, and power capacity. At the same time, since this circuit can be directly made on the PCB, the cost of purchasing external coupling devices is saved.
[0013] 2) The single-layer microstrip circuit method is adopted instead of the multi-layer stripline coupling method on the market. The volume is smaller than that of products on the market, the operating bandwidth is wider, and the indicators are better. The continuous wave RF signal power passing through the in-band can reach 150 watts, not lower than that of the same type of broadband coupler on the market. Due to the circuit structure of microstrip plus patch resistors, extremely low-cost production can be achieved. Description of the Drawings
[0014] Figure 1 It is a schematic diagram of the microstrip directional coupling structure;
[0015] Figure 2 It is a schematic diagram of the microstrip coupling structure;
[0016] Figure 3 It is a schematic diagram of the principle of the microstrip directional coupling circuit;
[0017] Figure 4 It is a schematic diagram of the principle of the signal attenuation circuit. Specific Embodiments
[0018] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present utility model.
[0019] Refer to Figures 1 - 4, the present utility model provides a technical solution: a microstrip directional coupler, which adopts a single-layer microstrip circuit and includes a microstrip directional coupling structure. The microstrip directional coupling structure includes a microstrip coupling structure. The microstrip coupling structure includes a first tooth-shaped structure. Multiple tooth-shaped microstrip structures are arranged on the first tooth-shaped structure, and the distance between each tooth-shaped microstrip structure is a preset distance; a second tooth-shaped structure is oppositely arranged relative to the first tooth-shaped structure, and multiple tooth-shaped microstrip structures with the same number as the first tooth-shaped structure are staggeredly arranged on the second tooth-shaped structure, so as to balance the coupling amplitude; microstrip lines are connected to both ends of the first tooth-shaped structure and the second tooth-shaped structure. After the microstrip lines of the four ports enter the first tooth-shaped structure and the second tooth-shaped structure, the line width decreases, so as to optimize the port standing wave; the cross depth of the tooth-shaped microstrip structures on the first tooth-shaped structure and the second tooth-shaped structure is a preset depth, and the length is a preset length, so that the size of the microstrip directional coupler is within a preset size; the first tooth-shaped structure and the second tooth-shaped structure are used to balance the coupling signal amplitude and optimize the coupling signal directivity.
[0020] In this embodiment, since the operating frequency band of the coupling circuit is 2.5 GHz to 6 GHz, which is an ultra-wideband, it is necessary to perform an equalization design on the coupling amplitude. And because the operating frequency is relatively high and exceeds the self-resonant frequencies of most lumped parameter elements (resistors, capacitors, inductors), it is impossible to use lumped parameter elements (resistors, capacitors, inductors) for the equalization circuit design. The equalization method adopted is a multi-segment tooth-shaped microstrip structure.
[0021] In some embodiments, the preset size is 12.01 mm * 4.94 mm.
[0022] In some embodiments, the line width of the microstrip lines at the four ports of the first tooth-shaped structure and the second tooth-shaped structure is 1.1 mm before entering the first tooth-shaped structure and the second tooth-shaped structure, and 1 mm after entering.
[0023] In some embodiments, the preset depth is 0 mm, the preset length is 0.9 mm, the preset distance is 0.31 mm, and 7 tooth-shaped microstrip structures are arranged on both the first tooth-shaped structure and the second tooth-shaped structure.
[0024] In some embodiments, it further includes a microstrip directional coupling circuit. The microstrip directional coupling circuit includes a signal input port, a coupler, a radio frequency output load port, a signal attenuation circuit, a radio frequency power signal coupling output port, and a coupler isolation port. The coupler is respectively connected to the signal input port, the radio frequency output load port, the signal attenuation circuit, and the coupler isolation port. The signal attenuation circuit is connected to the radio frequency power signal coupling output port. The signal input port, the radio frequency output load port, the radio frequency power signal coupling output port, and the coupler isolation port are respectively grounded after passing through a load; the microstrip directional coupling circuit operates in a preset frequency band.
[0025] In some embodiments, the preset frequency band is 2.5 GHz to 6 GHz.
[0026] The above are only the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the concept described herein through the above teachings or the techniques or knowledge in related fields. Any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.
Claims
1. A microstrip directional coupler, characterized in that: A single-layer microstrip circuit is adopted, which includes a microstrip directional coupling structure. The microstrip directional coupling structure includes a microstrip coupling structure. The microstrip coupling structure includes a first toothed structure. A plurality of toothed microstrip structures are arranged on the first toothed structure, and the distance between each toothed microstrip structure is a preset distance; a second toothed structure is arranged opposite to the first toothed structure, and a plurality of toothed microstrip structures with the same number as the first toothed structure are arranged in a staggered manner on the second toothed structure, so as to balance the coupling amplitude; microstrip lines are connected to both ends of the first toothed structure and the second toothed structure. After the microstrip lines of the four ports enter the first toothed structure and the second toothed structure, the line width decreases, so as to optimize the port standing wave; the cross depth of the toothed microstrip structures on the first toothed structure and the second toothed structure is a preset depth, and the length is a preset length, so that the size of the microstrip directional coupler is within a preset size; the first toothed structure and the second toothed structure are used to balance the coupling signal amplitude and optimize the coupling signal directivity.
2. The microstrip directional coupler according to claim 1, characterized in that: The preset size is 12.01mm * 4.94mm.
3. The microstrip directional coupler according to claim 1, characterized in that: The line width of the microstrip lines of the four ports of the first toothed structure and the second toothed structure is 1.1mm before entering the first toothed structure and the second toothed structure, and 1mm after entering.
4. The microstrip directional coupler according to claim 1, wherein: The preset depth is 0mm, the preset length is 0.9mm, the preset distance is 0.31mm, and 7 toothed microstrip structures are arranged on both the first toothed structure and the second toothed structure.
5. The microstrip directional coupler according to any one of claims 1-4, characterized in that: It further includes a microstrip directional coupling circuit. The microstrip directional coupling circuit includes a signal input port, a coupler, a radio frequency output load port, a signal attenuation circuit, a radio frequency power signal coupled output port and a coupler isolation port. The coupler is respectively connected to the signal input port, the radio frequency output load port, the signal attenuation circuit and the coupler isolation port. The signal attenuation circuit is connected to the radio frequency power signal coupled output port. The signal input port, the radio frequency output load port, the radio frequency power signal coupled output port and the coupler isolation port are respectively grounded after passing through a load; the microstrip directional coupling circuit operates in a preset frequency band.
6. The microstrip directional coupler according to claim 5, wherein: The preset frequency band is 2.5GHZ - 6GHZ.