Beam switching antenna system based on reconfigurable technology

Abstract

The invention discloses a beam switching antenna system based on a reconfigurable technology. The beam switching antenna system based on the reconfigurable technology comprises a multi-unit antenna array, a Nolan 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 signal energy is further distributed by the Nolan matrix feed network, so that the output signal meets the amplitude and phase conditions of a single beam, a double beam or a wide beam to feed the multi-unit antenna array; therefore, flexible switching among a single beam, double beams and a wide beam is realized, and the method has the advantages of low system overhead, low power consumption, rich beam types and flexible switching. The method is widely applied to the technical field of wireless communication.

Description

Technical Field

[0001] The invention relates to the technical field of wireless communications, and in particular to a beam switching antenna system based on reconfigurable technology. Background Art

[0002] High reliability and low latency communication is one of the application requirements in the fifth, sixth and more advanced wireless communication systems. Antennas, as essential components of the RF front end of communication systems, are evolving towards multi-antenna, multi-beam and small size in advanced communication systems. Beamforming antennas have the characteristics of multi-beam and directional radiation, which can reduce interference and increase system channel capacity, and are an important technology in multi-antenna systems. However, existing beamforming antennas have disadvantages such as large system overhead, high power consumption and few beam types. Summary of the invention

[0003] In view of the technical problems of the current flexible multi-beam antenna system, such as high overhead, high power consumption, and few beam types, the object of the present invention is to provide a beam switching antenna system based on reconfigurable technology.

[0004] An embodiment of the present invention includes a beam switching antenna system based on a reconfigurable technology, and the beam switching antenna system based on a reconfigurable technology includes:

[0005] A multi-element antenna array; the multi-element antenna array comprises a plurality of antenna elements;

[0006] Nolan matrix feed network; the Nolan matrix feed network comprises a plurality of input terminals and a plurality of output terminals, and any output terminal of the Nolan matrix feed network is respectively connected to a corresponding one of the antenna units;

[0007] A reconfigurable power divider; the reconfigurable power divider comprises an input end and multiple output ends, any output end of the reconfigurable power divider is respectively connected to a corresponding input end of the Nolan matrix feeding network, and the reconfigurable power divider is used to equally distribute the signal energy received at its input end to part or all of its output ends.

[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 arranged on the dielectric substrate; wherein the Nolan matrix feed network and the reconfigurable power divider are arranged on the top surface of the dielectric substrate, and a metal ground is provided on the bottom surface of the dielectric substrate.

[0010] Furthermore, the number of the antenna units is 3, and each of the antenna units includes 3 groups of butterfly-shaped log-periodic end-fire antennas and a microstrip line connecting each of the butterfly-shaped log-periodic end-fire antennas.

[0011] Furthermore, each group of the butterfly log-periodic end-fire antennas includes a pair of fan-shaped metal patches. In the same butterfly log-periodic end-fire antenna, one fan-shaped metal patch is arranged on the top surface of the dielectric substrate and connected to the output end 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 connected to the metal ground through a microstrip line. The projections of the two fan-shaped metal patches on the dielectric substrate are symmetrical.

[0012] Further, 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 end of the first coupler is connected to the fourth port of the Nolan matrix feeding network, and another input end of the first coupler is connected to an output end of the second coupler through the first phase shifter;

[0014] One output end of the first coupler is connected to the seventh port of the Nolan matrix feeding network through the third phase shifter, and another output end of the first coupler is connected to an input end of the third coupler;

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

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

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

[0018] Further, 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 amount of the first phase shifter and the second phase shifter is 45°, the phase shift amount of the third phase shifter is 90°, and the phase shift amount of the fourth phase shifter is -90°.

[0020] Furthermore, a metal structure in a shape of a cross is etched on the surfaces of the first coupler, the second coupler and the third coupler respectively.

[0021] Further, 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 end of the first reconfigurable impedance matching network and the input end of the second reconfigurable impedance matching network;

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

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

[0025] The eighth switch is used to controllably connect or disconnect the connection between the output end 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 end 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 end 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 output ends of the reconfigurable power divider.

[0029] Further, the reconfigurable power divider further 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 the connection between one end of the first matching resistor and the first port;

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

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

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

[0034] Further, 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 branch, an open-circuit branch, a switch and a microstrip transmission line;

[0035] In the first reconfigurable impedance matching network, one end of the short-circuited branch is connected to the open-circuited branch through a switch, one end of the short-circuited branch 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-circuited branch is grounded;

[0036] 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;

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

[0038] The beneficial effects of the present invention are: in the beam switching antenna system based on reconfigurable technology in 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 satisfies the amplitude and phase conditions of a single beam, dual beam or wide beam to feed a multi-unit antenna array, thereby realizing flexible switching of single beam, dual beam and wide beam, and has the advantages of low system overhead, low power consumption, rich beam types and flexible switching. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0041] Figure 3Schematic diagrams of two structures of reconfigurable impedance matching networks in the embodiments;

[0042] Figure 4 is a circuit layout of a reconfigurable power divider in an embodiment;

[0043] Figure 5 It is a structural schematic diagram of the Nolan matrix feeding network in the embodiment;

[0044] Figure 6 A circuit layout of a Nolan matrix feeding network in an embodiment;

[0045] Figure 7 is a schematic structural diagram of a multi-unit antenna array and antenna units therein in an embodiment;

[0046] Figure 8 A top view of a real object of a beam switching antenna system based on a reconfigurable technology in an embodiment;

[0047] Fig. 9 A bottom view of a beam switching antenna system based on a reconfigurable technology in an embodiment;

[0048] Fig.10 A comparison diagram of the reflection coefficient and transmission coefficient results of the simulation and measurement for the reconfigurable power divider in the embodiment;

[0049] Fig.11 A comparison diagram of the reflection coefficient and transmission coefficient results of the Nolan matrix feed network simulation and measurement in the embodiment;

[0050] Fig.12 The radiation pattern simulated for the three-element antenna array in the embodiment;

[0051] Fig.13 A comparison diagram of the reflection coefficients of the simulated and measured beam switching antenna system based on the reconfigurable technology in the embodiment;

[0052] Fig.14 It is a comparison diagram of the radiation patterns of the simulation and measurement for the beam switching antenna system based on the reconfigurable technology in the embodiment. DETAILED DESCRIPTION

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

[0054] Reference Figure 1The reconfigurable power divider includes an input terminal and multiple output terminals, the Nolan matrix feed network includes multiple input terminals and multiple output terminals, and the multi-unit antenna array includes multiple antenna units; any output terminal of the reconfigurable power divider is respectively connected to a corresponding input terminal of the Nolan matrix feed network, and any output terminal of the Nolan matrix feed network is respectively connected to a corresponding antenna unit; when Figure 1 When the beam switching antenna system based on reconfigurable technology shown is working, a signal is input to the input end of the reconfigurable power divider. The reconfigurable power divider is used to equally distribute the signal energy received at its input end to part or all of its output ends. The Nolan matrix feeding network further distributes the signal energy, and its output signal meets the amplitude and phase conditions of a single beam, a dual beam or a wide beam. Some or all of the antenna units in the multi-unit antenna array receive the signal energy distributed and adjusted by the reconfigurable power divider and the Nolan matrix feeding network, and the antenna units that receive the signal energy radiate the signal energy into the free space. By switching different working states of the reconfigurable power divider, a specific antenna unit in the multi-unit antenna array can be selected to receive the signal energy, thereby realizing flexible switching among single beam, dual beam and wide beam.

[0055] In this embodiment, the circuit structures such as the reconfigurable power divider, the Nolan matrix feed network and the multi-element antenna array are fixed on the dielectric substrate by using a microstrip process. For example, a good conductor such as gold, silver or copper is printed on the PCB by using a PCB printing process, thereby forming the reconfigurable power divider, the Nolan matrix feed network and the 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 feeding 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.

[0057] In this embodiment, the structure of the reconfigurable power divider is as follows: Figure 2 See 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 reconfigurable impedance matching network, the second reconfigurable impedance matching network, the third reconfigurable impedance matching network and the fourth reconfigurable impedance matching network shown in FIG. 1 are simplified structural diagrams. Their specific structures are as follows Figure 3 See Figure 3 , the components included in 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 are the same, but the first reconfigurable impedance matching network forms a unique structure, while the structures of the second reconfigurable impedance matching network, the third reconfigurable impedance matching network and the fourth reconfigurable impedance matching network are the same.

[0059] Specifically, 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 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 switch included therein is a first switch (switch 1), one end of the short-circuit branch is connected to the open-circuit branch through the first switch (switch 1), one end of the short-circuit branch is port 0, which serves as the input end of the first reconfigurable impedance matching network and is connected to one end of the microstrip transmission line, the other end of the microstrip transmission line serves as the output end of the first reconfigurable impedance matching network, is connected to the second switch (switch 2), the third switch (switch 3) and the fourth switch (switch 4), and the other end of the short-circuit branch is grounded. The first switch (switch 1) is used to controllably connect or disconnect the connection between the open-circuit branch and the short-circuit branch. For example, when the first switch (switch 1) is disconnected, the open-circuit branch in the first reconfigurable impedance matching network will be disconnected from the short-circuit branch, and when the first switch (switch 1) is closed, the open-circuit branch is connected to the short-circuit branch.

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

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

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

[0064] The reconfigurable impedance matching network in this embodiment realizes impedance reconfiguration by controlling whether the open-circuit branch 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) is controllably connected or disconnected between one end of the first matching resistor and the first port (port 1), the twelfth switch (switch 12) is controllably connected or disconnected between one end of the second matching resistor and the second port (port 2), and the thirteenth switch (switch 13) is controllably connected or disconnected between one end of the third matching resistor and the third port (port 3).

[0066] In this embodiment, refer to Figure 2, the second switch (switch 2) controllably connects or disconnects the connection between the output end of the first reconfigurable impedance matching network and the input end of the second reconfigurable impedance matching network, the third switch (switch 3) controllably connects or disconnects the connection between the output end of the first reconfigurable impedance matching network and the input end of the third reconfigurable impedance matching network, the fourth switch (switch 4) controllably connects or disconnects the connection between the output end of the first reconfigurable impedance matching network and the input end of the fourth reconfigurable impedance matching network; the eighth switch (switch 8) controllably connects or disconnects the connection between the output end 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 end of the third reconfigurable impedance matching network and the second port (port 2) of the reconfigurable power divider; the tenth switch (switch 10) controllably connects or disconnects the connection between the output end 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 in FIG. Figure 3 The input end (port 0) of the first reconfigurable impedance matching network serves as the input end of the entire reconfigurable power divider, and the first port (port 1), the second port (port 2) and the third port (port 3) serve as the output ends of the reconfigurable power divider.

[0068] In this embodiment, the first reconfigurable impedance matching network belongs to the reconfigurable impedance matching network of the first structure, and the second reconfigurable impedance matching network, the third reconfigurable impedance matching network and the fourth reconfigurable impedance matching network belong to the reconfigurable impedance matching network of the second structure. Since the positions of the microstrip transmission lines contained in the reconfigurable impedance matching networks of the two structures are different, the impedance matching values ​​corresponding to the reconfigurable impedance matching networks of the two structures are different. Generally, the width of the microstrip transmission line in the reconfigurable impedance matching network of the first structure is adjusted first to perform impedance matching, and then the length of the microstrip transmission line in the reconfigurable impedance matching network of the second structure is adjusted to further adjust the impedance matching.

[0069] In this embodiment, Figure 3 The reconfigurable impedance matching network shown Figure 2 The reconfigurable power divider shown in FIG. Figure 4 shown.

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

[0071] In this embodiment, each switch such as switch 1 to switch 13 can be implemented using a device such as a diode. Specifically, a diode has two states, on and off, so that the switch can realize the on-off function of the circuit, and the on-off state of the diode is affected by the DC bias, so a DC bias circuit can be set to realize the on-off state control of the diode, and realize that the switch state of each switch such as switch 1 to switch 13 is independently controllable.

[0072] Reference Figure 3 In the specific circuit implementation of the reconfigurable power divider in this embodiment, 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. In addition, a choke inductor can be loaded at the connection between the DuPont line of the DC bias circuit of the diode and the high-frequency circuit, and a DC blocking capacitor can be loaded at the connection between the port and the high-frequency circuit and the connection between the metal electrically connected to the diode.

[0073] Due to the influence of diode parasitic parameters, choke inductance, DC blocking capacitor, etc., the microstrip transmission line connecting the second impedance matching network to the input and output ports can be fine-tuned; specifically, impedance matching is performed by adjusting the width of the two sections of the microstrip transmission line connecting the input and output ports. Secondly, the three reconfigurable impedance matching networks of the second structure after impedance matching has been adjusted are connected to the microstrip transmission lines between switch 2 and switch 8, switch 3 and switch 9, and switch 4 and switch 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 feeding network is as follows: Figure 5 See Figure 5, the Nolan matrix feeding 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), etc. In this embodiment, the first coupler, the second coupler and the third coupler are all miniaturized branch line orthogonal couplers with distributed printed capacitors, wherein the coupling ratio of the first coupler is 3dB, and the coupling ratios of the second coupler and the third coupler are 0dB; the first phase shifter, the second phase shifter, the third phase shifter and the fourth phase shifter are all microstrip transmission line delay phase shifters, wherein the phase shift amount of the first phase shifter and the second phase shifter is 45°, the phase shift amount of the third phase shifter is 90°, and the phase shift amount of the fourth phase shifter is -90°.

[0075] In this embodiment, orthogonal couplers such as the first coupler (coupler 1) and phase shifters such as the first phase shifter (phase shifter 1) are connected through 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 end (labeled as 1) of the first coupler (coupler 1) is connected to the fourth port (port 4) of the Nolan matrix feeding network, and the other input end (labeled as 2) of the first coupler (coupler 1) is connected to an output end (labeled as 3) of the second coupler (coupler 2) through the first phase shifter (phase shifter 1).

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

[0078] Reference Figure 5 , one input end (labeled as 1) of the second coupler (coupler 2) is connected to the fifth port (port 5) of the Nolan matrix feeding network, another input end (labeled as 2) of the second coupler (coupler 2) is connected to the sixth port (port 6) of the Nolan matrix feeding network, and another output end (labeled as 4) of the second coupler (coupler 2) is connected to another input end (labeled as 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] Referring 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 shown Nolan matrix feeding network, its corresponding circuit layout is as Figure 6 shown.

[0082] Referring to Figure 6 , the surfaces of the first coupler, the second coupler and the third coupler in the Nolan matrix feeding network are respectively etched with a "field" - shaped metal structure, and 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, thus 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 elements therein is as Figure 7 shown. Referring to Figure 7 the left half of Figure 7 In this embodiment, the multi - unit antenna array is provided with 3 antenna elements, so the multi - unit antenna array can also be called a three - unit antenna array. Referring to

[0084] the right half of Figure 8 shown, each antenna element 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. Fig. 9 Referring to Figure 8, the multi-element antenna array is provided with 3 antenna elements, wherein the first antenna element is connected to the first output end (port 7) of the Nolan matrix feeding network through a microstrip line, the second antenna element is connected to the second output end (port 8) of the Nolan matrix feeding network through a microstrip line, and the third antenna element is connected to the third output end (port 9) of the Nolan matrix feeding network through a microstrip line; refer to Fig. 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 lines, and the diode on-off control is achieved by changing the bias voltage.

[0085] In this embodiment, by changing the bias voltage of the diode used as switch 1-13 and thus changing its on-off state, the reconfigurable power divider can realize outputting the input energy to the output port in one, two or three equal parts. Figure 2 and Figure 4 The signal energy input to port 0 in the table is directly fed to one output port (for example, any one of port 1, port 2 and port 3), corresponding to state 1, state 2 and state 3 in Table 1; bisection refers to the input energy being fed to two output ports (for example, any two of port 1, port 2 and port 3) in bisection, corresponding to state 4, state 5 and state 6 in Table 1; trisection refers to the input energy being fed to three output ports (port 1, port 2 and port 3) in trisection, corresponding to state 7 in Table 1.

[0086] Table 1 Diode coding table in different states

[0087]

[0088] In this embodiment, port 1 in the reconfigurable power divider is connected to port 4 in the Nolan matrix feed network, so when port 1 has signal energy output, the signal energy will be input from port 4 to the Nolan matrix feed network and output from port 7 to a connected antenna unit; similarly, port 2 is connected to port 5, and when port 2 has signal energy output, the signal energy will be input from port 5 to the Nolan matrix feed network and output from port 8 to a connected antenna unit; port 3 is connected to port 6, and when port 3 has signal energy output, the signal energy will be input from port 6 to the Nolan matrix feed network and output from port 9 to a connected antenna unit. Therefore, according to the coding control shown in Table 1, the on and off of each diode used as switch 1-switch 13 can control the output port of the signal energy, so that it is output by the corresponding antenna unit in the multi-unit antenna array. Therefore, the beam switching antenna system based on reconfigurable technology in this embodiment can achieve technical effects according to 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 feeding network in a directionally controlled manner. By changing the on-off state of the diode in the reconfigurable power divider through the DC control circuit, the reconfigurable power divider can realize flexible feeding of the Nolan matrix feeding network, that is, independently feeding one port, simultaneously feeding two ports, or simultaneously feeding three ports;

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

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

[0092] The technical effect of the present invention is mainly brought about by the structure of the present invention. When manufacturing the antenna system of the present invention, firstly, the size 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 according to the center frequency of the antenna to be realized and the target power division ratio; then, the Nolan matrix feeding network is designed according to the number of output ports of the reconfigurable power divider and the number of antenna array units; further, the antenna units working in the target frequency band are designed and arranged in an array; then, the designed reconfigurable power divider, the Nolan matrix feeding network and the multi-unit antenna array are connected with 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 various parameters in this embodiment are as follows Figure 4 , Figure 7 , Figure 6 shown.

[0094] according to Figure 4 , Figure 7 , Figure 6 The values ​​marked in the figure are used to manufacture reconfigurable power dividers, Nolan matrix feed networks, and antenna array structures with corresponding sizes, and the above values ​​are simulated. At the same time, the manufactured antenna system is measured. The simulation and measurement results are shown in Figure 10-Figure 14 shown.

[0095] The comparison of the reflection coefficient and transmission coefficient results of the reconfigurable power divider simulation and measurement is shown in the figure below. Fig.10 As shown. Fig.10It can be seen that the reconfigurable power divider in this embodiment can realize single-port output of port 1, port 2, and port 3 in state 1, state 2, and state 3 respectively; in state 4, state 5, and state 6, it can realize dual-port equal power output at port 1 and port 2, port 1 and port 3, and port 2 and port 3 respectively; in state 7, it can realize triple-port equal power output at port 1, port 2, and port 3. The measured insertion loss is 1.5-3dB lower than the simulation, which is caused by the deviation caused by the DuPont line, the parasitic effect of the diode, and the processing error.

[0096] The comparison of the reflection coefficient and transmission coefficient results of the Nolan matrix feed network simulation and measurement is shown in the figure below. Fig.11 As shown. Fig.11 It can be seen that the ports of the Nolan matrix feeding network in this embodiment are well matched and have high port isolation, and the function of equal power distribution can be achieved; at the same time, when input port 1, port 2, and port 3 are excited separately, the phase differences of adjacent output ports are 0°, -120°, and 120°, respectively.

[0097] The radiation pattern simulated for the three-element antenna array is shown below: Fig.12 As shown. Fig.12 It can be seen that the three-unit 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] Comparison of simulated and measured reflection coefficients for a beam switching antenna system based on reconfigurable technology Fig.13 As shown. Fig.13 It can be seen that in the present embodiment, the reflection coefficient of the antenna system in the 4.9-5.1 GHz frequency band is better than -10 dB in each state.

[0099] The comparison of the radiation patterns of the simulated and measured beam switching antenna system based on reconfigurable technology is shown in the figure below. Fig.14 As shown. Fig.14It can be seen that 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 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 of 90°±45°; in state 7, the antenna system can achieve a wide-beam radiation pattern with a 3dB beam width of 39°-132°. The maximum measured gains of the single-beam, dual-beam and wide-beam radiation patterns are 4.6-5.2dBi, 2.1dBi and 1.03dBi respectively. The average gain loss between measurement and simulation is 2.7dBi, and the additional loss mainly comes from the deviation caused by the DuPont line in the reconfigurable power divider, the diode parasitic effect and the system circuit processing error.

[0100] All the above results were measured by a vector network analyzer and a spherical far-field darkroom in a real environment with a substrate material of Rogers4003C, a dielectric constant of 3.38, and a substrate thickness of 0.813 mm. It can be found from the above simulation and test comparison charts that the simulation and measured curves are basically consistent. The beam switching antenna system based on reconfigurable technology can achieve three radiation patterns: single beam, dual beam, and wide beam. It has the advantages of low system overhead, low power consumption, rich beam types, and flexible switching, indicating that the solution of the present invention is feasible.

[0101] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature, or it may be indirectly fixed or connected to the other feature. In addition, the descriptions of up, down, left, right, etc. used in the present disclosure are only relative to the relative positional relationship of the components of the present disclosure in the accompanying drawings. The singular forms of "a", "" and "the" used in the present disclosure are also intended to include the plural forms, unless the context clearly indicates other meanings. In addition, unless otherwise defined, all technical and scientific terms used in this embodiment have the same meaning as those generally understood by those skilled in the art. The terms used in the specification of this embodiment are only for describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this embodiment includes any combination of one or more related listed items.

[0102] It should be understood that, although the term first, second, third etc. may be adopted to describe various elements in the present disclosure, these elements should not be limited to these terms. These terms are only used to distinguish the same type of elements from each other. For example, without departing from the scope of the present disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element. The use of any and all examples or exemplary language ("for example", "such as" etc.) provided by the present embodiment is only intended to better illustrate embodiments of the present invention, and unless otherwise required, the scope of the present invention will not be limited.

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

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

[0105] Further, the method can be implemented in any type of computing platform that is operably connected to a suitable computer, including but not limited to a personal computer, a minicomputer, a mainframe, a workstation, a network or distributed computing environment, a separate or integrated computer platform, or in communication with a charged particle tool or other imaging device, etc. Various aspects of the present invention can be implemented in 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, an optical read and / or write storage medium, a RAM, a ROM, etc., so that it can be read 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 process described herein. In addition, the machine-readable code, or part thereof, can be transmitted via a wired or wireless network. When such media includes instructions or programs that implement the above steps in conjunction with a microprocessor or other data processor, the invention of this embodiment includes these and other different types of non-transitory computer-readable storage media. When programmed according to the methods and techniques of the present invention, the present invention also includes the computer itself.

[0106] The computer program can be applied to input data to perform the functions of the present embodiment, thereby converting the input data to generate output data stored in a 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 present invention, the converted data represents a physical and tangible object, including a specific visual depiction of the physical and tangible object produced on the display.

[0107] The above are only preferred embodiments of the present invention. The present invention is not limited to the above embodiments. As long as the technical effects of the present invention are achieved by the same means, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention. Within the scope of protection of the present invention, its technical solutions and / or implementation methods may have various modifications and changes.

Claims

1. A beam switching antenna system based on reconfigurable technology, characterized in that: The beam switching antenna system based on reconfigurable technology includes: A multi-element antenna array; the multi-element antenna array comprises a plurality of antenna elements; Nolan matrix feed network; the Nolan matrix feed network comprises a plurality of input terminals and a plurality of output terminals, and any output terminal of the Nolan matrix feed network is respectively connected to a corresponding one of the antenna units; A reconfigurable power divider; the reconfigurable power divider comprises an input end and multiple output ends, any output end of the reconfigurable power divider is respectively connected to a corresponding input end of the Nolan matrix feeding network, and the reconfigurable power divider is used to equally distribute the signal energy received at its input end to part or all of its output ends.

2. The beam switching antenna system based on reconfigurable technology according to claim 1 is characterized in that: The beam switching antenna system based on reconfigurable technology also includes: A dielectric substrate; the multi-element antenna array, the Nolan matrix feed network and the reconfigurable power divider are all arranged on the dielectric substrate; wherein the Nolan matrix feed network and the reconfigurable power divider are arranged on the top surface of the dielectric substrate, and a metal ground is provided on the bottom surface of the dielectric substrate.

3. The beam switching antenna system based on reconfigurable technology according to claim 2, characterized in that: The number of the antenna units is 3, and each of the antenna units includes 3 groups of butterfly-shaped log-periodic end-fire antennas and microstrip lines connecting the butterfly-shaped log-periodic end-fire antennas.

4. The beam switching antenna system based on reconfigurable technology according to claim 3 is characterized in that: Each group of the 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 connected to the output end 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 connected to the metal ground through a microstrip line. The projections of the two fan-shaped metal patches on the dielectric substrate are symmetrical.

5. The beam switching antenna system based on reconfigurable technology according to claim 3 is characterized in that: 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; One input end of the first coupler is connected to the fourth port of the Nolan matrix feeding network, and another input end of the first coupler is connected to an output end of the second coupler through the first phase shifter; One output end of the first coupler is connected to the seventh port of the Nolan matrix feeding network through the third phase shifter, and another output end of the first coupler is connected to an input end of the third coupler; One input end of the second coupler is connected to the fifth port of the Nolan matrix feed network, another input end of the second coupler is connected to the sixth port of the Nolan matrix feed network, and another output end of the second coupler is connected to another input end of the third coupler through the second phase shifter; One output end of the third coupler is connected to the eighth port of the Nolan matrix feed network through the fourth phase shifter, and the other output end of the third coupler is connected to the ninth port of the Nolan matrix feed network; The fourth port, the fifth port and the sixth port serve as input ports of the Nolan matrix feeding network, and the seventh port, the eighth port and the ninth port serve as output ports of the Nolan matrix feeding network.

6. The beam switching antenna system based on reconfigurable technology according to claim 5, 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 3 dB, and the coupling ratio of the second coupler and the third coupler is 0 dB; 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 amount of the first phase shifter and the second phase shifter is 45°, the phase shift amount of the third phase shifter is 90°, and the phase shift amount of the fourth phase shifter is -90°.

7. The beam switching antenna system based on reconfigurable technology according to claim 6, characterized in that: A metal structure in the shape of a cross is etched on the surfaces of the first coupler, the second coupler and the third coupler respectively.

8. The beam switching antenna system based on reconfigurable technology according to claim 5, characterized in that: 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 end of the first reconfigurable impedance matching network and the input end of the second reconfigurable impedance matching network; The third switch is used to controllably connect or disconnect the connection between the output end of the first reconfigurable impedance matching network and the input end of the third reconfigurable impedance matching network; The fourth switch is used to controllably connect or disconnect the connection between the output end of the first reconfigurable impedance matching network and the input end of the fourth reconfigurable impedance matching network; The eighth switch is used to controllably connect or disconnect the connection between the output end 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 end 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 end 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 output ends of the reconfigurable power divider.

9. The beam switching antenna system based on reconfigurable technology according to claim 8, characterized in that: The reconfigurable power divider further 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 the connection between one end of the first matching resistor and the first port; The twelfth switch is used to controllably connect or disconnect the connection between one end of the second matching resistor and the second port; The thirteenth switch is used to controllably connect or disconnect the connection between one end of the third matching resistor and the third port; The other ends of the first matching resistor, the second matching resistor and the third matching resistor are grounded.

10. The beam switching antenna system based on reconfigurable technology according to claim 8 or 9, characterized in that: 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 branch, an open-circuit branch, a switch and a microstrip transmission line; In the first reconfigurable impedance matching network, one end of the short-circuited branch is connected to the open-circuited branch through a switch, one end of the short-circuited branch 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-circuited branch 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 connection between the open-circuit branch and the short-circuit branch.

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