CN112599968A - Low-profile ultra-wideband sine broken line antenna and ultra-wideband communication terminal - Google Patents
Low-profile ultra-wideband sine broken line antenna and ultra-wideband communication terminal Download PDFInfo
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Abstract
The invention belongs to the technical field of communication antennas, and discloses a low-profile ultra-wideband sine broken line antenna and an ultra-wideband communication terminal, wherein the low-profile ultra-wideband sine broken line antenna comprises: the device comprises four sine broken line radiation arms, two groups of coplanar miniaturized barrons, two ultrathin printing wave-absorbing layers and a back cavity; the sine broken line radiator is positioned on the back cavity opening surface; the miniaturized coplanar balun is positioned at the bottom of the back cavity, and the output ends of the two groups of baluns are respectively connected with the feed points of the pair of sine broken line radiating arms through two thin metal columns; and the two ultrathin printing wave absorbing layers are loaded between the balun and the meander line antenna at a certain interval. The invention generates dual-polarization ultra-wideband radiation by a sine broken line radiation arm and a coplanar miniaturized balun, and utilizes an ultra-thin printed wave-absorbing layer in a back cavity to inhibit back radiation so as to realize unidirectional radiation. The polarization antenna has the advantages of low profile, ultra wide band, light weight, low cost and flexible configuration, and can be used for various platforms.
Description
Technical Field
The invention belongs to the technical field of communication antennas, and particularly relates to a low-profile ultra-wideband sine broken line antenna and an ultra-wideband communication terminal.
Background
At present: the sine broken line antenna is a broadband antenna with excellent performance and is widely applied to military and civil fields such as ultra-wideband communication, electronic warfare, broadband frequency spectrum monitoring, broadband passive guidance and the like. Considering the design requirements of the actual carrier, the antenna generally needs to be designed to radiate unidirectionally. The commonly used design method of the one-way radiation of the sine broken line antenna is loading of a back cavity. Theoretically, for a single frequency point, if the bottom of the back cavity is a quarter wavelength away from the antenna radiation antenna, the reflected wave and the direct wave can be superposed in phase to improve the gain. Furthermore, the antenna radiation arm can be tightly attached to the back cavity to realize unidirectional radiation based on the in-phase reflection band gap. The above method, however, requires that the antenna be spaced a quarter wavelength from the bottom of the back cavity and is not suitable for ultra-wideband antennas. And the in-phase reflection band gap constructed based on the resonance mechanism cannot realize ultra-wideband design at present. Another compromise method is to fill the back cavity with a wave-absorbing material to absorb the back radiation to form a unidirectional radiation. However, the depth of the antenna cavity is larger due to the required larger thickness of the traditional carbon powder-doped sponge wave-absorbing material. Further, the antenna needs to be combined with iron-based wave-absorbing materials for use in order to cover low-frequency bands, so that the antenna has a large section, heavy weight and high cost.
Through the above analysis, the problems and defects of the prior art are as follows: the conventional sine broken line antenna has the advantages of high integral section height, large size, heavy weight and high manufacturing cost.
Current approaches to solving the above problems still focus on the design of reflection suppressing materials. The in-phase reflection band gap structure can hardly cover a continuous working broadband due to the dependence on the periodic resonant structure, and although the multi-band characteristic is constructed by adopting a multi-layer nested resonant structure, the efficient absorption and continuous broadband absorption effect cannot be formed. Ultra-wideband design is difficult. The conventional wave-absorbing material is limited by the mechanism, the sponge is doped with carbon powder with a certain thickness, the reduction of the thickness of the sponge brings serious reduction of the absorptivity and bandwidth, and if the ultra-wideband absorption is realized on a low section, the engineering challenge is very large if the absorption mechanism is not broken through.
However, in various application scenarios such as communication, electronic warfare, detection, etc., the ultra-wideband multi-polarization low-profile antenna has wide application. Advantages may be realized if the antenna can be designed to be compact and small with a low profile. On one hand, the irregularity degree of the carrier platform can be reduced; for example, on a high-speed aircraft, the fluid characteristics of the aircraft can be greatly improved by reducing the depth of an embedded cavity or the protruding height, and the design of a compact pneumatic layout is realized. On the other hand, the weight stress of the antenna as a platform load can be reduced, which is particularly important in aircraft design. In addition, if the cost is reduced by the novel design scheme, the construction cost reduction and large-scale production of the system are greatly facilitated.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a low-profile ultra-wideband sine broken line antenna and an ultra-wideband communication terminal.
The invention is realized in this way, a low-profile ultra-wideband sinusoidal meander line antenna, comprising: the device comprises four sine broken line radiation arms, two groups of coplanar miniaturized barrons, two ultrathin printing wave-absorbing layers and a back cavity;
the sine broken line radiator is positioned on the back cavity opening surface; the miniaturized coplanar balun is positioned at the bottom of the back cavity, and the output ends of the two groups of baluns are respectively connected with the feed points of the pair of sine broken line radiating arms through two thin metal columns; and the two ultrathin printing wave absorbing layers are loaded between the balun and the meander line antenna at a certain interval.
The antenna radiating structure and balun combination described above achieves the advantage of a very compact dual polarization design. The ultra-thin printing wave-absorbing material realizes the advantages of thin section, light weight and low cost while meeting the wave-absorbing effect.
Further, the sinusoidal broken line radiation arm is formed by scanning a sinusoidal curve by 22.5 degrees around the origin.
Further, the 4 radiation arms are obtained by copying the single arm by rotating 90 degrees around the origin in sequence.
Furthermore, the miniaturized coplanar balun realizes broadband matching and balance transformation based on a gradual change structure, the tail end of the miniaturized coplanar balun is provided with a fork and is positioned at the bottom of the back cavity, the miniaturized coplanar balun is placed in parallel with the antenna, and the miniaturized coplanar balun is connected with a pair of sine broken line radiation arm feed points through two thin metal columns.
Furthermore, the ultra-thin printing wave-absorbing layer is formed by a band-loss annular printing unit to form a frequency selective surface, and ultra-wide band wave-absorbing is realized by double-layer combination.
Further, the sine broken line antenna unit comprises a radiation arm with a plurality of sections of sine curves; the radiation arms are folded back and forth at a certain angle and are connected into a whole in a staggered manner to form a non-closed structure, namely, the other radiation arms are connected with the other radiation arms end to end except that one end of each of the first section of radiation arm and the last section of radiation arm is not connected with the other radiation arms;
the length of a radiation arm in the sine broken line antenna unit is gradually increased from the center of the substrate to the circumferential direction; in the same sine broken line antenna unit, the sine curve of each radiation arm is formed according to the following formula:
wherein r and
is the polar coordinate of a point on the sinusoid, alphapIs the angular span of the unit, RpIs the radial starting distance of the p-th unit, the p +1 th segment and the p-th segment radial startingThe point distance is determined by the scale factor taupBy Rp＝τp-1·Rp-1And (6) determining.
Further, the sine broken line antenna unit is formed into a self-complementing pattern, and the angle span delta between every two adjacent radiation arms is set to be 22.5 degrees, so that the connecting part of every two radiation arms can be at least inserted and nested in a gap part formed by the two radiation arms corresponding to the adjacent sine broken line antenna unit; when the four sinusoidal broken line antenna units are arranged in the same direction in the circumferential direction, two adjacent sinusoidal broken line antenna units can be mutually inserted and nested; the four-arm sine broken line helical antenna;
the plane feed balun 20 realizes broadband matching and balanced transformation based on a gradual change structure;
the planar feed balun is placed in parallel with the antenna and adopts a bent structure to solve the arrangement;
the two balun ends are disconnected and feed the two pairs of oscillators through the bifurcation and the connecting line respectively.
Furthermore, a back cavity with an ultrathin printing wave-absorbing layer is provided to realize the one-way radiation of the sine broken line antenna, the back cavity is a cylinder with an opening at one end, and the ultrathin printing wave-absorbing layer is arranged in the back cavity;
the ultrathin printing wave-absorbing layer adopts a double-layer band loss FSS unit;
the medium between the floor and the lossy FSS adopts foam with light weight and dielectric constant close to vacuum;
the FSS unit adopts an annular structure, a specific wave-absorbing material unit and a loss-carrying FSS wave-absorbing screen equivalent circuit model, and the corresponding impedance is as follows:
ZFSS＝R-j[(1-ω2LC)/(ωC)]；
input impedance Z of free space wave-absorbing structureinImpedance Z equal to frequency selective surfaceFSSSurface impedance Z with dielectric platedThe parallel connection of (1):
whereinZd＝jZm TE,TMtan(βd),ZTE,TMSelecting the impedance of the surface FSS to a conductive floor covered with a medium for the frequency, beta being the propagation constant, d being the thickness of the medium;
the unit parameters are D25.74 mm, dpatch 21.5mm, wpatch 4.45mm, the ink sheet resistance of the lower layer is 70 omega/sq, the ink sheet resistance of the upper layer is 200 omega/sq, FR4 is adopted for a film printed with the resistance ink, and the thickness t is 0.14 mm.
Another object of the present invention is to provide an ultra-wideband communication terminal using the low-profile ultra-wideband sinusoidal meander line antenna.
The invention also aims to provide a broadband spectrum monitoring terminal which uses the low-profile ultra-wideband sinusoidal broken line antenna.
By combining all the technical schemes, the invention has the advantages and positive effects that: the wave-absorbing material is designed by combining the dual advantages of the traditional Salisbury wave-absorbing screen and the frequency selection surface. The traditional Salisbury wave-absorbing screen is one quarter of the wavelength of the conductive floor, and consists of a wave-absorbing screen with specific surface resistance and a dielectric material. The invention adopts a printing double-layer band loss Frequency Selective Surface (FSS) unit to replace a Salisbury wave-absorbing screen unit. Through the combined optimization of the printed unit pattern and the surface resistance, the absorption frequency band of the upper layer band loss FSS, the coupling absorption frequency band and the bottom layer FSS absorption frequency band construct an ultra-wide wave absorption frequency band. The narrow-band constraint of the quarter wavelength of the Salisbury wave-absorbing screen is avoided. Meanwhile, the film can be processed and manufactured by printing on the film. The cost, weight and bandwidth of the device have great advantages. The engineering upper band loss wave-absorbing FSS film can be supported by foam with light weight and dielectric constant close to vacuum.
Compared with the prior art, the invention has the following advantages:
(1) the invention replaces the traditional sponge and ferrite wave-absorbing material based on the double-layer ultrathin printing wave-absorbing layer, and realizes the ultra-wideband absorption of 9 frequency doubling. Because the ultra-thin printing wave-absorbing layer is formed by printing films, the mutual distance is relatively small. The cavity depth is greatly reduced after the antenna is used for a cavity-backed antenna. Has the advantages of low profile, low cost, light weight and ultra-bandwidth.
(2) The invention adopts a miniaturized coplanar bent microstrip line balun, realizes broadband matching and balanced transformation by using a gradual change structure, has a bifurcation at the tail end, is positioned at the bottom of a back cavity, is arranged in parallel with an antenna, and is respectively connected with a pair of sinusoidal fold line radiation arm feed points through two thin metal columns. The problem that the balun of the traditional vertical feed cannot be orthogonally placed is solved, and the compact structural design, the space compatibility with wave-absorbing materials and the dual-polarization synchronous feed are synchronously realized.
(3) The dual-polarization feed system is based on the reasonable design of the dual-pair complementary sine broken line radiation arms and the feed system, dual-polarization feed is realized through a single aperture, and various application scenes such as single-line polarization, double-line polarization, single circular polarization, double circular polarization and the like can be used by combining the combined application of an electric bridge or other feed systems.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained from the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a low-profile ultra-wideband sinusoidal meander antenna provided by an embodiment of the invention.
Figure 2 is a side view of the low profile ultra-wideband sinusoidal meander antenna shown in figure 1 according to an embodiment of the present invention.
Fig. 3 is a top view of the four-arm sinusoidal meander spiral antenna radiator shown in fig. 1 according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of a model of the balun end bifurcation shown in fig. 5 according to an embodiment of the present invention.
Fig. 5 is a structural diagram of a unit structure and an installation structure of the wave-absorbing material shown in fig. 1 according to an embodiment of the invention.
Fig. 6 is a schematic diagram of an equivalent circuit model of the FSS wave-absorbing screen with loss shown in fig. 9 according to an embodiment of the present invention.
Fig. 7 is a schematic diagram of a reflection coefficient curve of the double-layer structure type wave-absorbing material shown in fig. 9 under a vertical incidence condition according to an embodiment of the present invention.
Fig. 8 is a schematic diagram of standing wave ratio simulation and test results of two input ports of the antenna shown in fig. 2 according to an embodiment of the present invention.
Fig. 9 is a schematic diagram of simulation results of circular polarization axial gain and axial ratio of the antenna shown in fig. 2 according to the embodiment of the present invention.
Fig. 10 is a graph showing simulated circularly polarized radiation patterns of the antenna shown in fig. 2 at 2GHz according to an embodiment of the present invention.
Fig. 11 is a schematic diagram of an antenna shown in fig. 2 simulating a circularly polarized radiation pattern at 6GHz according to an embodiment of the present invention.
Fig. 12 is a graph showing simulated circularly polarized radiation patterns of the antenna shown in fig. 2 at 10GHz according to an embodiment of the present invention.
Fig. 13 is a graph showing simulated circularly polarized radiation patterns of the antenna shown in fig. 2 at 14GHz according to an embodiment of the present invention.
Fig. 14 is a graph showing simulated circularly polarized radiation patterns of the antenna shown in fig. 2 at 18GHz according to an embodiment of the present invention.
Fig. 15 is a simulated linearly polarized radiation pattern of the antenna shown in fig. 2 at 2GHz according to an embodiment of the present invention.
Fig. 16 is a simulated linear polarization radiation pattern of the antenna shown in fig. 2 at 6GHz according to an embodiment of the present invention.
Fig. 17 is a graph showing simulated linear polarization radiation patterns of the antenna shown in fig. 2 at 10GHz according to an embodiment of the present invention.
Fig. 18 is a simulated linear polarization radiation pattern of the antenna shown in fig. 2 at 14GHz according to an embodiment of the present invention.
Fig. 19 is a simulated linearly polarized radiation pattern of the antenna of fig. 2 at 18GHz according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Aiming at the problems in the prior art, the invention provides a low-profile ultra-wideband sine broken line antenna and an ultra-wideband communication terminal, and the invention is described in detail below with reference to the accompanying drawings.
As shown in fig. 1 to 19, the low-profile ultra-wideband sinusoidal meander antenna provided by the embodiment of the invention includes a four-arm sinusoidal meander spiral antenna 10, two groups of plane index baluns 20, two layers of structural wave-absorbing material 30, and a metal back cavity 40.
Specifically, the four-arm sine meander-line helical antenna 10 includes four identical sine meander- line antenna elements 11, 12, 13, 14 and a layer of dielectric substrate, that is, the four sine meander-line antenna elements 11 to 14 have the same structure and size, and may be regarded as that one sine meander-line antenna element 11 is sequentially rotated and copied by an angle of 90 ° to form the sine meander- line antenna elements 12, 13, 14, thereby forming the four-arm sine meander-line helical antenna 10.
In an embodiment, one of the meander line antenna elements, such as meander line antenna element 11, is specifically described as an example. The meander line antenna element 11 comprises a radiating arm 110 with a plurality of sections of sinusoidal curve. Each radiation arm 110 is folded back and forth at a certain angle and is staggered to form a non-closed structure, that is, except that one end of each of the first radiation arm 110 and the last radiation arm 110 is not connected with other radiation arms 110, the other radiation arms are all connected with other radiation arms 110 end to end. For example, the meander line antenna element 11 may be designed as 10 radiating arms 110, the length of the 10 radiating arms 110 is gradually changed, the shortest radiating arm 110 has the highest operating frequency, whereas the shortest radiating arm 110 has the lowest operating frequency. Therefore, the low frequency operating frequency of the antenna can be extended by increasing the length of the radiating arm 110.
Further, as shown in fig. 3, the length of the radiation arm 110 in the sine meander antenna element 11 gradually increases from the center of the substrate to the circumferential direction. More specifically, in the same meander line antenna element 11, the sinusoid of each radiating arm 110 is formed according to the following formula:
wherein r and
is the polar coordinate of a point on the sinusoid, alphapIs the angular span of the unit, RpIs the radial starting distance of the p-th cell. The distance between the p +1 th segment and the p-th segment radial starting point is determined by the scale factor taupBy Rp＝τp-1·Rp-1And (6) determining.
In a preferred embodiment, in order to form the meander antenna element 11 as a self-complementary pattern, the angular span δ between each two adjacent radiating arms 110 is set to 22.5 °, so that the connecting portion of each two radiating arms 110 can be at least inserted and nested in the gap portion formed by the two corresponding radiating arms of the adjacent meander antenna element. When the four sinusoidal meander line antenna elements 11-14 are provided and arranged in the same direction in the circumferential direction, two adjacent sinusoidal meander line antenna elements can be inserted into each other. The four-arm sine broken line helical antenna 10 is essentially a non-frequency-variable antenna, has a wide bandwidth, and can improve the isolation among the sine broken line antenna units 11-14 and reduce the size of the antenna in a mutually non-contact nesting mode, and in addition, the size of the antenna is effectively reduced in a terminal loading resistance mode.
Specifically, the planar feed balun 20 implements broadband matching and balance transformation based on a gradual change structure.
Furthermore, the plane feed balun and the antenna are placed in parallel, and the arrangement is solved by adopting a bent structure.
Furthermore, in practical application, the tail ends of the two baluns are disconnected and respectively feed the two pairs of oscillators through the branches and the connecting wires, so that the problem that the baluns of the traditional vertical feed cannot be orthogonally placed is solved, the structural compact design, the space compatibility with the wave-absorbing material and the dual-polarization synchronous feed are synchronously realized. As shown in particular in fig. 4.
The invention designs a back cavity with an ultrathin printing wave-absorbing layer to realize the one-way radiation of the sine broken line antenna. Specifically, the back cavity is a cylinder with an opening at one end, and the ultrathin printing wave-absorbing layer is arranged in the back cavity.
The traditional Salisbury wave-absorbing screen is composed of a wave-absorbing screen with a specific surface resistance and a medium material, wherein the wave-absorbing screen is one fourth of the wavelength of a conductive floor, and the reflection field is inhibited by offsetting the direct reflection field of the wave-absorbing screen and the field which penetrates out of the wave-absorbing screen again after being reflected for multiple times between the wave-absorbing screen and the floor. The traditional Salisbury wave-absorbing screen only has a single resonance frequency point, and in a frequency range lower than or higher than the resonance frequency point, the wave-absorbing screen is respectively influenced by inductive reactance or capacitive reactance components generated by a grounding dielectric slab, so that higher reflectivity is generated.
The ultrathin printing wave-absorbing layer is formed by replacing a Salisbury wave-absorbing screen unit with a double-layer band loss FSS unit on the basis of a traditional Salisbury wave-absorbing screen.
Further, the medium between the floor and the lossy FSS is a foam that is lightweight and has a dielectric constant close to vacuum.
Further, the FSS unit adopts an annular structure preferably selected from a cross shape, an annular shape and a patch shape, and the specific wave-absorbing material unit structure is described with reference to fig. 5.
Specifically, an equivalent circuit model of the FSS wave-absorbing screen with loss is shown in fig. 6. The corresponding impedances are:
ZFSS＝R-j[(1-ω2LC)/(ωC)]；
input impedance Z of free space wave-absorbing structureinImpedance Z equal to frequency selective surfaceFSSSurface impedance Z with dielectric platedThe parallel connection of (1):
wherein Zd＝jZm TE,TMtan(βd),ZTE,TMThe impedance of the surface FSS to a conductive floor covered with a medium is selected for the frequency. Beta is the propagation constant and d is the medium thickness.
In a preferred embodiment, the testThe reflection coefficient from free space to the wave-absorbing material is considered to be
Therefore get
And Z isFSSTaking appropriate values such that Zin＝Z0At this time, the reflection coefficient is the smallest, and the efficiency of absorbing electromagnetic waves by the wave-absorbing material is the highest.
Further, in order to further expand the bandwidth, the invention adopts a double-layer band loss FSS to form the wave-absorbing material, because:
the two layers of band loss frequency selective surfaces FSS can generate absorption at respective resonant frequency bands; the lower layer band loss frequency selective surface FSS can serve as a reflecting surface outside the self resonant frequency band, so that the upper layer band loss frequency selective surface FSS generates a new wave absorbing frequency band; the frequency selective surface FSS causes a phase lag at the low frequency end, resulting in a peak absorption.
According to the design principle and the structure of the structural wave-absorbing material, ultra-wideband wave absorption with the frequency band covering 2GHz-18GHz can be realized.
In a preferred embodiment, the unit parameters D is 25.74mm, dpatch is 21.5mm, wpatch is 4.45mm, the sheet resistance of the lower layer ink is 70 Ω/sq, the sheet resistance of the upper layer ink is 200 Ω/sq, FR4 is used for a film printed with resistive ink, and the thickness t is 0.14mm, which is specifically described in conjunction with fig. 5. At this time, the reflection coefficient curve of the double-layer structure type wave-absorbing material under the condition of vertical incidence is shown in fig. 7.
The ultra-thin printing wave-absorbing layer can realize the ultra-wide band absorption of 9 frequency doubling. Because the ultra-thin printing wave-absorbing layer is formed by printing films, the mutual distance is relatively small. The cavity depth is greatly reduced after the antenna is used for a cavity-backed antenna. Has the advantages of low profile, low cost, light weight and ultra-bandwidth.
Figure 1 shows a sine broken line antenna loaded with a balun and wave-absorbing material back cavity. As shown in fig. 2, the balun and the double-layer ultra-thin printed wave-absorbing layer are both placed in the back cavity of the antenna. The balun is positioned at the bottom of the cavity, the double-layer ultrathin printing wave-absorbing layer is loaded between the balun dielectric plate and the antenna, and the tail ends of the two groups of baluns are connected with the antenna feed point through four thin metal columns.
At this time, the antenna back cavity depth from the antenna radiation surface to the balun back surface is only 15 mm. Compared with the traditional Sinuous antenna, the antenna designed by the invention realizes the reduction of the cavity back depth by about 60 percent, and has good low-profile advantage. In addition, the size of the antenna aperture is effectively reduced by means of loading the resistor at the tail end, the diameter of the antenna is only 59mm, and the aim of low-profile miniaturization is achieved.
The technical effects of the present invention will be described in detail with reference to simulations.
The antenna performance is analyzed below. The port standing wave ratio and isolation performance of the antenna are first analyzed. Fig. 8 is a standing wave ratio simulation result of two input ports of the antenna, and it can be seen from the figure that the simulated standing wave ratios of the frequency bands of 2 to 18GHz are both below 2, which shows that good matching between the balun and the antenna is achieved.
And analyzing the characteristics of gain and directional diagram of the antenna in two working states of circular polarization and linear polarization.
And verifying the circular polarization of the antenna by adopting a simulation result. Fig. 9 is a simulation result of the axial gain of the antenna, and it can be seen that the gain of the antenna at the low frequency end of 2 to 3GHz is lower due to the smaller size of the antenna and the loading resistance at the end, but the gain of the antenna is basically stabilized above 4dB as the frequency increases. Fig. 9 shows the axial ratio characteristic of the antenna simulation synchronously. It can be seen that the axial ratio performance of the balun rear antenna designed by the paper is good, and is less than 1.5dB in the full frequency band. Fig. 10-14 show simulated circularly polarized radiation patterns of the antenna at several frequency points, and it can be seen from the simulation results that the antenna exhibits better circularly polarized characteristics. And the antenna keeps good beam width characteristic in the whole frequency band, 3dB beam width can cover +/-30 degrees, and most application scenes of the antenna are met.
And verifying the working mode of the linear polarization of the antenna by adopting a simulation result. Due to the symmetry of the antenna, the paper only gives a single polarization simulation result corresponding to one port. Fig. 15-19 show simulated normalized radiation patterns of the antenna at several frequency points, and it can be seen that the antenna maintains good beam width characteristics in the whole frequency band. The 3dB beamwidth may cover ± 30 °.
In conclusion, the antenna designed by the invention has good circular polarization and linear polarization working characteristics, and compared with the traditional sponge and iron-oxygen combined wave-absorbing material, the thickness of the antenna designed by the invention is reduced from 30mm to about 12 mm; a weight reduction of about 25%; the cost is far less than that of the sponge and iron oxide combined wave-absorbing material. Therefore, the antenna designed by the paper has very great application value and potential.
In the description of the present invention, "a plurality" means two or more unless otherwise specified; the terms "upper", "lower", "left", "right", "inner", "outer", "front", "rear", "head", "tail", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
The above description is only for the purpose of illustrating the present invention and the appended claims are not to be construed as limiting the scope of the invention, which is intended to cover all modifications, equivalents and improvements that are within the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. A low-profile ultra-wideband sinusoidal meander line antenna, comprising: the device comprises four sine broken line radiation arms, two groups of coplanar miniaturized barrons, two ultrathin printing wave-absorbing layers and a back cavity;
the sine broken line radiator is positioned on the back cavity opening surface; the miniaturized coplanar balun is positioned at the bottom of the back cavity, and the output ends of the two groups of baluns are respectively connected with the feed points of the pair of sine broken line radiating arms through two thin metal columns; and the two ultrathin printing wave absorbing layers are loaded between the balun and the meander line antenna at a certain interval.
2. The low-profile ultra-wideband meander antenna of claim 1, wherein the meander radiating arm is formed by a 22.5 ° sweep of a sinusoid around an origin.
3. The low-profile ultra-wideband sinusoidal meander antenna of claim 2, wherein the 4 radiating arms are replicated from a single arm rotated 90 ° sequentially about the origin.
4. The low-profile ultra-wideband sinusoidal meander antenna as recited in claim 1, wherein said miniaturized coplanar balun is based on a tapered structure to achieve wideband matching and balanced transformation, with its ends bifurcated and located at the bottom of the back cavity and placed parallel to the antenna, each connected to a pair of feeding points of the radiating arms of the sinusoidal meander line by two thin metal posts.
5. The low-profile ultra-wideband sinusoidal meander line antenna of claim 1, wherein the ultra-thin printed wave-absorbing layer is a frequency selective surface formed by a lossy annular printed element, and the ultra-thin printed wave-absorbing layer is a double-layer combination for ultra-wideband wave absorption.
6. The low profile ultra-wideband sinusoidal meander antenna of claim 1, wherein the sinusoidal meander antenna element includes a plurality of sections of radiating arms that are sinusoidal; the radiation arms are folded back and forth at a certain angle and are connected into a whole in a staggered manner to form a non-closed structure, namely, the other radiation arms are connected with the other radiation arms end to end except that one end of each of the first section of radiation arm and the last section of radiation arm is not connected with the other radiation arms;
the length of a radiation arm in the sine broken line antenna unit is gradually increased from the center of the substrate to the circumferential direction; in the same sine broken line antenna unit, the sine curve of each radiation arm is formed according to the following formula:
wherein r and
is the polar coordinate of a point on the sinusoid, alphapIs the angular span of the unit, RpIs the radial starting distance of the p-th unit, and the radial starting point distances of the p +1 th segment and the p-th segment are determined by the scaling factor taupBy Rp＝τp-1·Rp-1And (6) determining.
7. The low-profile ultra-wideband sinusoidal meander antenna of claim 1, wherein the sinusoidal meander antenna elements are formed as a self-complementary pattern, and the angular span δ between each two adjacent radiating arms is set to 22.5 °, so that the connecting portion of each two radiating arms is at least inserted and nested in the gap portion formed by the two corresponding radiating arms of the adjacent sinusoidal meander antenna elements; when the four sinusoidal broken line antenna units are arranged in the same direction in the circumferential direction, two adjacent sinusoidal broken line antenna units can be mutually inserted and nested; the four-arm sine broken line helical antenna;
the plane feed balun 20 realizes broadband matching and balanced transformation based on a gradual change structure;
the planar feed balun is placed in parallel with the antenna and adopts a bent structure to solve the arrangement;
the two balun ends are disconnected and feed the two pairs of oscillators through the bifurcation and the connecting line respectively.
8. The low-profile ultra-wideband sine meander line antenna of claim 1, having a back cavity with an ultra-thin printed wave-absorbing layer for realizing unidirectional radiation of the sine meander line antenna, wherein the back cavity is a cylinder with an opening at one end, and the ultra-thin printed wave-absorbing layer is disposed therein;
the ultrathin printing wave-absorbing layer adopts a double-layer band loss FSS unit;
the medium between the floor and the lossy FSS adopts foam with light weight and dielectric constant close to vacuum;
the FSS unit adopts a ring structure.
9. An ultra-wideband communication terminal, characterized in that the ultra-wideband communication terminal uses the low-profile ultra-wideband sinusoidal meander line antenna as claimed in any of claims 1-8.
10. A broadband spectrum monitoring terminal is characterized in that the broadband spectrum monitoring terminal uses the low-profile ultra-wideband sine broken line antenna as claimed in any one of claims 1-8.
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| CN202011367430.9A CN112599968A (en) | 2020-11-27 | 2020-11-27 | Low-profile ultra-wideband sine broken line antenna and ultra-wideband communication terminal |
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| CN202011367430.9A CN112599968A (en) | 2020-11-27 | 2020-11-27 | Low-profile ultra-wideband sine broken line antenna and ultra-wideband communication terminal |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117293560A (en) * | 2023-11-24 | 2023-12-26 | 陕西海积信息科技有限公司 | Ultra-wideband dual polarized lens antenna |
| CN117317576A (en) * | 2023-11-29 | 2023-12-29 | 福建福大北斗通信科技有限公司 | Broadband four-arm helical antenna |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102593585A (en) * | 2012-03-09 | 2012-07-18 | 哈尔滨工业大学（威海） | Integrated balun feed sine antenna device |
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| CN102593585A (en) * | 2012-03-09 | 2012-07-18 | 哈尔滨工业大学（威海） | Integrated balun feed sine antenna device |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117293560A (en) * | 2023-11-24 | 2023-12-26 | 陕西海积信息科技有限公司 | Ultra-wideband dual polarized lens antenna |
| CN117293560B (en) * | 2023-11-24 | 2024-03-15 | 陕西海积信息科技有限公司 | Ultra-wideband dual polarized lens antenna |
| CN117317576A (en) * | 2023-11-29 | 2023-12-29 | 福建福大北斗通信科技有限公司 | Broadband four-arm helical antenna |
| CN117317576B (en) * | 2023-11-29 | 2024-02-06 | 福建福大北斗通信科技有限公司 | Broadband four-arm helical antenna |
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