Planar end-fire pattern reconfigurable antenna and radio device

Abstract

The present application provides a planar end-fire reconfigurable antenna and radio equipment, relating to the field of antenna technology. The planar end-fire reconfigurable antenna comprises: a substrate; four pairs of parallel double wires, each pair of parallel double wires being disposed on the upper and lower surfaces of the substrate; four pairs of coupling branches, each pair of coupling branches being disposed on the upper and lower surfaces of the substrate; four groups of PIN diodes, each group of PIN diodes being disposed on the upper and lower surfaces of the substrate, each group of PIN diodes corresponding to a pair of parallel double wires; four pairs of annular microstrip lines, each pair of annular microstrip lines being connected to the ends of corresponding parallel double wires, each pair of annular microstrip lines being disposed on the upper and lower surfaces of the substrate; four metal through-holes, each metal through-hole being connected to the ends of corresponding annular microstrip lines; a feed coaxial line, the feed coaxial line being disposed at the center point of the substrate; and four bias circuits for providing bias voltages to each group of PIN diodes.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a planar end-fire pattern reconfigurable antenna and a radio device. Background Art

[0002] Currently, radars search for signals through real-time scanning, requiring the antenna's radiation beam to continuously change (beam scanning). This allows the radar to acquire signals from a specific direction in real time while eliminating interference from other directions, enabling real-time monitoring. Improving the performance of beam scanning antennas requires a larger radiation beam coverage area. Furthermore, space resources are very scarce on certain lightweight payload platforms, placing higher demands on antenna size.

[0003] Antenna beam state switching is usually achieved using phased array technology, but this technology requires the use of a large number of phase shifting and power division components, which are costly, heavy, and occupy a large area, which is not conducive to the overall lightweight and miniaturized design of the system.

[0004] Reconfiguring the field distribution using electrically adjustable elements such as PIN diodes and varactors can also achieve rapid scanning of the antenna's radiation beam. Using the Yagi principle, adjustable steering or reflective elements near the main radiator can achieve variable directional radiation states. However, to achieve a wider range of radiation states and cover a larger radiation range, reconfigurable pattern antennas require the inclusion of more parasitic structures, which inevitably increase antenna size.

[0005] Therefore, how the pattern reconfigurable antenna can achieve flexible and diverse pattern reconfigurable states while maintaining a compact structure and cover a wide-angle radiation range is currently an important research topic. Summary of the Invention

[0006] In view of this, the present application provides a planar end-fire pattern reconfigurable antenna and radio equipment, which can achieve flexible and diverse pattern reconfigurable states while maintaining a compact structure.

[0007] In a first aspect, an embodiment of the present application provides a planar end-fire reconfigurable antenna, comprising:

[0008] substrate;

[0009] Four pairs of parallel double lines, the four pairs of parallel double lines are arranged along the -x axis, -y axis, +x axis and +y axis respectively, and each pair of parallel double lines is respectively provided on the upper surface and the lower surface of the substrate;

[0010] Four pairs of coupling branches, the four pairs of coupling branches are arranged along the -x axis, -y axis, +x axis and +y axis respectively, each pair of coupling branches is respectively provided on the upper surface and the lower surface of the substrate, and there is a coupling gap between each pair of coupling branches and the adjacent parallel double wires, and the coupling branches are excited by the coupling gap to form a corresponding current distribution;

[0011] Four groups of PIN diodes, each group of PIN diodes contains two PIN diodes, and the two PIN diodes in each group are respectively arranged on the upper surface and the lower surface of the substrate. Each group of PIN diodes corresponds to a pair of parallel double wires. The on and off states of the four groups of PIN diodes are controlled by four bias voltages to realize the control of the current distribution on the four pairs of parallel double wires;

[0012] Four pairs of annular microstrip lines, each pair of annular microstrip lines is connected to the end of a corresponding parallel double line, and each pair of annular microstrip lines is respectively arranged on the upper surface and the lower surface of the substrate;

[0013] four metal through holes, each metal through hole being connected to an end of a corresponding annular microstrip line so as to connect two semicircular ring structures included in the annular microstrip line;

[0014] A feeding coaxial line is arranged at the center point of the substrate and is used for feeding power;

[0015] Four bias circuits are provided, each bias circuit being configured to provide a bias voltage to each group of PIN diodes.

[0016] The above-mentioned planar end-fire reconfigurable antenna according to the embodiment of the present application may also have the following additional technical features:

[0017] In the above technical solution, optionally, each pair of coupling branches includes two branches, the two branches are mirror-symmetrical about the corresponding coordinate axis, and are respectively arranged on the upper surface and the lower surface of the substrate.

[0018] In any of the above technical solutions, optionally, each branch of the coupling branch includes a straight portion and an inclined portion;

[0019] There is a coupling gap between the straight part and its adjacent parallel double lines, and the inclined part has an inclination of 45°.

[0020] In any of the above technical solutions, optionally, each group of PIN diodes includes two PIN diodes, one PIN diode is arranged on one branch of the corresponding parallel double wire, and the other PIN diode is arranged on the other branch of the corresponding parallel double wire.

[0021] In any of the above technical solutions, optionally, each pair of annular microstrip lines includes two semicircular ring structures, which are mirror-symmetrical about corresponding coordinate axes and are respectively arranged on the upper surface and the lower surface of the substrate.

[0022] In any of the above technical solutions, optionally, the method further includes:

[0023] A pair of patches of the same size are respectively arranged on the upper and lower surfaces of the center point of the substrate. The inner core of the feed coaxial line passes through the substrate and is connected to the patch arranged on the upper surface, and the outer core of the feed coaxial line is connected to the patch arranged on the lower surface.

[0024] In any of the above technical solutions, optionally, a chip inductor and a chip resistor are set in each bias circuit, the chip inductor is used to achieve mutual isolation between RF and DC signals, and the chip resistor is used to control the current intensity to protect the circuit.

[0025] In any of the above technical solutions, optionally, four independent bias voltages are used to control the on-off current in four pairs of parallel double wires. The resonant state of the coupled branches and the ring microstrip lines is controlled by the current in the parallel double wires, and different coupled branches and ring microstrip lines are excited to produce different radiation pattern responses.

[0026] In any of the above technical solutions, optionally, currents with the same amplitude and opposite phases are distributed on a pair of parallel double wires in a conducting state, the current distributions cancel each other out, and the parallel double wires themselves do not generate radiation;

[0027] A pair of parallel double lines in the conducting state provide reverse feeding for the corresponding connected annular microstrip lines. Then the corresponding connected annular microstrip lines and the corresponding metal through holes together form an equivalent current loop in the φ plane, which is equivalent to a magnetic current element along the z axis.

[0028] The corresponding adjacent coupling branches of a pair of parallel double wires in the on state are excited, the current distributions of the straight parts of the coupling branches cancel each other out, and the current distributions of the inclined parts of the coupling branches are superimposed to form corresponding current elements; the magnetic current element and the current element form a pair of complementary radiation elements.

[0029] In a second aspect, an embodiment of the present application provides a radio device, including: a planar end-fire pattern reconfigurable antenna as in the first aspect.

[0030] The planar end-fire pattern reconfigurable antenna of the embodiment of the present application adopts a planar single-layer PCB single-feed structure, and realizes eight end-fire radiation states within the operating frequency band by simply controlling the on-off state of four groups of PIN diodes, covering a 360° range of the end-fire direction.

[0031] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0033] Figure 1 One of the structural schematic diagrams of the planar end-fire reconfigurable antenna according to an embodiment of the present application is shown;

[0034] Figure 2 The second structural diagram of the planar end-fire reconfigurable antenna according to an embodiment of the present application is shown;

[0035] Figure 3 The third structural diagram of the planar end-fire reconfigurable antenna according to an embodiment of the present application is shown;

[0036] Figure 4 The impedance matching of the embodiment of the present application in eight selected radiation states is shown. 11 |parametric curve;

[0037] Figure 5 The normalized radiation patterns of the embodiment of the present application in eight radiation states, in the θ=90° plane, at a frequency of 3.5 GHz are shown;

[0038] Figure 6 A graph showing the variation of the maximum gain with frequency in eight radiation states of an embodiment of the present application is shown.

[0039] The corresponding relationship between the component names and the reference numerals in the accompanying drawings is as follows:

[0040] Substrate 1, coupling branch 2, parallel double line 3, ring microstrip line 4, metal through hole 5, feeding coaxial line 6, PIN diode 7, PIN diode 8, PIN diode 9, PIN diode 10, patch 11, coupling gap 12, bias circuit 13. DETAILED DESCRIPTION

[0041] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0042] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0043] The planar end-fire pattern reconfigurable antenna and radio device provided in the embodiments of the present application are described in detail below with reference to specific embodiments and their application scenarios in conjunction with the accompanying drawings. The following embodiments and features in the embodiments may be combined with each other unless there is a conflict.

[0044] The embodiment of the present application provides a planar end-fire pattern reconfigurable antenna, such as Figure 1 、 Figure 2 as well as Figure 3 As shown, the planar end-fire reconfigurable antenna includes: a substrate 1, four pairs of parallel double lines 3, four pairs of coupling branches 2, four groups of PIN diodes, four pairs of ring microstrip lines 4, four metal through holes 5, a feeding coaxial line 6 and four bias circuits 13.

[0045] Among them, four pairs of parallel double lines 3 are obtained by rotating and replicating around the center of symmetry at intervals of 90°, that is, adjacent parallel double lines 3 are perpendicular to each other and are arranged along the -x axis, -y axis, +x axis and +y axis directions respectively. The two branches of each pair of parallel double lines 3 are respectively arranged on the upper surface and the lower surface of the substrate 1.

[0046] Four pairs of coupling branches 2 are formed by rotating and replicating the four pairs of coupling branches 2 at 90° intervals around the center of symmetry. The four pairs of coupling branches 2 are arranged along the -x, -y, +x, and +y axes, respectively. Each pair of coupling branches 2 is disposed on the upper and lower surfaces of the substrate 1. A coupling gap 12 exists between each pair of coupling branches 2 and the adjacent parallel double wires 3. Excitation through the coupling gap 12 generates a corresponding current distribution.

[0047] In one embodiment, each pair of coupling branches 2 includes two branches, which are mirror-symmetrical about the corresponding coordinate axis and are respectively disposed on the upper and lower surfaces of the substrate 1. That is, the right branch of each pair of coupling branches 2 is disposed on the upper surface of the substrate 1, and the left branch of each pair of coupling branches 2 is disposed on the lower surface of the substrate 1.

[0048] Each branch of the coupling branch 2 includes a straight portion and an inclined portion; there is a coupling gap 12 between the straight portion and the adjacent parallel double line 3, so that the coupling branch 2 can be excited, and the inclined portion has a 45° inclination angle, forming an effective current distribution.

[0049] Four groups of PIN diodes, including PIN diode 7, PIN diode 8, PIN diode 9, and PIN diode 10, are provided on the upper and lower surfaces of substrate 1, respectively. Each group of PIN diodes corresponds to a pair of parallel double wires 3. The on and off states of the four groups of PIN diodes are controlled by four bias voltages, thereby controlling the current distribution on the four pairs of parallel double wires 3.

[0050] A PIN diode is provided on each of the upper and lower branches of the parallel double wire 3. The two PIN diodes corresponding to a pair of parallel double wires 3, located on the upper and lower layers of the substrate 1, are considered a group. A bias voltage is used to synchronously control the on and off states of the two PIN diodes in a group.

[0051] Four pairs of looped microstrip lines 4 are replicated by rotating around a center of symmetry at 90° intervals. Each pair of looped microstrip lines 4 is connected to the end of a corresponding parallel double line 3. Each pair of looped microstrip lines 4 is disposed on the upper and lower surfaces of substrate 1. Each pair of looped microstrip lines 4 comprises two semicircular ring structures, which are mirror-symmetrical about the corresponding coordinate axis and disposed on the upper and lower surfaces of substrate 1, respectively.

[0052] There are four metal through-holes 5 , each of which is connected to the end of the corresponding ring microstrip line 4 , so that the two semicircular ring structures included in the ring microstrip line 4 are connected. The ring microstrip line 4 and the metal through-holes 5 together constitute a complete ring resonant structure.

[0053] The feeding coaxial line 6 is arranged at the center point of the substrate 1 to feed the entire antenna.

[0054] To facilitate soldering of the feed coaxial line 6, in one embodiment of the present application, the planar end-fire reconfigurable antenna further includes: a pair of patches 11 of equal size, disposed on the upper and lower surfaces of the center point of the substrate 1, respectively. The inner core of the feed coaxial line 6 passes through the substrate 1 and is connected to the patch 11 disposed on the upper surface, while the outer core of the feed coaxial line 6 is connected to the patch 11 disposed on the lower surface. The patch 11 may be a rectangular patch.

[0055] Four bias circuits 13 are provided, each for providing a bias voltage to each group of PIN diodes. Each bias circuit 13 includes a chip inductor and a chip resistor. The chip inductor isolates the RF and DC signals, while the chip resistor controls the current intensity to protect the circuit.

[0056] In this embodiment of the present application, four independent bias voltages are used to control the current flow in four pairs of parallel doublets 3. The resonant states of the coupled branches 2 and the ring microstrip lines 4 are controlled by the current flow in the parallel doublets 3, exciting different coupled branches 2 and ring microstrip lines 4, thereby producing different radiation pattern responses. Eight of the sixteen bias voltage combinations are selected, resulting in eight end-fire states, designated State 1 through State 8. The beam directions of adjacent states are spaced 45° apart, and the eight radiation states cover a 360° end-to-end range.

[0057] The four groups of PIN diodes (PIN diode 7, PIN diode 8, PIN diode 9, and PIN diode 10) are denoted as S1 to S4 in a counterclockwise direction. Table 1 lists the relationships between the on and off states of the four groups of PIN diodes and the beam pointing achieved within the scanning plane (θ = 90°) for the eight radiation states achieved.

[0058] Table 1

[0059]

[0060] By controlling the on-off state of four groups of PIN diodes, the current distribution on the four pairs of parallel double wires is controlled. The currents with the same amplitude and opposite phases are distributed on a pair of parallel double wires in the on state. The current distributions cancel each other out, and the parallel double wires themselves do not generate radiation. On the one hand, a pair of parallel double wires in the on state provide reverse feeding for the corresponding connected annular microstrip lines. The upper and lower branches of the annular microstrip lines are connected by metal through-holes, thereby forming an equivalent current loop in the φ plane, which is equivalent to a magnetic current element along the z-axis. On the other hand, the corresponding adjacent coupling branch pairs of a pair of parallel double wires in the on state are excited, and the current distributions of the straight parts of the coupling branches cancel each other out, and the current distributions of the inclined parts of the coupling branches are superimposed to form corresponding current elements. In summary, a pair of parallel double wires in the on state excites a corresponding pair of complementary radiation element pairs. Based on the principle of complementarity, the present application constructs four pairs of complementary radiation element pairs through a compact structure to form corresponding good directional radiation.

[0061] Therefore, the present application controls the on-off states of four groups of PIN diodes to stimulate different pairs of complementary radiation elements, thereby forming different directional radiation responses, flexibly switching the beam direction, and achieving the reconfigurable pattern function.

[0062] Figure 4 The impedance matching of the embodiment of the present application in eight selected radiation states is shown. 11 |parametric curves, Figure 4 In the figure, the vertical axis is |S 11| (dB), the horizontal axis is frequency (GHz), it can be concluded that in the eight radiation states, |S can be satisfied in the frequency range of 3.36GHz to 3.72GHz. 11 |Less than -10dB, showing good impedance matching performance.

[0063] Figure 5 The normalized radiation pattern of the embodiment of the present application in eight radiation states, in the θ=90° plane, and at the 3.5GHz frequency point is shown. It gradually switches from state 1 to state 8, and the radiation beam direction (in the θ=90° plane) rotates synchronously counterclockwise in steps of 45°, and the front-to-back ratio of each state is better than 11dB, showing good directional end-fire radiation characteristics and flexible beam switching capabilities.

[0064] Figure 6 The graph showing the variation of the maximum gain with frequency in eight radiation states of the embodiment of the present application is shown. Figure 6 In the figure, the ordinate is the maximum gain (dBi) and the abscissa is the frequency (GHz). The maximum gain in states 2 / 4 / 6 / 8 is higher than that in states 1 / 3 / 5 / 7. Within the operating frequency band (3.36 GHz to 3.72 GHz), the maximum gain in states 1 / 3 / 5 / 7 is higher than 2.6 dBi, and the maximum gain in states 2 / 4 / 6 / 8 is higher than 4.5 dBi.

[0065] It should be noted that if the structural dimensions of this design are proportionally enlarged or reduced, it can be used in other frequency bands.

[0066] In summary, this application utilizes a planar single-layer PCB single-feed structure, achieving eight end-fire radiation states within the operating frequency band simply by controlling the on / off states of four groups of PIN diodes, covering a 360° range of end-fire directions. Compared to the prior art, this application has the following beneficial effects:

[0067] (1) The directional pattern reconfigurable antenna provided in this application adopts a single-layer PCB substrate structure, which has low cost and processing difficulty and is light in weight. In addition, the antenna abandons the traditional method of using a reflector to achieve directional radiation, avoiding the reflector's occupation of the antenna size. The overall antenna structure is cleverly designed, ensuring the compactness of the structure and facilitating system integration.

[0068] (2) The directional pattern reconfigurable antenna provided in this application can control the on and off states of four pairs of complementary radiating elements through a simple voltage control combination, thereby realizing a variety of radiation pattern states within the same operating frequency band, covering a 360° range in the end-fire direction, and the radiation beam switching is flexible and fast.

[0069] An embodiment of the present application also provides a radio device, including: a planar end-fire pattern reconfigurable antenna as described above, and can achieve the same technical effect. To avoid repetition, it will not be described here.

[0070] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be noted that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0071] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A planar end-fire reconfigurable antenna, characterized in that: include: substrate; Four pairs of parallel double lines, the four pairs of parallel double lines are arranged along the -x axis, the -y axis, the +x axis and the +y axis respectively, and each pair of parallel double lines is respectively provided on the upper surface and the lower surface of the substrate; Four pairs of coupling branches, the four pairs of coupling branches are arranged along the -x axis, the -y axis, the +x axis, and the +y axis, respectively, each pair of coupling branches is respectively provided on the upper surface and the lower surface of the substrate, a coupling gap is provided between each pair of coupling branches and the adjacent parallel double wires, and the coupling branches are excited by the coupling gap to form a corresponding current distribution; four groups of PIN diodes, each group of PIN diodes comprising two PIN diodes, the two PIN diodes in each group being disposed on the upper and lower surfaces of the substrate, respectively, each group of PIN diodes corresponding to a pair of parallel double wires, and the on and off states of the four groups of PIN diodes being controlled by four bias voltages to achieve control of current distribution on the four pairs of parallel double wires; Four pairs of annular microstrip lines, each pair of the annular microstrip lines being connected to the ends of corresponding parallel double lines, and each pair of the annular microstrip lines being respectively arranged on the upper surface and the lower surface of the substrate; Four metal through holes, each of the metal through holes is connected to an end of a corresponding annular microstrip line, so as to connect the two semicircular ring structures included in the annular microstrip line; A feeding coaxial line, which is arranged at the center point of the substrate and is used for feeding power; Four bias circuits are provided, each bias circuit being configured to provide the bias voltage to each group of the PIN diodes.

2. The planar end-fire reconfigurable antenna according to claim 1, wherein: Each pair of coupling branches includes two branches, which are mirror-symmetrical about corresponding coordinate axes and are respectively arranged on the upper surface and the lower surface of the substrate.

3. The planar end-fire reconfigurable antenna according to claim 2, wherein: Each branch of the coupling branch comprises a straight portion and an inclined portion; There is a coupling gap between the straight portion and the adjacent parallel double line, and the inclined portion is inclined at an angle of 45°.

4. The planar end-fire reconfigurable antenna according to claim 1, wherein: Each group of PIN diodes includes two PIN diodes, one PIN diode is arranged on one branch of the corresponding parallel double wires, and the other PIN diode is arranged on the other branch of the corresponding parallel double wires.

5. The planar end-fire reconfigurable antenna according to claim 1, wherein: Each pair of the annular microstrip lines includes two semicircular ring structures, which are mirror-symmetrical about corresponding coordinate axes and are respectively arranged on the upper surface and the lower surface of the substrate.

6. The planar end-fire reconfigurable antenna according to claim 1, wherein: Also includes: A pair of patches of the same size are respectively arranged on the upper surface and the lower surface of the center point of the substrate. The inner core of the feed coaxial line passes through the substrate and is connected to the patch arranged on the upper surface. The outer core of the feed coaxial line is connected to the patch arranged on the lower surface.

7. The planar end-fire reconfigurable antenna according to claim 1, wherein: A chip inductor and a chip resistor are provided in each bias circuit. The chip inductor is used to achieve mutual isolation between radio frequency and direct current signals, and the chip resistor is used to control the current intensity to protect the circuit.

8. The planar end-fire reconfigurable antenna according to claim 1, wherein: The on-off control of the current in the four pairs of parallel double wires is achieved through four independent bias voltages. The resonant state of the coupling branches and the ring microstrip lines is controlled by the current in the parallel double wires, and different coupling branches and the ring microstrip lines are excited to produce different radiation pattern responses.

9. The planar end-fire reconfigurable antenna according to claim 8, wherein: A pair of parallel wires in the on state distribute currents with the same amplitude and opposite phases, and the current distributions cancel each other out, so the parallel wires themselves do not generate radiation. A pair of parallel double lines in the conducting state provide reverse feeding for the corresponding connected annular microstrip lines. Then the corresponding connected annular microstrip lines and the corresponding metal through holes together form an equivalent current loop in the φ plane, which is equivalent to a magnetic current element along the z axis. The corresponding adjacent coupling branches of a pair of parallel double wires in the on state are excited, the current distributions of the straight parts in the coupling branches cancel each other out, and the current distributions of the inclined parts in the coupling branches are superimposed to form corresponding current elements; the magnetic current element and the current element form a pair of complementary radiation elements.

10. A radio device, characterized in that: include: The planar end-fire pattern reconfigurable antenna according to any one of claims 1 to 9.

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