An autonomous bandwidth-adjusting microstrip yagi rectenna and an autonomous power-supplying bandwidth-adjusting method

Abstract

The application relates to a self-adjusting bandwidth microstrip Yagi rectifier antenna and application, and belongs to the field of Internet of Things sensors. The application can be applied to Internet of Things sensors, and comprises a microstrip Yagi antenna and a rectifier. The microstrip Yagi antenna comprises a first substrate, an active oscillator, a reflector and a directive antenna. The rectifier comprises a microstrip line and an impedance changer. The application realizes self-power supply and saves electric energy. Meanwhile, the combination of a resistance voltage dividing circuit and a MOS tube is used. The combination of the DC voltage voltage dividing by the resistance voltage dividing circuit and the MOS tube controls the opening and closing of the directive antenna, various opening and closing combinations are formed, the bandwidth size is adjusted, and the problems that a traditional sensor needs active power supply and the communication bandwidth is narrow and unadjustable are solved.

Description

Technical Field

[0001] This invention relates to a microstrip Yagi rectifier antenna with autonomous bandwidth adjustment and a method for autonomous power supply and bandwidth adjustment, belonging to the field of Internet of Things (IoT) sensors. Background Technology

[0002] In recent years, with the rapid development of the Internet of Things (IoT) field, the number of IoT sensors has exploded exponentially, which has brought about the problems of power supply and battery life of sensor devices. To address this issue, most research has focused on developing low-power IoT technologies, such as Narrowband IoT (NB-IoT) and Bluetooth Low Energy (BLE).

[0003] Microstrip Yagi antennas are commonly used transceiver devices in the field of wireless communication. They generally include an active element, a directional antenna, and a reflector. The active element is used to transmit or receive signals of a certain frequency, the directional antenna is used for directional transmission and reception and to amplify the signal, and the transmitter is used to reflect the microwave energy at the back end to reduce losses.

[0004] However, the above technologies still have not gotten rid of the pain points of traditional IoT sensors: 1) They need to be powered by batteries and need to be replaced manually every time. This not only consumes a lot of financial, material and human resources, but also puts a huge pressure on the environment with the waste batteries; 2) In order to save energy, the sensors currently used in the market only support narrowband communication, which results in problems such as slow communication speed and low information processing efficiency.

[0005] Furthermore, current sensors on the market cannot dynamically adjust their receiving bandwidth according to the amount of information received, causing congestion in communication between the two. For example, although CN106340950B collects vibration energy around the sensor network and converts it into electrical energy, and controls the electronic switch switching circuit to switch between the first capacitor and the supercapacitor to supply power according to the current required in the sensor network, it still cannot achieve dynamic adjustment of bandwidth according to the amount of information. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides a microstrip Yagi rectifier antenna with self-adjustable bandwidth, applicable to Internet of Things (IoT) sensors. The antenna includes a microstrip Yagi antenna and a rectifier. The microstrip Yagi antenna comprises a first substrate, an active element, a reflector, and a directional antenna. The reflector is printed on the bottom edge of the first substrate.

[0007] The active oscillator is printed on top of the reflector. The active oscillator is in the shape of an "L" rotated 180 degrees and its bottom passes through the reflector and connects to the bottom edge below the first substrate.

[0008] Multiple directional antennas are printed on top of the active vibrator and are externally connected to a resistor voltage divider circuit. The resistor voltage divider circuit is connected to the rectifier and can divide the voltage to each of the directional antennas. Each directional antenna has a breakpoint, and each breakpoint is connected to a MOS transistor. The MOS transistor can control the opening and closing of each directional antenna.

[0009] The rectifier includes a second substrate connected below the first substrate. The second substrate has microstrip lines and an impedance transformer printed sequentially from top to bottom. A high-order harmonic filter is also printed to the left or right of the impedance transformer. The impedance transformer can match the input impedance of the rectifier with the output impedance of the Yagi antenna, allowing more microwave energy to enter the diode. The high-order harmonic filter can return the high-order harmonics to the rectifier for re-rectification, improving the rectifier's rectification efficiency.

[0010] The connection between the microstrip Yagi antenna and the rectifier is also provided with a feed port.

[0011] In one embodiment of the present invention, the plurality of guiding antennas are all linear guiding antennas and are parallel; preferably, the number of guiding antennas is three; the three guiding antennas are connected across four MOSFETs, two guiding antennas are connected across a first MOSFET and a fourth MOSFET respectively, and the other guiding antenna is connected across a second MOSFET and a third MOSFET connected in parallel; the first MOSFET, the third MOSFET, and the fourth MOSFET are all P-channel depletion type; the second MOSFET is an N-channel enhancement type; the turn-off voltages of the first MOSFET, the third MOSFET, and the fourth MOSFET are 1.5V, 1.5V, and 2.5V respectively; the turn-on voltage of the second MOSFET is 3.5V.

[0012] In one embodiment of the present invention, the impedance transformer is three impedance transformers of different lengths; each of the impedance transformers is connected to a high-order harmonic filter.

[0013] In one embodiment of the present invention, both the first substrate and the second substrate are made of epoxy resin glass fiberboard, with a relative permittivity of [missing information]. The dielectric loss angle is 0.02.

[0014] It should be noted that the active oscillator, reflector, and directional antenna described in this invention are not limited to single-sided / double-sided printing on the first substrate, and the scope of protection should be determined by the claims.

[0015] This invention also provides a method for autonomously powering and adjusting the bandwidth of a microstrip Yagi rectifier antenna, applied to the aforementioned microstrip Yagi rectifier antenna, the method comprising the following steps:

[0016] Step 1: The transmitting end transmits a signal with corresponding power according to the actual amount of information processed, which is received by the active dipole of the microstrip Yagi antenna;

[0017] Step 2: The rectifier rectifies the microwave signal into a DC voltage, which is then collected by a resistor divider circuit. After being divided by the resistor divider circuit, the voltage is output to each of the directional antennas of the microstrip Yagi antenna, so that the grid of each directional antenna can be allocated a different voltage. At the same time, the DC voltage rectified by the rectifier is also transmitted to the sensor for power supply. The voltages allocated to each directional antenna form an arithmetic sequence, and the maximum value will not exceed the total voltage rectified by the rectifier.

[0018] Step 3: Each MOSFET on the directional antenna is equipped with a different turn-on or turn-off voltage and can autonomously turn on or off according to the voltage magnitude allocated to it, thereby controlling each directional antenna to be in a connected or disconnected state.

[0019] Different combinations of connecting or disconnecting directional antennas will change the current flow pattern on the antenna surface, causing the antenna's resonant point to change, thereby generating different bandwidths and thus achieving autonomous adjustment of signal bandwidth.

[0020] In one embodiment of the present invention, step one further utilizes the simulation software Ansys HFSS to optimize the structural dimensions of the microstrip Yagi antenna.

[0021] In one embodiment of the present invention, MOSFETs are classified into P-channel depletion type and N-channel enhancement type, which have high-voltage turn-off and high-voltage turn-on characteristics, respectively. Furthermore, MOSFETs have a relatively small impact on signals, can be regarded as ideal conductors when turned on, and can be regarded as complete insulators when turned off.

[0022] It should be noted that in this invention, "above" and "below" are both with reference to the first substrate, "below" refers to the direction of the second substrate relative to the first substrate, and "above" refers to the direction of the first substrate relative to the second substrate; the bottom edge of the first substrate is the edge on the first substrate used for connecting to the second substrate.

[0023] The beneficial effects of this invention are:

[0024] 1. This invention is equipped with a rectifier connected to a microstrip Yagi antenna, which can receive microwave energy from the external environment and convert it into DC voltage, thereby directly powering the sensor and saving energy. At the same time, the DC voltage is controlled by the combination of a resistor voltage divider circuit and a MOSFET to control the opening and closing of the antenna, forming a variety of opening and closing combinations to adjust different bandwidths, thus solving the problem that traditional sensors require active power supply and have narrow and unadjustable communication bandwidth.

[0025] 2. The present invention is configured such that three of the guiding antennas are connected across four MOS transistors, and one of the guiding antennas is connected in parallel with two MOS transistors, which can cope with various bandwidth adjustment situations, has wide applicability and more precise range.

[0026] 3. This invention utilizes a rectifier to convert microwave energy into DC output, thus solving the defect that traditional Yagi antennas cannot convert microwave energy into DC output.

[0027] 4. This invention uses a microstrip Yagi antenna, which is simple to manufacture, has strong anti-interference ability, low cost, and has high gain and strong directivity.

[0028] 5. This invention uses a gallium nitride high-efficiency rectifier, which can achieve an efficiency of over 50% within the operating range of the system, with a peak efficiency close to 80%, and has high rectification efficiency. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure in one embodiment of the present invention.

[0030] Figure 2 This is an overall workflow diagram of one embodiment of the present invention.

[0031] Figure 3 This is an explanatory diagram illustrating the dimensions of a microstrip Yagi antenna in one embodiment of the present invention.

[0032] Figure 4 This is an explanatory diagram illustrating the dimensions of the rectifier in one embodiment of the present invention.

[0033] Figure 5 This is a graph showing the relationship between the efficiency and power of a rectifier in one embodiment of the present invention.

[0034] Figure 6 This is a schematic diagram showing the connection of the antenna when the DC output is 1V in one embodiment of the present invention.

[0035] Figure 7 This is the bandwidth curve obtained by HFSS simulation software when the DC output is 1V in one embodiment of the present invention.

[0036] Figure 8 This is a schematic diagram showing the connection of the antenna when the DC output is 5V in one embodiment of the present invention.

[0037] Figure 9 This is the bandwidth curve obtained by HFSS simulation software when the DC output is 5V in one embodiment of the present invention.

[0038] Figure 10 This is a schematic diagram showing the connection of the antenna when the DC output is 10V in one embodiment of the present invention.

[0039] Figure 11 This is the bandwidth curve obtained by HFSS simulation software when the DC output is 10V in one embodiment of the present invention.

[0040] In the figure, 1: first substrate, 2: active oscillator, 3: reflector, 41: first directional antenna, 42: second directional antenna, 43: third directional antenna, 51: first MOSFET, 52: second MOSFET, 53: third MOSFET, 54: fourth MOSFET, 6: microstrip line, 7: impedance changer, 8: high-order harmonic filter, 9: resistor voltage divider circuit, 10: second substrate. Detailed Implementation

[0041] Example 1

[0042] like Figure 1 As shown, this invention provides a microstrip Yagi rectifier antenna with self-adjustable bandwidth, which can be applied to Internet of Things (IoT) sensors, such as... Figure 1 , Figure 2 As shown, it includes a microstrip Yagi antenna and a rectifier. The microstrip Yagi antenna includes a first substrate 1, an active element 2, a reflector 3, and a directional antenna.

[0043] There are two reflectors 3, both of which are printed on the bottom edge of the first substrate 1. The direction of the bottom edge where the reflector 3 is located is the bottom of the first substrate 1, and the direction relative to the bottom edge where the reflector 3 is located is the top of the first substrate 1.

[0044] The active oscillator 2 is printed on top of the reflector 3. The active oscillator 2 is shaped like an "L" rotated 180 degrees and its bottom passes between the two reflectors 3 and connects to the bottom edge of the first substrate 1. The active oscillator 2 is printed on both the front and back sides.

[0045] The three directional antennas are printed on top of the active oscillator 2 and are externally connected to a resistor voltage divider circuit 9. From bottom to top, they are the first directional antenna 41, the second directional antenna 42, and the third directional antenna 43. Each directional antenna has a breakpoint, and each breakpoint is connected to a MOSFET. A total of four MOSFETs are connected: the breakpoints of the first directional antenna 41 and the third directional antenna 43 are connected to the first MOSFET 51 and the fourth MOSFET 54 respectively, and the breakpoint of the second directional antenna 42 is connected to the second MOSFET 52 and the third MOSFET 53 connected in parallel.

[0046] The first MOSFET 51, the third MOSFET 53, and the fourth MOSFET 54 are all P-channel depletion type; the second MOSFET 52 is an N-channel enhancement type; the turn-off voltages of the first MOSFET 51, the third MOSFET 53, and the fourth MOSFET 54 are 1.5V, 1.5V, and 2.5V, respectively; and the turn-on voltage of the second MOSFET 52 is 3.5V.

[0047] The rectifier includes a second substrate 10 and is connected below the first substrate 1. The second substrate 10 has microstrip lines 6 and impedance transformers 7 printed sequentially from top to bottom. The impedance transformers 7 are divided into three segments, and each segment has a high-order harmonic filter 8 printed on its left side.

[0048] The connection between the microstrip Yagi antenna and the rectifier is also provided with a feed port.

[0049] like Figure 2 As shown, the present invention also provides an application of a microstrip Yagi rectifier antenna with autonomously adjustable bandwidth in IoT sensors, including a method for autonomously powering and adjusting the bandwidth of the microstrip Yagi rectifier antenna, the method comprising the following steps:

[0050] Step 1: The transmitting end transmits a microwave signal with corresponding power according to the actual amount of information processed, which is received by the microstrip Yagi antenna;

[0051] Step 2: The rectifier rectifies the microwave signal into a DC voltage, which is then collected by the resistor voltage divider circuit 9. After being divided by the resistor voltage divider circuit, the voltage is output to each of the directional antennas of the microstrip Yagi antenna, so that the grid of each directional antenna can be allocated a different voltage. At the same time, the DC voltage rectified by the rectifier is also transmitted to the sensor for power supply.

[0052] Step 3: The MOSFET on each directional antenna automatically turns on or off according to the assigned voltage, thereby controlling the directional antenna to be in a connected or disconnected state. Different combinations of connected or disconnected directional antennas will produce different bandwidths, thus realizing the autonomous adjustment of signal bandwidth.

[0053] Example 2

[0054] The structural dimensions of the microstrip Yagi antenna in step one of Example 1 were designed and optimized using the simulation software Ansys HFSS.

[0055] Both the first substrate 1 and the second substrate 10 are made of epoxy resin fiberglass board (FR4), with a relative permittivity of... The dielectric loss angle is 0.02, and the length is... Width is Thickness is .

[0056] like Figure 3 As shown, both reflectors on the first substrate 1 are set to have a length of... Width is This is used to reflect the back lobe energy of the antenna, enhancing its gain and directivity; the active element 2 is defined as consisting of a [missing information - likely a specific element or structure]. Width is A rectangle and a length of Width is The two are composed of rectangles, and the connection between them is a right trapezoid;

[0057] All three directional antennas are set to have a length of [missing information]. Width is The vertical distance from the first guiding antenna 41 to the top of the active dipole 2 is set as follows: The distance between the second guiding antenna 42 and the first guiding antenna 41 is The distance between the second directing antenna 42 and the third directing antenna 43 is .

[0058] Each of the guiding antennas has a spacing of... The breakpoint is used to place the MOS transistor. The distance from the right end of the breakpoint of the first guide antenna 41 to the right end of the first guide antenna 41 is... The distance from the right end of the break point of the second directing antenna 42 to the right end of the second directing antenna 42 is The distance from the right end of the break point of the third directional antenna to the right end of the third directional antenna 43 is .

[0059] The types and turn-off voltage settings of the four MOSFETs are shown in Table 1:

[0060]

[0061] Table 1

[0062] The rectifier is a high-efficiency gallium nitride rectifier; the length of microstrip line 6 is set to be... The lengths of the three segments of the impedance transformer 7 are set as follows: , , And the connection lengths are respectively , , High-order harmonic filter 8, such as Figure 5 As shown, the rectifier's efficiency can reach over 50% within the system's operating range, with a peak efficiency approaching 80%.

[0063] The resistor divider circuit 9 includes three 10kΩ resistors, which are connected to three directional antennas respectively.

[0064] After optimization using simulation software, the dimensional parameters are shown in Table 2:

[0065]

[0066] Table 2

[0067] Example 3

[0068] The optimized microstrip Yagi rectifier antenna with self-adjusting bandwidth from Example 2 is applied to IoT sensors with relatively low information processing requirements, realizing a method for self-powered bandwidth adjustment of a microstrip Yagi rectifier antenna. The method includes the following steps:

[0069] Step 1: Due to the small amount of information to be processed, the transmitting end emits a microwave signal with low receiving power and narrow bandwidth, which is received by the microstrip Yagi antenna.

[0070] Step 2: The rectifier rectifies the signal and outputs a DC voltage of about 1V to the resistor divider circuit 9. After voltage division, the voltage is output to each of the directional antennas of the microstrip Yagi antenna, so that the voltage allocated to the gate of each directional antenna is less than 1V. At the same time, the DC voltage rectified by the rectifier is also transmitted to the sensor for power supply.

[0071] Step 3: According to Table 1, at this time, the first MOSFET 51, the third MOSFET 53, and the fourth MOSFET 54 are all in the ON state, as follows: Figure 6 As shown, all three directional antennas are connected. According to HFSS simulation software, the -10 dB bandwidth is 1.1 GHz, as shown in the results. Figure 7 As shown.

[0072] Example 4

[0073] The optimized microstrip Yagi rectifier antenna with self-adjusting bandwidth from Example 2 is applied to IoT sensors with high information processing volumes to realize a method for self-powered bandwidth adjustment of the microstrip Yagi rectifier antenna. The method includes the following steps:

[0074] Step 1: Due to the large amount of information to be processed, the transmitting end emits a microwave signal with moderate receiving power and moderate bandwidth, which is received by the microstrip Yagi antenna.

[0075] Step 2: The rectifier rectifies the signal and outputs a DC voltage of about 5V to the resistor voltage divider circuit 9. After voltage division, the voltage is output to the microstrip Yagi antenna, so that the grid of each directional antenna can be allocated with voltages of 1.67V, 3.33V, and 5V respectively. At the same time, the DC voltage rectified by the rectifier is also transmitted to the sensor for power supply.

[0076] Step 3: According to Table 1, at this time, the first MOSFET 51, the second MOSFET 52, and the third MOSFET 53 are all in the off state, and only the fourth MOSFET 54 is in the on state. Figure 8 As shown, only the third directional antenna 43 is connected. According to the HFSS simulation software, the -10 dB bandwidth is 1.55 GHz, as shown in the figure. Figure 9 As shown.

[0077] Example 5

[0078] The optimized microstrip Yagi rectifier antenna with self-adjusting bandwidth from Example 2 is applied to IoT sensors with high information processing volumes to realize a method for self-powered bandwidth adjustment of the microstrip Yagi rectifier antenna. The method includes the following steps:

[0079] Step 1: Due to the large amount of information to be processed, the transmitting end emits a microwave signal with high receiving power and wide bandwidth, which is received by the microstrip Yagi antenna.

[0080] Step 2: The rectifier rectifies the signal and outputs a DC voltage of about 10V to the resistor voltage divider circuit 9. After voltage division, the voltage is output to the microstrip Yagi antenna, so that the grid of each directional antenna can be allocated with voltages of 3.33V, 6.66V, and 10V respectively. At the same time, the DC voltage rectified by the rectifier is also transmitted to the sensor for power supply.

[0081] Step 3: According to Table 1, at this time, the first MOSFET 51, the third MOSFET 53, and the fourth MOSFET 54 are all in the off state, and only the second MOSFET 52 is in the on state. Figure 10 As shown, only the second directional antenna 42 is connected. According to the HFSS simulation software, the -10 dB bandwidth is 1.96 GHz, as shown in the results. Figure 11 As shown.

[0082] Therefore, it can be seen that the present invention can adjust the three bandwidths respectively under the three conditions of small, large and very large information processing volume, with high accuracy and strong adaptability; and can generate ideal bandwidth based on autonomous rectification power supply.

[0083] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A microstrip Yagi rectifier antenna with self-adjustable bandwidth, applicable to Internet of Things (IoT) sensors, characterized in that, It includes a microstrip Yagi antenna and a rectifier. The microstrip Yagi antenna includes a first substrate, an active element, a reflector, and a directional antenna. The reflector is printed on the bottom edge of the first substrate. The active oscillator is printed on top of the reflector. The active oscillator is in the shape of an "L" rotated 180 degrees and its bottom passes through the reflector and connects to the bottom edge below the first substrate. Multiple directional antennas are printed on top of the active vibrator and are externally connected to a resistor voltage divider circuit. The resistor voltage divider circuit is connected to the rectifier and can divide the voltage to each of the directional antennas. Each directional antenna has a breakpoint, and each breakpoint is connected to a MOS transistor. The MOS transistor can control the opening and closing of each directional antenna. The rectifier includes a second substrate and is connected below the first substrate. The second substrate has microstrip lines and an impedance transformer printed sequentially from top to bottom. A high-order harmonic filter is also printed on the left or right side of the impedance transformer. The connection between the microstrip Yagi antenna and the rectifier is also provided with a feed port; the number of the directional antennas is three. The multiple directional antennas are all linear directional antennas and are parallel; three of the directional antennas are connected across four MOSFETs, two of the directional antennas are connected across the first MOSFET and the fourth MOSFET respectively, and the other directional antenna is connected across the second MOSFET and the third MOSFET in parallel; the first MOSFET, the third MOSFET, and the fourth MOSFET are all P-channel depletion type; the second MOSFET is N-channel enhancement type.

2. The microstrip Yagi rectifier antenna with self-adjustable bandwidth according to claim 1, characterized in that, The turn-off voltages of the first, third, and fourth MOSFETs are 1.5V, 1.5V, and 2.5V, respectively; the turn-on voltage of the second MOSFET is 3.5V.

3. The microstrip Yagi rectifier antenna with self-adjustable bandwidth according to claim 1, characterized in that, The impedance transformer consists of three impedance transformers of different lengths; each impedance transformer is connected to a high-order harmonic filter.

4. The microstrip Yagi rectifier antenna with self-adjustable bandwidth according to claim 1, characterized in that, The first substrate and the second substrate are made of epoxy resin glass fiber board, with a relative permittivity and a dielectric loss angle of 0.

02.

5. A method for autonomously powering and adjusting the bandwidth of a microstrip Yagi rectifier antenna, applied to the microstrip Yagi rectifier antenna of claim 1, characterized in that, The method includes the following steps: Step 1: The transmitting end transmits a microwave signal with corresponding power according to the actual amount of information processed, which is received by the microstrip Yagi antenna; Step 2: The rectifier rectifies the microwave signal into a DC voltage, which is then collected by the resistor voltage divider circuit. After being divided by the resistor voltage divider circuit, the voltage is output to each of the directional antennas of the microstrip Yagi antenna, so that the grid of each directional antenna can be allocated a different voltage. At the same time, the DC voltage rectified by the rectifier is also transmitted to the sensor for power supply. Step 3: The MOSFET on each directional antenna automatically turns on or off according to the assigned voltage, thereby controlling the directional antenna to be in a connected or disconnected state. Different combinations of connected or disconnected directional antennas will produce different bandwidths, thus realizing the autonomous adjustment of signal bandwidth.

6. The method according to claim 5, characterized in that, In step one, the structural dimensions of the microstrip Yagi antenna are optimized using the simulation software Ansys HFSS; the rectifier is a gallium nitride high-efficiency rectifier, including a broadband impedance transformer, a gallium nitride diode and a second and third harmonic filter.

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