Three polarization slot antennas of grid seam ground capacitive load Stepped Impedance
Technical field
The present invention relates to a kind of slot antenna, three polarization slot antennas of especially a kind of grid seam ground capacitive load Stepped Impedance.
Background technology
Slot antenna is the antithesis antenna of element antenna, has a wide range of applications.But, common slot antenna not only radiates the length of the line of rabbet joint itself 1/2nd wavelength, and radiate and also need to bigger Metal ground around the line of rabbet joint and amass, big 1/2nd wavelength of length of the length ratio line of rabbet joint on usual metal ground, big 1/2nd wavelength of width of the width ratio line of rabbet joint on metal ground.Multipolarization MIMO can effectively improve spectrum efficiency and channel capacity, in order to MIMO technology may apply to the terminal that volume is little, it is necessary to the not like-polarized co-located placement of antenna.The radiation of antenna can be produced occlusion effect by bigger metal ground, slot antenna is made to be not suitable for co-located multiple-input and multiple-output (MIMO) application, when using in particular as multi-polarization antenna, the isolation caused between the cross polarization variation of antenna, antenna port is deteriorated by big metal ground, and these all will cause the decline of spectrum efficiency and channel capacity.The impedance of the line of rabbet joint is very big simultaneously, and the impedance matching also making slot antenna feeding transmission line is relatively difficult.The simultaneously development of modern communications also requires that antenna can multiband operation and two frequency bands can regulate respectively.
Summary of the invention
Technical problem: the purpose of the present invention is to propose to three polarization slot antennas of a kind of grid seam ground capacitive load Stepped Impedance, this antenna has been possible not only to multiple working band, and multiple frequency band can regulate respectively;This antenna can reduce the length of the radiation line of rabbet joint and the area on metal ground, and have and suppress cross polarization, improvement to isolate, reduce the effect blocked.
Technical scheme: three polarization slot antennas of the grid seam ground capacitive load Stepped Impedance of the present invention include the grid seam ground capacitive load Stepped Impedance antenna of three single polarizations being mutually perpendicular to placement;The grid seam ground capacitive load Stepped Impedance antenna of each single polarization includes medium substrate, the metal that is arranged on medium substrate and the radiation line of rabbet joint, microstrip feed line;The one side of medium substrate is metal ground, and the another side of medium substrate is the conduction band of microstrip feed line;Metal has the radiation line of rabbet joint on the ground, and the shape of the radiation line of rabbet joint is rectangle, and the radiation line of rabbet joint is positioned at the center on metal ground;The metal grid slot array that a plurality of parallel gate seam is constituted on the ground, the shape of grid seam is rectangle, and grid seam is positioned at the surrounding of the radiation line of rabbet joint, and grid seam is mutually perpendicular to the radiation line of rabbet joint;The short at one end of grid seam;The other end open circuit of grid seam, is positioned at the edge of medium substrate;Two terminal shortcircuits of the radiation line of rabbet joint;At radiation line of rabbet joint mid portion, there is several Capacitance parallel connection to be connected across two edges of the radiation line of rabbet joint so that the characteristic impedance step-down of radiation line of rabbet joint mid portion, form the low-resistance line of rabbet joint;The remainder of the radiation line of rabbet joint is the high resistant line of rabbet joint, and the high resistant line of rabbet joint constitutes the Stepped Impedance radiation line of rabbet joint together with the low-resistance line of rabbet joint, produces a relatively low low frequency operation frequency band of frequency and the higher high-frequency work frequency band of a frequency;Also being the ground plane of described microstrip feed line, one end of microstrip feed line is the port of antenna metal, and the other end of the conduction band of microstrip feed line strides across the high resistant line of rabbet joint and stretches a segment length to terminal, the open-end of microstrip feed line;The conduction band of microstrip feed line has two parts to constitute, and Part I conduction band is the position just having crossed over the high resistant line of rabbet joint from the port of antenna to it, and the remainder of the conduction band of microstrip feed line is Part II conduction band.
Change the thickness of medium substrate, pcrmeability and dielectric constant, the high resistant line of rabbet joint and the characteristic impedance of the low-resistance line of rabbet joint can be changed, change the height impedance ratio of the Stepped Impedance radiation line of rabbet joint, and then change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.
Change the length of the low-resistance line of rabbet joint, low-resistance line of rabbet joint position in the radiation line of rabbet joint, the electrical length of the radiation line of rabbet joint can be regulated, to realize antenna miniaturization in various degree, it is also possible to change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.
Change Part II conduction band length and width, thus it is possible to vary the operating frequency of antenna, working band width and radiation the line of rabbet joint electrical length.
Change the spacing of adjacent gate seam in grid slot array, the width of grid seam, grid seam short-circuit end from the distance of the radiation line of rabbet joint, thus it is possible to vary the electrical length of the operating frequency of antenna, the width of working band and the radiation line of rabbet joint.
Change the quantity of loading capacitance, capacitance and spacing, it is possible to regulate the characteristic impedance of the low-resistance line of rabbet joint, change the height impedance ratio of the Stepped Impedance radiation line of rabbet joint, and then change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.
Change the width of the radiation line of rabbet joint, it is possible to regulate the characteristic impedance of the low-resistance line of rabbet joint and the high resistant line of rabbet joint, change the height impedance ratio of the Stepped Impedance radiation line of rabbet joint, and then change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.
The electrical length of grid seam should not be taken at 1/4th, to avoid causing resonance radiation, causes cross-polarized rising.
Capacitance parallel connection is loaded into two edges of the radiation line of rabbet joint, the characteristic impedance not only making line of rabbet joint transmission line is reduced to and is prone to and feeding transmission lines matching volume, but also reducing the phase velocity of line of rabbet joint transmission line so that the length of the half-wavelength radiation line of rabbet joint reduces, it is achieved the miniaturization of the radiation line of rabbet joint and then antenna.The operating frequency of low frequency operation frequency band and the operating frequency of high-frequency work frequency band of three polarization slot antennas of grid seam ground capacitive load Stepped Impedance are mainly determined by the resonant frequency of the radiation line of rabbet joint, but the operating frequency of antenna and matching degree can also be adjusted by the length and width that the size on metal ground, microstrip feed line conduction band are in the radiation position of the line of rabbet joint, Part II conduction band.Owing to the radiation existing low-resistance line of rabbet joint of the line of rabbet joint has again the high resistant line of rabbet joint, constitute the radiation line of rabbet joint of Stepped Impedance, not only make antenna miniaturization, reduce cross polarization, also reduce the size on metal ground, improve isolation and reduce the occlusion effect on metal ground, and it is also possible that antenna has multiple working band, and change relative length and the impedance of the low-resistance line of rabbet joint and the high resistant line of rabbet joint, it is possible to adjust the position of two working bands respectively.The radiation line of rabbet joint is formed periodic loading by metal grid seam on the ground, makes again the radiation line of rabbet joint become periodic slow-wave structure, further reduces the electric size of antenna;Simultaneously because the direction of grid seam is vertical with the direction of the radiation line of rabbet joint, inhibit metal on the ground along the electric current in radiation line of rabbet joint direction, and make the more concentration along the remaining CURRENT DISTRIBUTION radiating line of rabbet joint direction, thus reducing cross-polarized radiation, improve the isolation between antenna port, also reduce the size on metal ground, reduce the occlusion effect on metal ground.
Beneficial effect: three polarization slot antennas of the grid seam ground capacitive load Stepped Impedance of the present invention provide the benefit that, this antenna can reduce the electric size of whole antenna, realize miniaturization, this antenna has been possible not only to multiple frequency band simultaneously, and multiple frequency band can regulate respectively, also there is the cross polarization of suppression antenna, improve and isolate between port, and reduce the effect blocked on metal ground.
Accompanying drawing explanation
Fig. 1 is three polarization slot antenna overall structure schematic diagrams of grid seam ground capacitive load Stepped Impedance
Fig. 2 be grid seam ground capacitive load Stepped Impedance three polarization slot antennas in single polarization grid seam ground capacitive load Stepped Impedance antenna structural representation.
Figure has: the grid seam ground capacitive load Stepped Impedance antenna 13 of medium substrate 1, metal ground 2, the radiation line of rabbet joint 3, microstrip feed line 4, conduction band 5, grid seam 6, electric capacity 7, the low-resistance line of rabbet joint 8, the high resistant line of rabbet joint 9, port 10, Part I conduction band 11, Part II conduction band 12 and single polarization.
Detailed description of the invention
Below in conjunction with drawings and Examples, the invention will be further described.
Embodiment of the present invention is: three polarization slot antennas of grid seam ground capacitive load Stepped Impedance include the grid seam ground capacitive load Stepped Impedance antenna 13 of three single polarizations being mutually perpendicular to placement;The grid seam ground capacitive load Stepped Impedance antenna 13 of each single polarization includes medium substrate 1, the metal that is arranged on medium substrate 1 ground 2 and the radiation line of rabbet joint 3, microstrip feed line 4;The one side of medium substrate 1 is metal ground 2, and the another side of medium substrate 1 is the conduction band 5 of microstrip feed line 4;Having the radiation line of rabbet joint 3 on metal ground 2, the shape of the radiation line of rabbet joint 3 is rectangle, and the radiation line of rabbet joint 3 is positioned at the center on metal ground 2;On metal ground 2, the grid of a plurality of parallel gate seam 6 composition stitch 6 arrays, and the shape of grid seam 6 is rectangle, and grid seam is positioned at the surrounding of the radiation line of rabbet joint 3, and grid seam 6 is mutually perpendicular to the radiation line of rabbet joint 3;The short at one end of grid seam 6;The other end open circuit of grid seam 6, is positioned at the edge of medium substrate 1;Two terminal shortcircuits of the radiation line of rabbet joint 3;At the radiation line of rabbet joint 3 mid portion, there is several electric capacity (7) to be connected in parallel across two edges of the radiation line of rabbet joint 3 so that the characteristic impedance step-down of the radiation line of rabbet joint 3 mid portion, form the low-resistance line of rabbet joint 8;The remainder of the radiation line of rabbet joint 7 is the high resistant line of rabbet joint 9, and the high resistant line of rabbet joint 9 constitutes Stepped Impedance together with the low-resistance line of rabbet joint 8 and radiates the line of rabbet joint 3, produces a relatively low low frequency operation frequency band of frequency and the higher high-frequency work frequency band of a frequency;Metal ground 2 is also the ground plane of described microstrip feed line 4, and one end of microstrip feed line 4 is the port 10 of antenna, and the other end of the conduction band 5 of microstrip feed line 4 strides across the high resistant line of rabbet joint 9 and stretches a segment length to terminal, the open-end of microstrip feed line 4;The conduction band 5 of microstrip feed line has two parts to constitute, and Part I conduction band 11 is the position just having crossed over the high resistant line of rabbet joint 9 from the port 10 of antenna to it, and the remainder of the conduction band of microstrip feed line is Part II conduction band 12.
Change the thickness of medium substrate 1, pcrmeability and dielectric constant, the high resistant line of rabbet joint 9 and the characteristic impedance of the low-resistance line of rabbet joint 8 can be changed, change the height impedance ratio of the Stepped Impedance radiation line of rabbet joint 3, and then change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.
Change the length of the low-resistance line of rabbet joint 8, the low-resistance line of rabbet joint 8 position in the radiation line of rabbet joint 3, the electrical length of the radiation line of rabbet joint 3 can be regulated, to realize antenna miniaturization in various degree, it is also possible to change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.
Change Part II conduction band 12 length and width, thus it is possible to vary the operating frequency of antenna, working band width and radiation the line of rabbet joint 3 electrical length.
Change that grid stitch the spacing of the seam of adjacent gate in 6 arrays 6, the width of grid seam 6, grid stitch 6 short-circuit ends distance from the radiation line of rabbet joint 3, thus it is possible to vary the electrical length of the operating frequency of antenna, the width of working band and the radiation line of rabbet joint 3.
Change the quantity of loading capacitance (7), capacitance and spacing, the characteristic impedance of the low-resistance line of rabbet joint 8 can be regulated, change the height impedance ratio of the Stepped Impedance radiation line of rabbet joint 3, and then change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.
Change the width of the radiation line of rabbet joint 3, it is possible to regulate the characteristic impedance of the low-resistance line of rabbet joint 8 and the high resistant line of rabbet joint 9, change the height impedance ratio of the Stepped Impedance radiation line of rabbet joint 3, and then change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.
The operating frequency of low frequency operation frequency band and the operating frequency of high-frequency work frequency band of three polarization slot antennas of grid seam ground capacitive load Stepped Impedance are mainly determined by the resonant frequency of the radiation line of rabbet joint 3, but the operating frequency of antenna and matching degree can also be adjusted by the metal ground size of 2, the conduction band 5 of microstrip feed line 4 length and width in the radiation position of the line of rabbet joint 3, Part II conduction band 12.Owing to the radiation existing low-resistance line of rabbet joint 8 of the line of rabbet joint 3 has again the high resistant line of rabbet joint 9, constitute the radiation line of rabbet joint 3 of Stepped Impedance, not only make antenna miniaturization, reduce cross polarization, also reduce the size on metal ground 2, improve isolation and reduce the occlusion effect on metal ground 2, and it is also possible that antenna has multiple working band, and change the low-resistance line of rabbet joint 8 and the relative length of the high resistant line of rabbet joint 9, position and impedance, it is possible to adjust the position of two working bands respectively.The radiation line of rabbet joint 3 is formed periodic loading by the grid seam 6 on metal ground 2, makes again the radiation line of rabbet joint 3 become periodic slow-wave structure, further reduces the electric size of antenna;Simultaneously because the direction of grid seam 6 is vertical with the direction of the radiation line of rabbet joint 3, inhibit the electric current along the radiation line of rabbet joint 3 direction on metal ground 2, and make the more concentration along the remaining CURRENT DISTRIBUTION radiating the line of rabbet joint 3 direction, thus reducing cross-polarized radiation, improve the isolation between antenna port, also reduce the size on metal ground 2, reduce the occlusion effect on metal ground 2.
In technique, three polarization slot antennas of grid seam ground capacitive load Stepped Impedance both can adopt common printed circuit board (PCB) (PCB) technique, it would however also be possible to employ the integrated circuit technologies such as LTCC (LTCC) technique or CMOS, Si substrate realize.Wherein electric capacity 7 can select the patch capacitor 7 of corresponding encapsulation the distance according to electric capacity 7 two pins electrode according to operating frequency, selects the width of the low-resistance line of rabbet joint 8.On manufacturing, the grid of three single polarizations seam ground capacitive load Stepped Impedance antenna 13 can be mutually perpendicular to by draw-in groove and be installed together, or is mutually perpendicular to by binding agent and is bonded together, or two kinds of methods use together.
In accordance with the above, the present invention can just be realized.