A dual-frequency bidirectional rectenna with wide power range

Abstract

The application discloses a dual-frequency bidirectional rectification antenna with a wide power range, relates to the technical field of communication, and discloses the following technical scheme: two first rectangular grooves and a second rectangular groove are etched on a rectangular metal patch, so that the antenna only resonates at a high frequency band and is a directional radiation mode; L-shaped metal patches are arranged on two sides of the rectangular metal patch, so that the antenna resonates at the high frequency band and a low frequency band, and the low frequency band is an omnidirectional radiation mode; and a rectification circuit combining a rectification branch working at a low input power and a rectification branch working at a high input power is designed; the two rectification branches switch and rectify electromagnetic waves collected by the antenna at the high frequency band and the low frequency band through the directional radiation mode and the omnidirectional radiation mode, so that high conversion efficiency in a wide power range is realized.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a dual-frequency bidirectional rectifying antenna with a wide power range. Background Art

[0002] With the development of information technology, the Internet of Things, Internet of Vehicles, smart homes, environmental monitoring and medical testing are being used more and more widely. Sensors are indispensable to these applications. However, due to the limitations of the working scenarios of sensors, the battery capacity is generally small. Therefore, how to solve the power supply problem has become an important topic. In order to solve the power supply problem of small and low-power devices, wireless power supply methods have emerged. General wireless power supply methods, such as wind power generation, solar power generation, and mechanical power generation, are greatly affected by the environment and the implementation process is relatively complex. They are not suitable for stable and continuous power supply for small and low-power devices. Radio frequency energy harvesting technology has received widespread attention due to its advantages such as simple conversion process and easy compatibility with wireless communication systems.

[0003] RF energy harvesting is a method of powering electronic devices by collecting electromagnetic waves in space and converting them into direct current. In the RF energy harvesting system, the rectenna is its main component, consisting of a receiving antenna and a rectifier circuit. The receiving antenna is the front-end part of the RF energy harvesting system and is used to capture electromagnetic wave energy in the environment. The rectifier circuit converts the received electromagnetic wave energy into direct current energy and outputs it to the back-end equipment for use.

[0004] RF energy harvesting can be divided into ambient RF energy harvesting and wireless energy transmission according to the collection method. In ambient RF linear energy harvesting technology, the RF energy in free space comes from all directions, so the antenna is required to have omnidirectional radiation characteristics. In directional wireless energy transmission, since the transmitted RF energy comes from a fixed direction, the Friis equation requires the antenna to have high-gain directional radiation characteristics. Therefore, in order to be used for both ambient wireless energy harvesting and directional wireless energy transmission, the antenna is required to have both omnidirectional and high-gain directional radiation characteristics. When performing ambient RF energy harvesting, the output power of the antenna can be as low as microwatts, while the output power of the antenna can reach more than 20dBm when performing directional wireless energy transmission. Therefore, the rectifier circuit is required to be able to rectify the RF energy output by the antenna within a wide input power range.

[0005] Traditional rectennas are mostly directional and omnidirectional, and it is difficult for them to have both high-gain directional radiation characteristics and omnidirectional radiation characteristics. At the same time, it is difficult to achieve high conversion efficiency within a wide power range. As a result, it is difficult for rectennas at this stage to be used in both ambient RF energy collection and wireless energy transmission applications, limiting their widespread application. Summary of the Invention

[0006] The embodiments of the present invention provide a dual-band, bidirectional rectenna with a wide power range, which can solve the problem in the prior art that current rectennas are difficult to simultaneously have high-gain directional radiation characteristics and omnidirectional radiation characteristics, and at the same time are difficult to achieve high conversion efficiency within a wide power range, so that current rectennas are difficult to be used in both ambient RF energy collection and wireless energy transmission application environments.

[0007] An embodiment of the present invention provides a dual-frequency bidirectional rectenna with a wide power range, comprising a dual-frequency bidirectional receiving antenna and a rectifier circuit;

[0008] The dual-band bidirectional receiving antenna includes a rectangular metal patch disposed on the top surface of a first dielectric substrate, wherein two first rectangular grooves are etched on the inner side of the rectangular metal patch symmetrically about the longitudinal axis of the rectangular metal patch, and two second rectangular grooves are etched on the side of the rectangular metal patch symmetrically about the transverse axis of the rectangular metal patch;

[0009] L-shaped metal patches are respectively provided on both sides of the rectangular metal patch, and a coaxial probe is passed through the inner side of the rectangular metal patch;

[0010] The rectifier circuit includes a single-branch matching network arranged on the top surface of the second dielectric substrate and connected to the coaxial probe, wherein the single-branch matching network is respectively connected to a first rectifier branch and a second rectifier branch, and the various parts of the rectifier circuit are connected via a microstrip transmission line;

[0011] A first rectangular groove and a second rectangular groove are etched on the rectangular metal patch to enable the antenna to resonate in a high frequency band and to have a directional radiation mode; an L-shaped metal patch is provided on both sides of the rectangular metal patch to enable the antenna to resonate in a low frequency band and to have an omnidirectional radiation mode;

[0012] The high-frequency and low-frequency electromagnetic waves received by the antenna in the directional radiation mode and the omnidirectional radiation mode are input into the rectification circuit through the coaxial probe; when the single-branch matching network detects that the electromagnetic wave is a low-power electromagnetic wave, the electromagnetic wave enters the first rectification branch for rectification; when the single-branch matching network detects that the electromagnetic wave is a high-power electromagnetic wave, the electromagnetic wave enters the second rectification branch for rectification.

[0013] Preferably, a defective ground plate is provided on the bottom surface of the first dielectric substrate, and the coaxial probe passes through the defective ground plate.

[0014] Preferably, the first rectifying branch is composed of a plurality of open branches, a capacitor C1 and a diode D1 are connected between a branch of the first rectifying branch and a branch of the branch matching network, and a terminal branch of the first rectifying branch is connected to a load RL1;

[0015] The diode D1 is a HSMS285B diode.

[0016] Preferably, the second rectifying branch is composed of a plurality of open branches, a capacitor C2 and a diode D2 are connected between a branch of the second rectifying branch and a branch of the single-branch matching network, and a terminal branch of the second rectifying branch is connected to a load RL2;

[0017] The diode D2 is a HSMS286B diode.

[0018] Preferably, the branches contained in the first rectifying branch and the second rectifying branch can form an output straight-through filter, and the output straight-through filter is composed of four open branches, and the lengths of the four open branches correspond to a quarter wavelength of 2.45GHz, 4.9GHz, 5.8GHz and 11.6GHz respectively.

[0019] Preferably, the first dielectric substrate is a polytetrafluoroethylene F4B dielectric substrate, the dielectric constant of the dielectric substrate is 2.55, the loss tangent is 0.0017, and the thickness is 2 mm;

[0020] The second dielectric substrate is a Rogers 4350B dielectric substrate, and the dielectric constant of the dielectric substrate is 3.66, the loss tangent is 0.0037, and the thickness is 0.762 mm.

[0021] Preferably, the resonant frequency of the dual-frequency bidirectional receiving antenna in the directional radiation mode is 5.8 GHz, and the resonant frequency of the dual-frequency bidirectional receiving antenna in the omnidirectional radiation mode is 2.45 GHz.

[0022] The embodiment of the present invention provides a dual-band bidirectional rectenna with a wide power range. Compared with the prior art, the embodiment of the present invention has the following advantages:

[0023] The present invention etches two first rectangular grooves and a second rectangular groove on a rectangular metal patch respectively, so that the antenna resonates only in the high frequency band and is in a directional radiation mode. At the same time, L-shaped metal patches are provided on both sides of the rectangular metal patch, so that the antenna resonates simultaneously in the high frequency band and the low frequency band, and is in an omnidirectional radiation mode in the low frequency band. A rectifier circuit is designed that combines a rectifier branch working at low input power and a rectifier branch working at high input power. The two rectifier branches switch and rectify the electromagnetic waves collected by the antenna in the high frequency band and the low frequency band through the directional radiation mode and the omnidirectional radiation mode, thereby achieving high conversion efficiency within a wide power range.

[0024] In addition, the antenna can collect electromagnetic waves in dual frequency bands through directional radiation mode and omnidirectional radiation mode, and can be used for both ambient RF energy collection and wireless energy transmission systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A front view structural diagram of a receiving antenna of a dual-frequency bidirectional rectenna with a wide power range according to an embodiment of the present application;

[0026] Figure 2 A back view structural diagram of a receiving antenna of a dual-frequency bidirectional rectenna with a wide power range according to an embodiment of the present application;

[0027] Figure 3 A front view structural diagram of a rectenna circuit of a dual-frequency bidirectional rectenna with a wide power range according to an embodiment of the present application;

[0028] Figure 4 A first rectification branch diagram of a rectenna circuit of a dual-frequency bidirectional rectenna with a wide power range according to an embodiment of the present application;

[0029] Figure 5 A simulation and test result diagram of a return loss of a receiving antenna of a dual-frequency bidirectional rectenna with a wide power range according to an embodiment of the present application;

[0030] Figure 6 A simulation and test result diagram of a radiation pattern of a receiving antenna of a dual-frequency bidirectional rectenna with a wide power range at 2.45 GHz according to an embodiment of the present application;

[0031] Figure 7 A simulation and test result diagram of a radiation pattern of a receiving antenna of a dual-frequency bidirectional rectenna with a wide power range at 5.8 GHz according to an embodiment of the present application;

[0032] Figure 8 A simulation and test result diagram of a conversion efficiency of a rectenna circuit of a dual-frequency bidirectional rectenna with a wide power range at 2.45 GHz varying with input power according to an embodiment of the present application;

[0033] Figure 9 A simulation and test result diagram of a conversion efficiency of a rectenna circuit of a dual-frequency bidirectional rectenna with a wide power range at 5.8 GHz varying with input power according to an embodiment of the present application.

[0034] Wherein: 1, rectangular metal patch, 2, L-shaped metal patch, 3, first rectangular groove, 4, second rectangular groove, 5, defective ground plate, 6, first dielectric substrate, 7, second dielectric substrate, 8, single-stub matching network, 9, diode D1, 10, diode D2, 11, first rectification branch, 12, second rectification branch, 13, capacitor C1, 14, capacitor C2, 15, load RL1, 16, load RL2. DETAILED DESCRIPTION

[0035] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, features specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0038] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0039] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0040] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0041] See also Figures 1 to 3 An embodiment of the present invention provides a dual-frequency bidirectional rectifying antenna with a wide power range, comprising a dual-frequency bidirectional receiving antenna and a rectifying circuit.

[0042] The dual-band bidirectional rectenna consists of a rectangular metal patch 1, an L-shaped metal patch 2, a first rectangular groove 3, a second rectangular groove 4, a defect ground plate 5, a first dielectric substrate 6 and a coaxial probe. The rectangular metal patch 1 and the L-shaped metal patch 2 constitute a radiation patch; the radiation patch is arranged on the top surface of the first dielectric substrate 6, four symmetrical rectangular grooves are etched on the rectangular metal patch 1, two first rectangular grooves 3 are arranged on the left and right sides of the inner side of the rectangular metal patch 1, and two second rectangular grooves 4 are opened on the upper and lower sides of the rectangular metal patch 1.

[0043] Among them, the first dielectric substrate 6 is F4B material with a dielectric constant of 2.55, a loss tangent of 0.0017, and a thickness of 2 mm; the rectangular metal patch 1 is 61 mm long and 24 mm wide; the L-shaped metal patch 2 has a short side length of 32 mm and a short side width of 2.5 mm, a long side length of 34 mm and a long side width of 3 mm; the first rectangular groove 3 has a length of 17.8 mm and a width of 2.5 mm; the second rectangular groove 4 has a length of 4.5 mm and a width of 2 mm.

[0044] The rectifier circuit includes a single-branch matching network 8, a diode D1, a diode D2, a first rectifier branch 11, a second rectifier branch 12, a capacitor C1, a capacitor C2, a load RL1, and a load RL2. The output end of the dual-band bidirectional receiving antenna is connected to the input end of the rectifier circuit, wherein the various parts of the rectifier circuit are connected through a microstrip transmission line. The single-branch matching network 8 is the matching circuit of the rectifier circuit. The diodes D1 and D2 are the rectifier diodes of the rectifier circuit. The diode D1 is HSMS285B and the diode D2 is HSMS28 6B; The first rectifying branch 11 and the second rectifying branch 12 both include output pass filters, specifically consisting of four microstrip open branches and three microstrip transmission lines, the lengths of the four open branches corresponding to a quarter wavelength of 2.45 GHz, 4.9 GHz, 5.8 GHz and 11.6 GHz, respectively; and the rectifying circuit is arranged on the second dielectric substrate 7, which is a Rogers 4350B dielectric substrate with a dielectric constant of 3.66, a thickness of the substrate of 0.762 mm, and a loss tangent of 0.0037.

[0045] The two branches work at high and low input power respectively, and together achieve high conversion efficiency under a wide input power range. At low input power, most of the RF power is transmitted to the first rectifier branch, while at high input power, most of the RF power is transmitted to the second rectifier branch. At the same time, the first rectifier branch and the second rectifier branch have good impedance matching with the input end at the fundamental frequency, that is, P in =P in1 +P in2 , then the power distribution of the two branches P in1 / P in2 =|Z in2 | / |Z in1 |. Among them, |Z in1 | represents the input impedance Z of the first rectifier branch in1 The modulus value, |Z in2 | represents the input impedance Z of the second rectifier branch in2 The modulus of the input impedance between the two branches is inversely proportional to the modulus of the input impedance between the two branches. in1 | needs to increase with the increase of input power, thereby gradually reducing the distribution ratio of RF energy; and |Z in2|It needs to gradually decrease with the increase of input power, so as to gradually increase the distribution ratio of RF energy. Within the entire input power range, the states of the rectifier circuit can be divided into three types: (1) When the input power is low, the input impedance amplitude of the first rectifier branch 11 is much smaller than that of the second rectifier branch 12. Most of the power enters the first rectifier branch 11 and is rectified by the diode D1. The diode D2 of the second rectifier branch 12 is basically in the cut-off state. The conversion efficiency of the rectifier circuit is determined by the rectification efficiency of the first rectifier branch 11; (2) When the input power is medium, the input impedance amplitudes of the first rectifier branch 11 and the second rectifier branch 12 are close, and the power is almost evenly distributed to the two branches. At this time, the diodes D1 and D2 are rectified at the same time; (3) When the input power is high, most of the input power enters the second rectifier branch 12 and is rectified by the diode D2. The diode D1 in the first rectifier branch 11 is basically in the cut-off state. The diode D2 rectifies the RF signal with a higher conversion efficiency than the diode D1 at high input power.

[0046] The input impedance of the diode is shown in formula (1), Z D is the input impedance of the diode, θ on Is half of the conduction angle (0<θ on <π / 2), the input admittance of the diode is as shown in formulas (2)-(4):

[0047]

[0048] Y D =1 / Z D =Re(Y D )+jIm(Y D ) (2)

[0049]

[0050] As shown in formula (4), the imaginary part of the diode input admittance Im(Y D ) is a positive inductive reactance, so the imaginary part of the input impedance Im(Z D ) is a negative capacitive reactance. Let the input conductance Re(Y D ) and input susceptance Im(Y D ) for θ on Taking the derivative, the result is as follows:

[0051]

[0052] For the convenience of analysis, the above formula is simplified as follows:

[0053] α=1-cos2θ on (7)

[0054] β=(π-θ on )sinθ on +cos 3 θ on -cosθ on (8)

[0055] The simplified formulas (5) and (6) are:

[0056]

[0057] Formulas (9) and (10) are represented by α and β respectively. When θ on When α and β change in the range of 0 to π / 2, they are always positive, that is, Re(Y D ) and Im(Y D ) for θ on The derivative of Re(Y D ) and Im(Y D ) is an increasing function, Re(Z D ) and Im(Z D ) is a decreasing function, indicating that the modulus of the real and imaginary parts of the diode input impedance increases with θ on By adding a T-type short-circuit structure after the diode in each branch, the input impedance of the two rectifier branches can be made to show an increasing and decreasing trend respectively. Taking the first rectifier branch as an example, Figure 4 Short-circuit lines TL3 and TL4 are connected in parallel after microstrip line TL1. The length of TL4 is λ / 2, which corresponds to 2.45 GHz. When the input signal is 2.45 GHz, TL3 is short-circuited by TL4, and TL1 is adjusted so that the input impedance of the first rectifier branch is an increasing function of the input power. When the input signal is 5.8 GHz, the electrical length of TL3 is adjusted to change the combined input impedance of TL1, TL3, and TL4, so that the input impedance of the first rectifier branch at 5.8 GHz is also an increasing function of the input power. The same principle applies to the second rectifier branch.

[0058] The present invention is based on the high-order mode theory and combines the bidirectional radiation mechanism and the principle of the adaptive power distribution rectifier circuit to design the dual-frequency bidirectional rectenna of the present invention, including:

[0059] Step 1: Simulate and analyze the initial patch antenna. Two first rectangular grooves 3 are etched in the upper rectangular metal patch 1, and the length of the rectangular metal patch 1 is set to 61 mm and the width is set to 24 mm to obtain dual-band high-gain characteristics.

[0060] Step 2: Based on the required resonant frequency of the antenna and without changing the antenna radiation pattern, two second rectangular grooves 4 are etched in the upper rectangular metal patch 1. The length of the second rectangular groove 4 is 4.5 mm and the width is 2 mm to achieve an antenna design with single-frequency directional radiation.

[0061] Step 3: Based on the results of step 2, add a new resonant frequency to the antenna and design it to achieve bidirectional radiation. Add two L-shaped metal patches 2 at the zero point of the electric field generated by the antenna at 5.8 GHz, achieving omnidirectional radiation at 2.45 GHz and high-gain directional radiation at 5.8 GHz.

[0062] Step 4: The rectifier circuit is a radio frequency rectifier circuit, including a matching circuit, a rectifier diode and a pass-through filter; the matching circuit uses a microstrip single-branch matching network 8; at the same time, based on the principle of adaptive power distribution, the rectifier circuit is composed of two different rectifier branches, the first rectifier branch 11 uses an HSMS285B diode operating at a lower power, and the second rectifier branch 12 uses an HSMS286B diode operating at a higher power; the pass-through filter is designed with four open branches, and in order to avoid the input impedance of the pass-through filter at the fundamental frequency affecting the input impedance of the rectifier branch, the power distribution of the two rectifier branches is changed; and while suppressing the fundamental frequency and the second harmonic, the input impedance of the pass-through filter is adjusted to a higher value close to the open circuit.

[0063] like Figure 5 The figure shows the simulation and test results of the return loss of the antenna of the present invention. Figure 6 The figure shows the simulation and test results of the radiation pattern of the antenna of the present invention at 2.45GHz. Figure 7 The figure shows the simulation and test results of the radiation pattern of the antenna of the present invention at 5.8 GHz. Figure 8 The figure shows the simulation and test results of the conversion efficiency of the rectifier circuit of the antenna of the present invention at 2.45GHz as a function of input power. Figure 9 The figure shows the simulation and test results of the conversion efficiency of the rectifier circuit of the antenna of the present invention at 5.8 GHz as a function of input power. It can be seen from the figure that the antenna operates at 2.45 GHz and 5.8 GHz, and omnidirectionally radiates at 2.45 GHz and directionally radiates with high gain at 5.8 GHz. The antenna of the present invention can achieve high conversion efficiency within a wide input power range, meeting the different requirements of the RF energy harvesting system for the antenna radiation pattern in different application scenarios and the requirement that the rectifier circuit maintains high conversion efficiency within a wide input power range.

[0064] The antenna designed by the present invention can be used for both ambient RF energy collection and directional wireless energy transmission. First, by slotting the electric field zero point of the high-gain directional antenna to suppress undesired resonant frequency bands, the antenna resonates only at 5.8 GHz and is in a high-gain directional radiation mode. Second, by adding a pair of bent L-shaped metal patches at the electric field zero points on both sides of the rectangular antenna and reducing the size of the ground plate on both sides, resonance is generated at 2.45 GHz and an omnidirectional radiation mode is achieved without affecting the antenna performance at 5.8 GHz. The antenna is fed by an eccentric coaxial probe. At the same time, the rectifier circuit consists of two rectifier branches operating at low input power and high input power, respectively. By loading a T-type short-circuit structure after the parallel diode of each branch, the input impedance of the two rectifier branches can be made to show increasing and decreasing trends, respectively. According to the change of the impedance ratio under different input powers, the input RF power is automatically distributed, so that the rectifier branches can be automatically switched at high and low input powers, ultimately achieving high conversion efficiency over a wide power range.

[0065] When the input signal is 2.45 GHz, the conversion efficiency of the rectifier circuit is greater than 50% in the input power range of 9-26 dBm. When the input signal is 5.8 GHz, the conversion efficiency is greater than 30% in the ranges of 2-11.5 dBm and 23.5-27 dBm, and greater than 20% in the range of -2-27 dBm. This fully demonstrates that the dual-frequency bidirectional rectenna designed in the present invention can achieve high conversion efficiency in a wide input power range.

[0066] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A dual-band bidirectional rectenna with a wide power range, characterized in that: include: Dual-band bidirectional receiving antenna and rectifier circuit; The dual-band bidirectional receiving antenna comprises a rectangular metal patch (1) arranged on the top surface of a first dielectric substrate (6), wherein the inner side of the rectangular metal patch (1) is symmetrically etched with two first rectangular grooves (3) about a longitudinal axis of the rectangular metal patch (1) perpendicular to the long side, and the side of the rectangular metal patch (1) is symmetrically etched with two second rectangular grooves (4) about a transverse axis of the rectangular metal patch (1) parallel to the long side; L-shaped metal patches (2) are respectively provided on both sides of the horizontal axis of the rectangular metal patch (1) parallel to the long side, and a coaxial probe is passed through the inner side of the rectangular metal patch (1); The rectifier circuit comprises a single-branch matching network (8) arranged on the top surface of the second dielectric substrate (7) and connected to the coaxial probe, the single-branch matching network (8) being respectively connected to a first rectifier branch (11) and a second rectifier branch (12), and the various parts of the rectifier circuit being connected via a microstrip transmission line; A first rectangular groove (3) and a second rectangular groove (4) are etched on the rectangular metal patch (1) to enable the antenna to resonate in a high frequency band and to be in a directional radiation mode; L-shaped metal patches (2) are respectively provided on both sides of the rectangular metal patch (1) to enable the antenna to resonate in a low frequency band and to be in an omnidirectional radiation mode; The high-frequency and low-frequency electromagnetic waves received by the antenna in the directional radiation mode and the omnidirectional radiation mode are input into the rectification circuit through the coaxial probe; when the single-branch matching network (8) detects that the electromagnetic wave is a low-power electromagnetic wave, the electromagnetic wave enters the first rectification branch (11) for rectification; when the single-branch matching network (8) detects that the electromagnetic wave is a high-power electromagnetic wave, the electromagnetic wave enters the second rectification branch (12) for rectification.

2. The dual-frequency bidirectional rectenna with a wide power range according to claim 1, characterized in that: A defective grounding plate (5) is provided on the bottom surface of the first dielectric substrate (6), and the coaxial probe penetrates the defective grounding plate (5).

3. The dual-frequency bidirectional rectenna with a wide power range according to claim 1, characterized in that: The first rectifying branch (11) is composed of a plurality of open branches, a capacitor C1 (13) is connected between a branch of the first rectifying branch (11) and a branch of the branch matching network (8), one end of the capacitor C1 (13) connected to a branch of the branch matching network (8) is connected to a diode D1 (9), and a terminal branch of the first rectifying branch (11) is connected to a load RL1 (15); The diode D1 (9) is a HSMS285B diode.

4. The dual-frequency bidirectional rectenna with a wide power range according to claim 1, characterized in that: The second rectifying branch (12) is composed of a plurality of open branches, a capacitor C2 (14) is connected between a branch of the second rectifying branch (12) and a branch of the single-branch matching network (8), one end of the capacitor C2 (14) connected to a branch of the branch matching network (8) is connected to a diode D2 (10), and a terminal branch of the second rectifying branch (12) is connected to a load RL2 (16); The diode D2 (10) is a HSMS286B diode.

5. The dual-frequency bidirectional rectenna with a wide power range according to claim 1, characterized in that: The branches contained in the first rectifying branch (11) and the second rectifying branch (12) can form an output straight-through filter, and the output straight-through filter is composed of four open-circuit branches, and the lengths of the four open-circuit branches correspond to a quarter wavelength of 2.45 GHz, 4.9 GHz, 5.8 GHz and 11.6 GHz respectively.

6. The dual-frequency bidirectional rectenna with a wide power range according to claim 1, characterized in that: The first dielectric substrate (6) is a polytetrafluoroethylene F4B dielectric substrate, the dielectric constant of the dielectric substrate is 2.55, the loss tangent is 0.0017, and the thickness is 2 mm; The second dielectric substrate (7) is a Rogers 4350B dielectric substrate, the dielectric constant of the dielectric substrate is 3.66, the loss tangent is 0.0037, and the thickness is 0.762 mm.

7. The dual-frequency bidirectional rectenna with a wide power range according to claim 1, characterized in that: The resonant frequency of the dual-frequency bidirectional receiving antenna in the directional radiation mode is 5.8 GHz, and the resonant frequency of the dual-frequency bidirectional receiving antenna in the omnidirectional radiation mode is 2.45 GHz.

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