CN209641841U - Band logical frequency-selective surfaces structure, shield door and antenna house - Google Patents

Abstract

The utility model discloses a kind of band logical frequency-selective surfaces structures, shield door and antenna house, the band logical frequency-selective surfaces structure is formed by multilayer printed circuit board Close stack, the multilayer printed circuit board is respectively top layer printed wiring board, middle layer printed wiring board and bottom printed wiring board, the top layer printed wiring board and bottom printed wiring board are a bar printing wiring board, the middle layer printed wiring board is muti-piece printed wiring board, every bar printing wiring board is made of M*N identical periodic cells splicings, the center of each periodic cells has the first circular hole in the top layer printed wiring board and bottom printed wiring board, the side wall of first circular hole is coated with metal material.The characteristics of the utility model has double zero points in terms of frequency response, and frequency selectivity is good, and insertion loss is small, the feature insensitive to polarization of ele direction, has quality small in terms of physical structure, and structure is simple, easy processing.

Description

Bandpass frequency selective surface structures, screen doors and radomes

technical field

The utility model relates to a frequency-selective surface structure, in particular to a band-pass frequency-selective surface structure, a screen door and a radome, and belongs to the frequency-selective surface technology.

Background technique

Frequency Selective Surface (FSS) is a two-dimensional structure with resonant units arranged periodically. Its frequency response depends not only on the frequency of the incident electromagnetic wave, but also on the incident angle and polarization direction of the incident electromagnetic wave. There are two types of traditional frequency selective surfaces, one is a band-pass frequency selective surface composed of an arrangement of slot units, and the other is a band-stop frequency selective surface composed of an arrangement of metal patches. Since the frequency selective surface has a special frequency response to space electromagnetic waves, it has important application value in both civil and military fields. The design of high-performance frequency selective surface plays an important role in the development of technology.

According to investigation and understanding, the existing technologies are:

1) Scholar D.M.Pozar proposed in 1990 to use a coupling hole to couple two patch resonators to design a bandpass frequency selective surface. This frequency selective surface can form a frequency response characteristic with two transmission poles.

2) Scholars Sarabandi and Behdad proposed to use non-resonant devices to design band-pass frequency selective surfaces. Each layer of metal layer that makes up the frequency selective surface will not resonate to the incident electromagnetic wave of a certain frequency band, but the combination of multi-layer metal layers is in the electromagnetic wave. Under the combined action, they can be equivalent to a corresponding series or parallel LC circuit to generate resonance, thereby forming a frequency selective surface with bandpass characteristics.

3) Scholar Luo Guoqing proposed to use a Substrate integrated waveguide (SIW for short) structure to design a bandpass frequency selective surface. By using the cavity mode of the dielectric integrated waveguide, the corresponding transmission pole is introduced, and the transmission zero point is introduced through the cross-coupling between cavities to improve the passband characteristics.

4) Scholar Shen Zhongxiang proposed to use a three-dimensional bandpass frequency selective surface composed of a two-dimensional periodic shielded microstrip line array. Compared with the traditional two-dimensional frequency selective surface, this three-dimensional frequency selective surface achieves better frequency response characteristics. The obvious disadvantage is that the processing and assembly increase the difficulty to a certain extent.

Utility model content

The first purpose of the utility model is to solve the defects of the above-mentioned prior art, and provide a bandpass frequency selective surface structure, which has double zeros in frequency response, good frequency selectivity, small insertion loss, and Insensitive to the polarization direction, it has the characteristics of small mass, simple structure and easy processing in terms of physical structure.

The third object of the present invention is to provide a screen door comprising the above band-pass frequency selective surface structure.

The third object of the present invention is to provide a radome comprising the above-mentioned bandpass frequency selective surface structure.

The first purpose of the utility model can be achieved by taking the following technical solutions:

A bandpass frequency selective surface structure formed by closely stacking multi-layer printed circuit boards, said multi-layer printed circuit boards are respectively top layer printed circuit board, middle layer printed circuit board and bottom layer printed circuit board, said top layer printed circuit board Both the printed circuit board and the bottom printed circuit board are a printed circuit board, and the printed circuit board in the middle layer is a plurality of printed circuit boards, and each printed circuit board is composed of M*N identical periodic unit splicing, and the printed circuit board in the top layer The center of each periodic unit in the board and the bottom printed circuit board has a first round hole, and the side wall of the first round hole is plated with metal material; wherein, M≥12, N≥12.

Further, the radius of the first circular hole is 7mm-8mm.

Further, the center of each periodic unit in the intermediate layer printed circuit board has a second round hole, the side wall of the second round hole is plated with metal material, and the radius of the second round hole is larger than that of the first round hole. The radius of the hole.

Further, the radius of the second circular hole is 17mm-18mm.

Further, the four corners of each periodic unit have a quarter circular hole, the side walls of the quarter circular hole are plated with metal materials, and the radius of the quarter circular hole at the four corners of M*N periodic units are the same.

Further, the radius of the quarter circular hole at the four corners of each periodic unit is 6 mm to 7 mm.

Further, the thickness of each printed circuit board is 1mm-2mm.

Further, the printed circuit boards in the middle layer are three printed circuit boards.

The second purpose of the utility model can be achieved by taking the following technical solutions:

A shielded door comprising the above-mentioned bandpass frequency selective surface structure.

The third purpose of the utility model can be achieved by taking the following technical solutions:

A radome comprising the bandpass frequency selective surface structure described above.

Compared with the prior art, the utility model has the following beneficial effects:

1. The center of each periodic unit in the top printed circuit board and the bottom printed circuit board of the present utility model has a round hole, and the side wall of the round hole is plated with metal material to form two circular resonant windows respectively. Resonant window coupling can produce a bandpass frequency response characteristic of double transmission poles.

2. The center of each periodic unit in the intermediate printed circuit board of the present utility model has a round hole, the side wall of the round hole is coated with metal material, and the radius of the round hole is larger than that of the top printed circuit board and the bottom printed circuit board The radius of the round hole in the center of each periodic unit, the round hole in the center of each periodic unit in the middle layer printed circuit board and the copper foil on the uppermost printed circuit board of the middle layer printed circuit board, the middle layer printed circuit board The copper foil on the lower surface of the bottom printed circuit board together forms a metal cavity, through which the non-resonant mode of TM110 is introduced, thereby introducing the transmission zero point of the low resistance band and improving the transmission characteristics.

3. The four corners of each periodic unit of the utility model have a quarter round hole. When every four periodic units are spliced together, the four quarter round holes can form a complete circle, and each layer of printed circuit The entire circle of the plate constitutes a plurality of circular through-holes, and through the circular through-holes, according to the principle of interaction with high-order modes, the transmission zero point of the high-resistance band is introduced to improve the transmission characteristics.

Description of drawings

FIG. 1 is a schematic structural diagram of a bandpass frequency selective surface structure according to an embodiment of the present invention.

FIG. 2 is a three-dimensional structure diagram of each periodic unit stack of a multilayer printed circuit board in the bandpass frequency selective surface structure of the embodiment of the present invention.

Fig. 3 is a front structural diagram of each periodic unit stack of a multilayer printed circuit board in the bandpass frequency selective surface structure of the embodiment of the present invention.

Fig. 4 is a side structural view of each periodic unit stack of the multilayer printed circuit board in the bandpass frequency selective surface structure of the embodiment of the present invention.

FIG. 5 is an electromagnetic simulation curve of the frequency response of the bandpass frequency selective surface structure of the embodiment of the present invention.

Among them, 1-the first printed circuit board, 2-the second printed circuit board, 3-the third printed circuit board, 4-the fourth printed circuit board, 5-the fifth printed circuit board, 6-the first round hole, 7 - circular resonant window, 8 - second circular hole, 9 - metal cavity, 10 - quarter circular hole, 11 - circular through hole.

Detailed ways

The utility model will be further described in detail below in conjunction with the embodiments and accompanying drawings, but the implementation of the utility model is not limited thereto.

Example:

As shown in Figures 1 to 4, this embodiment provides a band-pass frequency selective surface structure, which is formed by closely stacking five printed circuit boards (PCB for short), and each of the five printed circuit boards is It is a printed circuit board with copper on the upper and lower surfaces, and the five printed circuit boards are the first printed circuit board 1, the second printed circuit board 2, the third printed circuit board 3, the fourth printed circuit board 4 and the fifth printed circuit board 5, wherein the first printed circuit board 1 constitutes the top layer printed circuit board, the second printed circuit board 2, the third printed circuit board 3 and the fourth printed circuit board 4 constitute the middle layer printed circuit board, and the fifth printed circuit board 5 constitutes the bottom layer Printed circuit boards, each printed circuit board is 1.6mm, and it is composed of M*N identical periodic units spliced together; wherein, M≥12, N≥12, due to the large number of periodic units, the present embodiment The number of periodic units of 4*4 is shown in FIG. 1 .

Further, the center of each periodic unit in the top layer printed circuit board (the first printed circuit board 1) and the bottom printed circuit board (the fifth printed circuit board 5) has a first circular hole 6, and the center of the first circular hole 6 The side wall is plated with metal material, and its radius is 7.4mm. The first round hole 6 of the top printed circuit board and the first round hole 6 of the bottom printed circuit board form two circular resonant windows 7 respectively. Since each printed circuit board The thickness of the two circular resonant windows 7 is 1.6 mm, so the thickness of the two circular resonant windows 7 is also 1.6 mm. Through the coupling of the circular resonant windows 7, a band-pass frequency response characteristic of double transmission poles can be produced.

Further, the center of each periodic unit in the intermediate layer printed wiring board (the second printed wiring board 2, the third printed wiring board 3 and the fourth printed wiring board 4) has a second circular hole 8, and the second circular hole The side wall of 8 is plated with metal material, and its radius is 17.4mm. The second circular hole 8 in the center of each periodic unit in the middle layer printed circuit board is connected with the copper foil on the upper surface of the second printed circuit board 2 and the fourth printed circuit board. The copper foils on the lower surface of the board 4 together form a metal cavity 9, through the metal cavity 9, the non-resonant mode of TM110 is introduced, thereby introducing the transmission zero point of the low resistance band, and improving the transmission characteristics.

Further, the top printed wiring board (the first printed wiring board 1), the middle printed wiring board (the second printed wiring board 2, the third printed wiring board 3 and the fourth printed wiring board 4) and the bottom printed wiring board (the first printed wiring board Five printed circuit boards 5) The four corners of each periodic unit have a quarter hole 10, the side wall of the quarter hole 10 is coated with a metal material, and its radius is 6.5mm, every four periodic When the units are spliced together, four quarter-round holes 10 can form a full circle, and the full circles of five printed circuit boards form a plurality of circular through holes 11. Since the thickness of each printed circuit board is 1.6mm, The thickness of the circular through hole 11 is also 8mm, through the circular through hole 11, according to the principle of interaction with the higher order mode, a transmission zero point of the high resistance band is introduced to improve the transmission characteristics.

The metal material plated on the side walls of the first circular hole 6, the second circular hole 8 and the quarter circular hole 10 in this embodiment can be any one of aluminum, iron, tin, copper, silver, gold and platinum , or an alloy of any one of aluminum, iron, tin, copper, silver, gold and platinum, preferably copper.

The band-pass frequency selection surface structure S parameter performance electromagnetic simulation curve of the present embodiment is as shown in Figure 5, among the figure S11 is the return loss of the input port, and S21 is the forward transmission coefficient from the input port to the output port, from the figure It can be seen that the bandpass frequency selective surface structure has two resonance points, forming a transmission passband of 9.42GHz-9.57GHz, allowing electromagnetic waves with frequencies in this frequency band to pass through the selective surface, while electromagnetic waves outside this frequency band are It cannot pass through the selection surface. At the same time, the transmission zeros on both sides of the out-of-band can effectively improve the roll-off characteristics of the out-of-band and enhance the frequency selection characteristics.

The band-pass frequency selective surface structure of this embodiment can be used in the civilian field, and is specifically applied to shielded doors. The band-pass frequency selective surface structure can be covered by the door body. The shielded door can be an electromagnetic shielded door, which can be integrated into a building In addition, the shielded door can also be a shielded door of a microwave oven, which suppresses the microwave radiation in the furnace and ensures the safety of users.

The band-pass frequency selective surface structure of this embodiment can be used in the military field, and is specifically applied to a radome. The band-pass frequency selective surface structure can be covered by a skin layer. The radome can be a target radar radome, effectively reducing the Radar cross-section, to achieve the role of electromagnetic stealth.

In summary, the utility model has the characteristics of double zero points in frequency response, good frequency selectivity, small insertion loss, and insensitivity to the polarization direction of electromagnetic waves, and has the characteristics of small mass, simple structure and easy processing in terms of physical structure .

The above is only a preferred embodiment of the utility model patent, but the scope of protection of the utility model patent is not limited thereto, any skilled person familiar with the technical field within the disclosed scope of the utility model patent, according to The technical scheme of the utility model patent and the equivalent replacement or change of the utility model concept all belong to the protection scope of the utility model patent.

Claims (10)

1. A band-pass frequency selective surface structure is characterized in that: it is formed by closely stacking multilayer printed circuit boards, and the multilayer printed circuit boards are respectively top layer printed circuit board, middle layer printed circuit board and bottom layer printed circuit board , the top printed circuit board and the bottom printed circuit board are both a printed circuit board, the intermediate printed circuit board is a plurality of printed circuit boards, and each printed circuit board is composed of M*N identical periodic unit splicing , the center of each periodic unit in the top printed circuit board and the bottom printed circuit board has a first circular hole, and the sidewall of the first circular hole is plated with a metal material; wherein, M≥12, N≥12. 2. The bandpass frequency selective surface structure according to claim 1, characterized in that: the radius of the first circular hole is 7mm-8mm. 3. The bandpass frequency selective surface structure according to claim 1, characterized in that: the center of each periodic unit in the intermediate layer printed circuit board has a second circular hole, and the side wall of the second circular hole Metal material is plated, and the radius of the second circular hole is larger than the radius of the first circular hole. 4. The bandpass frequency selective surface structure according to claim 3, characterized in that: the radius of the second circular hole is 17mm˜18mm. 5. The bandpass frequency selective surface structure according to claim 1, characterized in that: the four corners of each periodic unit have a quarter hole, and the side walls of the quarter hole are coated with metal material , the radii of quarter circular holes at the four corners of the M*N periodic units are all the same. 6. The bandpass frequency selective surface structure according to claim 5, characterized in that: the radius of the quarter circular hole at the four corners of each periodic unit is 6mm-7mm. 7. The bandpass frequency selective surface structure according to any one of claims 1-6, wherein the thickness of each printed circuit board is 1mm-2mm. 8. The band-pass frequency selective surface structure according to any one of claims 1-6, characterized in that: said intermediate printed circuit boards are three printed circuit boards. 9. A shielded door, characterized in that it comprises the band-pass frequency selective surface structure according to any one of claims 1-8. 10. A radome, characterized in that it comprises the bandpass frequency selective surface structure according to any one of claims 1-8.