Full-polarization high-gain wideband conformal antenna

Abstract

The application relates to a full polarization high-gain wide-band conformal antenna, belongs to the technical field of electromagnetic propagation and energy collection, and particularly relates to a full polarization high-gain wide-band conformal antenna and a small-size rectifier circuit. The application conforms to the inner wall of an energy collection box by using an improved structure simple Yagi antenna, expands the working frequency band range of the antenna, is convenient for integration with equipment, and reduces the size of the energy collection device. The application designs an ultra-wide-band and compact structure quadrature coupler which is integrated at the bottom of the device. The quadrature coupler can realize 3db coupling in a wide frequency band range, evenly divides the energy received by each port into two paths, and solves the problem of low efficiency caused by the imbalance of the rectifier link in the prior art. The rectifier is small in size, has a good joint simulation effect, and is convenient for integration. The antenna can work in different radio frequencies and power ranges.

Description

Technical Field

[0001] This invention relates to a fully polarized high-gain wideband conformal antenna, belonging to the field of electromagnetic transmission and wireless energy harvesting technology, and particularly to a fully polarized high-gain wideband conformal antenna and a small-size rectifier circuit. Background Technology

[0002] With the development of modern communication technology, the use of electromagnetic waves in the daily environment is becoming increasingly common. However, with the continuous expansion of IoT system applications, various small devices such as heat / humidity / smoke sensors and smart gas / water / electricity meters are widely used in daily life. These sensor devices are often limited by the environment and cannot have their batteries replaced in a timely manner. Therefore, harvesting radio frequency energy in space to power low-power devices has attracted increasing attention from researchers. This method enhances the adaptability and robustness of the power supply system. Wireless energy harvesting technology collects electromagnetic energy from the nearby environment and then uses a rectifier to convert the captured electromagnetic energy into DC power to power low-power devices such as wireless sensors. This solves the problem of difficult power supply maintenance, reduces the physical design difficulties of power supply equipment, reduces environmental pollution caused by battery consumption, and also reduces electromagnetic pollution.

[0003] Existing technologies, such as patent document CN113690612A published on November 23, 2021, describe a fully polarized rectifier antenna and energy transmission system with a wide bandwidth and power range. This system uses a 3D type wide half-power beam fully polarized antenna to collect spatial electromagnetic waves. At the same time, it uses three Lange couplers to connect and divide the energy output from the antenna port 2 into four equal parts, which are then connected to four rectifier circuits and finally loaded onto the same load. This design has a wide bandwidth and a wide dynamic range, but the overall system size is relatively large.

[0004] To collect more radio frequency (RF) energy, antennas often need to be designed for omnidirectional, multi-polarization reception. Furthermore, since most electromagnetic waves used for wireless communication in the environment are linearly polarized waves in any direction, dual-polarized antennas are often used to receive linearly polarized electromagnetic waves with arbitrary incident polarization angles to avoid polarization mismatch during collection. However, in this case, the RF energy obtained by the two polarization ports of the antenna is different. If a rectifier circuit is cascaded after it, the unbalanced input power will lead to a decrease in rectification efficiency, making energy integration difficult. Expanding the bandwidth and dynamic range of the rectifier can increase its versatility, while reducing its size while maintaining performance allows for easier conformal integration into devices. However, most existing technologies widen the bandwidth by increasing the operating frequency or by using maximum power point tracking (MPPT) technology to embed detection algorithms in the control chip of the circuit to extend the power range. But such methods result in a larger rectifier circuit size, which is not conducive to integration into small devices.

[0005] Based on the above analysis, the main problems currently facing space-based wireless energy harvesting are: most existing energy harvesting systems are linearly polarized, which causes rectification imbalances in the harvested energy, resulting in low efficiency; the overall size is large, making it inconvenient to conform to small devices; and existing energy harvesting devices are inefficient at collecting energy that is not sensitive to polarization and has a wide incident angle. Summary of the Invention

[0006] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a fully polarized high-gain wideband conformal antenna and a small-size rectifier circuit.

[0007] The technical solution of this invention is:

[0008] A fully polarized high-gain wideband conformal antenna includes eight antenna elements, a ground plane, an energy harvesting box, four orthogonal couplers, and eight rectifier circuits.

[0009] The antenna elements are improved Yagi antenna elements, each including a dipole antenna and a director, with eight antenna elements sharing a common ground plane. Each antenna element is used to collect radio frequency (RF) energy. The antenna elements are connected to a ground plane slot line via parallel double lines, and the slot line is connected to an orthogonal coupler via a microstrip line. The RF energy collected by the antenna elements is transmitted to the slot line via the parallel double lines, then from the slot line to the microstrip line, and finally to the orthogonal coupler. Each orthogonal coupler has two input ports and two output ports, and each output port of the four orthogonal couplers is connected to a rectifier circuit.

[0010] The energy harvesting box is a square box. Two conformal antenna elements are located on the inner walls of each of the four sides of the box. The antenna elements on the left and right sides of the corners of the dielectric substrate form a pair, with each pair of antennas connected by an orthogonal coupler. The four orthogonal couplers are mounted on the floor.

[0011] The arm of the vibrator antenna is bent to shorten the arm length. At the same time, a groove is cut along the floor where the parallel double lines connect with the floor. The groove line is perpendicular to the side wall and the end of the groove line is rounded at 90° and has a circular hole. The extension lines of the two groove lines at the corner of each energy harvesting box intersect perpendicularly.

[0012] The antenna unit vibrator arm is 36mm long and 23.31mm high, and the width of the slot line is 0.5mm. There are four elliptical slots on the floor, and the orthogonal coupler is located in the elliptical slot. Each elliptical slot is located in the two slot lines where the extension lines intersect.

[0013] The orthogonal coupler consists of upper and lower transmission belts, divided into two layers. The first layer of the orthogonal coupler includes a first elliptical transmission line and a triangular outer shell, and the second layer of the orthogonal coupler includes a second elliptical transmission line. The first layer of the orthogonal coupler is located above the floor, and the second elliptical transmission line is coplanar with the floor.

[0014] The bottom of the square box is made of Rogers board, and the lower surface of the Rogers board is covered with a copper floor.

[0015] The dielectric substrate is FR4 material;

[0016] The end of the groove is rounded at 90° and has a circular hole.

[0017] The rectifier circuit includes three capacitors, three inductors, and two rectifier diodes; the three capacitors are capacitor C1, capacitor C2, and capacitor C3; the three inductors are inductor L1, inductor L2, and inductor L3; and the two rectifier diodes are rectifier diode D1 and rectifier diode D2.

[0018] The output of the quadrature coupler is connected to one end of inductor L1, one end of inductor L2, and one end of capacitor C1 via microstrip lines. The other end of inductor L1 is grounded via a microstrip line, the other end of capacitor C1 is grounded via a microstrip line, the other end of inductor L2 is connected to one end of capacitor C2 via a microstrip line, the other end of capacitor C2 is connected to one end of rectifier diode D1 and one end of rectifier diode D2 via a microstrip line, the other end of rectifier diode D1 is grounded via a microstrip line, the other end of rectifier diode D2 is connected to one end of inductor L3, the other end of inductor L3 is connected to the load via a microstrip line, the other end of inductor L3 is connected to one end of capacitor C3 via a microstrip line, and the other end of capacitor C3 is grounded via a microstrip line.

[0019] The microstrip line connected to the other end of the rectifier diode D1 has a horizontal span of 2.25 mm and a vertical span of 3.4 mm, and forms a 90° upward bend at a horizontal distance of 1 mm.

[0020] The microstrip line connected to the other end of the inductor L3 is a T-shaped microstrip line. One horizontal end of the T-shaped microstrip line is connected to the other end of the inductor L3, the other horizontal end of the T-shaped microstrip line is connected to the load, and the vertical end of the T-shaped microstrip line is connected to one end of the capacitor C3.

[0021] The beneficial effects of this invention are:

[0022] 1. The fully polarized high-gain wideband conformal antenna of the present invention utilizes the conformal design of the energy harvesting box wall, therefore it does not require any additional structure and does not occupy any space inside the energy harvesting box.

[0023] 2. The fully polarized high-gain wideband antenna of the present invention is conformally mounted on the inner walls of the four corners of the energy harvesting box. The symmetrical distribution makes it more flexible in use and can meet the actual engineering requirements by combining different antenna elements and different antenna arrangements.

[0024] 3. The antenna element of the fully polarized high-gain wideband conformal antenna of the present invention is bent, which not only expands the bandwidth and reduces the antenna size, but also forms a wider beam at the zenith, which fully covers the airspace range, which is conducive to collecting more radio frequency energy and improving energy collection efficiency.

[0025] 4. Because each antenna element of the fully polarized high-gain wideband conformal antenna of the present invention is placed vertically, two forms of left-hand circular polarization and right-hand circular polarization can be achieved at different ports by superimposing linearly polarized antennas. This fully polarized design allows the antenna to capture electromagnetic waves of arbitrary polarization in space, which is beneficial to collect more radio frequency energy and improve energy collection efficiency.

[0026] 5. The application of the orthogonal coupler in this invention realizes the transformation from unbalanced to balanced power. When combined with the receiving antenna, it can maintain stable rectification efficiency under different incident polarization waves.

[0027] 6. Although the antennas of the present invention are designed for radio frequency energy harvesting, they can also be used for other purposes, such as in communication equipment transceivers, where one antenna element of the harvester is used for communication, while other antenna elements are used for radio frequency energy harvesting.

[0028] 7. This invention integrates the rectifier circuit at the output end of the receiving antenna, resulting in a smaller size and more compact structure.

[0029] 8. The rectifier circuit of the present invention adds an inductor to the load path again, which has the function of blocking AC and passing DC, further improving the efficiency of the rectifier.

[0030] 9. The ground plane of the present invention is shared by the antenna unit, the orthogonal coupler and the rectifier, and also serves as the antenna reflector. It has a high degree of overall integration and is easy to process and use. Attached Figure Description

[0031] Figure 1 This is a top view of the fully polarized high-gain wideband antenna of the present invention;

[0032] Figure 2 This is a rear view of the fully polarized high-gain wideband antenna of the present invention;

[0033] Figure 3 This is a schematic diagram of the overall structure of the fully polarized high-gain wideband antenna of the present invention;

[0034] Figure 4This is a schematic diagram of the antenna element of the present invention;

[0035] Figure 5 This is a schematic diagram of the orthogonal coupler structure of the present invention;

[0036] Figure 6 S-parameters of unit (a) of the present invention;

[0037] Figure 7 S-parameters of unit (b) of the present invention;

[0038] Figure 8 This invention relates to the voltage difference between the two ports caused by different incident angles at 0° polarization in Embodiment 1.

[0039] Figure 9 This refers to the difference in rectified voltage between the two ports caused by different incident angles when polarized at 90° in Embodiment 1 of the present invention.

[0040] Figure 10 These are the radiation patterns of antenna element b in Embodiment 1 of the present invention at different frequencies in the H-plane and E-plane.

[0041] Figure 11 Schematic diagram of the rectifier of the present invention;

[0042] Figure 12 This is the DC conversion efficiency obtained from the joint simulation of the rectifier and antenna of the present invention;

[0043] Figure 13 This is a three-arm antenna element applicable to the present invention;

[0044] Figure 14 This is a multi-bend dipole wall antenna element applicable to the present invention.

[0045] Figure 15 This is an elliptical dipole arm antenna element applicable to the present invention;

[0046] Figure 16 The present invention is a symmetrical circular slot line and an orthogonal coupler microstrip line.

[0047] Figure 17 The present invention is applicable to elliptical slot lines and orthogonal coupler microstrip lines;

[0048] Figure 18 This is a circular orthogonal coupler transmission line applicable to the present invention. Detailed Implementation

[0049] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0050] A fully polarized high-gain wideband antenna includes eight improved Yagi antenna elements, four orthogonal couplers, and a rectifier circuit; the four orthogonal couplers are orthogonal coupler I, orthogonal coupler II, orthogonal coupler III, and orthogonal coupler IV.

[0051] Each antenna element includes a vibrating antenna 1 and a director 2, and the eight antenna elements share a common ground plane 20.

[0052] Each antenna element is conformally mounted on the inner wall of the energy harvesting box 4. The energy harvesting box 4 is a square box with a length of 136mm, a width of 122mm, and a height of 34.5mm. The back of the energy harvesting box 4 is covered with copper as a ground plane 20.

[0053] The antenna unit is used to collect radio frequency energy;

[0054] The two antenna units on the inner walls on both sides of the corner of the energy harvesting box 4 are marked as a pair. The eight antenna units are antenna unit a, antenna unit b, antenna unit c, antenna unit d, antenna unit e, antenna unit f, antenna unit g, and antenna unit h. That is, antenna unit a and antenna unit b are a pair, antenna unit c and antenna unit d are a pair, antenna unit e and antenna unit f are a pair, and antenna unit g and antenna unit h are a pair.

[0055] Antenna element a and antenna element b are connected to slot line 18 via parallel double line 3, and slot line 18 is connected to orthogonal coupler I via microstrip line 6;

[0056] Antenna element c and antenna element d are connected to slot line 18 via parallel double line 3, and slot line 18 is connected to orthogonal coupler Ⅱ via microstrip line 6;

[0057] Antenna element e and antenna element f are connected to slot line 18 via parallel double line 3, and slot line 18 is connected to orthogonal coupler I and II via microstrip line 6;

[0058] Antenna element g and antenna element h are connected to slot line 18 via parallel double line 3, and slot line 18 is connected to orthogonal coupler IV via microstrip line 6.

[0059] The antenna element has an arm length of 36mm and a height of 23.31mm. The antenna element 1 is bent, and its feed point is connected to the ground plane 20 via a parallel double line 3. There are eight slot lines 18 on the ground plane 20. One end of each slot line 18 shares an endpoint with the end of the parallel double line 3. The extensions of the two slot lines 18 at each corner of the energy harvesting box intersect perpendicularly. The width of the slot line 18 is 0.5mm.

[0060] There are four elliptical slots 8 on the floor 20, each orthogonal coupler is located in one elliptical slot 8, and each ellipse 8 is located in two slot lines 18 whose extensions intersect.

[0061] The orthogonal coupler is shaped like an "X" and consists of upper and lower transmission strips, divided into two layers. The first layer of the orthogonal coupler includes a first elliptical transmission line 7 and a triangular shell 5. The triangular shell 5 has a circular slot for the transmission of the first elliptical transmission line 7, and the diameter of the circular slot is 9.68 mm. The first elliptical transmission line 7 is connected to the microstrip line 6 through port 10. The second layer of the orthogonal coupler is a second elliptical transmission line 19. The first layer of the orthogonal coupler is located above the floor 20, and the second elliptical transmission line 19 is coplanar with the floor 20. The first layer and the second layer of the orthogonal coupler are connected by hollow metal cylinders 12, 13, 14, 15, and 16. The diameter of the hollow metal cylinders is 0.91 mm and the height is 0.81 mm. The ends of the first elliptical transmission line 7 and the second elliptical transmission line 19 serve as the output ports 9 of the orthogonal coupler, and the output ports are connected to the rectifier circuit.

[0062] The bottom of the energy harvesting box is made of Rogers board, and the lower surface of the Rogers board is covered with a copper layer as a floor 20.

[0063] The sidewalls of the energy harvesting box are made of FR4 sheet material;

[0064] The end of the groove 18 is rounded at 90° and has a circular hole;

[0065] The rectifier circuit includes six microstrip lines, three capacitors, three inductors, and a load;

[0066] The microstrip line 1 of the rectifier circuit is 3mm long and 1mm wide. Its front end is connected to the output terminal of the quadrature coupler and its end end is connected to the inductor L2.

[0067] The rectifier circuit microstrip line 2 is 1mm long and 1mm wide, and is connected to inductor L2, capacitor C2 and rectifier diode at the front and rear.

[0068] The upper part of the microstrip line 3 of the rectifier circuit is connected to the inductor L1 and the capacitor C1 respectively, and the lower part is drilled to connect to the back side as the circuit ground. The diameter of the rectifier hole is 0.3mm.

[0069] The L-shaped microstrip line 4 of the rectifier circuit has a horizontal span of 2.25 mm and a vertical span of 3.4 mm. It has a 90° bend at a horizontal position of 1 mm. Its front end is connected to the rectifier diode 2, and its end is punched to connect to the back side as the circuit ground.

[0070] The front end of the rectifier circuit L3 is connected to another rectifier diode, and the rear end is connected to the horizontal front end of the T-shaped microstrip line 5. The horizontal end of the microstrip line 5 is connected to the load for power supply. The horizontal span of the microstrip line 5 is 6mm, the vertical span is 1.8mm, the width of the horizontal microstrip line is 1mm, and it extends downward by 0.8mm at 4mm to form a T-shaped microstrip line.

[0071] The front end of the rectifier circuit C3 is connected to the vertical port of the T-shaped microstrip line 5, the end of capacitor C3 is connected to the front end of the microstrip line 6, and the end of the microstrip line 6 is punched to connect to the back side as a circuit ground.

[0072] Example 1

[0073] like Figure 1 , Figure 2 and Figure 3 As shown, the antenna unit includes: 1 folded dipole antenna, 2 director, and eight antenna units sharing a single reflector, which is the floor 20 on the lower surface of the energy harvesting box. The floor 20 also serves as the floor for orthogonal couplers I, II, III, and IV, and the eight rectifiers. Depending on specific requirements, the floor can be divided into several sections, giving each antenna its own independent floor. The antennas are divided into four pairs: (a)(b); (c)(d); (e)(f); (g)(h). The output of each pair of antennas is connected to orthogonal couplers I, II, III, and IV, respectively. Each antenna arm is 36mm long and 23.31mm high. The antennas are bent to extend the operating frequency band. The four pairs of antennas are conformally mounted on the inner walls of the four corners of the square energy harvesting box. The end of each antenna is connected to a parallel double line. At the intersection of the parallel double line 3 and the floor 20, a slot 18 is formed along the floor at the bottom of the energy harvesting box. The slot 18 connects to a microstrip line 6, cleverly utilizing this method to transmit energy to the orthogonal couplers.

[0074] As can be seen, copper plating serves as the ground plane 20 on the back of the energy harvesting box, with elliptical slots 8 cut out at its four corners to facilitate better coupling of the second layer of elliptical transmission lines 19 of the orthogonal coupler. This energy harvesting box 4 is 136mm long, 122mm wide, and 34.5mm high.

[0075] like Figure 4 The diagram shown is a schematic of an antenna element.

[0076] like Figure 5 As shown, the quadrature coupler consists of two layers. The first layer comprises 7 elliptical transmission lines and 5 triangular housings, with 6 being a triangular housing to facilitate the passage of transmission line 7 through a circular slot with a diameter of 9.68 mm. The second layer consists of elliptical transmission line 19 on the same side as the ground plane 20. The upper and lower layers are connected by metal through-holes 8, 9, 10, 11, 12, 13, 14, 15, and 16, with a diameter of 0.91 mm and a height of 0.81 mm. 17 is the output terminal of the quadrature coupler, connected to the microstrip rectifier circuit. The bottom of the energy harvesting box 4 is located in the middle and uses Rogers board material, while the four side walls of the energy harvesting box 4 use FR4 board material.

[0077] This invention proposes a novel 90-degree 3dB coupler design with ultra-wideband and compact sides. The coupler has two right-angled sides of 20.8mm, composed of two elliptical microstrip lines coupled through a circular slot. This ensures equal energy at both output ports, enabling a subsequent cascaded rectifier circuit to balance the input power and resolve the reduced rectification efficiency caused by energy imbalance in the rectifier link, as mentioned in the previous technical problem.

[0078] like Figure 6 , Figure 7 As shown, the antenna of the present invention is an ultra-wideband antenna with an absolute bandwidth of 1.6 GHz to 3 GHz and a relative bandwidth of 68%, which can receive electromagnetic waves from various frequency bands more efficiently. Since the surrounding environment of these antenna elements is highly symmetrical, only the S-parameters of elements 1 and 2 are given. The isolation between antenna elements a and b and all other antenna elements is higher than 15 dB.

[0079] like Figure 8 , Figure 9 As shown, the voltage difference between ports 1 and 2 caused by different incident angles at 0° and 90° polarization clearly shows that after adding the quadrature coupler, the energy of the two ports is basically the same when the incident angle changes from -60° to 60°. However, without the quadrature coupler, the energy difference between the two ports can reach up to 2V when the incident angle changes from -60° to 60°, which significantly improves the rectification efficiency of the system.

[0080] like Figure 10 As shown, the radiation patterns of antenna element b in the E-plane and H-plane at different frequencies are as follows: Figure 9 As shown, the antenna element's highest H-plane gains at 1.84, 2.2, 2.4, and 2.6 GHz are 4.96, 5.74, 6.4, and 6.17 dBi, respectively, and its highest E-plane gains are 5.7, 6.04, 6.2, and 6.33 dBi, respectively. These frequencies were chosen because they are downlink frequencies for 3G, 4G, and Wi-Fi, and have relatively high intensity in ambient waves. This high-gain design significantly improves the efficiency of receiving electromagnetic waves from space.

[0081] Example 2

[0082] Figure 11 It is a miniaturized microstrip line rectifier, the rectifier circuit including six microstrip lines, three capacitors, three inductors and a load;

[0083] The rectifier circuit microstrip line 21 is 3mm long and 1mm wide, with its front end connected to the output terminal of the quadrature coupler and its end connected to the inductor L2. The rectifier circuit microstrip line 22 is 1mm long and 1mm wide, and is connected to the inductor L2, capacitor C2, and rectifier diode at both ends.

[0084] The upper part of the microstrip line 23 of the rectifier circuit is connected to the inductor L1 and the capacitor C1 respectively, and the lower part is drilled to connect to the back side as the circuit ground. The diameter of the rectifier hole is 0.3mm.

[0085] The L-shaped microstrip line 24 of the rectifier circuit has a horizontal span of 2.25 mm and a vertical span of 3.4 mm. It has a 90° bend at a horizontal position of 1 mm. Its front end is connected to the rectifier diode 2, and its end is punched to connect to the back side as the circuit ground.

[0086] The front end of the rectifier circuit L3 is connected to another rectifier diode, and the rear end is connected to the horizontal front end of the T-shaped microstrip line 25. The horizontal end of the microstrip line 25 is connected to the load for power supply. The horizontal span of the microstrip line 25 is 6mm, the vertical span is 1.8mm, the width of the horizontal microstrip line is 1mm, and it extends downward by 0.8mm at 4mm to form a T-shaped microstrip line.

[0087] The front end of the rectifier circuit C3 is connected to the vertical port of the T-shaped microstrip line 25, the end of the capacitor C3 is connected to the front end of the microstrip line 26, and the end of the microstrip line 26 is punched to connect to the back side as a circuit ground.

[0088] In use, each rectifier circuit is connected to the output of each quadrature coupler to convert the received radio frequency signal into DC energy to power small devices.

[0089] The antenna and rectifier were co-simulated in ADS. By adjusting the position of the microstrip rectifier and adding an inductor after the rectifier diode to block the reflection of higher harmonics, the rectification efficiency was effectively improved. Figure 12 The results are from a co-simulation. At an incident voltage of 0 dBm, the rectifier efficiency can reach over 80% in the 2.1 GHz–2.4 GHz range, and at an incident voltage of -10 dBm, the rectifier efficiency can reach over 80% in the 2.05 GHz–2.15 GHz and 2.27 GHz–2.37 GHz ranges. None of the above examples included a cover for the energy harvesting box; adding a cover may have some impact on the overall performance.

[0090] Example 3

[0091] The Yagi antenna element of this invention can be three dipole arms, such as... Figure 13 As shown, increasing the number of bends in the oscillator arm is as follows: Figure 14 As shown, the shape of the oscillator arm can also be changed, such as... Figure 15 As shown, other forms of slotted lines and orthogonal coupler microstrip lines can also be used, such as... Figure 16 as well as Figure 17 As shown, it can also be used as follows Figure 18 The transmission lines of the circular orthogonal coupler shown are examples.

[0092] In summary, this invention proposes a fully polarized, high-gain, wideband conformal antenna and a small-size rectifier circuit. This antenna not only improves circuit matching performance and efficiency over a wide bandwidth and power range, but also enables reception of waves with different incident angles and full polarization. The use of orthogonal couplers facilitates the conversion of power imbalance to balance. Furthermore, the high-gain antenna design allows for more effective reception of radio frequency energy over a wider range, making it suitable for electromagnetic wireless energy harvesting.

[0093] Protection point:

[0094] 1. The antenna, orthogonal coupler, and rectifier can operate in other frequency ranges.

[0095] 2. The energy collection box can be any other size, any other shape, such as a cylinder or a sphere, and can be made of any material.

[0096] 3. The number and position of antenna elements can be changed. Antenna elements can be arranged on the wall of the energy harvesting box in other ways. At the same time, antenna elements can be printed on the outer or inner wall of the packaging box, or partially printed on the outer or inner wall of the packaging box.

[0097] 4. The antenna elements can be of different types, and the number of directors and antenna arms can be different.

[0098] 5. The groove can be etched on the bottom strip or the ground can be cut into several pieces.

[0099] 6. The energy transfer between the antenna and the orthogonal coupler can be varied.

[0100] 7. The metal cylinder in an orthogonal coupler can also be a metal through hole.

[0101] 8. The bandpass filter section in the rectifier can be either a low-pass filter or a high-pass filter.

[0102] 9. The metal through-holes in the finishing tool can also be metal cylinders.

[0103] 10. The number of inductors added to the load branch in a rectifier can vary.

[0104] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the embodiments described above. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A full polarization high gain wideband conformal antenna, characterized in that: The conformal antenna comprises eight antenna units, a floor, an energy collection box, four quadrature couplers and eight rectifier circuits; the energy collection box is a square box, two antenna units are conformal on the inner wall of each side of the energy collection box, each antenna unit is a linear polarization antenna, the antenna units on the left and right sides of the corners of the energy collection box are a pair, each pair of antennas is connected with a quadrature coupler, and the linearly polarized wave can be synthesized into circularly polarized wave by vertically placing each pair of antennas and connecting them with the quadrature coupler; the microstrip line connected with the other end of the inductor L3 is a T-shaped microstrip line; the antenna unit is an improved Yagi antenna unit, the dipole arm of the antenna unit is bent, each antenna unit comprises a dipole antenna and a director, and all the antenna units share a ground; the feeding point of the antenna unit is connected with a parallel double line, the parallel double line extends on the side wall and is connected with the floor, a slot is opened along the floor at the connection position of the parallel double line and the floor, the slot line is perpendicular to the side wall, the end of the slot line is rounded with a 90° fillet, and a circular hole is formed at the end of the slot line, and each slot line is connected with a microstrip line to transmit energy to the quadrature coupler; the back of the energy collection box is covered with copper as the floor, four slots are opened at the four corners of the floor, each quadrature coupler is located in a slot and is installed on the floor, and the slot of each quadrature coupler is located in the two slot lines intersecting the extension line; the quadrature coupler has two input ports and two output ports, each input port is connected with an antenna unit, one quadrature coupler is connected with two antenna units, and each output port is connected with a rectifier circuit.

2. The full polarization high gain wideband conformal antenna according to claim 1, characterized in that: The quadrature coupler equally divides the radio frequency energy collected by the antenna unit connected with each input port, and the divided energy is output at the two output ports, and each quadrature coupler equally divides the energy received by the two antenna units.

3. The full polarization high gain wideband conformal antenna according to claim 1, characterized in that: Each rectifier circuit comprises three capacitors, three inductors and two rectifier diodes; the three capacitors are capacitor C1, capacitor C2 and capacitor C3, the three inductors are inductor L1, inductor L2 and inductor L3, and the two rectifier diodes are rectifier diode D1 and rectifier diode D2.

4. The full polarization high gain wideband conformal antenna according to claim 3, characterized in that: The inductors L1 and L2 and the capacitors C1 and C2 are connected into an F-shaped structure through a microstrip line, the output end of the quadrature coupler is connected with the F-shaped structure through a microstrip line, one end of the F-shaped structure is connected with the rectifier diodes D1 and D2 through a microstrip line, the other end of the rectifier diode D1 is connected with the ground through a microstrip line, the rectifier diode D2 is connected with the load through the inductor L3 and the microstrip line, and the other end of the inductor L3 is connected with the ground through a microstrip line and the capacitor C3.

5. The full polarization high gain wideband conformal antenna according to claim 1, characterized in that: The copper layer on the back of the energy harvesting box serves as the floor of the antenna, the orthogonal coupler and the rectifier, and the reflector of the antenna.

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