A broadband filtering antenna based on grid slotted patch

Abstract

The invention discloses a broadband filtering antenna based on a grid slotted patch, comprising a first, a second and a third dielectric plate arranged in sequence from bottom to top; a first air layer exists between the first and the second dielectric plates; a second air layer exists between the second and the third dielectric plates; a third copper clad layer is formed on the upper surface of the third dielectric plate, and a grid slotted patch is arranged on the third copper clad layer; a second copper clad layer is formed on the upper surface of the second dielectric plate, and a rectangular patch is arranged on the second copper clad layer; a ground plate is arranged on the upper surface of the first dielectric plate, a first copper clad layer is formed on the lower surface, a coupling aperture is arranged on the ground plate, the first copper clad layer is arranged on the first, the second and the third half-wavelength U-shaped resonators and coupling feed lines, and input ports are made on the upper and lower surfaces of the first dielectric plate. The invention is a fourth-order filtering antenna based on filter comprehensive design, which works stably in the range of 2.27GHz-2.57GHz, S11<-10dB, and the gain is maintained at about 7.5dBi, the whole antenna structure is simple and compact, and it is easy to process and low in cost.

Description

Technical Field

[0001] The invention relates to the technical field of antennas, and in particular to a broadband filtering antenna based on a grid slotted patch. Background Art

[0002] With the rapid development of wireless communications and the commercial use of 5G communication systems, higher requirements are placed on the communication capacity and transmission rate of wireless communication systems. In addition, 5G communication systems have certain requirements for the filtering characteristics of antennas. Patch antennas are widely used in wireless communication systems due to their light weight, small size, easy conformality, easy processing, and low cost. However, microstrip patch antennas are often limited by their narrow working bandwidth. For the bandwidth expansion of patch antennas, many scholars have proposed many technologies for broadband filtering patch antennas through continuous improvement and research on their characteristics. However, some methods will lead to problems such as reduced efficiency, reduced gain, and unstable radiation patterns.

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

[0004] In 1995, Professor Li Qifang and his graduate students proposed to add U-shaped slots to widen the bandwidth. Loading U-shaped slots makes the patch form a multi-tuned circuit, thus widening the frequency band. Many subsequent methods of adding slots to widen the bandwidth are also based on this principle.

[0005] Professor Zhang Xiuyin and others proposed a method of using slots on the patch and loading short-circuit posts to realize a filtering antenna.

[0006] In general, there are many studies on the design of broadband antennas and filtering antennas in existing work, but many designed filtering antennas have limited bandwidth or only filter in a certain direction, not omnidirectional filtering. Some methods achieve bandwidth widening and filtering by forming multiple tuning loops by adding gaps, etc., but the gain and waveform of the antenna will be affected. In order to overcome the problem of narrow bandwidth caused by the design of filtering antennas using filter synthesis design methods, the present invention proposes a broadband filtering antenna based on a grid slotted patch. 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 broadband filtering antenna based on a grid slotted patch, which is a fourth-order filtering antenna based on filter comprehensive design. The antenna can work stably in the range of 2.27GHz-2.57GHz, S11<-10dB in the frequency range of 2.27GHz-2.57GHz, and the gain in the frequency range of 2.27GHz-2.57GHz is maintained at about 7.5dBi. 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 broadband filtering antenna based on a grid slotted patch, comprising a first dielectric plate, a second dielectric plate and a third dielectric plate; the second dielectric plate is located above the first dielectric plate, and there is a first air layer between them, which is used to improve the gain of the antenna; the third dielectric plate is located above the second dielectric plate, and there is a second air layer between them, which is used to reduce the reflection coefficient of the antenna within the bandwidth; a third copper clad layer is formed on the upper surface of the third dielectric plate, and a grid slotted patch formed by the intersection and division of square patches through multiple horizontal slot lines and multiple vertical slot lines is provided on the third copper clad layer, which is used to improve the bandwidth of the antenna and reduce the reflection coefficient within the passband; a second copper clad layer is formed on the upper surface of the second dielectric plate, and a rectangular patch is provided on the second copper clad layer as the main radiation source of the entire antenna; a ground plane is provided on the upper surface of the first dielectric plate, A first copper clad layer is formed on its lower surface, a coupling aperture is provided on the ground plate, a first half-wavelength U-shaped resonator, a second half-wavelength U-shaped resonator, a third half-wavelength U-shaped resonator, and a coupling feeder are respectively provided on the first copper clad layer, and input ports are made on the upper and lower surfaces of the first dielectric plate, the second half-wavelength U-shaped resonator is located between the first half-wavelength U-shaped resonator and the third half-wavelength U-shaped resonator, the coupling feeder is located on one side of the third half-wavelength U-shaped resonator and is connected to the input port, and can couple the energy fed from the input port to the third half-wavelength U-shaped resonator, the third half-wavelength U-shaped resonator couples the energy to the second half-wavelength U-shaped resonator, the second half-wavelength U-shaped resonator couples the energy to the first half-wavelength U-shaped resonator, and the first half-wavelength U-shaped resonator couples the energy to the rectangular patch through the coupling aperture, thereby realizing a fourth-order filtering function.

[0009] Furthermore, the grid slotted patch is formed by dividing a square patch through the intersection of five horizontal slot lines and three vertical slot lines, and is divided into 24 small rectangular patches.

[0010] Furthermore, the input port is a 50 ohm impedance matching port.

[0011] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0012] 1. The operating frequency of the antenna of the present invention exceeds the frequency range of 2.27 GHz-2.57 GHz, and the relative bandwidth exceeds 12.4%.

[0013] 2. The gain of the antenna of the present invention is very flat within the frequency range of 2.27 GHz to 2.57 GHz, and remains stable within a range of about 7.5 dB.

[0014] 3. The antenna of the present invention is a fourth-order filter antenna designed based on a comprehensive filter design method and has excellent filtering characteristics.

[0015] 4. The directional pattern of the antenna of the present invention has good characteristics in the frequency range of 2.27 GHz-2.57 GHz.

[0016] 5. The antenna of the present invention is simple to process, light in weight, low in processing cost, wide in working bandwidth, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a stereoscopic diagram of the broadband filtering antenna based on the grid slotted patch of the present invention.

[0018] Figure 2 It is a side view of the broadband filtering antenna based on the grid slotted patch of the present invention.

[0019] Figure 3 It is a schematic diagram of the upper surface of the third dielectric plate of the present invention.

[0020] Figure 4 It is a schematic diagram of the upper surface of the second dielectric plate of the present invention.

[0021] Figure 5 It is a schematic diagram of the lower surface of the first dielectric plate of the present invention.

[0022] Figure 6 is the reflection coefficient S of the broadband filtering antenna based on the grid slotted patch of the present invention 11 Simulation results and gain curves.

[0023] Figure 7 This is a simulation result diagram of the directional pattern of the broadband filtering antenna based on the grid slotted patch at 2.4 GHz of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with specific embodiments.

[0025] See also Figures 1 to 5As shown, the broadband filtering antenna based on the grid slotted patch provided in this embodiment includes a first dielectric plate 1, a second dielectric plate 2 and a third dielectric plate 3; the second dielectric plate 2 is located above the first dielectric plate 1, and there is a first air layer 8 between them, and the main function of the first air layer 8 is to improve the gain of the antenna; the third dielectric plate 3 is located above the second dielectric plate 2, and there is a second air layer 9 between them, and the second air layer 9 is mainly used to reduce the reflection coefficient of the antenna within the bandwidth; a third copper clad layer 7 is formed on the upper surface of the third dielectric plate 3, and a grid slotted patch 10 is provided on the third copper clad layer 7, and the grid slotted patch 10 is formed by the intersection and division of a square patch through five horizontal slot lines and three vertical slot lines, and is divided into 24 small rectangular patches, the length of the square patch is 44.5 mm, and the line width of the eight slot lines is 0.5 mm, and its main function is to improve the bandwidth of the antenna and reduce the reflection coefficient in the passband; a second copper clad layer 6 is formed on the upper surface of the second dielectric plate 2, and a rectangular patch 11 is provided on the second copper clad layer 6, which serves as the main radiation source of the entire antenna and as a filter The last level of the comprehensive design; the upper surface of the first dielectric plate 1 is provided with a ground plate 5, and the lower surface thereof is formed with a first copper-clad layer 4, the ground plate 5 is provided with a coupling aperture 12, the first copper-clad layer 4 is respectively provided with a first half-wavelength U-shaped resonator 13, a second half-wavelength U-shaped resonator 14, a third half-wavelength U-shaped resonator 15, and a coupling feeder 16, and an input port 17 is made on the upper and lower surfaces of the first dielectric plate 1, the second half-wavelength U-shaped resonator 14 is located between the first half-wavelength U-shaped resonator 13 and the third half-wavelength U-shaped resonator 15. The coupling feed line 16 is located on one side of the third half-wavelength U-shaped resonator 15 and is connected to the input port 17, so as to couple the energy fed from the input port 17 to the third half-wavelength U-shaped resonator 15, the third half-wavelength U-shaped resonator 15 couples the energy to the second half-wavelength U-shaped resonator 14, the second half-wavelength U-shaped resonator 14 couples the energy to the first half-wavelength U-shaped resonator 13, and the first half-wavelength U-shaped resonator 13 couples the energy to the rectangular patch 11 through the coupling aperture 12, thereby realizing a fourth-order filtering function.

[0026] In the design, the dielectric constants of the first dielectric plate 1, the second dielectric plate 2 and the third dielectric plate 3 are all 2.55, and the loss tangent is 0.0029. The thickness of the first dielectric plate 1 is 0.8 mm, and the thickness of the second dielectric plate 2 and the third dielectric plate 3 are both 1.5 mm. The thickness of the first air layer 8 is 2 mm, and the thickness of the second air layer 9 is 14 mm. The input port 17 is a 50 ohm impedance matching port.

[0027] See also Figure 6 As shown, the reflection coefficient S of the broadband filtering antenna of this embodiment is shown. 11Simulation results of the reflection coefficient |S 11 The frequency range of |<-10dB exceeds the frequency interval of 2.27GHz-2.57GHz, and the relative bandwidth exceeds 12.4%. In the frequency range of 2.27GHz-2.57GHz, the gain is flat and remains at around 7.5dBi.

[0028] See also Figure 7 As shown in FIG. 1 , the simulated directions of the E-plane and H-plane of the broadband filtering antenna of this embodiment at a frequency of 2.4 GHz are shown. As can be seen from the figure, the directional pattern of the antenna of the present invention meets the required characteristics.

[0029] 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 broadband filtering antenna based on a grid slotted patch, characterized in that: It comprises a first dielectric plate, a second dielectric plate and a third dielectric plate; the second dielectric plate is located above the first dielectric plate, and there is a first air layer between them, which is used to improve the gain of the antenna; the third dielectric plate is located above the second dielectric plate, and there is a second air layer between them, which is used to reduce the reflection coefficient of the antenna within the bandwidth; a third copper-clad layer is formed on the upper surface of the third dielectric plate, and a grid slotted patch formed by the intersection and division of square patches by multiple horizontal slot lines and multiple vertical slot lines is arranged on the third copper-clad layer, which is used to improve the bandwidth of the antenna and reduce the reflection coefficient within the passband; a second copper-clad layer is formed on the upper surface of the second dielectric plate, and a rectangular patch is arranged on the second copper-clad layer as the main radiation source of the entire antenna; a grounding plate is provided on the upper surface of the first dielectric plate, and a first copper-clad layer is formed on the lower surface thereof, and a A coupling aperture is provided, a first half-wavelength U-shaped resonator, a second half-wavelength U-shaped resonator, a third half-wavelength U-shaped resonator, and a coupling feeder are respectively provided on the first copper clad layer, and input ports are made on the upper and lower surfaces of the first dielectric plate, the second half-wavelength U-shaped resonator is located between the first half-wavelength U-shaped resonator and the third half-wavelength U-shaped resonator, the coupling feeder is located on one side of the third half-wavelength U-shaped resonator and is connected to the input port, and can couple the energy fed from the input port to the third half-wavelength U-shaped resonator, the third half-wavelength U-shaped resonator couples the energy to the second half-wavelength U-shaped resonator, the second half-wavelength U-shaped resonator couples the energy to the first half-wavelength U-shaped resonator, and the first half-wavelength U-shaped resonator couples the energy to the rectangular patch through the coupling aperture, thereby realizing a fourth-order filtering function; The grid slotted patch is formed by dividing a square patch through the intersection of five horizontal slot lines and three vertical slot lines, and is divided into 24 small rectangular patches; The input port is a 50 ohm impedance matching port.

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