A low profile serially fed beam reconfigurable antenna

Abstract

The present invention discloses a low-profile serially fed beam reconfigurable antenna, which belongs to the technical field of microwave antenna engineering. The present invention solves the problem that existing beam reconfigurable antennas are difficult to meet the requirements of modern communication systems for low-profile, miniaturized, and integrated antennas. The present invention obtains dynamic beam reconfiguration capability by adjusting the radiation phase of each radiating unit, and the antenna adopts a serial feeding network to greatly reduce the antenna profile compared with the traditional transmission array. In addition, the antenna provided by the present invention also has the advantages of high integration, low feeding loss, high radiation efficiency, fast beam scanning speed, simple structure, light weight, easy conformality, and low cost.

Description

Technical Field

[0001] The invention relates to a low-profile serial feeding beam reconfigurable antenna, belonging to the technical field of microwave antenna engineering. Background Art

[0002] Antennas are key components in wireless communication systems, and the characteristics of antennas directly determine the performance of the entire communication system. Modern communication systems have a strong demand for low-profile, low-cost, beam-reconfigurable antennas. Beam-reconfigurable antennas mainly come in two forms: mechanical scanning antennas and phased array antennas. Mechanical scanning antennas are the earliest form of beam-reconfigurable antennas, consisting of a servo system and an antenna feeder system. During the operation of a mechanical scanning antenna, the antenna beam pointing always remains relatively stationary with the antenna array surface, and the antenna posture is controlled by the back-end servo system to achieve beam scanning. The working principle of this type of antenna is relatively simple and the design difficulty is relatively low, but the mechanical servo system is relatively large in size and weight, consumes high power, and has a slow beam scanning speed. Compared with mechanical scanning antennas, phased array antennas have the advantages of fast scanning speed, short communication link establishment time, and multi-target tracking. Traditional phased array antennas are usually composed of hundreds or even thousands of radiating elements, and each radiating element is equipped with an independent transmit / receive (T / R) component. However, it is precisely because of the existence of a large number of T / R components that the phased array is expensive. At the same time, the complex heat dissipation structure not only makes the phased array antenna bulky and heavy, but also affects the electromagnetic characteristics of the antenna. Compared with phased array antennas, reflectarray and transmission array antennas do not require complex power distribution networks, avoid the use of a large number of T / R components, and effectively reduce antenna costs. However, the feed horn and antenna array surface in the antenna need to maintain a certain distance, which significantly increases the overall profile of the antenna, making it difficult to meet the requirements of modern communication systems for low-profile, miniaturized, and integrated antennas. Summary of the invention

[0003] In view of the above problems, the present invention proposes a small-sized and low-cost beam reconfigurable antenna, which can greatly improve the performance of modern wireless communication, radar and navigation systems.

[0004] The technical solution of the present invention:

[0005] A low-profile serially fed beam reconfigurable antenna comprises a plurality of structural units arranged in an array form, wherein the structural unit comprises, from top to bottom, a metal radiation layer, an upper dielectric substrate, a metal floor layer, a dielectric substrate bonding layer, a lower dielectric substrate and a metal feeding layer stacked in sequence;

[0006] The length direction of the upper dielectric plate is the y-axis direction, the width direction is the x-direction, and the height direction is the z-axis direction.

[0007] It is further defined that the antenna is composed of structural units that are laid out in series along the x-axis direction, and the number of the structural units is more than 3.

[0008] It is further defined that the length and width of the structural unit are Py and Px respectively, the value range of Py is 0.3λ0-0.7λ0, and the value range of Px is 0.1λ0-0.35λ0, where λ0 is the free space wavelength of the center operating frequency.

[0009] It is further defined that the metal radiation layer is composed of a metal patch, a regulating element and a feeding point arranged on the upper surface of the upper dielectric substrate, a pair of metal patches are symmetrically arranged on the upper surface of the upper dielectric substrate along the y-axis, and the long-distance edges of the two metal patches are connected to the metal floor through grounding metal vias; the feeding point is located between the close-distance edges of the two metal patches, the metal floor has a hollow structure, the feeding point is connected to the metal feeding layer through the feeding metal via, and the feeding metal via passes through the hollow structure on the metal floor, and the feeding point is connected to the two metal patches through the regulating element respectively.

[0010] It is further defined that the metal patch is rectangular, trapezoidal, circular or elliptical.

[0011] It is further defined that the control element is a PIN diode, a varactor diode, a field effect transistor, an RF-MEMS or a liquid crystal switch.

[0012] It is further defined that the metal feed layer is composed of a microstrip transmission line, a branch feed line, a DC feed line, a capacitor and an inductor arranged on the lower surface of the lower dielectric substrate, one end of the branch feed line is connected to the microstrip transmission line through the capacitor, and the other end is connected to the feeding point of the metal radiation layer through a feeding metal via, and the branch feed line is also connected to the DC feed line through the inductor.

[0013] It is further defined that the capacitor is a lumped component or a microwave structure exhibiting a capacitive effect.

[0014] It is further defined that the microwave structures exhibiting the capacitance effect are microstrip gaps, interdigitated microstrip structures, and the like.

[0015] The present invention has the following beneficial effects: the present invention obtains dynamic beam reconfiguration capability by adjusting the radiation phase of each radiation unit, and the antenna adopts a serial feeding network to greatly reduce the antenna profile compared with the traditional transmission array. In addition, the antenna also has the advantages of high integration, low feeding loss, high radiation efficiency, fast beam scanning speed, simple structure, light weight, easy conformality, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the layered structure of a low-profile serially fed beam reconfigurable antenna;

[0017] Figure 2 Schematic diagram of the metal radiation layer structure;

[0018] Figure 3 It is a schematic diagram of the metal feed layer structure;

[0019] Figure 4 is a cross-sectional view of the structural unit;

[0020] Figure 5 This is a diagram of the array far-field scanning result of Example 1;

[0021] In the figure, 1-metal radiation layer, 2-upper dielectric substrate, 3-metal floor layer, 4-dielectric substrate bonding layer, 5-lower dielectric substrate, 6-metal feeding layer, 7-grounding metal via, 8-metal patch, 9-1-first regulating element, 9-2-second regulating element, 10-feeding point, 11-microstrip transmission line, 12-branch feeding line, 13-DC feed line, 14-capacitor, 15-inductor, 16-feeding metal via, 17-hollow structure. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0023] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0024] Embodiment 1:

[0025] Low profile serially fed beam reconfigurable antenna operating at 5.45 GHz:

[0026] The antenna is composed of 31 structural units laid out in series along the x-axis. Figure 1 As shown, the structural unit includes a metal radiation layer 1, an upper dielectric substrate 2, a metal floor layer 3, a dielectric substrate bonding layer 4, a lower dielectric substrate 5 and a metal feed layer 6 stacked in sequence. The width Px of the structural unit is 11.4 mm, and the length Py is 60 mm. The cross-sectional thickness of the antenna is only 0.046λ0.

[0027] The upper dielectric substrate 2 is Rogers RT5880 with a thickness of 1.57 mm. The lower dielectric substrate 5 is Rogers RT5880 with a thickness of 0.787 mm. The dielectric substrate adhesive layer 4 is Rogers RO4450F with a thickness of 0.1 mm.

[0028] like Figure 2 As shown, the metal radiation layer 1 is composed of a metal patch 8, a first regulating element 9-1, a second regulating element 9-2 and a feeding point 10 arranged on the upper surface of the upper dielectric substrate. A pair of rectangular metal patches 8 are arranged symmetrically on the upper surface of the upper dielectric substrate 2 along the y-axis. The long-distance edges of the two metal patches 8 are connected to the metal floor layer 3 through the grounding metal vias 7; the feeding point 10 is located between the short-distance edges of the two metal patches 8. The metal floor layer 3 has a hollow structure 17 to prevent the feeding metal via 16 from forming a short circuit with the metal floor layer 3. The feeding point 10 is connected to the metal feeding layer 6 through the feeding metal via 16, and the feeding metal via 16 passes through the hollow structure 17 on the metal floor, and the feeding point 10 is connected to the two metal patches 8 through the first regulating element 9-1 and the second regulating element 9-2 respectively. The length W of the rectangular metal patch 8 is x 9.5mm, width W y The first regulating element 9-1 and the second regulating element 9-2 are PIN diodes capable of regulating the on-off of microwave circuits, and the model number is MACOMMADP-000907-14020.

[0029] like Figure 3 As shown, the metal feed layer 6 is composed of a microstrip transmission line 11, a branch feed line 12, a DC feed line 13, a capacitor 14 and an inductor 15 arranged on the lower surface of the lower dielectric substrate 5. One end of the branch feed line 12 is connected to the microstrip transmission line 11 through the capacitor 14, and the other end is connected to the feeding point 10 of the metal radiation layer 1 through the feeding metal via 16. The purpose of loading the capacitor 14 on the branch feed line 12 is to prevent the DC signal from entering the microstrip transmission line 11 and thus short-circuiting the first control element 9-1 and the second control element 9-2. The capacitor 14 can be a lumped component or a microwave structure showing a capacitive effect, and the other end of the branch feed line 12 is also connected to the DC feed line 13 through the inductor 15. The inductor 15 loaded on the DC feed line 13 can form a microwave circuit breaker to suppress the microwave signal from entering the DC bias network. The DC feed line 13 provides a control voltage signal for the first control element 9-1 and the second control element 9-2. The lumped capacitance value of the capacitor 14 is 2.1pF. The value of the inductor 15 is 8 nH. The width W1 of the microstrip transmission line 11 is 2.6 mm. The length l1 of the branch feed line 12 is 11 mm, and the width W2 is 0.8 mm.

[0030] The DC signal controls the on and off of the first control element 9-1 and the second control element 9-2 through the DC feeder; when the first control element 9-1 is "off" and the second control element 9-2 is "on" (here "off" means RF disconnection and "on" means RF short circuit), when the first control element 9-1 is "on" and the second control element 9-2 is "off" (here "off" means RF disconnection and "on" means RF short circuit), these two state working modes can make the radiation phase of the structural unit produce a phase difference of 180°.

[0031] Assume that the reference wave in the above microstrip transmission line is The radiation wave converted by phase modulation of the metal radiation layer is When the radiation wave needs to be realized After confirmation, you can To obtain the phase response of the metal radiation layer According to the phase response The "on" and "off" working states of the control element can be obtained, and then the control element can be controlled through the DC feeder to achieve the required radiation wave

[0032] The far-field simulation of the above antenna is carried out, and the results are Figure 4 As shown by Figure 4 It can be seen that the low-profile serial-fed beam reconfigurable antenna can achieve ±60° beam scanning, with a maximum actual gain of 13.0 dBi and a minimum gain of 10.2 dBi within the scanning range.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A low profile serially fed beam reconfigurable antenna, characterized in that: It comprises a plurality of structural units arranged in an array, wherein the structural units comprise, from top to bottom, a metal radiation layer, an upper dielectric substrate, a metal floor layer, a dielectric substrate bonding layer, a lower dielectric substrate and a metal feed layer stacked in sequence; The length direction of the upper dielectric substrate is the y-axis direction, the width direction is the x-axis direction, and the height direction is the z-axis direction; The length and width of the structural unit are Py and Px respectively, the value range of Py is 0.3λ0-0.7λ0, and the value range of Px is 0.1λ0-0.35λ0, wherein λ0 is the free space wavelength of the central operating frequency; The metal radiation layer is composed of a metal patch, a regulating element and a feeding point arranged on the upper surface of the upper dielectric substrate. A pair of metal patches are arranged symmetrically on the upper surface of the upper dielectric substrate along the y-axis, and the long-distance edges of the two metal patches are connected to the metal floor through grounding metal vias; the feeding point is located between the short-distance edges of the two metal patches, and the metal floor has a hollow structure. The feeding point is connected to the metal feeding layer through the feeding metal via, and the feeding metal via passes through the hollow structure on the metal floor, and the feeding point is connected to the two metal patches through two regulating elements respectively; The control element is a PIN diode, a varactor diode, a field effect transistor, an RF-MEMS or a liquid crystal switch; The metal feed layer is composed of a microstrip transmission line, a branch feed line, a DC feed line, a capacitor and an inductor arranged on the lower surface of the lower dielectric substrate. One end of the branch feed line is connected to the microstrip transmission line through the capacitor, and the other end is connected to the feeding point of the metal radiation layer through a feeding metal via, and the branch feed line is also connected to the DC feed line through the inductor.

2. A low profile serially fed beam reconfigurable antenna according to claim 1, characterized in that: The antenna is composed of structural units that are laid out in series along the x-axis direction, and the number of the structural units is more than 3.

3. A low profile serially fed beam reconfigurable antenna according to claim 1, characterized in that: The metal patch is rectangular, trapezoidal, circular or elliptical.

4. A low profile serially fed beam reconfigurable antenna according to claim 1, characterized in that: The capacitor is a lumped component or a microwave structure showing a capacitor effect.

5. A low profile serially fed beam reconfigurable antenna according to claim 4, characterized in that: The microwave structure showing the capacitance effect is a microstrip gap or an interdigitated microstrip structure.

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