The fractal double-frequency micro-strip antenna of a kind of multiband
Technical field
The utility model belongs to the satellite antenna technical field, is specifically related to a kind of fractal double-frequency micro-strip antenna of multiband that is used for the miniaturization of big-dipper satellite double frequency dot system.
Background technology
At present, China has succeeded in sending up navigation positioning satellite of 4 Big Dippeves and No. two navigation positioning satellites of 7 Big Dippeves, has built up navigation experiment system of the Big Dipper, and is building No. two global position systems of the Big Dipper covering the whole world.Antenna must an indispensable part as satellite communication system, is directly determining the performance of satellite communication system.No. two satellite communication systems of the Big Dipper of China work in B1 and B3 frequency range, up (tranmitting frequency) L frequency range and descending (receive frequency) S frequency range.Usually use double frequency or multifrequency to compensate the time-delay that ionospheric propagation causes, this just requires antenna all to have good working performance on each frequency.In addition, because the satellite communication signal is a circularly polarised wave, antenna should present circular polarization.In today of information technology fast development, extensive use along with satellite communication system, research to the satellite communication system reception antenna emerges in an endless stream, and as one pole, bipolar, spiral, four arm spirals and microstrip antenna structure, all can be used in the various antennas of satellite communication system.Section is low, volume is little because of having for traditional microstrip antenna, in light weight, can be conformal, easy of integration, feeding classification flexibly, be convenient to obtain advantages such as linear polarization and circular polarization, in mobile communication, satellite communication, the guided missile remote measurement, many fields such as Doppler radar have obtained to use widely, are the defectives of microstrip antenna but gain limited always.Along with the continuous development of digital communication technology, wireless network no longer only is a kind of means of computer link network online, and it is wireless, and mobile advantage is brought more comprehensive, novel, quick, cheap communication way for people.
Adopt the Fractal Geometry Theory of 20th century of fractal structure late nineteen seventies proposition to be paid attention to widely in recent years.Nineteen ninety D.L.Jaggard proposes fractal electrodynamics, determines the fractal new direction that combines with Maxwell's electromagnetic theory.By designing suitable fractal structure, make the shared bulk of antenna reduce, and the performance of antenna remain unchanged substantially, then reaches the purpose of antenna miniaturization.At present, the fractal structure that adopts aspect antenna miniaturization mainly contains the array of Koch, Hilbert, Peano, Minkowski, 3/2Curve curve and corresponding fractal structure composition etc.In the mobile communication technology field, the fractal structure antenna furtherd investigate have that important project is worth and theory significance.
The utility model content
The utility model provides a kind of multiband fractal double-frequency micro-strip antenna for solving the problem in the present technology, and it has, and return loss is low, gain is high, it is little to disturb, and can be locked in flexibly and easily in the Big Dipper series global position system by demand.
The utility model is achieved by the following technical solutions:
The fractal double-frequency micro-strip antenna of a kind of multiband of the utility model, it comprises ground connection reflecting plate, high dielectric constant substrate and joint, the two sides of described high dielectric constant substrate is covered with the metal good conductor, its front is provided with outer fractal paster and interior fractal paster, is the slit between described outer fractal paster and the interior fractal paster; Described outer fractal paster is provided with the low-frequency range power feed hole, and described interior fractal paster is provided with the high band power feed hole; Described low-frequency range power feed hole is to pass the cavity of high dielectric constant substrate, and the metal inner core of copper axis is connected with outer fractal paster by the low-frequency range power feed hole; Described high band power feed hole is to pass the cavity of high dielectric constant substrate, the metal inner core of copper axis is connected with interior fractal paster by the high band power feed hole, and the outer core of the copper axis in power feed hole and the power feed hole links to each other with the ground connection reflecting plate of high dielectric constant substrate back.
Described ground connection reflecting plate is positioned at the back side of high dielectric constant substrate, has four clearance channels on it, and its length of side is 5mm ~ 20mm, and width is 0.5mm ~ 3mm.
Described four clearance channels are first clearance channel and second clearance channel that has pbg structure, and first clearance channel is a pair of to be positioned at about rectangle ground connection reflecting plate groove on two limits, and second clearance channel is the groove on a pair of two limits up and down that are positioned at rectangle ground connection reflecting plate.
The relative dielectric constant of described high dielectric constant substrate is shaped as rectangle greater than 7.
The diagonal angle of described outer fractal paster and interior fractal paster is respectively the corner cut shape, and described corner cut is an isosceles right triangle.
Described high dielectric constant substrate is the cuboid of 50mm * 50mm * 3mm.
Described, the length of side of outer fractal paster is 45mm ± 0.01mm, and hem width is 44mm ± 0.01mm; The length of side of interior fractal paster is 30mm ± 0.01mm, and hem width is 29mm ± 0.01mm.
Described first clearance channel and second clearance channel, the length of side is respectively 12mm ± 0.01mm, and the width in each slit is 1mm ± 0.01mm.
Described low-frequency range power feed hole be radius be 0.5mm ± 0.01mm, highly for 3mm ± 0.01mm; Described high band power feed hole be radius be 0.5mm ± 0.01mm, highly for 3mm ± 0.01mm.
The utility model compared with prior art has following significant advantage:
1, the utility model has used fractal miniaturization technology, utilize the nested structure of radiation patch to realize multifrequency covering/advantages such as high radiation resistance, and in conjunction with the pbg structure of ground plane, complex optimum by series technique, realize the miniaturization of antenna, can satisfy the requirement of big-dipper satellite communication system well.
2, owing to adopted above structure, this antenna has the characteristics of directed radiation, and can realize that intelligence is controlled.The embodiment intermediate-frequeney point is, 1.620GHz and 2.510GHz, and its working frequency range corresponds to 1.610GHz ~ 1.630GHz and 2.490GHz ~ 2.530GHz, and absolute bandwidth corresponds to 20MHz and 40MHz.
3, owing to adopted above structure, we can reasonably optimize the size of fractal paster on the good conductor radiating surface and the size of good conductor ground plane PBG square opening, cover all frequency ranges of big-dipper satellite communication system as required, make it reach good electromagnetic property.
In a word, the utlity model has that size is little, radiation characteristic good, be subjected to that such environmental effects is little, cost is low and be easy to advantages such as integrated, can satisfy of the requirement of big-dipper satellite communication system antenna.
Description of drawings
Fig. 1 is a Facad structure schematic diagram of the present utility model.
Fig. 2 is a structure schematic diagram of the present utility model.
Each part description among the figure:
1, outer fractal paster; 2, interior fractal paster; 3, low-frequency range power feed hole; 4, high band power feed hole; 5, high dielectric constant substrate; 6, slit; 7, corner cut; 8, fractal corner cut; 9, ground connection reflecting plate; 10, first clearance channel; 11, second clearance channel.
Embodiment
The utility model is described in further detail below in conjunction with accompanying drawing.
Referring to Fig. 1, Fig. 2.
The fractal double-frequency micro-strip antenna of a kind of multiband of the utility model, it comprises ground connection reflecting plate, high dielectric constant substrate 5, joint, the two sides of described high dielectric constant substrate 5 is covered with the metal good conductor, its front is provided with outer fractal paster 1 and interior fractal paster 2, is slit 6 between described outer fractal paster 1 and the interior fractal paster 2; Described outer fractal paster 1 is provided with low-frequency range power feed hole 3, and described interior fractal paster 2 is provided with high band power feed hole 4; Described low-frequency range power feed hole 3 is for passing the cavity of high dielectric constant substrate, and the metal inner core of copper axis is connected with outer fractal paster 1 by low-frequency range power feed hole 3; Described high band power feed hole 4 is for passing the cavity of high dielectric constant substrate, the metal inner core of copper axis is connected with interior fractal paster 2 by high band power feed hole 4, and the outer core of the copper axis in power feed hole 3 and the power feed hole 4 links to each other with the ground connection reflecting plate 9 at high dielectric constant substrate 5 back sides.
Wherein, the current potential in the inner core of copper axis is a positive potential, and the signal of telecommunication is connected in the antenna on two independently fractal chip units by inner core, realizes radiated electromagnetic wave; And the outer core of copper axis is a negative potential, plays the effect of ground connection.
Described ground connection reflecting plate 9 is positioned at the back side of high dielectric constant substrate 5, has four clearance channels on it, and its length of side is 5mm ~ 20mm, and width is 0.5mm ~ 3mm.
Described four clearance channels are first clearance channel 10 and second clearance channel 11 that has pbg structure, first clearance channel 10 is a pair of to be positioned at about rectangle ground connection reflecting plate groove on two limits, and second clearance channel 11 is the grooves on a pair of two limits up and down that are positioned at rectangle ground connection reflecting plate.
The relative dielectric constant of described high dielectric constant substrate 5 is shaped as rectangle greater than 7;
The interior ring longer wide-edge representative value of described outer fractal paster 1 is 30mm ~ 40mm, and outer shroud longer wide-edge representative value is 40mm ~ 50mm.
The diagonal angle of described outer fractal paster 1 and interior fractal paster 2 is respectively the corner cut shape, and described corner cut is an isosceles right triangle.
Described high dielectric constant substrate is the cuboid of 50mm * 50mm * 3mm.
Described, the length of side of outer fractal paster 1 is 45mm ± 0.01mm, and hem width is 44mm ± 0.01mm; The length of side of interior fractal paster 2 is 30mm ± 0.01mm, and hem width is 29mm ± 0.01mm.
Described first clearance channel 10 and second clearance channel 11, the length of side is 12mm ± 0.01mm, the width in each slit is 1mm ± 0.01mm.
Described low-frequency range power feed hole 3 be radius be 0.5mm ± 0.01mm, highly for 3mm ± 0.01mm; Described high band power feed hole 4 be radius be 0.5mm ± 0.01mm, highly for 3mm ± 0.01mm.
Fractal corner cut 8 is different from corner cut 7 among the figure, and the effect of corner cut 7 is to realize circular polarization, and fractal corner cut 8 purposes are to realize miniaturization Design.Fractal corner cut 8 is an equilateral triangle.
Adopt the form feed of copper axis offset-fed in the utility model, as shown in Figure 2, this feed form makes that the clawback loss parameter of antenna is lower, and gain increases.
The working frequency range of the utility model antenna is 1.610GHz ~ 1.630GHz and 2.490GHz ~ 2.530GHz.All below 10dB, the minimum echo loss at the 1.620GHz place is-17.5dB the return loss of this working frequency range internal antenna (S11); Minimum echo loss at the 2.510GHz place is-13.5dB to show that the return loss performance at whole passband internal antenna can both reach the requirement index.Thereby can be advantageously applied in the satellite communication systems such as the Big Dipper and GPS.
The utlity model has directional radiation properties, can satisfy the requirement of big-dipper satellite system, antenna is respectively 2dB and 5dB in the gain of 1.620GHz and two frequencies of 2.510GHz, and radiance is superior.