A duplex antenna

Abstract

The present invention relates to the field of wireless communication technology, and in particular to a duplex antenna. The duplex antenna described in the present invention is a single integrated duplex antenna. Specific signals need to be transmitted and received at specific ports and cannot leak to another port. The first port is connected to a monopole antenna for receiving energy fundamental signals, and the second port is connected to a slot antenna for reflecting harmonic signals. Isolation between ports is formed by different resonant current modes, without the need for additional duplex filters or power dividers to achieve duplex operation of the antenna. The feed lines of the monopole antenna and the slot antenna are zigzag, which increases the isolation between the ports. The present invention provides a duplex antenna with self-contained port isolation, which can further and effectively reduce the node area, thereby achieving the miniaturization of the receiving node of the wireless sensor network.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communications, and in particular to a duplex antenna. Background Art

[0002] With existing technologies, the 5G era is seeing an increasing number of sensor-based IoT scenarios. In some specialized applications, wireless energy transfer (WET) technology is required to power sensors. Research on wireless energy transmission is gaining momentum. Traditional research has focused primarily on the focusing characteristics of wireless energy signals. However, recent research has begun to examine the alignment between the focusing paths of the energy transmitter (TX) and the energy receiver (RX). A common approach involves transmitting a signal from the RX to the TX for position sensing, adjusting the TX's radiation performance and thus ensuring stable wireless energy transmission efficiency. There are various approaches to selecting a feedback signal, and using a signal at a different frequency from the energy signal to provide feedback on the RX's energy reception status is ideal. Some solutions use the intermodulation signal generated by a dual-tone input signal as the feedback signal. However, this signal is too close to the primary frequency signal, dissipating too much energy and reducing the final power supply. Other solutions use harmonic signals generated by a single-tone signal through a rectifier as the feedback signal. Harmonic frequencies are farther from the primary frequency and generally do not significantly affect the final DC output energy. This solution presents a challenge in antenna design. Because the harmonic signals differ significantly from the primary frequency signal, two separate antennas are used to transmit and receive wireless energy. This results in low antenna utilization and a relatively large antenna area. Using dual-band antennas can effectively reduce the number of antennas and their area, but subsequent duplex filtering circuits are required to separate the fundamental and harmonic signals, resulting in a still-larger number of wireless sensor network receiving nodes. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the problem in the prior art that a dual-frequency antenna needs to be connected to a duplex filter circuit to separate the fundamental signal and the harmonic signal.

[0004] To solve the above technical problems, the present invention provides a duplex antenna, comprising:

[0005] dielectric substrate;

[0006] A patch oscillator is located on the top surface of the dielectric substrate and is provided with a polygonal window;

[0007] a zigzag monopole antenna, located on the bottom surface of the dielectric substrate, one end of which is connected to the reflection of the first edge of the polygonal window on the bottom surface of the dielectric substrate and is connected to the first microstrip feeder for receiving the fundamental wave power signal;

[0008] a meander feed line, located on the bottom surface of the dielectric substrate, one end of which is connected to the reflection of the second edge of the polygonal window on the bottom surface of the dielectric substrate and is connected to the second microstrip feed line, the meander feed line and the patch element forming a slot antenna for reflecting harmonic signals;

[0009] a first port connected to the first microstrip feeder;

[0010] The second port is connected to the second microstrip feeding line.

[0011] Preferably, the operating frequency of the meander monopole antenna is 0.915 GHz, and the operating frequency of the slot antenna is 1.83 GHz.

[0012] Preferably, the polygonal window is a parallelepiped window, and the lengths of the upper and lower parallel sides are smaller than the lengths of the other sides.

[0013] Preferably, one end of the zigzag monopole antenna is connected to the mapping of the left vertex of the parallel hexagonal window on the bottom surface of the dielectric substrate;

[0014] One end of the zigzag feed line is connected to the mapping of the right vertex of the parallelepiped window on the bottom surface of the dielectric substrate.

[0015] Preferably, the first fold line segment of the zigzag feed line is parallel to the line connecting the left and right vertices of the parallel hexagonal window, the second fold line segment bends upward and is perpendicular to the first fold line segment, and the third fold line segment bends rightward and is parallel to the first fold line segment.

[0016] Preferably, the first fold line segment of the zigzag monopole antenna is parallel to the connecting line of the left and right vertices of the parallel hexagonal window, the second fold line segment bends downward and is perpendicular to the first fold line segment, and the third fold line segment bends left and is parallel to the first fold line segment.

[0017] Preferably, the first microstrip feeding line and the second microstrip feeding line are both perpendicular to a line connecting the left vertex and the right vertex of the parallel hexagonal window.

[0018] Preferably, the first port and the second port are located on the same side of the dielectric substrate.

[0019] Preferably, the width of the meander monopole antenna is smaller than the width of the first microstrip feed line, and the width of the meander feed line is smaller than the width of the second microstrip feed line.

[0020] Preferably, the dielectric substrate is an FR4 substrate, which has a dielectric constant of 4.4 and a loss tangent of 0.02.

[0021] The above technical solution of the present invention has the following advantages over the prior art:

[0022] The duplex antenna described in the present invention is a single integrated duplex antenna. Specific signals need to be transmitted and received at specific ports and cannot leak to another port. The first port is connected to the monopole antenna for receiving the energy fundamental signal, and the second port is connected to the slot antenna for reflecting the harmonic signal. Isolation between the ports is formed by the different resonant current modes, and no additional duplex filter or power divider is required to achieve duplex operation of the antenna. The feed lines of the monopole antenna and the slot antenna are zigzag, which increases the isolation between the ports. The present invention provides a duplex antenna with built-in port isolation, which can further and effectively reduce the node area, thereby achieving the miniaturization of the receiving node of the wireless sensor network. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0024] Figure 1 This is a schematic diagram of a duplex antenna provided by an embodiment of the present invention;

[0025] Figure 2 This is a side view of a duplex antenna provided by an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of the characteristic mode analysis results;

[0027] Figure 4 This is a schematic diagram of the current distribution of the duplex antenna at 0.915 GHz;

[0028] Figure 5 This is a schematic diagram of the current distribution of the duplex antenna at 1.83 GHz;

[0029] Figure 6 are the antenna coplanar and cross-polarization diagrams;

[0030] Figure 7 This is the antenna impedance simulation diagram;

[0031] Figure 8 This is a schematic diagram of antenna simulation reflection coefficient and port isolation.

[0032] Description of the drawings: 1- dielectric substrate; 2- patch oscillator; 3- meandering monopole antenna; 4- meandering feed line; 5- first microstrip feed line; 6- second microstrip feed line; 7- first port; 8- second port. DETAILED DESCRIPTION

[0033] The core of the present invention is to provide a duplex antenna. The duplex antenna with built-in port isolation can further and effectively reduce the node area, thereby realizing the miniaturization of the receiving node of the wireless sensor network.

[0034] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0035] The present invention provides a duplex antenna comprising:

[0036] A dielectric substrate, wherein the dielectric substrate is an FR4 substrate having a dielectric constant of 4.4 and a tangent loss of 0.02;

[0037] A patch oscillator is located on the top surface of the dielectric substrate and is provided with a polygonal window;

[0038] a zigzag monopole antenna, located on the bottom surface of the dielectric substrate, one end of which is connected to the reflection of the first edge of the polygonal window on the bottom surface of the dielectric substrate and is connected to the first microstrip feeder for receiving the fundamental wave power signal;

[0039] A zigzag feed line is located on the bottom surface of the dielectric substrate, one end of which is connected to the reflection of two edges of the polygonal window on the bottom surface of the dielectric substrate and is connected to the second microstrip feed line. The zigzag feed line and the patch element form a slot antenna for reflecting harmonic signals, with an operating frequency of 1.83 GHz.

[0040] a first port connected to the first microstrip feeder;

[0041] The second port is connected to the second microstrip feeding line.

[0042] The duplex antenna described in the present invention is a single integrated duplex antenna. Specific signals need to be transmitted and received at specific ports and cannot leak to another port. The first port is connected to the monopole antenna for receiving the energy fundamental signal, and the second port is connected to the slot antenna for reflecting the harmonic signal. Isolation between the ports is formed by the different resonant current modes, and no additional duplex filter or power divider is required to achieve duplex operation of the antenna. The feed lines of the monopole antenna and the slot antenna are zigzag, which increases the isolation between the ports. The present invention provides a duplex antenna with built-in port isolation, which can further and effectively reduce the node area, thereby achieving the miniaturization of the receiving node of the wireless sensor network.

[0043] Based on the above embodiments, this embodiment further describes the duplex antenna in detail. Figure 1 and Figure 2 As shown:

[0044] Based on the practical application of the wireless energy transmission terminal, the present invention needs to receive a 0.915 GHz power signal and reflect a 1.83 GHz harmonic signal, that is, the operating frequency of the zigzag monopole antenna is 0.915 GHz and the operating frequency of the slot antenna is 1.83 GHz.

[0045] The resonant frequency of the slot antenna is determined by the polygonal window, while the resonant frequency of the monopole antenna is determined by its length. The polygonal window is a parallelepiped window, and the lengths of the upper and lower parallel sides are shorter than the other sides. This can achieve a lower antenna operating frequency within a limited area and realize miniaturization.

[0046] One end of the zigzag monopole antenna is connected to the mapping of the left vertex of the parallel hexagonal window on the bottom surface of the dielectric substrate; one end of the zigzag feed line is connected to the mapping of the right vertex of the parallel hexagonal window on the bottom surface of the dielectric substrate, maximizing the size of the wide gap so that a longer low-frequency monopole antenna can be arranged in a smaller window.

[0047] The first microstrip feed line and the second microstrip feed line are both perpendicular to the connecting line of the left vertex and the right vertex of the parallel hexagonal window; the first port and the second port are located on the same side of the dielectric substrate, making the subsequent rectifier circuit connection convenient.

[0048] The first fold line segment of the zigzag feed line is parallel to the connecting line of the left and right vertices of the parallel hexagonal window, the second fold line segment bends upward and is perpendicular to the first fold line segment, and the third fold line segment bends rightward and is parallel to the first fold line segment.

[0049] The first fold line segment of the zigzag monopole antenna is parallel to the connecting line of the left and right vertices of the parallel hexagonal window, the second fold line segment bends downward and is perpendicular to the first fold line segment, and the third fold line segment bends leftward and is parallel to the first fold line segment.

[0050] The width of the meander monopole antenna is smaller than the width of the first microstrip feed line, and the width of the meander feed line is smaller than the width of the second microstrip feed line, so as to adjust the impedance matching of the port and obtain better return loss.

[0051] Based on the above embodiments, this embodiment provides specific dimensions of the duplex antenna:

[0052] The dimensions of the FR4 dielectric substrate are Ws = 108 mm, Ls = 100 mm;

[0053] The lengths of the sides of the parallelepiped window are Ls1 = 25.55 mm, Ls2 = 25.55 mm, Ls3 = 42 mm, and Ls4 = 39.65 mm;

[0054] The width of the first microstrip feed line and the second microstrip feed line are Wf1 = 3 mm, and the lengths are Lf1 = 55.3 mm and Lf2 = 55.3 mm;

[0055] The width of the zigzag feeder and the zigzag monopole antenna is Wf2 = 2 mm, the first zigzag line segment L4 of the zigzag feeder is 25.5 mm, the second zigzag line segment L6 is 4.4 mm, and the third zigzag line segment L5 is 6.4 mm; the first zigzag line segment L1 of the zigzag monopole antenna is 28.8 mm, the second zigzag line segment L2 is 20.35 mm, and the third zigzag line segment L3 is 18.35 mm.

[0056] like Figure 3 The figure shows the result of characteristic mode analysis. It can be seen from the figure that the resonance mode of this antenna structure at 915MHz is mode 7, and the resonance mode at 1.83GHz is mode 2. Figure 4 and Figure 5 Then Figure 2 The antenna current distribution in the resonant mode is shown in Figure 2. Figure 4 It is obvious that at low frequency (0.915GHz), the current is concentrated near the microstrip line, such as Figure 5 , at high frequency (1.83GHz), the current is distributed along the edge of the PCB substrate.

[0057] like Figure 6 Shown are the coplanar and cross-polarization diagrams of the antenna; Figure 7 The impedance simulation diagram of the two ports of the duplex antenna is shown in Figure 2. The input impedance at 915MHz and 1830MHz is close to the center of the Smith chart, which indicates good matching.

[0058] Figure 8 The figure shows the simulated return loss and port isolation of the high- and low-frequency ports of the duplex antenna. As can be seen from the figure, the return loss values ​​at the 915MHz and 1800MHz frequencies both exceed -15dB, and the mutual isolation between the different frequency ports is also better than -10dB.

[0059] A windowed patch antenna fed by a microstrip line achieves miniaturization of duplex antennas. At 915MHz and 1830MHz, return loss exceeds 15dB, isolation exceeds 10dB, and antenna gain is approximately 3dB, meeting design requirements. This allows for both wireless energy transmission and the return of position information to passive receivers.

[0060] Based on the above embodiment, HFSS was used for modeling and simulation. After the simulation results met the standards, the simulation model of the antenna was exported for processing and manufacturing. The plate material was FR4 with a dielectric constant of 4.4, a loss tangent of 0.02, and a thickness of 1.6 mm.

[0061] A phase-adjustable transmitting antenna is placed 2 meters away from the test antenna. The transmitting antenna transmits a point-frequency signal with a frequency of 915 MHz and a power of 1 watt. The 915 MHz port of the antenna to be tested is connected to the input of the rectifier circuit, and the 1830 MHz port is connected to the harmonic output of the rectifier circuit. After receiving the power signal through the 915 MHz antenna, the rectifier circuit generates an 1830 MHz harmonic signal and reflects it back to the transmitter through the 1830 MHz antenna. After receiving the harmonic signal, the transmitting antenna injects it into the spectrum analyzer. Adjust the posture of the transmitting antenna until the harmonic frequency amplitude on the spectrum analyzer is the largest. Change the distance between the transmitting antenna and the test antenna, and record the harmonic signal strength received by the spectrum analyzer. The distance and the harmonic signal strength received by the spectrum analyzer should be inversely proportional, which proves that the present invention can be used as a rectifier circuit antenna to feedback corresponding position information.

[0062] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A duplex antenna, characterized in that: include: dielectric substrate; A patch oscillator is located on the top surface of the dielectric substrate and is provided with a polygonal window; The polygonal window is a parallelepiped window, and the lengths of the upper and lower parallel sides are shorter than the lengths of the other sides; a zigzag monopole antenna, located on the bottom surface of the dielectric substrate, one end of which is connected to the mapping of the left vertex of the parallelepiped window on the bottom surface of the dielectric substrate and is connected to the first microstrip feeder for receiving the fundamental wave power signal; a zigzag feed line, located on the bottom surface of the dielectric substrate, one end of which is connected to the mapping of the right vertex of the parallel hexagonal window on the bottom surface of the dielectric substrate and is connected to the second microstrip feed line, the zigzag feed line and the patch element forming a slot antenna for reflecting harmonic signals; a first port connected to the first microstrip feeder; The second port is connected to the second microstrip feeding line.

2. The duplex antenna according to claim 1, wherein: The operating frequency of the zigzag monopole antenna is 0.915 GHz, and the operating frequency of the slot antenna is 1.83 GHz.

3. The duplex antenna according to claim 1, wherein: The first fold line segment of the zigzag feed line is parallel to the connecting line of the left and right vertices of the parallel hexagonal window, the second fold line segment bends upward and is perpendicular to the first fold line segment, and the third fold line segment bends rightward and is parallel to the first fold line segment.

4. The duplex antenna according to claim 1, wherein: The first fold line segment of the zigzag monopole antenna is parallel to the connecting line of the left and right vertices of the parallel hexagonal window, the second fold line segment bends downward and is perpendicular to the first fold line segment, and the third fold line segment bends leftward and is parallel to the first fold line segment.

5. The duplex antenna according to claim 1, wherein: The first microstrip feeding line and the second microstrip feeding line are both perpendicular to a line connecting the left vertex and the right vertex of the parallel hexagonal window.

6. The duplex antenna according to claim 5, wherein: The first port and the second port are located on the same side of the dielectric substrate.

7. The duplex antenna according to claim 1, wherein: The width of the meander monopole antenna is smaller than the width of the first microstrip feed line, and the width of the meander feed line is smaller than the width of the second microstrip feed line.

8. The duplex antenna according to claim 1, wherein: The dielectric substrate is an FR4 substrate, which has a dielectric constant of 4.4 and a tangent loss of 0.02.

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