A dual circularly polarized beam reconfigurable microstrip antenna

Abstract

The present invention discloses a dual circular polarization beam reconfigurable microstrip antenna, comprising a first and a second dielectric plate, a first, a second, a third, and a fourth voltage control module; an air layer exists between the two dielectric plates; a copper layer is provided on the upper surface of the second dielectric plate; a circular patch, a first, a second, a third, a fourth, a fifth, a sixth, a seventh, and an eighth fan-shaped parasitic patch, a first, a second, a third, and a fourth variable capacitance diode, a first, a second, a third, a fourth, a fifth, a sixth, a seventh, and an eighth patch inductor, and a first, a second, a third, a fourth, a fifth, a sixth, a seventh, and an eighth voltage control interface are provided on the copper layer; a ground plane with a cross-coupling aperture is provided on the upper surface of the first dielectric plate, a copper layer is provided on the lower surface, a first and a second coupling feeder and a branch line directional coupler are provided on the copper layer on the upper and lower surfaces of the first dielectric plate, respectively, a first and a second input port are made. The present invention can realize a beam scanning angle range of ±20°, and the beam scanning on the two surfaces of ±45°, the reflection coefficient S 11 Below ‑10dB.

Description

Technical Field

[0001] The invention relates to the technical field of antennas, and in particular to a dual circular polarization beam reconfigurable microstrip antenna. Background Art

[0002] With the rapid development of wireless communications, higher requirements are placed on the communication capacity and transmission rate of the system. Patch antennas are widely used in the design of front-end transmitting and receiving antennas of wireless communication systems due to their advantages such as light weight, small size, easy conformality, easy processing, and low cost. With the increasing application of 5G technology and the rapid growth of wireless communication users, there is an urgent need to make full use of spectrum resources in the limited spectrum resource division and improve the utilization rate of spectrum resources, thereby improving the performance of wireless communication systems. Beamforming is one of the effective solutions to meet this demand. Beamforming technology is increasingly used in personal communication systems (PCS), satellite communication systems, wireless local loops, wireless local area networks (LANs), and wireless ATM systems. The design of circularly polarized beam reconfigurable antennas using microstrip antennas has great research significance.

[0003] The existing technologies are investigated and understood as follows:

[0004] Professor Xiao Shaoqiu and others used the Butler matrix to design a broadband circularly polarized multi-beam antenna array. They designed a Butler matrix based on broadband directional couplers and broadband phase shifters, and used broadband circularly polarized antennas to form a four-unit antenna array, and used a phase shift network to achieve circularly polarized beamforming.

[0005] Professor A. Khidre and others proposed a design method for electrically steerable multi-beam circularly polarized antennas. A varactor diode is loaded on the parasitic patch, and the characteristics of the parasitic unit are changed by changing the capacitance value of the varactor diode to achieve beam control.

[0006] In general, there are many studies on beam reconfigurable microstrip antennas in existing work, but many design methods use methods such as phase feeding networks, which are easy to cause energy loss and the design is relatively complicated. Therefore, it is of great significance to design a simple dual circularly polarized beam reconfigurable antenna. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and propose a dual circular polarization beam reconfigurable microstrip antenna, the working frequency of the antenna is 2GHz, and by adjusting the capacitance value of the varactor diode, a beam scanning angle range of ±20° can be achieved, and beam scanning on two planes of ±45° can be achieved. During the entire adjustment process, the reflection coefficient S11 is basically maintained below -10dB. The entire antenna structure is simple and compact, and it is easy to process and low in cost.

[0008] To achieve the above-mentioned purpose, the technical solution provided by the present invention is: a dual circular polarization beam reconfigurable microstrip antenna, comprising a first dielectric plate, a second dielectric plate, a first voltage control module, a second voltage control module, a third voltage control module and a fourth voltage control module; the second dielectric plate is located above the first dielectric plate, and there is an air layer between the two dielectric plates, which is used to improve the gain of the antenna; a copper cladding layer is formed on the upper surface of the second dielectric plate, and a circular patch, a first fan-shaped parasitic patch, a second fan-shaped parasitic patch, a third fan-shaped parasitic patch, a fourth fan-shaped parasitic patch are respectively provided on the copper cladding layer. raw patch, the fifth fan-shaped parasitic patch, the sixth fan-shaped parasitic patch, the seventh fan-shaped parasitic patch, the eighth fan-shaped parasitic patch, the first varactor diode, the second varactor diode, the third varactor diode, the fourth varactor diode, the first chip inductor, the second chip inductor, the third chip inductor, the fourth chip inductor, the fifth chip inductor, the sixth chip inductor, the seventh chip inductor, the eighth chip inductor, the first voltage control interface, the second voltage control interface, the third voltage control interface, the fourth voltage control interface, the fifth voltage control interface, the sixth voltage control interface, the seventh voltage control interface, the first Eight voltage control interfaces; the circular patch is located in the middle of the copper layer and serves as the main radiation source of the entire antenna; the first fan-shaped parasitic patch and the second fan-shaped parasitic patch are connected through a first varactor diode to form a parasitic unit, and are symmetrical about the first varactor diode; the third fan-shaped parasitic patch and the fourth fan-shaped parasitic patch are connected through a second varactor diode to form a parasitic unit, and are symmetrical about the second varactor diode; the fifth fan-shaped parasitic patch and the sixth fan-shaped parasitic patch are connected through a third varactor diode to form a parasitic unit, and are symmetrical about the third varactor diode. The seventh sector-shaped parasitic patch and the eighth sector-shaped parasitic patch are connected through a fourth varactor diode to form a parasitic unit, and are symmetrical about the fourth varactor diode; the above four parasitic units are evenly distributed around the circular patch and are on the same circumference, with the same center as the circular patch, and the two parasitic units are mirror-symmetrical about the symmetry axis of the circular patch, and the center point of the varactor diode is at the ±45° intersection line position passing through the center of the circular patch. By adjusting the capacitance value of the varactor diode, the current distribution generated by the four parasitic units can be different, thereby realizing the control of the beam direction;The first fan-shaped parasitic patch is connected to the first voltage control interface through the first patch inductor, the second fan-shaped parasitic patch is connected to the second voltage control interface through the second patch inductor, the first voltage control interface and the second voltage control interface are respectively connected to the first voltage control module, the third fan-shaped parasitic patch is connected to the third voltage control interface through the third patch inductor, the fourth fan-shaped parasitic patch is connected to the fourth voltage control interface through the fourth patch inductor, the third voltage control interface and the fourth voltage control interface are respectively connected to the second voltage control module, the fifth fan-shaped parasitic patch is connected to the fifth voltage control interface through the fifth patch inductor, the sixth fan-shaped parasitic patch is connected to the sixth voltage control interface through the sixth patch inductor, the fifth voltage control interface and the sixth voltage control interface are respectively connected to the third voltage control module, the seventh fan-shaped parasitic patch is connected to the seventh voltage control interface through the seventh patch inductor, the eighth fan-shaped parasitic patch is connected to the eighth voltage control interface through the eighth patch inductor, and the seventh voltage control The control interface and the eighth voltage control interface are respectively connected to the fourth voltage control module, wherein the function of the patch inductor is to block the current of the fan-shaped parasitic patch from entering the voltage control module through the voltage control interface; the upper surface of the first dielectric plate is provided with a grounding plate, and the lower surface thereof is formed with a copper cladding layer, and the grounding plate is provided with a cross coupling aperture, and the copper cladding layer on the lower surface of the first dielectric plate is respectively provided with a first coupling feeder, a second coupling feeder, and a branch line directional coupler for providing a signal with a phase difference of ±90°, and the copper cladding layers on the upper and lower surfaces of the first dielectric plate are respectively made with a first input port and a second input port, the first coupling feeder is connected to the first input port through the branch line directional coupler, and feeding through the first input port can realize right-hand circular polarization, the second coupling feeder is connected to the second input port through the branch line directional coupler, and feeding through the second input port can realize left-hand circular polarization, and the energy fed from the first input port and the second input port is finally coupled to the circular patch through the cross coupling aperture. ;

[0009] Furthermore, the first dielectric plate and the second dielectric plate are of the same size and material.

[0010] Furthermore, the cross-coupling aperture is located directly below the circular patch.

[0011] Furthermore, the branch line directional coupler is a 3dB / 90° directional coupler, and its input and output ports are both 50 ohm impedance matched.

[0012] Furthermore, the electrical lengths of the first coupling feed line and the second coupling feed line are the same.

[0013] Furthermore, the first input port and the second input port are both 50 ohm impedance matching ports.

[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0015] 1. The antenna of the present invention has an operating frequency of 2 GHz. The beam scanning angle can be changed by ±20° by adjusting the two ends of the varactor diode, and the angle can be changed in two planes of ±45°.

[0016] 2. The antenna of the present invention can maintain the reflection coefficient S while changing the beam direction 11 Below -10dB.

[0017] 3. The antenna of the present invention can realize two polarization modes: left-hand polarization and right-hand polarization.

[0018] 4. The antenna of the present invention is simple to process, light in weight, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional diagram of the dual circularly polarized beam reconfigurable microstrip antenna of the present invention.

[0020] Figure 2 It is a side view of the dual circularly polarized beam reconfigurable microstrip antenna of the present invention.

[0021] Figure 3 It is a top view of the dual circularly polarized beam reconfigurable microstrip antenna of the present invention.

[0022] Figure 4 The figure is a bottom view of the dual circularly polarized beam reconfigurable microstrip antenna of the present invention.

[0023] Figure 5 is the S of the dual circularly polarized beam reconfigurable microstrip antenna of the present invention. 11 and S 22 Simulation result diagram.

[0024] Figure 6 It is a diagram of the beam direction simulation result of the dual circularly polarized beam reconfigurable microstrip antenna of the present invention; in the figure, (a) is left-hand circular polarization at +45° plane, (b) is right-hand circular polarization at +45° plane, (c) is left-hand circular polarization at -45° plane, and (d) is right-hand circular polarization at -45° plane. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with specific embodiments.

[0026] See also Figures 1 to 4As shown, the dual circular polarization beam reconfigurable microstrip antenna provided in this embodiment includes a first dielectric plate 1, a second dielectric plate 2, a first voltage control module M1, a second voltage control module M2, a third voltage control module M3 and a fourth voltage control module M4; the second dielectric plate 2 is located above the first dielectric plate 1, and there is an air layer 6 between the two dielectric plates, and the main function of the air layer 6 is to improve the gain of the antenna; a copper clad layer 5 is formed on the upper surface of the second dielectric plate 2, and a circular patch 7, a first fan-shaped parasitic patch 8, a second fan-shaped parasitic patch 9, a third fan-shaped parasitic patch 10, a fourth fan-shaped parasitic patch 11, a third fan-shaped parasitic patch 12, a fourth fan-shaped parasitic patch 13, a fourth fan-shaped parasitic patch 14, a fourth fan-shaped parasitic patch 15, a fourth fan-shaped parasitic patch 16, a fourth fan-shaped parasitic patch 17, a fourth fan-shaped parasitic patch 18, a fourth fan-shaped parasitic patch 19, a fourth fan-shaped parasitic patch 20, a fourth fan-shaped parasitic patch 21, a fourth fan-shaped parasitic patch 22, a fourth fan-shaped parasitic patch 23, a fourth fan-shaped parasitic patch 24, a fourth fan-shaped parasitic patch 25, a fourth fan-shaped parasitic patch 26, a fourth fan-shaped parasitic patch 27, a fourth fan-shaped parasitic patch 28, a fourth fan-shaped parasitic patch 29, a fourth fan-shaped parasitic patch 30, a fourth fan-shaped parasitic patch 31, a fourth fan-shaped parasitic patch 32, a fourth fan-shaped parasitic patch 33, a fourth fan-shaped parasitic patch 34, a fourth fan-shaped parasitic patch 35, a fourth fan The fifth fan-shaped parasitic patch 12, the sixth fan-shaped parasitic patch 13, the seventh fan-shaped parasitic patch 14, the eighth fan-shaped parasitic patch 15, the first variable capacitance diode C1, the second variable capacitance diode C2, the third variable capacitance diode C3, the fourth variable capacitance diode C4, the first chip inductor L1, the second chip inductor L2, the third chip inductor L3, the fourth chip inductor L4, the fifth chip inductor L5, the sixth chip inductor L6, the seventh chip inductor L7, the eighth chip inductor L8, the first voltage control interface 16, the second voltage control interface 17, the third voltage control interface 18, the fourth voltage control interface 19, the fifth voltage control interface 20, the sixth voltage control interface 21, a seventh voltage control interface 22, an eighth voltage control interface 23; the circular patch 7 is located in the middle of the copper clad layer 5, serving as the main radiation source of the entire antenna; the first sector-shaped parasitic patch 8 and the second sector-shaped parasitic patch 9 are connected through a first varactor C1 to form a parasitic unit, and are symmetrical about the first varactor C1; the third sector-shaped parasitic patch 10 and the fourth sector-shaped parasitic patch 11 are connected through a second varactor C2 to form a parasitic unit, and are symmetrical about the second varactor C2; the fifth sector-shaped parasitic patch 12 and the sixth sector-shaped parasitic patch 13 are connected through a third varactor C3 to form a parasitic unit. element, and is symmetrical about the third varactor diode C3; the seventh fan-shaped parasitic patch 14 and the eighth fan-shaped parasitic patch 15 are connected through the fourth varactor diode C4 to form a parasitic unit, and are symmetrical about the fourth varactor diode C4; the above four parasitic units are evenly distributed around the circular patch 7, and are on the same circumference, with the same center as the circular patch 7, and the two parasitic units are mirror-symmetrical about the symmetry axis of the circular patch 7, the center point of the varactor diode is at the ±45° intersection line position passing through the center of the circular patch, and by adjusting the capacitance value of the varactor diode, the current distribution generated by the four parasitic units can be different, thereby realizing the control of the beam direction;The first fan-shaped parasitic patch 8 is connected to the first voltage control interface 16 through the first patch inductor L1, the second fan-shaped parasitic patch 9 is connected to the second voltage control interface 17 through the second patch inductor L2, the first voltage control interface 16 and the second voltage control interface 17 are respectively connected to the first voltage control module M1, the third fan-shaped parasitic patch 10 is connected to the third voltage control interface 18 through the third patch inductor L3, the fourth fan-shaped parasitic patch 11 is connected to the fourth voltage control interface 19 through the fourth patch inductor L4, the third voltage control interface 18 and the fourth voltage control interface The fifth sector-shaped parasitic patch 12 is connected to the fifth voltage control interface 20 through the fifth patch inductor L5, the sixth sector-shaped parasitic patch 13 is connected to the sixth voltage control interface 21 through the sixth patch inductor L6, the fifth voltage control interface 20 and the sixth voltage control interface 21 are connected to the third voltage control module M3 respectively, the seventh sector-shaped parasitic patch 14 is connected to the seventh voltage control interface 22 through the seventh patch inductor L7, the eighth sector-shaped parasitic patch 15 is connected to the eighth voltage control interface 23 through the eighth patch inductor L8, The seventh voltage control interface 22 and the eighth voltage control interface 23 are respectively connected to the fourth voltage control module M4, wherein the function of the above-mentioned patch inductor is to block the current of the fan-shaped parasitic patch from entering the voltage control module through the voltage control interface; the upper surface of the first dielectric plate 1 is provided with a grounding plate 4, and a copper-clad layer 3 is formed on its lower surface, and a cross-coupling aperture 24 is provided on the grounding plate 4, and the copper-clad layer 3 on the lower surface of the first dielectric plate 1 is respectively provided with a first coupling feed line 25, a second coupling feed line 26 and a branch line directional coupler 27 for providing a signal with a phase difference of ±90°, and in the The first input port 28 and the second input port 29 are respectively made on the copper-clad layer 3 on the upper and lower surfaces of the first dielectric plate 1. The first coupling feeder 25 is connected to the first input port 28 through a branch line directional coupler 27. Feeding through the first input port 28 can achieve right-hand circular polarization. The second coupling feeder 26 is connected to the second input port 29 through a branch line directional coupler 27. Feeding through the second input port 29 can achieve left-hand circular polarization. The energy fed from the first input port 28 and the second input port 29 is finally coupled to the circular patch 7 through the cross-coupling aperture 24. ;

[0027] In the design, the dielectric constants of the first dielectric plate 1 and the second dielectric plate 2 are both 2.55, and the loss tangent is 0.0029. The thicknesses of the first dielectric plate 1 and the second dielectric plate 2 are both 0.8 mm; the thickness of the air layer 6 is 2 mm. The length of the fan-shaped parasitic patch is taken at about one-quarter of the wavelength of the designed frequency. The values ​​of the patch inductance are all 270nH. The cross-coupling aperture 24 is located directly below the circular patch 7. The electrical lengths of the first coupling feed line 25 and the second coupling feed line 26 are the same. The branch line directional coupler 27 is a 3dB / 90° directional coupler with 50 ohm impedance matching at both input and output ports, which is used to achieve input signals with a phase difference of ±90°. The first input port 28 and the second input port 29 are both 50 ohm impedance matching ports.

[0028] See also Figure 5 As shown, the S of the dual circularly polarized beam reconfigurable microstrip antenna of this embodiment is shown. 11 and S 22 As can be seen from the figure, when changing different capacitance values, the reflection coefficient characteristics are basically unchanged, and the reflection coefficient remains below -10dB.

[0029] See also Figure 6 As shown, the beam direction simulation result of the dual circular polarization beam reconfigurable microstrip antenna of this embodiment is shown. It can be seen from the figure that when different capacitance values ​​are set, the beam direction can be changed from -20° to +20°. The +45° plane is a plane perpendicular to the dielectric plate where the three center points of the first and third varactor diodes C1, C3 and the circular patch 7 are located; the -45° plane is a plane perpendicular to the dielectric plate where the three center points of the second and fourth varactor diodes C2, C4 and the circular patch 7 are located.

[0030] The above-described embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A dual circular polarization beam reconfigurable microstrip antenna, characterized in that: The antenna comprises a first dielectric plate, a second dielectric plate, a first voltage control module, a second voltage control module, a third voltage control module and a fourth voltage control module; the second dielectric plate is located above the first dielectric plate, and an air layer is provided between the two dielectric plates to improve the gain of the antenna; a copper clad layer is formed on the upper surface of the second dielectric plate, and a circular patch, a first fan-shaped parasitic patch, a second fan-shaped parasitic patch, a third fan-shaped parasitic patch, a fourth fan-shaped parasitic patch, a fifth fan-shaped parasitic patch, a sixth fan-shaped parasitic patch, a seventh fan-shaped parasitic patch are respectively provided on the copper clad layer. patch, the eighth fan-shaped parasitic patch, the first varactor diode, the second varactor diode, the third varactor diode, the fourth varactor diode, the first patch inductor, the second patch inductor, the third patch inductor, the fourth patch inductor, the fifth patch inductor, the sixth patch inductor, the seventh patch inductor, the eighth patch inductor, the first voltage control interface, the second voltage control interface, the third voltage control interface, the fourth voltage control interface, the fifth voltage control interface, the sixth voltage control interface, the seventh voltage control interface, the eighth voltage control interface; the circular patch is located on the copper clad layer The middle position of the fan-shaped parasitic patch serves as the main radiation source of the entire antenna; the first fan-shaped parasitic patch and the second fan-shaped parasitic patch are connected through the first varactor diode to form a parasitic unit, and are symmetrical about the first varactor diode; the third fan-shaped parasitic patch and the fourth fan-shaped parasitic patch are connected through the second varactor diode to form a parasitic unit, and are symmetrical about the second varactor diode; the fifth fan-shaped parasitic patch and the sixth fan-shaped parasitic patch are connected through the third varactor diode to form a parasitic unit, and are symmetrical about the third varactor diode; the seventh fan-shaped parasitic patch The raw patch and the eighth fan-shaped parasitic patch are connected through a fourth varactor diode to form a parasitic unit, and are symmetrical about the fourth varactor diode; the above four parasitic units are evenly distributed around the circular patch and are on the same circumference and have the same center as the circular patch, and the two parasitic units are mirror-symmetrical about the symmetry axis of the circular patch, and the center point of the varactor diode is at the position of the ±45° intersection line passing through the center of the circular patch. By adjusting the capacitance value of the varactor diode, the current distribution generated by the four parasitic units can be different, thereby realizing the control of the beam direction;The first fan-shaped parasitic patch is connected to the first voltage control interface through the first patch inductor, the second fan-shaped parasitic patch is connected to the second voltage control interface through the second patch inductor, the first voltage control interface and the second voltage control interface are respectively connected to the first voltage control module, the third fan-shaped parasitic patch is connected to the third voltage control interface through the third patch inductor, the fourth fan-shaped parasitic patch is connected to the fourth voltage control interface through the fourth patch inductor, the third voltage control interface and the fourth voltage control interface are respectively connected to the second voltage control module, the fifth fan-shaped parasitic patch is connected to the fifth voltage control interface through the fifth patch inductor, the sixth fan-shaped parasitic patch is connected to the sixth voltage control interface through the sixth patch inductor, the fifth voltage control interface and the sixth voltage control interface are respectively connected to the third voltage control module, the seventh fan-shaped parasitic patch is connected to the seventh voltage control interface through the seventh patch inductor, the eighth fan-shaped parasitic patch is connected to the eighth voltage control interface through the eighth patch inductor, the seventh voltage control interface and the eighth voltage control interface are respectively connected to the fourth voltage control module, wherein, the above The function of the patch inductor is to block the current of the fan-shaped parasitic patch from entering the voltage control module through the voltage control interface; a grounding plate is provided on the upper surface of the first dielectric plate, and a copper-clad layer is formed on the lower surface thereof, and a cross-coupling aperture is provided on the grounding plate. The copper-clad layer on the lower surface of the first dielectric plate is respectively provided with a first coupling feeder, a second coupling feeder and a branch line directional coupler for providing a signal with a phase difference of ±90°, and a first input port and a second input port are respectively made on the copper-clad layers on the upper and lower surfaces of the first dielectric plate, the first coupling feeder is connected to the first input port through the branch line directional coupler, and feeding through the first input port can achieve right-hand circular polarization, the second coupling feeder is connected to the second input port through the branch line directional coupler, and feeding through the second input port can achieve left-hand circular polarization, and the energy fed from the first input port and the second input port is finally coupled to the circular patch through the cross-coupling aperture; the cross-coupling aperture is located directly below the circular patch; the branch line directional coupler is a 3dB / 90° directional coupler, and its input and output ports are both 50 ohm impedance matched. ; 2. The dual circular polarization beam reconfigurable microstrip antenna according to claim 1, characterized in that: The first dielectric plate and the second dielectric plate have the same size and material.

3. The dual circular polarization beam reconfigurable microstrip antenna according to claim 1, characterized in that: The electrical lengths of the first coupling feed line and the second coupling feed line are the same.

4. The dual circularly polarized beam reconfigurable microstrip antenna according to claim 1, characterized in that: The first input port and the second input port are both 50 ohm impedance matching ports.

Images