A beam switching antenna system based on reconfigurable technology

Abstract

The application discloses a beam switching antenna system based on a reconfigurable technology, and relates to the technical field of wireless communication.The beam switching antenna system based on the reconfigurable technology comprises a multi-element antenna array, a Nolen matrix feed network and a reconfigurable power divider.The reconfigurable power divider in the beam switching antenna system based on the reconfigurable technology can switch different working states, and the Nolen matrix feed network further distributes signal energy, so that the output signal of the reconfigurable power divider meets the amplitude and phase conditions of single-beam, double-beam or wide-beam to feed the multi-element antenna array, thereby realizing flexible switching of single-beam, double-beam and wide-beam, and having the advantages of small system overhead, low power consumption, rich beam types and flexible switching.The application is widely applied to the field of wireless communication technology.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a beam-switching antenna system based on reconfigurable technology. Background Technology

[0002] High-reliability, low-latency communication is a key requirement for fifth-generation, sixth-generation, and more advanced wireless communication systems. Antennas, as essential components of the radio frequency front-end of communication systems, are evolving towards multiple antennas, multiple beams, and smaller sizes in advanced communication systems. Beamforming antennas, with their multi-beam and directional radiation characteristics, can reduce interference and increase system channel capacity, making them an important technology in multi-antenna systems. However, existing beamforming antennas suffer from drawbacks such as high system overhead, high power consumption, and limited beam variety. Summary of the Invention

[0003] In view of the technical problems of high overhead, high power consumption and limited beam types in current flexible multi-beam antenna systems, the purpose of this invention is to provide a beam switching antenna system based on reconfigurable technology.

[0004] This invention includes a beam-switching antenna system based on reconfigurable technology, the beam-switching antenna system based on reconfigurable technology comprising:

[0005] A multi-element antenna array; the multi-element antenna array includes multiple antenna elements;

[0006] Nolan matrix feed network; the Nolan matrix feed network includes multiple input terminals and multiple output terminals, and each output terminal of the Nolan matrix feed network is connected to a corresponding antenna element;

[0007] A reconfigurable power divider; the reconfigurable power divider includes one input terminal and multiple output terminals, each output terminal of the reconfigurable power divider is connected to a corresponding input terminal of the Nolan matrix feed network, and the reconfigurable power divider is used to equally distribute the signal energy received at its input terminal to some or all of its output terminals.

[0008] Furthermore, the beam-switching antenna system based on reconfigurable technology also includes:

[0009] A dielectric substrate; the multi-element antenna array, the Nolan matrix feed network, and the reconfigurable power divider are all disposed on the dielectric substrate; wherein the Nolan matrix feed network and the reconfigurable power divider are disposed on the top surface of the dielectric substrate, and the bottom surface of the dielectric substrate is provided with a metal ground.

[0010] Furthermore, the number of antenna elements is three, and each antenna element includes three sets of butterfly log-periodic end-fire antennas, as well as microstrip lines connecting each butterfly log-periodic end-fire antenna.

[0011] Furthermore, each set of the butterfly log-periodic end-fire antennas includes a pair of sector-shaped metal patches. In the same butterfly log-periodic end-fire antenna, one sector-shaped metal patch is disposed on the top surface of the dielectric substrate and connected to the output end of the Nolan matrix feed network through a microstrip line, and the other sector-shaped metal patch is disposed on the bottom surface of the dielectric substrate and connected to the metal ground through a microstrip line. The projections of the two sector-shaped metal patches on the dielectric substrate are symmetrical.

[0012] Furthermore, the Nolan matrix feed network includes a first coupler, a second coupler, a third coupler, a first phase shifter, a second phase shifter, a third phase shifter, and a fourth phase shifter;

[0013] One input of the first coupler is connected to the fourth port of the Nolan matrix feed network, and the other input of the first coupler is connected to one output of the second coupler through the first phase shifter.

[0014] One output of the first coupler is connected to the seventh port of the Nolan matrix feed network via the third phase shifter, and the other output of the first coupler is connected to one input of the third coupler.

[0015] One input of the second coupler is connected to the fifth port of the Nolan matrix feed network, the other input of the second coupler is connected to the sixth port of the Nolan matrix feed network, and the other output of the second coupler is connected to the other input of the third coupler through the second phase shifter;

[0016] One output of the third coupler is connected to the eighth port of the Nolan matrix feed network via the fourth phase shifter, and the other output of the third coupler is connected to the ninth port of the Nolan matrix feed network.

[0017] The fourth, fifth, and sixth ports serve as input terminals of the Nolan matrix feed network, while the seventh, eighth, and ninth ports serve as output terminals of the Nolan matrix feed network.

[0018] Furthermore, the first coupler, the second coupler, and the third coupler are branch-line orthogonal couplers, the coupling ratio of the first coupler is 3dB, and the coupling ratio of the second coupler and the third coupler is 0dB;

[0019] The first phase shifter, the second phase shifter, the third phase shifter, and the fourth phase shifter are microstrip transmission line delay phase shifters. The phase shift of the first phase shifter and the second phase shifter is 45°, the phase shift of the third phase shifter is 90°, and the phase shift of the fourth phase shifter is -90°.

[0020] Furthermore, the surfaces of the first coupler, the second coupler, and the third coupler are respectively etched with a grid-shaped metal structure.

[0021] Furthermore, the reconfigurable power divider includes a first reconfigurable impedance matching network, a second reconfigurable impedance matching network, a third reconfigurable impedance matching network, a fourth reconfigurable impedance matching network, a second switch, a third switch, a fourth switch, an eighth switch, a ninth switch, and a tenth switch.

[0022] The second switch is used to controllably connect or disconnect the connection between the output terminal of the first reconfigurable impedance matching network and the input terminal of the second reconfigurable impedance matching network;

[0023] The third switch is used to controllably connect or disconnect the connection between the output terminal of the first reconfigurable impedance matching network and the input terminal of the third reconfigurable impedance matching network.

[0024] The fourth switch is used to controllably connect or disconnect the connection between the output terminal of the first reconfigurable impedance matching network and the input terminal of the fourth reconfigurable impedance matching network.

[0025] The eighth switch is used to controllably connect or disconnect the connection between the output of the second reconfigurable impedance matching network and the first port of the reconfigurable power divider.

[0026] The ninth switch is used to controllably connect or disconnect the connection between the output of the third reconfigurable impedance matching network and the second port of the reconfigurable power divider.

[0027] The tenth switch is used to controllably connect or disconnect the connection between the output of the fourth reconfigurable impedance matching network and the third port of the reconfigurable power divider.

[0028] The first port, the second port, and the third port serve as the output terminals of the reconfigurable power divider.

[0029] Furthermore, the reconfigurable power divider also includes a first matching resistor, a second matching resistor, a third matching resistor, an eleventh switch, a twelfth switch, and a thirteenth switch;

[0030] The eleventh switch is used to controllably connect or disconnect one end of the first matching resistor from the first port;

[0031] The twelfth switch is used to controllably connect or disconnect one end of the second matching resistor from the second port;

[0032] The thirteenth switch is used to controllably connect or disconnect one end of the third matching resistor from the third port;

[0033] The other ends of the first matching resistor, the second matching resistor, and the third matching resistor are grounded.

[0034] Furthermore, the first reconfigurable impedance matching network, the second reconfigurable impedance matching network, the third reconfigurable impedance matching network, and the fourth reconfigurable impedance matching network respectively include a short-circuit stub, an open-circuit stub, a switch, and a microstrip transmission line;

[0035] In the first reconfigurable impedance matching network, one end of the short-circuit stub is connected to the open-circuit stub via a switch. One end of the short-circuit stub serves as the input terminal and is connected to one end of the microstrip transmission line. The other end of the microstrip transmission line serves as the output terminal, and the other end of the short-circuit stub is grounded.

[0036] In any of the second, third, and fourth reconfigurable impedance matching networks, one end of the short-circuit stub is connected to the open-circuit stub via a switch, one end of the microstrip transmission line serves as the input, the other end of the microstrip transmission line serves as the output and is connected to one end of the short-circuit stub, and the other end of the short-circuit stub is grounded.

[0037] A switch in any reconfigurable impedance matching network is used to controllably connect or disconnect the connection between open-circuit and short-circuit branches.

[0038] The beneficial effects of the present invention are as follows: In the reconfigurable beam switching antenna system of the embodiment, the reconfigurable power divider can switch between different working states, and the signal energy is further distributed by the Nolan matrix feeding network, so that its output signal meets the amplitude and phase conditions of single beam, dual beam or wide beam to feed the multi-element antenna array, thereby realizing flexible switching between single beam, dual beam and wide beam, and has the advantages of low system overhead, low power consumption, rich beam types and flexible switching. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the basic structure of the beam-switching antenna system based on reconfigurable technology in the embodiment;

[0040] Figure 2 This is a schematic diagram of the reconfigurable power divider in the embodiment;

[0041] Figure 3This is a schematic diagram of the reconfigurable impedance matching network for two different structures in the embodiments;

[0042] Figure 4 This is the circuit layout of the reconfigurable power divider in the embodiment;

[0043] Figure 5 This is a schematic diagram of the Nolan matrix feed network in the embodiment;

[0044] Figure 6 This is the circuit layout of the Nolan matrix feed network in the embodiment;

[0045] Figure 7 This is a schematic diagram of the structure of the multi-element antenna array and the antenna elements therein in the embodiment;

[0046] Figure 8 This is a top view of the actual beam-switching antenna system based on reconfigurable technology in the embodiment.

[0047] Figure 9 This is a bottom view of the actual beam-switching antenna system based on reconfigurable technology in the embodiment.

[0048] Figure 10 This is a comparison chart of the reflection coefficient and transmission coefficient results from the simulation and measurement of the reconfigurable power divider in the embodiment.

[0049] Figure 11 This is a comparison chart of the reflection coefficient and transmission coefficient results from simulation and measurement of the Nolan matrix feeder network in the embodiment.

[0050] Figure 12 This is the radiation pattern simulated for a three-element antenna array in the embodiment;

[0051] Figure 13 This is a comparison chart of the reflection coefficients from simulation and measurement of a beam-switching antenna system based on reconfigurable technology in the embodiment.

[0052] Figure 14 The above is a comparison of the radiation patterns from simulation and measurement of a beam-switching antenna system based on reconfigurable technology, as shown in the examples. Detailed Implementation

[0053] In this embodiment, the basic structure of the beam-switching antenna system based on reconfigurable technology is as follows: Figure 1 As shown, it includes a reconfigurable power divider, a Nolan matrix feed network, and a multi-element antenna array.

[0054] Reference Figure 1The reconfigurable power divider includes one input terminal and multiple output terminals, the Nolan matrix feed network includes multiple input terminals and multiple output terminals, and the multi-element antenna array includes multiple antenna elements; any output terminal of the reconfigurable power divider is connected to a corresponding input terminal of the Nolan matrix feed network, and any output terminal of the Nolan matrix feed network is connected to a corresponding antenna element; when Figure 1 When the beam-switching antenna system based on reconfigurable technology is in operation, a signal is input to the input of the reconfigurable power divider. The reconfigurable power divider distributes the signal energy received at its input equally to part or all of its output. The Nolan matrix feed network further distributes the signal energy, and its output signal satisfies the amplitude and phase conditions for single-beam, dual-beam, or wide-beam operation. Some or all of the antenna elements in the multi-element antenna array receive the signal energy distributed and adjusted by the reconfigurable power divider and the Nolan matrix feed network. The antenna elements that receive the signal energy radiate the signal energy into free space. By switching different operating states of the reconfigurable power divider, specific antenna elements in the multi-element antenna array can be selected to receive the signal energy, thereby achieving flexible switching between single-beam, dual-beam, and wide-beam operation.

[0055] In this embodiment, the reconfigurable power divider, Nolan matrix feed network, and multi-element antenna array are all mounted on a dielectric substrate using microstrip technology. For example, good conductors such as gold, silver, or copper are printed onto a PCB using PCB printing technology to form the reconfigurable power divider, Nolan matrix feed network, and multi-element antenna array. The dielectric substrate is made of Rogers RO4003C material with a dielectric constant of 3.38-3.55 and a thickness of 0.813 mm.

[0056] Specifically, the dielectric substrate is divided into a top surface and a bottom surface. The Nolan matrix power supply network and the reconfigurable power divider are disposed on the top surface of the dielectric substrate, and a metal ground is provided on the bottom surface of the dielectric substrate.

[0057] In this embodiment, the structure of the reconfigurable power divider is as follows: Figure 2 As shown. (Refer to...) Figure 2 The reconfigurable power divider includes a first reconfigurable impedance matching network, a second reconfigurable impedance matching network, a third reconfigurable impedance matching network, a fourth reconfigurable impedance matching network, a second switch (switch 2), a third switch (switch 3), a fourth switch (switch 4), an eighth switch (switch 8), a ninth switch (switch 9), a tenth switch (switch 10), a first matching resistor, a second matching resistor, a third matching resistor, an eleventh switch (switch 11), a twelfth switch (switch 12), and a thirteenth switch (switch 13), etc.

[0058] Figure 2The first, second, third, and fourth reconfigurable impedance matching networks shown are simplified structural diagrams; their specific structures are as follows: Figure 3 As shown. (Refer to...) Figure 3 The first, second, third, and fourth reconfigurable impedance matching networks all contain the same components. However, the first reconfigurable impedance matching network has a unique structure, while the second, third, and fourth reconfigurable impedance matching networks have the same structure.

[0059] Specifically, the first, second, third, and fourth reconfigurable impedance matching networks all include components such as short-circuit stubs, open-circuit stubs, switches, and microstrip transmission lines.

[0060] Reference Figure 3 In the first reconfigurable impedance matching network, the included switch is a first switch (switch 1). One end of the short-circuit stub is connected to the open-circuit stub via the first switch (switch 1). One end of the short-circuit stub is port 0, serving as the input terminal of the first reconfigurable impedance matching network and connected to one end of the microstrip transmission line. The other end of the microstrip transmission line serves as the output terminal of the first reconfigurable impedance matching network, connected to the second switch (switch 2), the third switch (switch 3), and the fourth switch (switch 4). The other end of the short-circuit stub is grounded. The first switch (switch 1) is used to controllably connect or disconnect the connection between the open-circuit stub and the short-circuit stub. For example, when the first switch (switch 1) is open, the open-circuit stub in the first reconfigurable impedance matching network will disconnect from the short-circuit stub, and when the first switch (switch 1) is closed, the open-circuit stub and the short-circuit stub will connect.

[0061] Reference Figure 2 and Figure 3 Taking the second reconfigurable impedance matching network as an example, it includes a fifth switch (switch 5). One end of the short-circuit stub is connected to the open-circuit stub through the fifth switch (switch 5). One end of the microstrip transmission line serves as the input terminal of the second reconfigurable impedance matching network and is connected to the second switch (switch 2). The other end of the microstrip transmission line serves as the output terminal of the second reconfigurable impedance matching network and is connected to one end of the short-circuit stub. The output terminal is connected to the eighth switch (switch 8), and the other end of the short-circuit stub is grounded. The eighth switch (switch 8) is used to controllably connect or disconnect the connection between the open-circuit stub and the short-circuit stub. For example, when the eighth switch (switch 8) is open, the open-circuit stub in the second reconfigurable impedance matching network will disconnect from the short-circuit stub, and when the eighth switch (switch 8) is closed, the open-circuit stub and the short-circuit stub will connect.

[0062] Similarly, refer to Figure 2 and Figure 3 The third reconfigurable impedance matching network includes a sixth switch (switch 6). One end of the short-circuit stub is connected to the open-circuit stub via the sixth switch (switch 6). One end of the microstrip transmission line serves as the input of the second reconfigurable impedance matching network and is connected to the third switch (switch 3). The other end of the microstrip transmission line serves as the output of the second reconfigurable impedance matching network and is connected to one end of the short-circuit stub. The output is connected to the ninth switch (switch 9), and the other end of the short-circuit stub is grounded. The ninth switch (switch 9) is used to controllably connect or disconnect the connection between the open-circuit stub and the short-circuit stub.

[0063] Similarly, refer to Figure 2 and Figure 3 The fourth reconfigurable impedance matching network includes a seventh switch (switch 7). One end of the short-circuit stub is connected to the open-circuit stub via the seventh switch (switch 7). One end of the microstrip transmission line serves as the input of the second reconfigurable impedance matching network and is connected to the fourth switch (switch 4). The other end of the microstrip transmission line serves as the output of the second reconfigurable impedance matching network and is connected to one end of the short-circuit stub. The output is connected to the tenth switch (switch 10), and the other end of the short-circuit stub is grounded. The tenth switch (switch 10) is used to controllably connect or disconnect the connection between the open-circuit stub and the short-circuit stub.

[0064] The reconfigurable impedance matching network in this embodiment achieves impedance reconfigurability by controlling whether the open-circuit stub transmission line is connected to the circuit.

[0065] In this embodiment, refer to Figure 2 The other ends of the first matching resistor, the second matching resistor, and the third matching resistor are grounded. The eleventh switch (switch 11) can controllably connect or disconnect one end of the first matching resistor from the first port (port 1). The twelfth switch (switch 12) can controllably connect or disconnect one end of the second matching resistor from the second port (port 2). The thirteenth switch (switch 13) can controllably connect or disconnect one end of the third matching resistor from the third port (port 3).

[0066] In this embodiment, refer to Figure 2The second switch (switch 2) controllably connects or disconnects the connection between the output terminal of the first reconfigurable impedance matching network and the input terminal of the second reconfigurable impedance matching network; the third switch (switch 3) controllably connects or disconnects the connection between the output terminal of the first reconfigurable impedance matching network and the input terminal of the third reconfigurable impedance matching network; the fourth switch (switch 4) controllably connects or disconnects the connection between the output terminal of the first reconfigurable impedance matching network and the input terminal of the fourth reconfigurable impedance matching network; the eighth switch (switch 8) controllably connects or disconnects the connection between the output terminal of the second reconfigurable impedance matching network and the first port (port 1) of the reconfigurable power divider; the ninth switch (switch 9) controllably connects or disconnects the connection between the output terminal of the third reconfigurable impedance matching network and the second port (port 2) of the reconfigurable power divider; and the tenth switch (switch 10) controllably connects or disconnects the connection between the output terminal of the fourth reconfigurable impedance matching network and the third port (port 3) of the reconfigurable power divider.

[0067] In this embodiment, Figure 2 In the reconfigurable power divider shown, refer to Figure 3 The input terminal (port 0) of the first reconfigurable impedance matching network serves as the input terminal of the entire reconfigurable power divider, while the first port (port 1), the second port (port 2), and the third port (port 3) serve as the output terminals of the reconfigurable power divider.

[0068] In this embodiment, the first reconfigurable impedance matching network belongs to the first type of reconfigurable impedance matching network structure, while the second, third, and fourth reconfigurable impedance matching networks belong to the second type of reconfigurable impedance matching network structure. Because the positions of the microstrip transmission lines included in these two types of reconfigurable impedance matching networks are different, the impedance matching values ​​corresponding to these two structures are different. Generally, the impedance matching is achieved first by adjusting the width of the microstrip transmission lines in the first type of reconfigurable impedance matching network, and then the impedance matching is further adjusted by adjusting the length of the microstrip transmission lines in the second type of reconfigurable impedance matching network.

[0069] In this embodiment, it has Figure 3 The reconfigurable impedance matching network shown Figure 2 The reconfigurable power divider shown has the following circuit layout: Figure 4 As shown.

[0070] Specifically, in the specific circuit implementation of the reconfigurable power divider, switch 1 controls whether the open-circuit stub inside the reconfigurable impedance matching network of the first structure is connected to the network; switches 2, 3, and 4 respectively control whether the reconfigurable impedance matching network of the first structure (i.e., the first reconfigurable impedance matching network) is connected to the three impedance matching networks of the second structure (i.e., the second, third, and fourth reconfigurable impedance matching networks); switches 5, 6, and 7 respectively act as single-pole single-throw switches, controlling whether the open-circuit stub inside the three reconfigurable impedance matching networks of the second structure is connected to the network; switches 8 and 11, 9 and 12, and 10 and 13 respectively act as single-pole double-throw switches, controlling the system output port to connect to the second reconfigurable impedance matching network or the matching resistor.

[0071] In this embodiment, each switch, from switch 1 to switch 13, can be implemented using devices such as diodes. Specifically, a diode has two states: on and off, thus enabling the switch to control the circuit. The on / off state of the diode is affected by DC bias, so a DC bias circuit can be set up to control the on / off state of the diode, making the switching states of each switch, from switch 1 to switch 13, independently controllable.

[0072] Reference Figure 3 In this embodiment, in the specific circuit implementation of the reconfigurable power divider, the microstrip transmission lines connecting the input and output ports of the reconfigurable impedance matching network of the second structure and their placement are adjusted to achieve good impedance matching. Additionally, a choke inductor can be added at the connection point between the DuPont wire of the diode's DC bias circuit and the high-frequency circuit, and DC blocking capacitors can be added at the connection points between the port and the high-frequency circuit, as well as at the connections between metals electrically connected to the diode.

[0073] Due to the influence of diode parasitic parameters, choke inductance, and DC blocking capacitance, the microstrip transmission line connecting the input and output ports of the second type of impedance matching network can be fine-tuned. Specifically, impedance matching is achieved by adjusting the width of the two microstrip transmission lines connecting the input and output ports. Next, the three reconfigurable impedance matching networks of the second structure, after being adjusted for impedance matching, are connected to the microstrip transmission lines between switches 2 and 8, 3 and 9, and 4 and 10, respectively, and the positions of the three reconfigurable impedance matching networks of the second structure are fine-tuned to achieve impedance matching.

[0074] In this embodiment, the structure of the Nolan matrix feed network is as follows: Figure 5 As shown. (Refer to...) Figure 5The Nolan matrix feed network includes a first coupler (coupler 1), a second coupler (coupler 2), a third coupler (coupler 3), a first phase shifter (phase shifter 1), a second phase shifter (phase shifter 2), a third phase shifter (phase shifter 3), and a fourth phase shifter (phase shifter 4). In this embodiment, the first, second, and third couplers are all miniaturized branch-line orthogonal couplers with distributed printed capacitors, wherein the coupling ratio of the first coupler is 3dB, and the coupling ratio of the second and third couplers is 0dB; the first, second, third, and fourth phase shifters are all microstrip transmission line delay phase shifters, wherein the phase shift of the first and second phase shifters is 45°, the phase shift of the third phase shifter is 90°, and the phase shift of the fourth phase shifter is -90°.

[0075] In this embodiment, the first coupler (coupler 1) and other orthogonal couplers and the first phase shifter (phase shifter 1) and other phase shifters are connected by microstrip transmission lines. The width of the microstrip transmission line used for connection is determined according to the working passband, and the length and shape are determined according to the specific layout.

[0076] Reference Figure 5 One input terminal (labeled 1) of the first coupler (coupler 1) is connected to the fourth port (port 4) of the Nolan matrix feed network, and the other input terminal (labeled 2) of the first coupler (coupler 1) is connected to one output terminal (labeled 3) of the second coupler (coupler 2) through the first phase shifter (phase shifter 1).

[0077] Reference Figure 5 One output terminal (labeled 3) of the first coupler (coupler 1) is connected to the seventh port (port 7) of the Nolan matrix feed network through the third phase shifter (phase shifter 3), and the other output terminal (labeled 4) of the first coupler (coupler 1) is connected to one input terminal (labeled 1) of the third coupler (coupler 3).

[0078] Reference Figure 5 One input terminal (labeled 1) of the second coupler (coupler 2) is connected to the fifth port (port 5) of the Nolan matrix feed network, and the other input terminal (labeled 2) of the second coupler (coupler 2) is connected to the sixth port (port 6) of the Nolan matrix feed network. The other output terminal (labeled 4) of the second coupler (coupler 2) is connected to the other input terminal (labeled 2) of the third coupler (coupler 3) through the second phase shifter (phase shifter 2).

[0079] Reference Figure 5, one output terminal (labeled 3) of the third coupler (Coupler 3) is connected to the eighth port (Port 8) of the Nolan matrix feeding network through the fourth phase shifter (Phase Shifter 4), and the other output terminal (labeled 4) of the third coupler (Coupler 3) is connected to the ninth port (Port 9) of the Nolan matrix feeding network.

[0080] Refer to Figure 5 , the fourth port (Port 4), the fifth port (Port 5), and the sixth port (Port 6) serve as the input terminals of the Nolan matrix feeding network, and the seventh port (Port 7), the eighth port (Port 8), and the ninth port (Port 9) serve as the output terminals of the Nolan matrix feeding network.

[0081] In this embodiment, Figure 5 For the Nolan matrix feeding network shown, its corresponding circuit layout is as shown in Figure 6 shown.

[0082] Refer to Figure 6 , on the surfaces of the first coupler, the second coupler, and the third coupler in the Nolan matrix feeding network, a "field" - shaped metal structure is etched respectively. The specific dimensions of the "field" - shaped metal structure are determined according to the actual operating frequency and the coupler coupling ratio. By setting the "field" - shaped metal structure, the same coupler performance can be achieved with a smaller coupler volume, thereby reducing the circuit size of the Nolan matrix feeding network.

[0083] In this embodiment, the structure of the multi - unit antenna array and the antenna units therein is as shown in Figure 7 shown. Refer to Figure 7 the left - hand part of. In this embodiment, the multi - unit antenna array has 3 antenna units, so the multi - unit antenna array can also be called a three - unit antenna array. Refer to Figure 7 the right - hand part of. Each antenna unit includes 3 groups of butterfly - shaped log - periodic end - fire antennas and microstrip lines connecting the butterfly - shaped log - periodic end - fire antennas. Each group of butterfly - shaped log - periodic end - fire antennas includes a pair of fan - shaped metal patches. In the same butterfly - shaped log - periodic end - fire antenna, one fan - shaped metal patch is arranged on the top surface of the dielectric substrate and is connected to the output terminal of the Nolan matrix feeding network through a microstrip line, and the other fan - shaped metal patch is arranged on the bottom surface of the dielectric substrate and is connected to the metal ground through a microstrip line. The projections of the two fan - shaped metal patches on the dielectric substrate are symmetric with respect to the straight line where the microstrip line is located.

[0084] In this embodiment, the top view (the direction seen from the top surface of the dielectric substrate) of the physical object of the beam - switching antenna system based on the reconfigurable technology is as shown in Figure 8 shown, and the bottom view (the direction seen from the bottom surface of the dielectric substrate) is as shown in Figure 9 shown. Refer to Figure 8The multi-element antenna array has three antenna elements. The first antenna element is connected to the first output (port 7) of the Nolan matrix feed network via a microstrip line. The second antenna element is connected to the second output (port 8) of the Nolan matrix feed network via a microstrip line. The third antenna element is connected to the third output (port 9) of the Nolan matrix feed network via a microstrip line. (Refer to...) Figure 9 The beam-switching antenna system based on reconfigurable technology also includes a DC control circuit, which includes a DC power supply and a DC control switch. The DC control circuit is connected to several diodes of the reconfigurable power divider through DuPont wires, and the diode switching is controlled by changing the bias voltage.

[0085] In this embodiment, by changing the bias voltage of the diodes used as switches 1-13, thereby changing their on / off state, the reconfigurable power divider can achieve the output of input energy in equal parts, equal parts, or equal parts to the output port. Here, equal parts refers to the energy being divided from... Figure 2 and Figure 4 The signal energy input at port 0 is directly fed to one output port (e.g., any one of port 1, port 2, and port 3), corresponding to states 1, 2, and 3 in Table 1; bi-splitting means that the input energy is fed to two output ports (e.g., any two of port 1, port 2, and port 3) in equal parts, corresponding to states 4, 5, and 6 in Table 1; tri-splitting means that the input energy is fed to three output ports (port 1, port 2, and port 3) in equal parts, corresponding to state 7 in Table 1.

[0086] Table 1 Diode coding table under different conditions

[0087]

[0088] In this embodiment, port 1 of the reconfigurable power divider is connected to port 4 of the Nolan matrix feed network. Therefore, when port 1 outputs signal energy, this signal energy will be input from port 4 into the Nolan matrix feed network and output from port 7 to a connected antenna element. Similarly, port 2 is connected to port 5. When port 2 outputs signal energy, this signal energy will be input from port 5 into the Nolan matrix feed network and output from port 8 to a connected antenna element. Port 3 is connected to port 6. When port 3 outputs signal energy, this signal energy will be input from port 6 into the Nolan matrix feed network and output from port 9 to a connected antenna element. Therefore, by controlling the switching of each diode used as switch 1-switch 13 according to the coding shown in Table 1, the output ports of signal energy can be controlled, thereby output by the corresponding antenna elements in the multi-element antenna array. Therefore, the beam-switching antenna system based on reconfigurable technology in this embodiment can achieve the technical effect through the following working principle:

[0089] (1) The reconfigurable power divider outputs the energy of the system input port to the three input ports of the Nolan matrix power supply network in a directional manner. By changing the on / off state of the diodes in the reconfigurable power divider through the DC control circuit, the reconfigurable power divider can realize flexible power supply to the Nolan matrix power supply network, that is, independently powering one port, simultaneously powering two ports, or simultaneously powering three ports.

[0090] (2) The Nolan matrix feed network further distributes the energy, and its output signal satisfies the amplitude and phase conditions of single beam, dual beam or wide beam.

[0091] (3) The multi-element antenna array radiates the signal that has been distributed and adjusted by the reconfigurable power divider and the Nolan matrix feed network into free space. By switching different working states of the reconfigurable power divider, flexible switching between single beam, dual beam and wide beam can be achieved.

[0092] The technical advantages of this invention are mainly due to its structure. When manufacturing the antenna system of this invention, firstly, the dimensions of the microstrip transmission line in the reconfigurable power divider and the open-circuit and short-circuit transmission line branches of the reconfigurable impedance matching network are determined based on the desired center frequency and target power division ratio of the antenna. Then, the Nolan matrix feed network is designed based on the number of output ports of the reconfigurable power divider and the number of antenna array elements. Further, antenna elements operating in the target frequency band are designed and arranged in an array. Next, the designed reconfigurable power divider, Nolan matrix feed network, and multi-element antenna array are connected using microstrip transmission lines to obtain the antenna system. Finally, the antenna parameters are optimized according to the required performance.

[0093] After analysis and optimization, the specific settings of each parameter in this embodiment are as follows: Figure 4 , Figure 7 , Figure 6 As shown.

[0094] according to Figure 4 , Figure 7 , Figure 6 The numerical values ​​indicated in the figure are used to manufacture a reconfigurable power divider, a Nolan matrix feed network, and an antenna array structure of corresponding dimensions. Simulations are performed on these values, and the manufactured antenna system is then tested in real-world conditions. The simulation and test results are as follows: Figures 10-14 As shown.

[0095] The comparison chart of reflection coefficient and transmission coefficient results for the reconfigurable power divider from simulation and measurement is shown below. Figure 10 As shown. By Figure 10As can be seen, the reconfigurable power divider in this embodiment can achieve single-port output at ports 1, 2, and 3 in states 1, 2, and 3, respectively; in states 4, 5, and 6, it can achieve equal power output at ports 1 and 2, 1 and 3, and 2 and 3, respectively; and in state 7, it can achieve equal power output at ports 1, 2, and 3. The measured insertion loss is 1.5-3 dB lower than the simulation result, which is due to the deviation caused by the DuPont wire, the diode parasitic effect, and the manufacturing error.

[0096] The comparison of reflection coefficient and transmission coefficient results for the Nolan matrix feeder network from simulation and measurement is shown in the figure below. Figure 11 As shown. By Figure 11 It can be seen that the Nolan matrix power supply network in this embodiment has good port matching and high port isolation, and can realize the function of equal power distribution; at the same time, when the input ports 1, 2 and 3 are excited individually, the phase differences between adjacent output ports are 0°, -120° and 120° respectively.

[0097] The radiation pattern simulated for a three-element antenna array is as follows: Figure 12 As shown. By Figure 12 It can be seen that the three-element antenna array in this embodiment can achieve a wide beam radiation pattern when the three input ports are fed with equal amplitude and in phase.

[0098] The comparison of reflection coefficients between simulation and measurement for a beam-switching antenna system based on reconfigurable technology is shown in the figure below. Figure 13 As shown. By Figure 13 It can be seen that, in this embodiment, the reflection coefficient of the antenna system in the 4.9-5.1GHz frequency band is better than -10dB in all states.

[0099] Comparison of radiation patterns from simulation and measurement of a beam-switching antenna system based on reconfigurable technology is shown in the following figures. Figure 14 As shown. By Figure 14As can be seen, the antenna system in this embodiment can achieve five single-beam radiation patterns, one dual-beam radiation pattern, and one wide-beam radiation pattern. In states 1 to 5, the antenna system can achieve single-beam radiation patterns with beam pointing angles of 54°, 75°, 90°, 102°, and 123°, respectively; in state 6, the antenna system can achieve a dual-beam radiation pattern with a beam pointing angle of 90°±45°; and in state 7, the antenna system can achieve a wide-beam radiation pattern with a 3dB beamwidth of 39°-132°. The maximum measured gains for single-beam, dual-beam, and wide-beam radiation patterns are 4.6-5.2 dBi, 2.1 dBi, and 1.03 dBi, respectively. The average gain loss between measurement and simulation is 2.7 dBi. The additional loss mainly originates from the deviation caused by the DuPont wires in the reconfigurable power divider, diode parasitic effects, and system circuit fabrication errors.

[0100] All the above results were obtained using a vector network analyzer and a spherical far-field anechoic chamber under real-world conditions with a substrate material of Rogers 4003C, a dielectric constant of 3.38, and a substrate thickness of 0.813 mm. The simulation and test comparison charts show that the simulated and measured curves are in good agreement. The beam-switching antenna system based on reconfigurable technology can achieve single-beam, dual-beam, and wide-beam radiation patterns, offering advantages such as low system overhead, low power consumption, a rich variety of beam types, and flexible switching, demonstrating the feasibility of the proposed solution.

[0101] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "upper," "lower," "left," and "right" used in this disclosure are only relative to the relative positional relationships of the components of this disclosure in the accompanying drawings. The singular forms "a," "an," and "the" used in this disclosure are also intended to include the plural forms, unless the context clearly indicates otherwise. Moreover, unless otherwise defined, all technical and scientific terms used in this embodiment have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this embodiment specification is only for describing particular embodiments and is not intended to limit the invention. The term "and / or" as used in this embodiment includes any combination of one or more of the associated listed items.

[0102] It should be understood that although the terms first, second, third, etc., may be used to describe various elements in this disclosure, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, a first element may also be referred to as a second element without departing from the scope of this disclosure, and similarly, a second element may also be referred to as a first element. The use of any and all instances or exemplary language (“e.g.,” “such as,” etc.) provided in this embodiment is intended only to better illustrate embodiments of the invention and, unless otherwise required, does not impose a limitation on the scope of the invention.

[0103] It should be recognized that embodiments of the present invention can be implemented or carried out by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable storage medium. The method can be implemented using standard programming techniques—including a non-transitory computer-readable storage medium configured with a computer program, wherein such a storage medium causes the computer to operate in a specific and predefined manner—according to the methods and drawings described in the specific embodiments. Each program can be implemented in a high-level procedural or object-oriented programming language to communicate with the computer system. However, if desired, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language. Furthermore, for this purpose, the program can run on a programmed application-specific integrated circuit (ASIC).

[0104] Furthermore, the procedures described in this embodiment can be performed in any suitable order unless otherwise indicated by this embodiment or clearly contradicted by the context. The procedures (or variations and / or combinations thereof) described in this embodiment can be executed under the control of one or more computer systems configured with executable instructions, and can be implemented by hardware or a combination thereof as code (e.g., executable instructions, one or more computer programs, or one or more applications) that commonly executes on one or more processors. A computer program includes multiple instructions executable by one or more processors.

[0105] Furthermore, the method can be implemented in any suitable type of computing platform, including but not limited to personal computers, minicomputers, mainframes, workstations, networked or distributed computing environments, standalone or integrated computer platforms, or in communication with charged particle tools or other imaging devices, etc. Aspects of the invention can be implemented as machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, optical read and / or write storage medium, RAM, ROM, etc., such that it is readable by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the processes described herein. Furthermore, the machine-readable code, or portions thereof, can be transmitted via wired or wireless networks. The invention of this embodiment includes these and other different types of non-transitory computer-readable storage media when such media comprises instructions or programs that implement the steps above in conjunction with a microprocessor or other data processor. When programmed according to the methods and techniques of the invention, the invention also includes the computer itself.

[0106] A computer program can be applied to input data to perform the functions of this embodiment, thereby transforming the input data to generate output data stored in non-volatile memory. The output information can also be applied to one or more output devices, such as a display. In a preferred embodiment of the invention, the transformed data represents physical and tangible objects, including specific visual depictions of physical and tangible objects generated on the display.

[0107] The above are merely preferred embodiments of the present invention. The present invention is not limited to the above-described embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention, as long as they achieve the technical effects of the present invention by the same means, should be included within the scope of protection of the present invention. Within the scope of protection of the present invention, the technical solutions and / or implementation methods can have various modifications and variations.

Claims

1. A reconfigurable technology based beam switching antenna system, characterized by, The reconfigurable technology-based beam switching antenna system comprises: a multi-element antenna array; the multi-element antenna array comprises a plurality of antenna elements; a Nolen matrix feed network; the Nolen matrix feed network comprises a plurality of input terminals and a plurality of output terminals, and any output terminal of the Nolen matrix feed network is connected with a corresponding one of the antenna elements respectively; a reconfigurable power divider; the reconfigurable power divider comprises one input terminal and a plurality of output terminals, and any output terminal of the reconfigurable power divider is connected with a corresponding one of the input terminals of the Nolen matrix feed network respectively, and the reconfigurable power divider is used for equally dividing the signal energy received by its input terminal and distributing it to some or all of its output terminals; a dielectric substrate; the multi-element antenna array, the Nolen matrix feed network and the reconfigurable power divider are all arranged on the dielectric substrate; wherein the Nolen matrix feed network and the reconfigurable power divider are arranged on the top surface of the dielectric substrate, and the bottom surface of the dielectric substrate is provided with a metal ground plane; the number of the antenna elements is 3, and each of the antenna elements comprises three groups of butterfly-shaped log-periodic end-fire antennas and microstrip lines connecting the butterfly-shaped log-periodic end-fire antennas; each group of the butterfly-shaped log-periodic end-fire antennas comprises a pair of fan-shaped metal patches, in the same butterfly-shaped log-periodic end-fire antenna, one of the fan-shaped metal patches is arranged on the top surface of the dielectric substrate and connected with the output terminal of the Nolen matrix feed network through a microstrip line, and the other fan-shaped metal patch is arranged on the bottom surface of the dielectric substrate and connected with the metal ground plane through a microstrip line, and the projections of the two fan-shaped metal patches on the dielectric substrate are symmetrical.

2. The reconfigurable technology-based switched-beam antenna system of claim 1, wherein, the Nolen matrix feed network comprises a first coupler, a second coupler, a third coupler, a first phase shifter, a second phase shifter, a third phase shifter and a fourth phase shifter; one input terminal of the first coupler is connected to the fourth port of the Nolen matrix feed network, and the other input terminal of the first coupler is connected with one output terminal of the second coupler through the first phase shifter; one output terminal of the first coupler is connected to the seventh port of the Nolen matrix feed network through the third phase shifter, and the other output terminal of the first coupler is connected with one input terminal of the third coupler; one input terminal of the second coupler is connected to the fifth port of the Nolen matrix feed network, the other input terminal of the second coupler is connected to the sixth port of the Nolen matrix feed network, and the other output terminal of the second coupler is connected with the other input terminal of the third coupler through the second phase shifter; one output terminal of the third coupler is connected to the eighth port of the Nolen matrix feed network through the fourth phase shifter, and the other output terminal of the third coupler is connected to the ninth port of the Nolen matrix feed network; wherein the fourth port, the fifth port and the sixth port are used as the input terminals of the Nolen matrix feed network, and the seventh port, the eighth port and the ninth port are used as the output terminals of the Nolen matrix feed network.

3. The beam-switching antenna system based on reconfigurable technology according to claim 2, characterized in that: The first coupler, the second coupler, and the third coupler are branch-line orthogonal couplers. The coupling ratio of the first coupler is 3dB, and the coupling ratio of the second coupler and the third coupler is 0dB. The first phase shifter, the second phase shifter, the third phase shifter, and the fourth phase shifter are microstrip transmission line delay phase shifters. The phase shift of the first phase shifter and the second phase shifter is 45°, the phase shift of the third phase shifter is 90°, and the phase shift of the fourth phase shifter is -90°.

4. The reconfigurable technology-based switched-beam antenna system of claim 3, wherein, The surfaces of the first coupler, the second coupler, and the third coupler are respectively etched with a grid-shaped metal structure.

5. The reconfigurable technology-based switched-beam antenna system of claim 2, wherein, The reconfigurable power divider includes a first reconfigurable impedance matching network, a second reconfigurable impedance matching network, a third reconfigurable impedance matching network, a fourth reconfigurable impedance matching network, a second switch, a third switch, a fourth switch, an eighth switch, a ninth switch, and a tenth switch. The second switch is used to controllably connect or disconnect the connection between the output terminal of the first reconfigurable impedance matching network and the input terminal of the second reconfigurable impedance matching network; The third switch is used to controllably connect or disconnect the connection between the output terminal of the first reconfigurable impedance matching network and the input terminal of the third reconfigurable impedance matching network. The fourth switch is used to controllably connect or disconnect the connection between the output terminal of the first reconfigurable impedance matching network and the input terminal of the fourth reconfigurable impedance matching network. The eighth switch is used to controllably connect or disconnect the connection between the output of the second reconfigurable impedance matching network and the first port of the reconfigurable power divider. The ninth switch is used to controllably connect or disconnect the connection between the output of the third reconfigurable impedance matching network and the second port of the reconfigurable power divider. The tenth switch is used to controllably connect or disconnect the connection between the output of the fourth reconfigurable impedance matching network and the third port of the reconfigurable power divider. The first port, the second port, and the third port serve as the output terminals of the reconfigurable power divider.

6. The reconfigurable technology-based switched-beam antenna system of claim 5, wherein, The reconfigurable power divider also includes a first matching resistor, a second matching resistor, a third matching resistor, an eleventh switch, a twelfth switch, and a thirteenth switch; The eleventh switch is used to controllably connect or disconnect one end of the first matching resistor from the first port; The twelfth switch is used to controllably connect or disconnect one end of the second matching resistor from the second port; The thirteenth switch is used to controllably connect or disconnect one end of the third matching resistor from the third port; The other ends of the first matching resistor, the second matching resistor, and the third matching resistor are grounded.

7. The reconfigurable technology based beam switching antenna system of claim 5 or 6, wherein, The first reconfigurable impedance matching network, the second reconfigurable impedance matching network, the third reconfigurable impedance matching network, and the fourth reconfigurable impedance matching network each include a short-circuit stub, an open-circuit stub, a switch, and a microstrip transmission line, respectively. In the first reconfigurable impedance matching network, one end of the short-circuit stub is connected to the open-circuit stub through a switch, one end of the short-circuit stub serves as an input end and is connected to one end of a microstrip transmission line, the other end of the microstrip transmission line serves as an output end, and the other end of the short-circuit stub is grounded; In any one of the second reconfigurable impedance matching network, the third reconfigurable impedance matching network and the fourth reconfigurable impedance matching network, one end of the short-circuit stub is connected to the open-circuit stub through a switch, one end of the microstrip transmission line serves as an input end, the other end of the microstrip transmission line serves as an output end and is connected to one end of the short-circuit stub, and the other end of the short-circuit stub is grounded; The switch in any reconfigurable impedance matching network is used to controllably connect or disconnect the open-circuit stub and the short-circuit stub.

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