CN115693124A - S-band compact wide-beam end-fire antenna with parasitic structure - Google Patents
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Abstract
The invention discloses an S-band compact wide-beam end-fire antenna with a parasitic structure, which is characterized by comprising four parts: the printed balun feeds power by a coaxial cable; the antenna housing consists of two high-frequency printed boards with the thickness of 4mm, and a half-wave printed dipole, a printed balun structure and a planar reflector which are used as excitation units are etched on the inner wall of the antenna housing; a right-angle reflector conformal with the antenna mounting base, the right-angle reflector being a secondary reflector; a planar reflector, which is a parasitic planar structure coplanar with the printed dipoles, is a primary reflector. The angle reflector used in the invention enables the energy radiated by the antenna to be dispersed towards the directions of horizontal and pitching large angles, thereby widening the beam width of the end-fire antenna. Under the combined action of the planar reflector and the angle reflector, the printed dipole antenna has wide beam width while having end-fire capability.
Description
Technical Field
The invention belongs to the field of antennas, and relates to a printed dipole end-fire antenna with a parasitic structure.
Background
In an airborne spatial direction-finding system, the communications antenna is required to have a horizontal plane (H-plane) Φ: -93 ° to 93 °, pitch plane (E plane) θ: the coverage range of an airspace is between 30 and 30 degrees, the compact appearance structure is convenient for installation, and the multipath problem caused by the scattering of an airplane body is reduced as much as possible. The end-fire antenna can play a role in inhibiting multipath effects in the inter-machine communication due to the characteristic that the maximum gain direction of the end-fire antenna is positioned in the axial direction of the antenna.
In 1926, yagi-Uda antennas, i.e., octave antennas, were developed in conjunction with hdetsugu Yagi and athetis pacifier (Shintaro Uda) at the university of northeast empire china, japan, as shown in fig. 1. As a classical endfire antenna, it has been widely used due to its simple structure, light weight, low cost, good endface radiation, etc. A simple eight-mesh antenna generally consists of 5 to 6 parallel element units, including an inverted element, an excitation element, and a director element.
Through a large number of experiments, it can be known that a plurality of reflection elements have no significant influence on the performance of the eight-mesh antenna, and therefore, in practical applications, only one element is usually used as a reflection unit. In the radiation direction of the antenna, the end radiation characteristic of the eight-mesh antenna can be improved by increasing the number of the guide oscillators due to the effect of the induction current of the guide oscillators, and the eight-mesh antenna generally has 6 to 12 directors. The number, length, spacing and other factors of the leading elements and the reflecting elements determine the characteristics of the eight-mesh antenna such as radiation and impedance. The traditional eight-mesh antenna has good end-fire characteristics and high gain, and simultaneously has the defects of low input impedance, narrow bandwidth (about 2 percent), large overall dimension and the like, so that the application of the eight-mesh antenna in a limited environment is limited, and the requirements of an airborne direction-finding system on the antenna characteristics of a communication antenna, such as working bandwidth, installed overall dimension, coverage airspace and the like, are not met.
With the improvement of the printed board processing technology level and the research and development of the dielectric material characteristics, in 1989, a microstrip eight-mesh antenna taking a rectangular microstrip patch as a radiating unit is firstly proposed by John Huang [1], and compared with the traditional eight-mesh antenna, the microstrip eight-mesh antenna serving as a plane end-fire antenna has the advantages of low section, simple structure, small volume, light weight, easiness in processing and the like. Through experimental research, the antenna is found to be influenced by the reflection of the metal ground, so that the maximum radiation direction of an antenna array directional pattern deflects towards the opposite direction of the metal ground plane, and the real end radiation cannot be realized. The microstrip eight-mesh antenna has attracted attention of the majority of researchers, so that the microstrip eight-mesh antenna becomes a research hotspot at home and abroad. At the end of the nineties of the last century, qian [2] et al proposed a Quasi-Yagi endfire antenna (microstrip Quasi-octave antenna) fed by a coplanar coupling line and using a printed dipole as the radiating element, as shown in fig. 2. The antenna is similar to a traditional eight-eye antenna in structure and is composed of an exciting unit, a guiding unit and a reflecting unit. Two metal arms of the printed dipole unit with central feeding are fed by a microstrip balun structure consisting of two microstrip lines with equal width and phase difference of 180 degrees, and a truncated metal ground is used as a reflection unit of the antenna instead of a single reverse oscillator in the traditional eight-mesh antenna, so that the bandwidth of the antenna reaches 17 percent, and the gain reaches 6.5dBi. The microstrip quasi-eight-mesh antenna has a similar structure with the traditional eight-mesh antenna, the antenna parameters of the microstrip quasi-eight-mesh antenna and the traditional eight-mesh antenna are defined differently, the coupling mechanism is different, but the design concept is similar.
After 2000, researchers have conducted more intensive research on microstrip quasi-octal antennas, and proposed many methods for expanding antenna bandwidth and increasing antenna end-to-end radiation characteristics. By increasing the number of excitation vibrators; feeding the antenna using a broadband printed balun feed structure; the structure of the oscillator is changed, so that the antenna oscillator has broadband working characteristics and the like to widen the bandwidth of the microstrip quasi-octave antenna.
The research on the broadband end-fire antenna technology and the research on the electromagnetic metamaterial-loaded Quasi-Yagi antenna technology are described in the doctor's academic paper of "research on the broadband end-fire antenna key technology" of Sunyuan doctor, china, university of electronic technology, sunyuan, china, doctor, 12.29.2015 [3] doctor's academic paper.
In the research section of the technique of developing a Quasi-Yagi broadband endfire antenna, an author proposes a novel structure of a pair-developing Quasi-Yagi broadband endfire antenna, as shown in fig. 3. For the extension Quasi-Yagi antenna, a plurality of oscillator units are utilized to form multi-resonance, so as to achieve the purpose of widening the working frequency band of the antenna, and the antenna structure comprises: etching the half diamond oscillator inclined to the left on the top layer, etching the half diamond oscillator inclined to the right on the bottom layer and the truncated floor. The top layer oscillator is connected by a 50 omega microstrip line, and the bottom layer oscillator is connected by a 50 omega microstrip line and a truncated floor. The truncated floor is used as a reflecting surface, and stable end radiation characteristics of the developed Quasi-Yagi broadband end-fire antenna are realized.
The authors in the paper performed simulation analysis on the current distribution of the antenna using the HFSS, and the results showed that the current is mainly distributed in the long dipole units at the lower frequency band to obtain better low frequency characteristics, and the current is mainly concentrated in the short dipoles at the higher frequency band to obtain better high frequency characteristics, so that the antenna forms multiple resonances, the bandwidth of the antenna is expanded, and stable radiation is achieved. Compared with the traditional Quasi-Yagi end-fire antenna, the frequency bandwidth is improved by more than 79.6%, the working frequency band of the antenna is 5.5 GHz-17.3 GHz, and as shown in figure 4, the effective frequency bandwidth is 96.6%. But after 14GHz the pattern of the antenna deteriorates to a different extent as shown in figure 5.
And then, six novel opposite-rubbing Quasi-Yagi antenna units are uniformly arranged on the surface of the cylindrical metal elastomer at intervals of 60 degrees to form a broadband end-fire direction-finding antenna array. The electromagnetic simulation software HFSS simulates the novel pair of extension Quasi-Yagi broadband end-fire antenna arrays, the radiation pattern of the antenna arrays is warped by about 30 degrees due to the influence of the metal elastic bodies on the novel pair of extension Quasi-Yagi broadband end-fire antenna arrays, the radiation pattern of the novel pair of extension Quasi-Yagi broadband end-fire antenna arrays can cover the range of the internal angle area within +/-30 degrees of the axial direction, the gain is more than or equal to 0dB, and the simulation result is shown in figure 6.
In the sixth section of this paper, a search for electromagnetic metamaterial-loaded Quasi-Yagi antenna technology was analyzed. The electromagnetic metamaterial mainly comprises small structural units which are periodically arranged, such as an LC resonator, a complementary resonant ring or a magnetic resonator (ring resonator SRR), and the like, and the introduction of the ring resonator SRR into the antenna can enhance the directional radiation capability of the antenna, increase the gain of the antenna and influence the working bandwidth of the antenna. The electromagnetic characteristic of the metamaterial is combined with the design of a broadband Quasi-Yagi antenna, and the broadband high-gain end-fire characteristic is achieved. An "I" type electromagnetic metamaterial-loaded broadband Quasi-Yagi antenna is proposed in the thesis of grand yuan hua doctor, and as shown in fig. 7, the broadband Quasi-Yagi end-fire antenna is used, and two rows of "I" type electromagnetic structural units are included. The frequency bandwidth of the broadband Quasi-Yagi end-emitting antenna loaded by the electromagnetic metamaterial reaches 71%, the broadband Quasi-Yagi end-emitting antenna works in a frequency band range of 4.5-9.5GHz, the gain can reach 4-8dBi, and the gain is improved by 2dBi compared with the antenna without an I resonance structure.
As can be seen from fig. 8, the broadband Quasi-Yagi endfire antenna loaded by the electromagnetic metamaterial has a narrow radiation pattern and good endfire performance in an operating frequency band, and a half-power lobe of an H-plane is between 10 ° and 30 °. In fig. 8, blue curves represent E-plane and H-plane directional patterns of an unloaded "I" -type electromagnetic metamaterial antenna, and red curves represent E-plane and H-plane directional patterns of an unloaded electromagnetic metamaterial antenna.
In summary, in the article "wideband end fire technology research", the doctor, sun yuan, succeeded in developing a novel semi-rhombus oscillator pair extension structure wideband Quasi-Yagi end fire antenna and an electromagnetic metamaterial-loaded Quasi-Yagi end fire antenna by using methods of increasing the number of excited oscillators, a wideband feed network, loading electromagnetic metamaterials, and the like, widening the bandwidth of the conventional Quasi-Yagi end fire antenna, enhancing the end-to-end radiation capability of the Quasi-Yagi end fire antenna, making a great contribution to the research direction of the conventional Quasi-Yagi end fire antenna on the working frequency band and improving the end-to-end radiation capability with the wide researchers, but restricting the application scene of the wideband high-gain Quasi-Yagi end fire antenna by using the antennas as array element antennas in the array antennas, and covering a wider airspace range, such as missile-borne antenna arrays, and the like, after being grouped. When the antenna is used as a common airborne communication antenna, a single antenna cannot meet the requirement of airspace coverage in the communication process.
According to the analysis of the principle, simulation and test results of the broadband high-gain Quasi-Yagi end-fire antenna, it can be seen that the antenna generally has a beam width within a range of +/-30 degrees in the axial direction, and does not have a two-dimensional wide beam angle, the impedance matching and broadband characteristics of the antenna mainly depend on the design of a microstrip feed structure, and the impedance characteristics of the semi-open feed structure may be affected by external factors such as a metal mounting base of the antenna.
In the machine direction-finding system, the communication antenna is required to cover all angles in the angular domain range of-30 to 30 degrees of pitch angle and 0 to 360 degrees of horizontal plane, and the gain is more than or equal to 0dB. Due to the shielding of the aircraft vertical tail, wings, an aircraft body and the like on the coverage airspace of the airborne communication antenna, a single common omnidirectional antenna or the broadband high-gain Quasi-Yagi end-fire antenna explained in the foregoing is difficult to meet the airspace coverage requirement, especially the airspace coverage requirement in the pitching dimension, and the radiation characteristic of the omnidirectional antenna may cause multipath reflection with strong energy under a complex installation environment to influence the direction finding precision between the aircraft.
Disclosure of Invention
Aiming at the practical problems, a coverage horizontal plane (H plane) phi is designed: 93 ° to 93 °, pitch plane (E plane) θ: the wide-lobe end-fire antenna with the airspace range of-30 degrees to 30 degrees is respectively distributed in the front direction and the back direction of an airplane, so that the wide-lobe end-fire antenna can cover the pitch angle of-30 degrees to 30 degrees and the angular domain range of 0 degree to 360 degrees in the horizontal plane, the airspace covering requirement of inter-airplane communication is met, and meanwhile, the end-fire antenna can play a role in inhibiting the multipath effect in inter-airplane communication due to the characteristic that the maximum gain direction of the end-fire antenna is located in the axial direction of the antenna. Meanwhile, the antenna, a feed structure of the antenna and an antenna housing are integrally designed, a reflector of the antenna and an antenna mounting base are integrally designed, and the like, so that the antenna has a compact appearance structure and is beneficial to installation.
The S-band compact wide-beam end-fire antenna with the parasitic structure added in the invention can satisfy the requirement of covering a horizontal plane (H plane) phi as shown in fig. 9: -93 ° to 93 °, pitch plane (E plane) θ: all angles in the range of-30 degrees to 30 degrees and the gain is more than or equal to 0dB. The impedance bandwidth of the antenna can reach 2.95 GHz-4.22 GHz, about 35.4%; the actual working bandwidth is 3.2 GHz-3.7 GHz, about 14.5%. The wide-beam end-fire antenna consists of four parts: 1. etching a half-wave printed dipole, a printed balun and a planar reflector which are used as excitation units on the high-dielectric-constant microstrip plate by using the high-dielectric-constant microstrip plate as an antenna housing, and integrally designing the antenna housing; 2. the printed balun which realizes the balance-unbalance conversion function and uses the coaxial cable for feeding; 3. the parasitic structure is coplanar with the printed dipole, and the planar structure is a primary planar reflector of the antenna, so that the end-to-end radiation characteristic of the printed dipole is realized, the return loss of the antenna can be reduced, and the electrical property of the antenna is optimized; 4. the second-stage angle reflector conformal with the antenna mounting base can widen the beam width of an antenna radiation directional diagram, so that the antenna realizes wide beam end radiation.
According to the working principle of the printed dipole antenna, the printed dipole antenna belongs to a balanced antenna, the coaxial line feed belongs to an unbalanced feed, a printed balun needs to be designed due to the unbalance of the printed dipole antenna and the coaxial line feed, the length of the printed balun is approximately 0.25 lambda e Acting as a quarter wave impedance transformer. The excitation signal is fed in from the coaxial cable and is connected with the printed balun to feed the antenna, and the printed dipole antenna is attached to the high-dielectric-constant medium to generate surface waves which can be directly radiated to a free space; the size of a passive plane parasitic structure coplanar with the printed dipole antenna is slightly longer than the length of the radiating unit, the passive plane parasitic structure is a first-stage plane reflector of the wide-beam antenna, the reflector is sensitive relative to an induction signal, namely, the phase lags 90 degrees, the electromagnetic wave induced by the reflector radiates to the main oscillator, the radiation signal lags 90 degrees after passing through a path of a quarter wavelength, the difference between the radiation signal and a signal directly reaching the main oscillator from the direction of the reflector is just 180 degrees, and the cancellation effect is achieved, so that the backward direction is weakened, namely, the antenna has higher directivity, the end-direction radiation of the printed dipole is realized, and the reflector reflects the radiation of the antenna to a signal source, the return loss of the antenna is reduced, and the effect of improving the electrical performance of the antenna is achieved; the right-angle reflector is a reflector formed by two reflecting planes which are intersected to form an included angle of 90 degrees, and the distance between the right-angle reflector and the plane reflector which is integrally designed with the antenna base is slightly larger than 0.25 lambda e And the distance between the excitation vibrator and the excitation vibrator is slightly larger than 0.5 lambda e， The length is about 0.44 lambda, the reflector has the same reflection function as a plane reflector, the working principle is similar to that of the traditional angle reflector, the beam shape of an antenna radiation directional diagram is shaped by two plane reflectors forming an angle with each other, the traditional angle reflector enables the energy radiated by the antenna to be gathered, the directionality of the antenna is higher, the gain is larger, and the angle reflector used in the invention enables the energy radiated by the antenna to be large in horizontal and pitching directionsThe angular directions diverge, thereby widening the beam width of the end-fire antenna. Under the combined action of the planar reflector and the angle reflector, the printed dipole antenna has wide beam width while having end-fire capability. If only a planar reflector is used, the antenna cannot realize wide beam capability; if only a right-angle reflector is used, the directional diagram of the antenna is split into a plurality of lobes, and the capability of increasing the gain to be more than or equal to 0dB in the whole angular domain range cannot be realized.
As shown in fig. 9, the printed dipole antenna arm and the printed balun are of a composite structure, which is not easy to be analyzed precisely, and the antenna is divided into two parts, namely the dipole antenna arm and the printed balun, by a mode decomposition method [4 ]. The dipole antenna arms can be equivalent to a dipole with radius R = W/4, and a transmission line model is used for modeling [5], and an equivalent circuit model of the antenna is shown in fig. 10.
Input impedance formula of cylindrical symmetrical vibrator [4]]The input impedance of the obtained printed dipole antenna is Z dipole :
Wherein:
wherein 2L and W d The length and width of the printed dipole antenna are shown, α represents the surface current attenuation constant of the printed dipole, and β represents the phase constant. The printed dipole is wide, the radiation efficiency is high, and the influence on the radiation performance of the antenna is small when the slot is loaded. However, the wide vibrator produces end effect, the actual length of the vibrator is shortened, and the correction value is the width of the vibrator
I.e. the length of the printed dipole antenna is 2L e ：
The input impedance of the printed balun is:
Z balun ＝jZ ab tanθ ab L b
Z ab for the impedance characteristics of the equivalent coplanar waveguide at the slot between the two arms of the printed dipole, θ ab To correspond to the electrical length, L, of the microstrip line b To print the balun length. Epsilon e For the effective dielectric constant, the formula of the approximate solution to the equivalent dielectric constant can be derived from the approximate solution of the characteristic impedance of the zero-thickness microstrip as follows:
wherein epsilon r The dielectric constant of the high-frequency microstrip plate dielectric substrate is shown, h is the thickness of the high-frequency microstrip plate dielectric substrate, and W is the line width of the microstrip line on the high-frequency microstrip plate dielectric substrate.
λ e The equivalent wavelengths are:
wherein λ is 0 Is a free space wavelength.
Printed balun length L b Comprises the following steps:
z can be calculated by utilizing an engineering approximation formula of coplanar stripline impedance in free space of a medium substrate with a limited size ab ：
Wherein:
wherein S is the distance between dipole antenna arms, W b For printing the width of the balun lines, alpha c Representing the conductor attenuation constant of the transmission line, sn (theta) being an Jacobian elliptic function, K representing the Schltz-Crisstoff transform, K representing the Schltz-Crisstoff transform cps Is the aspect ratio coefficient of the coplanar printed balun.
As can be seen from fig. 10, the input impedance of the equivalent circuit model is:
the input impedance is 50 omega in design, and the initial value of each parameter in the antenna can be deduced by a formula.
The design of the antenna is a multivariable complex problem, accurate analysis and analysis are difficult, modeling and simulation are carried out by using high-frequency simulation software HFSS, and various parameters of the antenna are adjusted in the simulation process to optimize the performance of the antenna, so that the antenna can meet the requirements of covering airspace, gain and other electrical performance.
The dimensions of the printed dipole, printed balun, and planar reflector are as shown in fig. 11, etched on a 4mm thick microstrip plate with a dielectric constant of 4.1. The microstrip board is used as one part of the antenna housing, and needs to be riveted with the other part of the antenna housing and the base, so that the stress resistance of the printed board needs to be considered. Most of the microstrip plates contain polytetrafluoroethylene components, the bonding capability of the medium surface is poor, and the bonding and the treatment of a paint spraying process are not easy, so that the power loss caused by high dielectric constant is balanced in the material selection of the microstrip plates, and the epoxy glass fiber microstrip plates are selected. And finally obtaining all parameters of the antenna through simulation optimization. The length of the printed dipole oscillator arm is 10mm, and the width of the printed dipole oscillator arm is 3mm; the width of a gap at the seam opening position of two arms of the oscillator is 2mm; the length of the printed balun line is 15mm, and the width of the printed balun line is 2mm; the distance between the planar reflector and the upper edge of the printed dipole oscillator arm is 19mm; the planar reflector has a length of 23mm and a width of 4mm. The right-angle reflector and the base are integrally designed, the distance between the upper edge of the right-angle reflector and the lower edge of the plane reflector is 21mm, the length of the right-angle reflector is 40mm, and the width of the inclined plane is 18mm.
The simulation three-dimensional model of the antenna is shown in fig. 9, the simulation result of the standing wave is shown in fig. 13, the simulation result of the gain is shown in fig. 13 to 24, and the simulation result of the cross polarization is shown in fig. 25 to 29.
As shown in fig. 12, the simulation result of the standing wave shows that the impedance bandwidth of the antenna can reach 2.95GHz to 4.22GHz, which is about 35.4%; the actual working bandwidth is 3.2 GHz-3.7 GHz and about 14.5%, because the S-band compact wide-beam end-fire antenna cannot form multi-resonance when only one main excitation unit is provided, and when the size of the oscillator is far larger or far smaller than that of the oscillator
When the excitation unit is used, the radiation characteristic of the excitation unit is deteriorated at a low frequency point or a high frequency point; and the sizes of the plane reflector and the right-angle reflector are related to the wavelength of the working frequency, when the sizes of the plane reflector and the right-angle reflector are not in a certain proportional relation with the wavelength of the resonant frequency, the reflectors will fail, the end-fire characteristics and the lobe width of the antenna at high and low frequency points are deteriorated, and therefore the actual working bandwidth is slightly narrower than the impedance bandwidth. The actual working bandwidth can meet the use requirement of the communication link between the airborne space direction-finding system machines.
As shown in fig. 13 to fig. 24, it can be seen from the simulation results of the directional diagram that the beam width of the antenna in the actual working frequency band directional diagram is greater than the horizontal plane (H plane): -93 ° to 93 °, pitch plane (E plane) θ: -30 ° airspace coverage. As shown in fig. 28 and 29, the lobe width with the horizontal gain of 0dB or more can reach-110 to 110 degrees; as shown in fig. 21, the lobe width at which the pitch plane gain is 0dB or more can reach-40 ° to 40 °. The maximum gain in the working frequency band is 3.7 dB-4.5 dB, the front-to-back ratio is greater than 12dB, and an antenna directional pattern has good end-fire characteristics in the actual working frequency band.
As shown in fig. 25-29, the cross-polarization isolation of the antenna is greater than-15 dB.
On the basis of the theory of the traditional Yagi-Uda antenna, the Quasi-Yagi antenna is researched, the design thought and principle analysis of the broadband end-fire antenna in a thesis of the majority of scientific researchers are greatly inspired for the inventor, and the S-band compact type wide-beam end-fire antenna is successfully designed through the theoretical calculation and the simulation analysis in the thesis. The antenna has two different reflectors, so that the printed dipole antenna has good wide-beam end-fire characteristics, and the use requirement of a space direction-finding system on the communication antenna can be met.
Advantageous effects
Compared with a common broadband high-gain Quasi-Yagi end-fire antenna, the S-band compact wide-beam end-fire antenna can realize a horizontal plane (H plane) phi: -93 ° to 93 °, pitch plane (E plane) θ: the aircraft has the advantages that the aircraft covers the airspace within the range of-30 degrees to 30 degrees, the front end and the rear end of the aircraft are respectively provided with the antenna, all airspace angles with the aircraft as the original point and the pitching angle within the range of-30 degrees to 30 degrees can be covered, the antenna has the beam width wider than the horizontal plane and ranging from-90 degrees to 90 degrees, and after the aircraft is installed, for the aircraft with a larger size, fewer airspace covering blind spots can be generated, and the installation number of the airborne communication antennas can be effectively reduced.
The antenna can be easily expanded to other frequency bands by scaling the antenna proportion, so the antenna design principle can be widely applied to microwave and millimeter wave antennas.
Based on the design scheme of the antenna, the broadband, high-gain and wide-beam end-fire antenna can be developed by increasing the number of the excitation oscillators, using a broadband printed balun feed structure, changing the oscillator structure and other design ideas and combining design methods such as loading of electromagnetic metamaterials, special-shaped reflectors and the like.
The antenna has simple structure, does not need to import components and raw materials, can realize 100 percent localization, is easy to process, has low debugging difficulty and can be produced in large scale in batch.
Drawings
FIG. 1 is a conventional Yagi-Uda antenna (octal antenna);
FIG. 2 is a microstrip quasi-octave antenna;
fig. 3 is a diagram of a structure of a topology Quasi-Yagi broadband endfire antenna;
FIG. 4 is a diagram of a pair of develop Quasi-Yagi broadband endfire antenna standing waves;
fig. 5 illustrates the radiation pattern of a pair of antennas extending from Quasi-Yagi;
FIG. 6 is a graph of variation in Quasi-Yagi antenna array gain;
FIG. 7 is a diagram of a novel Quasi-Yagi antenna structure with an "I" shaped electromagnetic structure;
FIG. 8 shows the antenna radiation pattern test results for a loaded "I" resonant structure;
FIG. 9S band compact wide beam end-fire antenna simulation three-dimensional model;
FIG. 10 antenna equivalent model;
fig. 11 is a diagram of a compact wide-beam end-fire antenna printed-board for the S-band;
fig. 12S band compact wide beam end-fire antenna standing wave simulation results;
fig. 133.2GHz S-band compact wide-beam end-fire antenna two-dimensional direction simulation results;
fig. 143.2GHz S-band compact wide-beam end-fire antenna three-dimensional direction simulation result;
fig. 153.33GHz S-band compact wide-beam end-fire antenna two-dimensional direction simulation result;
FIG. 163.33GHz S-band compact wide-beam end-fire antenna three-dimensional direction simulation results;
FIG. 173.35GHz S-band compact wide-beam endfire antenna dimensional direction simulation results;
fig. 183.35GHz S-band compact wide-beam end-fire antenna three-dimensional direction simulation result;
fig. 193.4GHz S-band compact wide-beam end-fire antenna two-dimensional direction simulation result;
fig. 203.4GHz S-band compact wide-beam end-fire antenna three-dimensional direction simulation result;
fig. 213.5GHz S-band compact wide-beam end-fire antenna two-dimensional direction simulation result;
fig. 223.5GHz S-band compact wide-beam end-fire antenna three-dimensional direction simulation result;
FIG. 233.7GHz S-band compact wide-beam end-fire antenna two-dimensional direction simulation results;
figure 243.7GHz S-band compact wide-beam end-fire antenna three-dimensional direction simulation results;
the simulation result of the polarization isolation of the compact wide-beam end-fire antenna in the 253.2GHz S-band is shown;
fig. 263.33GHz S-band compact wide-beam end-fire antenna polarization isolation simulation results;
FIG. 273.4GHz S-band compact wide-beam end-fire antenna polarization isolation simulation result;
fig. 283.5GHz S-band compact wide-beam end-fire antenna polarization isolation simulation results;
FIG. 293.7GHz S-band compact wide-beam end-fire antenna polarization isolation simulation result;
fig. 30S is a schematic diagram of the overall dimensions of a compact wide-beam end-fire antenna in a band;
fig. 31 is a schematic structural view of a compact wide-beam end-fire antenna in the S-band;
wherein: 1. an antenna base; 2. a right-angle reflector; 3. a planar reflector; 4. an antenna cover; 5. printing dipole arms; 6. and printing the balun.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The outline dimensions of the S-band compact wide-beam end-fire antenna are schematically shown in fig. 30. The schematic structure is shown in fig. 31. The external dimension is as follows: length × width × height =70mm × 40mm × 66mm.
The internal structure of the S-band compact wide-beam end-fire antenna is shown in fig. 31. The antenna structure includes: 1. two microstrip plates with the thickness of 4mm and the dielectric constant of 4.1, wherein one microstrip plate is provided with a dipole arm, a balun and a planar reflector which are etched and printed on the surface, and the other microstrip plate is a pure medium base material with a copper coating layer on the front surface and the back surface stripped; 2. an antenna metal base integrally designed with the right-angle reflector; 3. TNC connectors with cut cable (other types of high frequency connectors are also possible); 4. some rivets and screws.
The specific assembly process implementation of the S-band compact wide-beam end-fire antenna is as follows:
1. the printed dipole arms, printed balun and planar reflector were fabricated as described above using a 4mm thick microstrip sheet with a dielectric constant of 4.1. And processing the optical plate without the copper-clad layer according to the overall dimension of the printed plate with the copper-clad structure. The surface of the printed board is provided with a groove, so that the coaxial cable is embedded in the microstrip board conveniently;
2. the external dimension of the right-angle reflector is designed to be integrated with the antenna base, and the structural form is shown in fig. 31.
3. Mounting a connector with a coaxial cable with the length of 120mm on an antenna base by using a screw, inserting a micro-strip plate with a copper-clad structure into the antenna base, welding a coaxial line outer conductor with a planar reflector and a printed balun at the position shown in the figure, reserving the length of a gap which spans the seam width of two arms of a printed dipole, subtracting a redundant coaxial line, stripping an outer shielding layer of the coaxial line, stripping a dielectric layer at a position 4mm away from the tail end of the coaxial line, and welding the core line of the coaxial cable;
4. and (3) fully coating the copper-coated surface of the printed board with epoxy resin without aluminum oxide powder, inserting a light board without a copper-coated structure into the antenna base, forcibly pressing the two micro-strip boards to uniformly coat the bonding surfaces of the two micro-strip boards with the epoxy resin, riveting the two printed boards with rivets, and then riveting the antenna base.
5. And after the epoxy resin is cured, spraying paint on the surface of the antenna.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.
Claims (5)
1. An S-band compact wide-beam end-fire antenna with a parasitic structure added is characterized by comprising four parts:
the printed balun is of a U-shaped structure and is fed by a coaxial cable;
the antenna housing consists of two trapezoidal high-frequency printed boards with the thickness of 4mm, and a half-wave printed dipole, a printed balun structure and a planar reflector which are used as excitation units are etched on the inner wall of the antenna housing;
a right-angle reflector conformal with the antenna mounting base, the right-angle reflector being a secondary reflector;
a planar reflector, the planar reflector being a parasitic planar structure coplanar with the printed dipoles, the planar reflector being a primary reflector.
2. The S-band compact wide-beam end-fire antenna of claim 1, wherein: the radome is composed of a high dielectric constant microstrip plate.
3. The S-band compact wide-beam end-fire antenna of claim 1, wherein: the end-fire antenna covers all angles in the range of-30 degrees to-30 degrees of the pitching plane and-93 degrees to-93 degrees of the horizontal plane, and the gain is more than or equal to 0dB; the impedance bandwidth of the antenna reaches 2.95 GHz-4.22 GHz; the actual working bandwidth is 3.2 GHz-3.7 GHz; has a beam width wider than-30 to 30 degrees on the pitching surface and-90 to 90 degrees on the horizontal surface.
4. The S-band compact wide-beam end-fire antenna of claim 1, wherein: the length of the printed dipole oscillator arm is 10mm, and the width of the printed dipole oscillator arm is 3mm; the width of a gap at the slotting position of the two arms of the oscillator is 2mm; the length of the printed balun line is 15mm, and the width of the printed balun line is 2mm; the distance between the planar reflector and the upper edge of the printed dipole oscillator arm is 19mm; the planar reflector has a length of 23mm and a width of 4mm.
5. The S-band compact wide-beam end-fire antenna of claim 1, wherein: the right-angle reflector and the base are integrally designed, the distance between the upper edge of the right-angle reflector and the lower edge of the plane reflector is 21mm, the length of the right-angle reflector is 40mm, and the width of the inclined plane is 18mm.
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| CN202211136560.0A CN115693124A (en) | 2022-09-19 | 2022-09-19 | S-band compact wide-beam end-fire antenna with parasitic structure |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202211136560.0A CN115693124A (en) | 2022-09-19 | 2022-09-19 | S-band compact wide-beam end-fire antenna with parasitic structure |
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