Circularly-polarized high-efficiency rectification antenna with F-class operating characteristics

Abstract

The invention discloses a circularly polarized high-efficiency rectifying antenna with F-class operating characteristics, which comprises a first dielectric substrate, a second dielectric substrate, a first surface structure positioned on the upper surface of the first dielectric substrate, a second surface structure positioned on the upper surface of the second dielectric substrate, and a third surface structure positioned on the lower surface of the second dielectric substrate, wherein the first surface structure comprises two L-shaped groove structures for realizing circular polarization radiation; a second surface structure including a split annular groove structure for controlling third harmonics and manipulating phases of the third harmonics; and the third surface structure comprises a feed network, a rectifier and a direct current filter which are used for being matched with the split annular groove to suppress second harmonics and regulate and control the impedance function of the second harmonics. By using the invention, the power loss and the insertion loss can be reduced, and the conversion efficiency is improved. The method can be widely applied to the field of wireless communication.

Description

Technical Field

[0001] This invention relates to the field of wireless communication, and more particularly to a circularly polarized high-efficiency rectified antenna with Class F operating characteristics. Background Technology

[0002] In recent years, with the rapid development of wireless sensor networks, wireless power transfer (WPT) and energy harvesting (EH) technologies have attracted widespread attention. As a core component of WPT and EH systems, rectifier antennas can capture electromagnetic energy from the environment and power low-power devices, thereby reducing reliance on traditional batteries. Therefore, achieving high RF-to-DC power conversion efficiency and miniaturization in rectifier antenna design has become an important goal.

[0003] The conversion efficiency of a rectifier antenna largely depends on the impedance matching between the antenna and the rectifier, as well as the losses of the rectifier diodes. Impedance matching is a fundamental and crucial aspect of RF circuit design, minimizing signal reflections at the load and maximizing power transfer. Besides the matching network, diode losses also reduce the rectifier's RF-to-DC conversion efficiency. To maximize conversion efficiency, some rectifiers employ harmonic tuning techniques, enabling them to operate in specific modes (such as Class C, Class E, Class F, and inverse Class F). -1 This is to reduce diode losses. Summary of the Invention

[0004] In view of this, in order to solve the technical problem of low conversion efficiency in existing rectifier antennas due to impedance matching loss and rectifier diode loss, this invention proposes a circularly polarized high-efficiency rectifier antenna with Class F operating characteristics, comprising a first dielectric substrate, a second dielectric substrate, a first surface structure located on the upper surface of the first dielectric substrate, a second surface structure located on the upper surface of the second dielectric substrate, and a third surface structure located on the lower surface of the second dielectric substrate, wherein: The first surface structure includes a square radiating patch containing two L-shaped slot structures for exciting two orthogonal resonant modes, thereby achieving circularly polarized radiation. The second surface structure includes a ground plane containing a split annular groove structure for controlling and manipulating the phase of the third harmonic. The third surface structure includes a feed network, a rectifier, and a DC filter for suppressing second harmonics and regulating second harmonic impedance in conjunction with the split annular groove; the feed network is provided with a circular stub, which cooperates with the classified annular groove structure in the second surface structure to control the phase of the rectifier diode; The metallized vias penetrate the first dielectric substrate, the second dielectric substrate, the first surface structure, the second surface structure, and the third surface structure. The metallized blind vias penetrate the second dielectric substrate, the second surface structure, and the third surface structure.

[0005] Based on the above scheme, this invention provides a circularly polarized high-efficiency rectifier antenna with Class F operating characteristics. It utilizes a centrally symmetrical L-shaped slot structure to achieve circular polarization, making it suitable for a wider range of applications. Simultaneously, the circular stub, combined with the split annular slot in the second surface structure, allows for control of the phase of the second and third harmonics of the rectifier diode, thereby optimizing the current and voltage waveforms on the diode, reducing overlapping area, and thus reducing power loss and improving rectification efficiency. This method eliminates the need for the rectifier's input matching network, reduces insertion loss, and also reduces the power dissipation of the rectifier diode, ultimately achieving high conversion efficiency and a small size. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the structure of a circularly polarized high-efficiency rectified antenna with Class F operating characteristics provided by the present invention. Figure 2 This is a schematic diagram of a circularly polarized high-efficiency rectified antenna with Class F operating characteristics, split into three separate surfaces, provided by the present invention. Figure 3 This is an equivalent schematic diagram of the third surface of a circularly polarized high-efficiency rectified antenna with Class F operating characteristics provided by the present invention. Figure 4 This is the radiation pattern of the rectifier antenna provided in an embodiment of the present invention; Figure 5 This is a graph showing the efficiency of the rectifier antenna and the change of output voltage with input power provided in an embodiment of the present invention; Figure 6 This is a graph showing the efficiency of the rectifier antenna and the change of output voltage with power density provided in an embodiment of the present invention.

[0007] Figure label: Reference numerals: 1, First surface; 11, First L-shaped groove; 12, Second L-shaped groove; 2, Second surface; 21, Split annular groove; 3, Third surface; 31, Feed network; TL1, First microstrip line; 311, Circular stub; C1, First capacitor; 32, Rectifier; 321, First diode; TL2, Second microstrip line; 33, DC filter; TL3, Third microstrip line; C2, Second capacitor; R1, Load. Detailed Implementation

[0008] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0009] It should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0010] It should be understood that the terms "system," "apparatus," "unit," and / or "module" used in this application are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0011] As indicated in this application, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0012] In the description of the embodiments of this application, "a plurality of" refers to two or more. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0013] Reference Figure 1 This is a schematic diagram of an optional example of a circularly polarized high-efficiency rectified antenna with Class F operating characteristics proposed in this invention. The rectified antenna proposed in this embodiment may include a first dielectric substrate and a second dielectric substrate, wherein: Both dielectric substrates are made of RO4003C material, each with a thickness of 1.524mm. The dimensions of the first dielectric substrate are... The dimensions of the second dielectric substrate are The diode used is HSMS2850; the operating frequency of this invention is 2.45GHz.

[0014] Based on the two dielectric substrates, it also includes a first surface structure 1 located on the upper surface of the first dielectric substrate, a second surface structure 2 located on the upper surface of the second dielectric substrate, a third surface structure 3 located on the lower surface of the second dielectric substrate, as well as metallized through holes and metallized blind holes. Metallized vias penetrate the first dielectric substrate, the second dielectric substrate, the first surface structure, the second surface structure, and the third surface structure; metallized blind vias penetrate the second dielectric substrate, the second surface structure, and the third surface structure. Schematic diagram of the three surface structures (see diagram) Figure 2 The first surface structure 1 has a first L-shaped groove 11 and a second L-shaped groove 12, and the first L-shaped groove 11 and the second L-shaped groove 12 are of equal shape and size and are located diagonally opposite to the square patch, in a centrally symmetrical distribution. The L-shaped groove can be used to excite two orthogonal resonant modes, thereby realizing circularly polarized radiation; the second surface structure 2 includes a split annular groove 21, which can be used to control the third harmonic and manipulate the phase of the third harmonic; the third surface structure 3 includes: a feed network 31, a rectifier 32, and a DC filter 33.

[0015] In some feasible embodiments, such as Figure 3 As shown, the first port of the feed network 31 of the third surface structure 3 is connected to the antenna signal output port, the second port of the feed network 31 is connected to the first port of the rectifier 32 and the first port of the DC filter 33, the second port of the rectifier 32 is grounded, and the second port of the DC filter 33 is connected to the load.

[0016] In some feasible embodiments, the feed network 31 includes a first microstrip line TL1, a first circular stub 311, and a first capacitor C1. The first port of the first microstrip line TL1 is connected to the antenna output port, and the second port of the first microstrip line TL1 is connected to the first port of the first capacitor C1. The third port of the first microstrip line TL1 is connected to the first circular stub 311. The second port of the first capacitor C1, the first port of the rectifier 32, and the first port of the DC filter 33 are connected. The circular stub 311 of the feed network 31, in conjunction with the split annular groove 21 in the second surface, can control the phase of the second and third harmonics of the rectifier diode, thereby optimizing the current and voltage waveforms on the diode, reducing the overlapping area, thereby reducing power loss and improving rectification efficiency. In some feasible preferred embodiments, the rectifier 32 includes a first diode 321 and a second microstrip line TL2; the first port of the first diode 321 is connected to the second port of the first capacitor C1 and the first port of the DC filter 33, the second port of the first diode 321 is connected to the first port of the second microstrip line TL2, and the second port of the second microstrip line TL2 is grounded. The rectifier utilizes the unidirectional conductivity characteristic of the diode to complete the AC to DC conversion.

[0017] In some preferred embodiments, the DC filter 33 includes a third microstrip line TL3 and a second capacitor C2; the first port of the third microstrip line TL3 is connected to the second port of the first capacitor C1 and the first port of the first diode 321, and the second port of the third microstrip line TL3 is connected to the first port of the first capacitor C1 and the first port of the load R1. Both the second ports of the first capacitor C1 and the second port of the load R1 are grounded. The DC filter 33 can smooth current ripples, reduce ripple, and output DC voltage to the load terminals.

[0018] Based on the above structure, the basic principle of this invention is as follows: First, the radiating patch has circular polarization performance, stably receiving RF signal input to the feed network; the circular stub of the feed network, combined with the split annular groove in the second surface, can control the phase of the second and third harmonics of the rectifier diode, thereby optimizing the current and voltage waveforms on the diode, reducing the overlapping area and thus reducing power loss and improving rectification efficiency; in this way, the input matching network of the rectifier is eliminated, reducing insertion loss and power dissipation of the rectifier diode, ultimately achieving high conversion efficiency and small size advantages. Then, the signal is converted from AC to DC by the rectifier utilizing the unidirectional conductivity of the diode; finally, the current ripple is smoothed by a filter, reducing ripple, and a DC voltage is output to the load terminals. Furthermore, a power management unit (PMU) equipped with maximum power point tracking (MPPT) is connected at the load terminal to stabilize the output voltage of the rectifier antenna.

[0019] like Figure 4 The image shows the radiation patterns of a circularly polarized high-efficiency rectified antenna with Class F operating characteristics in the planes at Ф=0° and Ф=90° at 2.45 GHz. It can be seen that the antenna exhibits good right-hand circularly polarized radiation characteristics and good gain, with a maximum gain of 5.9 dB.

[0020] like Figure 5 The figure shows the conversion efficiency and DC output voltage of a circularly polarized high-efficiency rectifier antenna with Class F operating characteristics under a load resistance of 1.6 kΩ. It can be seen that the maximum conversion efficiency reaches 70.6% when the input power is 0.93 dBm.

[0021] like Figure 6 The figure shows the DC output voltage and conversion efficiency of a circularly polarized high-efficiency rectified antenna with Class F operating characteristics as a function of power density. It can be seen that the maximum conversion efficiency is achieved at a power density of 4.5 mW / cm².

[0022] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A circularly polarized high-efficiency rectenna with class-F operation, characterized in that, The first surface structure, the first dielectric substrate, the second surface structure, the second dielectric substrate and the third surface structure, the first surface structure is located on the upper surface of the first dielectric substrate, the second surface structure is located on the upper surface of the second dielectric substrate, and the third surface structure is located on the lower surface of the second dielectric substrate, wherein: The first surface structure comprises a square radiation patch, and two L-shaped slot structures for exciting two orthogonal resonant modes are arranged on the square radiation patch; The second surface structure comprises a ground plate, and a split ring slot structure for controlling third harmonic is arranged on the ground plate; The third surface structure comprises a feed network, a rectifier and a DC filter, and a load, the rectifier and the DC filter are connected with the feed network respectively, and a circular stub is arranged on the feed network; The first surface structure, the first dielectric substrate, the second surface structure, the second dielectric substrate and the third surface structure are also penetrated by a metallized via hole; The second surface structure, the second dielectric substrate and the third surface structure are also penetrated by a metallized blind hole.

2. The circularly polarized high-efficiency rectenna with class-F operation according to claim 1, characterized in that, The first surface structure comprises a first L-shaped slot and a second L-shaped slot, the first L-shaped slot and the second L-shaped slot are equal in size and shape, and are located on the diagonal of the square patch in a center-symmetric distribution.

3. The circularly polarized high-efficiency rectenna with class-F operation according to claim 2, characterized in that The second surface structure comprises a first split ring slot, the first split ring slot comprises two split concentric circular ring slots and a rectangular slot at the inner circular ring diameter.

4. The circularly polarized high-efficiency rectenna with class-F operation according to claim 1, wherein The feed network further comprises a first microstrip line, a first circular stub and a first capacitor, wherein: The first port of the first microstrip line is connected with an antenna signal output port, the second port of the first microstrip line is connected with the first port of the first capacitor, and the third port of the first microstrip line is connected with the first circular stub; The second port of the first capacitor is connected with the first port of the rectifier and the first port of the DC filter.

5. The circularly polarized high-efficiency rectenna with class-F operation according to claim 4, characterized in that, The rectifier comprises a first diode and a second microstrip line, wherein: The first port of the first diode, the second port of the first capacitor and the first port of the DC filter are connected; The second port of the first diode is connected with the first port of the second microstrip line, and the second port of the second microstrip line is grounded.

6. The circularly polarized high-efficiency rectenna with class-F operation according to claim 5, wherein The DC filter comprises a third microstrip line and a second capacitor, wherein: The first port of the third microstrip line is connected with the second port of the first capacitor and the first port of the first diode, and the second port of the third microstrip line is connected with the first port of the second capacitor and the first port of the load; The second port of the second capacitor and the second port of the load are both grounded.

7. The circularly polarized high-efficiency rectenna with class-F operation according to claim 6, characterized in that The working process is as follows: The radio frequency signal is received by the radiation patch and input to the feed network; The phase of the diode harmonic is controlled through the circular stub of the feed network and the split ring slot in the second surface structure; The signal conversion from alternating current to direct current is performed via the rectifier; The signal is smoothed by the filter, and the direct current voltage is output to the load.

8. The circularly polarized high-efficiency rectenna with class-F operation according to claim 6, wherein Further comprising: At the load end, a power management unit with maximum power point tracking function is connected to stabilize the output voltage of the rectenna.

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