CN105811119A - Ultra wideband wave absorber based on resistance loading - Google Patents

Abstract

The invention discloses an ultra-broadband wave absorber based on resistance loading, which includes a dipole array antenna, a patch resistor, a metal floor, and four plastic screws for positioning and fixing the dipole array antenna and the metal floor. The sub-array antenna is composed of multiple identical dipoles arranged periodically like butterfly wings. The two welding points of a single chip resistor are respectively welded at both ends of the dipole arm to achieve a perfect match with a single dipole. The pole array antenna can receive electromagnetic waves and consume them through chip resistors, so as to achieve the purpose of absorbing waves. The present invention can be applied to microwave and millimeter wave anti-jamming systems, and has the advantages of simple structure, light weight, low cost, miniaturized unit, and short processing cycle, and can achieve different frequency ranges by designing dipole antennas in different frequency ranges. Absorption of electromagnetic waves in the frequency range.

Description

A UWB Absorber Based on Resistive Loading

technical field

The invention belongs to the technical field of microwave absorbing materials, and relates to an ultra-broadband absorber.

Background technique

With the rapid development of modern communication, more and more electromagnetic waves in space are becoming more and more complex, which will inevitably cause interference to other systems and make the system unable to work normally, and wave absorption also plays a vital role in the stealth of the antenna. It can reduce the radar cross-sectional area of the antenna, which is exactly what the stealth antenna pursues. With the development of electronic countermeasures technology, higher requirements are put forward for the absorbing structure. The direction of the planarization of the absorbing structure is developing. Therefore, the ultra-broadband research of absorbing structures is still a hotspot in the industry and academia.

In order to test the broadband characteristics of absorbing materials, Tang Yang et al. disclosed an ultra-thin broadband absorbing material based on frequency selective surface (Tang Yang, Gao Jinsong, Wang Yansong, Xu Nianxi, Chen Xin, Ultrathin based on frequency selective surface Broadband absorbing material, application number: CN201310613651, application date: 2013.11.25), realizes the broadband absorbing effect by printing a special pattern structure on the substrate, but the pattern of the absorbing material is relatively complicated, and the absorbing theory is relatively old, although In a wide frequency band, the reflection coefficient is less than -10dB, and there is still a lot of room for improvement in its absorbing effect. YupingShang et al. disclosed a way to realize broadband wave absorption by double-loop resistance (YupingShang, ZhongxiangShen, SeniorMember; IEEE, and ShaoqiuXiao, Member; IEEE, "On the Design of Single-Layer Circuit Analog Absorber Using Double-Square-LoopArray", IEEETRANSACTIONSONANTENNAPROPAGATION, VOL.61, NO.12, DECEMBER2013.pp.6022-6029), by designing a double-ring structure with a suitable size and adding chip resistors, using the equivalent circuit analysis method to achieve broadband microwave absorption. It’s just that the unit size of the double-ring structure is larger than that of the unit structure of the present invention, and the number of resistors is too large. In the microwave and millimeter wave frequency band, the size of the chip resistors is very small. It is necessary to weld such a large number of micro-resistors to the double-ring. It is very time-consuming and labor-intensive. In addition, the height of the double-ring structure from the metal floor is too large, which does not meet the requirements of low profile.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the above-mentioned technologies, and provide a method for realizing broadband microwave absorption. In the case of realizing high microwave absorption rate, the microwave absorption structure becomes very simple, the analysis thinking is clearer, and it has great advantages. innovative.

In order to achieve the above object, the technical solution adopted by the present invention is: a resistance-loaded ultra-broadband absorber, including a loaded dipole antenna array, a dielectric substrate, a metal floor, and a four plastic screws, the loaded dipole antenna array is printed on a single-layer dielectric substrate symmetrical dipole antenna periodic arrangement, the distance between the dipole antenna array is to make the antenna The mutual coupling between them is small and the gain of the antenna array is high; the four corners of the dipole antenna array dielectric substrate are drilled with four plastic through holes for positioning and fixing; the four corners of the metal floor are drilled with Four through holes for positioning; the thread diameter of the four plastic screw holes is the same as the diameter of the four screw holes on the metal floor and the four through holes on the dipole antenna array, and the four holes on the metal floor The positions of the through holes correspond to the positions of the four through holes on the dielectric substrate respectively. The dipole array antenna is connected to the metal floor through four plastic screws, and different distances can be realized by adjusting the distance between the floor and the dipole antenna. The change of absorption rate in different frequency bands.

Further, the unit of the loaded dipole antenna array is composed of a periodic arrangement of copper foils in the shape of butterfly wings, the real part of the input impedance of a single dipole antenna is very flat, and the imaginary part is very small, which can be compared with pure The resistors form a good match, and all the feed ports of the dipoles are replaced with chip resistors with a resistance value of 82 ohms of the model 0805.

Further, the length of the plastic screw should make the distance between the metal floor and the loaded dipole array antenna a required distance, so as to realize broadband wave absorption.

The technical principle of the present invention is: as a wave-absorbing material, the wave-absorbing material with a metal floor has greater applicability and stronger anti-interference ability. As a reciprocal element, the antenna can not only transmit electromagnetic waves but also receive electromagnetic waves. It is by using this reciprocity principle that when the antenna is used as a device for receiving electromagnetic waves, if the received electromagnetic waves can be lost with a lossy element, then we It will achieve a very good effect of absorbing. It’s just that the resistance values of our existing chip resistors are all integers without any imaginary part. If you want to match the dipole antenna well, then the requirements for the dipole antenna are very high. It requires a dipole The imaginary part of the antenna input impedance is very small (or zero) and the real part has a good resistance flatness in a certain broadband frequency range, so as to achieve broadband matching with the chip resistor, thereby achieving efficient wave absorption. However, the input impedance of the dipole antenna we invented has been proved to be that the imaginary part of the input impedance is very small, and the real part has good flatness in a certain broadband range, and a large reflection bandwidth can be obtained.

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

(1) The dipole array antenna used in the present invention is an array formed by printing a dipole antenna that looks like butterfly wings on a single-layer dielectric substrate. It has a simple structure, beautiful patterns, low design cost, It has the advantages of short preparation period and light weight.

(2) The present invention proposes a brand-new absorbing theory, which can be used for other forms of dipole antennas and even patch antennas to construct absorbers, and the absorbing effect is also greatly improved.

(3) The present invention can theoretically achieve any frequency band absorption by designing dipole antennas in different frequency bands, and provides a good solution for broadband low-frequency absorption.

The purpose, features and advantages of the present invention will be further described below with reference to the accompanying drawings in combination with the embodiments.

Description of drawings

Fig. 1 is an overall expanded schematic diagram of the present invention.

Figure 2 is the reflection coefficient of the present invention.

Figure 3 is the absorption rate of the present invention.

detailed description

In order to make the object of the present invention, the technical problem to be solved and the technical solution clearer, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a schematic diagram of the overall development of the present invention, including a loaded dipole antenna array 1, a dielectric substrate 2, a metal floor 3, and plastic screws 4 connecting the dipole antenna array and the metal floor. Described dipole antenna array is to be printed on the high loss FR4 (relative permittivity is 4.4, loss tangent is 0.02) dielectric substrate 2 that is printed on thickness 0.8mm Periodically arranged by many dipole units 11 Formed, the dipole unit 11 is made of copper sheets printed on the dielectric substrate 2 like butterfly wings, and the shape and size of each unit structure are exactly the same; the welding at both ends of the chip resistor 12 The points are respectively welded on the two arms of the dipole unit 11 as the main energy dissipation element, and the distance between the dipole units 11 must be consistent with the size of the chip resistor 12, so that the chip resistor 12 can work normally; The four corners of the dipole antenna array dielectric substrate are drilled with four through holes 21 for positioning and fixing; the metal floor 3 is drilled with four through holes 31 for positioning and fixing at its four corners, and the four plastic The diameter of the screw 4 is the same as the diameter of the four through holes 21 on the dipole array antenna and the diameter of the four through holes 31 on the metal floor, both are 2mm, and the positions of the four through holes on the dipole array antenna are the same as those on the metal floor. The positions of the four through holes on the floor are respectively the same, and the metal floor 3 and the dipole array antenna 2 are connected and fixed by 4 plastic screws 4, and the distance between the metal floor 3 and the dipole array antenna 1 is adjusted. Realize the effect of different absorption rates at different frequencies.

Figure 2 shows the reflection coefficient of the dipole array antenna's port welding chip resistor as the absorbing structure in this specific implementation, and its operating frequency range is 3.79GHz-11.79GHz, and the dipole array antenna in Figure 3 is used as the reflection The reflection coefficients of the antennas can be well matched.

Fig. 3 shows the absorption rate of the wave absorber when the port of the dipole array antenna is welded with chip resistors as the wave absorber in this specific implementation. It can be seen that good wave absorption can be achieved in the range of 3.79GHz-11.79GHz. 100% absorption can be achieved in some frequency bands.

Those skilled in the art will appreciate that the embodiments described here are to help readers understand the principles of the present invention, and it should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical revelations disclosed in the present invention without departing from the present invention, and these modifications and combinations are still within the protection scope of the present invention.

Claims (3)

1. An ultra-broadband absorber based on resistance loading, comprising a dipole antenna array (1), a dielectric substrate (2), a metal floor (3) and plastic screws (4) connecting the dipole antenna array and the metal floor ), it is characterized in that: described dipole antenna array (1) is arranged by the dipole unit (11) that is printed on the single-layer dielectric substrate (2) that arranges periodically, chip resistance (12 ) solder joints at two ends of the dipole unit (11) are respectively welded on the two arms of the dipole unit (11), and the number of the specific dipole unit can be determined according to the required absorbing space; on the dielectric substrate of the printed dipole antenna array (2) and the four corners of the metal floor (3) are respectively drilled with four substrate through holes (21) and four floor through holes (31) for positioning and fixing; the substrate through holes (21) and the floor The through holes (31) have the same diameter and are connected and fixed by the four plastic screws (4). 2. A kind of ultra-broadband wave absorber based on resistance loading according to claim 1, characterized in that: the dipole unit (11) is made of butterfly wings printed on the dielectric substrate (2). The shape and size of each unit structure are exactly the same; the chip resistor (12) is used as the main energy dissipation element, and its resistance value is adjusted according to the frequency range of the required wave absorption. 3. A kind of ultra-broadband wave absorber based on resistance loading according to claim 1, characterized in that: adjusting the length of the plastic screw (4) can change the metal floor (3) and the dipole array antenna ( 1) to realize the change of different absorption rates in different frequency bands.