Two-band MIMO inverse-F antenna for WLAN and WIMAX
Technical field
The present invention relates to a kind of MIMO antenna, be specifically related to the two-band MIMO inverse-F antenna of a kind of WLAN of being applied to and WIMAX, belong to inverse-F antenna field in communication.
Background technology
Along with the develop rapidly of radio communication industry, radio communication device is used in the electronic product of people's daily life in large quantities, such as notebook computer, smart mobile phone, vehicle electronics navigation system etc.Radio communication device is configured in electronic product inside conventionally, with internally-arranged type antenna, externally carries out data input and data output.Internally-arranged type antenna mainly comprises microstrip antenna, inverse-F antenna, flat helical antenna etc., inverse-F antenna have volume little, simple in structure, be easy to coupling and the advantage such as cost of manufacture is low, be therefore widely used in the wireless communication fields such as bluetooth, WLAN and WIMAX.
In recent years, WLAN (wireless local area network) (WirelessLocalAreaNetworks, WLAN) be widely used, WLAN utilizes wireless communication technology to transmit data aloft, speech and vision signal, make user's exchange message neatly, WLAN (wireless local area network) based on IEEE802.11 standard, permission is used without the 5.8GHz(5.725-5.825GHZ in ISM (IndustrialScientificMedical) frequency range of authorizing in LAN environment) radio-frequency range, in this frequency range, can carry out free wireless connections, such as family, office space, numerous occasions such as hotel and airport are used widely.
Worldwide interoperability for microwave access (WorldwideInteroperabilityforMicrowaveAccess, WIMAX) be also an emerging wireless access wide band technology, this technology is based on IEEE802.16 standard, can provide the high speed of Internet to connect, data transmission distance maximum can reach 50 kilometers, and WIMAX operates mainly in 2.5-2.69GHZ, 3.4-3.69GHZ and 5.25-5.85GHZ frequency range at present.
MIMO represents multiple-input and multiple-output, in the 4th third-generation mobile communication technical standard, is widely adopted, and in wlan standard of new generation, is generally used for IEEE802.11n, but also can be for other 802.11 technology.MIMO allows a plurality of antennas a plurality of spatial flows of sending and receiving simultaneously, and can distinguish and mail to or from the signal in different spaces orientation, thus make space become a kind of can be for improving the resource of performance, and can increase the coverage of wireless system.
For the antenna that is applied to WLAN and WIMAX field, requirement has the features such as electromagenetic wave radiation omni-directional, low-loss, simultaneously, restriction due to application background, the terminal of Wireless Telecom Equipment is more and more to future developments such as miniaturization, multifunctions, and therefore for the design of terminal antenna, also having proposed miniaturization, multiband and antenna has the requirements such as good reception and emission function to the signal of different directions.
In the patent application document that is 201010131036.5 for application number, a kind of double-frequency inverted F-type antenna is disclosed, low frequency oscillator by double-frequency inverted F-type antenna is bending, thereby has reduced the size of antenna, has reached the demand of the development trend of notebook computer mechanism design.But its structure is single, be difficult for receiving the signal of multiple directions.And in the patent document that is ZL200920118137.1 in the patent No., a kind of binary plane inverted F antenna array is disclosed, by utilizing adjacent inner edge and λ/2 slot antenna of the common formation of groove of two planar inverted-F antennas, but frequency that it exists central task is single, design is comparatively complicated and without MIMO function, and be difficult for the shortcoming that combines with now flexible and changeable communication equipment.
Therefore, the structure that increases the central task frequency of inverse-F antenna and change inverse-F antenna makes it meet more multi-communication devices, and the range of application that further expands inverse-F antenna just becomes the key issue that must solve.
Summary of the invention
Technical problem to be solved by this invention is to overcome the deficiencies in the prior art, a kind of two-band MIMO inverse-F antenna for WLAN and WIMAX is provided, adopt two space lengths close, exciting current PHASE DISTRIBUTION differs the radiating element antenna technology of 180 degree, this operating frequency of antenna is at 3.51-3.67GHz, 5.72-5.86GHz in scope, resonance frequency is respectively 3.6GHz and 5.8GHz, antenna all can either receive the signal from multiple directions in 3.6GHz frequency range and 5.8GHz frequency range simultaneously, also can to multiple directions, transmit simultaneously, there is good MIMO function.
The present invention specifically solves the problems of the technologies described above by the following technical solutions:
For the two-band MIMO inverse-F antenna of WLAN and WIMAX, comprise substrate, ground plane, two radiating elements, feed, wherein said substrate is covered and is formed ground plane by copper face; On two parallel surfaces of described ground plane, remove respectively copper face and form two grooves, and the setting that is centrosymmetric of two grooves; Two radiating elements are placed on respectively in two grooves symmetrically; Described each radiating element one end is connected with copper billet, on groove, is provided with the first perforate with copper billet corresponding position, and described copper billet contacts and is grounded with the ground plane of bottom portion of groove through the first perforate; Described feed is used to each radiating element that feed is provided.
As a preferred technical solution of the present invention: by the front surface excision of described ground plane, for increasing antenna gain.
As a preferred technical solution of the present invention: also comprise the short circuit wiring for reducing return loss, one end of described short circuit wiring connects ground plane, and the other end of short circuit wiring connects radiating element; Described short circuit wiring comprises internal short-circuit wiring and external short circuit wiring.
As a preferred technical solution of the present invention: be provided with the second perforate with radiating element corresponding position on described two grooves, described feed is positioned at the second perforate and is connected feed is provided with radiating element.
As a preferred technical solution of the present invention: the corresponding radiating element feedback of described the second perforate point arranges, and described feed directly connects radiating element feedback point through the second perforate.
As a preferred technical solution of the present invention: the operating frequency of described antenna is within the scope of 3.51-3.67GHz and 5.72-5.86GHz, and resonance frequency is respectively 3.6GHz and 5.8GHz.
As a preferred technical solution of the present invention: the F shape antenna that described two radiating elements form by copper face forms.
As a preferred technical solution of the present invention: described substrate is made with FR4 material.
As a preferred technical solution of the present invention: described substrate is rectangular structure.
As a preferred technical solution of the present invention: described the first perforate and the second perforate are rectangular body opening.
The present invention adopts technique scheme, can produce following technique effect:
Two-band MIMO inverse-F antenna for WLAN and WIMAX of the present invention, adopt two radiating elements that space length is close, in conjunction with exciting current PHASE DISTRIBUTION, differ the radiating element antenna technology of 180 degree, make this operating frequency of antenna can be within the scope of 3.51-3.67GHz, 5.72-5.86GHz, resonance frequency is respectively 3.6GHz and 5.8GHz, antenna all can either receive the signal from multiple directions in 3.6GHz frequency range and 5.8GHz frequency range simultaneously, also can to multiple directions, transmit, there is good MIMO function simultaneously.And, improve to a certain extent stability, reduced the return loss of antenna, realize low-loss, omni-directional, can be widely used in the wireless communication fields such as bluetooth and WLAN (wireless local area network).
Accompanying drawing explanation
Fig. 1 is the structural representation of the two-band MIMO inverse-F antenna for WLAN and WIMAX of the present invention.
Fig. 2 is vertical view of the present invention.
Fig. 3 is that antenna radiation unit of the present invention is the S(1 in the feed situation of port, 1) the simulation curve figure of parameter.
Fig. 4 is that antenna radiation unit of the present invention is the S(2 in the feed situation of port, 2) the simulation curve figure of parameter.
Fig. 5 is that antenna radiation unit of the present invention is the simulation curve figure of the standing-wave ratio parameter in the feed situation of port.
Wherein label is explained: 1-substrate, 2-ground plane, 3-groove, 4-radiating element, 5-feed, 6-the second perforate, 7-copper billet, 8-the first perforate, the wiring of 9-internal short-circuit, the wiring of 10-external short circuit.
Embodiment
Below in conjunction with Figure of description, embodiments of the present invention are described.
With reference to Fig. 1, the present invention has designed a kind of two-band MIMO inverse-F antenna for WLAN and WIMAX, comprises substrate 1, ground plane 2, two radiating elements 4, feed 5, and wherein said substrate 1 is covered and formed ground plane 2 by copper face; On two parallel surfaces of described ground plane 2, remove respectively copper face and form two grooves 3, and the setting that is centrosymmetric of two grooves 3; At the upper and lower centre of surface of ground plane 2 cut-out copper face symmetrically, obtain two grooves 3.Two radiating elements 4 are placed on respectively in two grooves 3 symmetrically; The shape of two radiating elements 4 is identical, and the F shape antenna forming by copper face forms.Described each radiating element 4 one end are connected with copper billet 7, by copper billet 7, radiating element can be grounded, in order to realize copper billet 7 ground connection, on groove 3, be provided with the first perforate 8 with copper billet 7 corresponding positions, described copper billet 7 contacts and is grounded with the ground plane 2 of groove 3 bottoms through the first perforate 8; Described feed 5 is used to each radiating element 4 that feed is provided; Branch by two radiating elements 4 also differs 180 degree in conjunction with electromagenetic wave radiation PHASE DISTRIBUTION and obtains dual-band antenna.
Substrate 1 can be rectangular structure, the both sides of substrate 1 have identical structure, setting is divided at Qie Cheng center with claiming, two radiating elements 4 are to lay respectively at upper and lower surface non-intersect, but the current and phase difference that two feed provides is 180 degree, make the electromagenetic wave radiation direction quadrature of two radiating elements.
By the front surface excision of described ground plane 2, excision front surface can reduce copper face antenna is transmitted and received to electromagnetic absorption, thereby increases the gain of antenna.Front surface is seen from Fig. 1, and to be substrate 1 can meet in the face of beholder.
On each groove 3, cut two cuboids that differ in size, obtain first perforate 8 for ground connection of cuboid and for placing the second perforate 6 of feed 5, but hole is not limited to rectangular structure, its section rectangle as shown in Figure 2.
One end connecting copper block 7 of each radiating element 4, it belongs to a part for antenna radiation unit, the first perforate 8 is arranged on groove 3 and copper billet 7 corresponding positions, and copper billet 7 can be placed in the first perforate 8, and copper billet 7 can contact better ground connection is provided with ground plane 5 through the first perforate 8.
The second perforate 6 is for placing feed 5, and it is to arrange with radiating element 4 corresponding positions on each groove 3, realizes feed supply.If the second perforate 6 is positioned at radiating element 4 feedback point places, feed 5 directly connects radiating element 4 feedback points through the second perforate 6, shortens feed 5 and radiating element feedback point distance, can improve better for electrical stability.
Antenna also comprises the short circuit wiring for reducing return loss, and one end of short circuit wiring connects ground plane 2, and the other end of short circuit wiring connects radiating element 4; Short circuit wiring comprises internal short-circuit wiring 9 and external short circuit wiring 10, is copper face, act as the return loss that reduces antenna.
The present invention adopts two radiating elements that space length is close, in conjunction with the exciting current PHASE DISTRIBUTION commonly known in the art 180 degree technology that differ, set up antenna, the operating frequency of this antenna is within the scope of 3.51-3.67GHz and 5.72-5.86GHz, and resonance frequency is respectively 3.6GHz and 5.8GHz.
In order to verify that antenna of the present invention can receive the signal from multiple directions in two-band simultaneously, also can to multiple directions, transmit simultaneously, spy proves with experiment.
According to structure shown in Fig. 1, set up antenna, above-mentioned antenna substrate 1 adopts rectangular structure, can make with common FR4 material, thickness is 2.6mm, length is 53.0mm, and width is 9.15mm, and the section rectangle length of cuboid the first perforate 8 is 2.1mm, width is 1.8mm, the section rectangle length of cuboid the second perforate 6 is 1.8mm, and width is 1.8mm, and substrate 1 is covered by copper face, as ground plane 2, thickness is 0.018mm.
With reference to Fig. 3, provided the S(1 in the feed situation that antenna two radiating elements are port, 1) the simulation curve figure of parameter, with reference to Fig. 4, S(2 in the feed situation that to have provided antenna radiation unit be port, 2) the simulation curve figure of parameter, antenna radiation unit 4 frequency bandwidths are respectively 3.51-3.67GHz, 5.72-5.86GHz as we can see from the figure, and the resonance frequency of antenna is respectively 3.6GHz and 5.8GHz.
With reference to Fig. 5, provided the simulation curve figure of the standing-wave ratio parameter in the feed situation that antenna radiation unit 4 is port, standing-wave ratio coefficient VSWR1, the VSWR2 of antenna are all less than 2.0:1 at 3.51-3.67GHz, 5.72-5.86GHz wave band as we can see from the figure, all can meet the index demand of WLAN and WIMAX.
Design parameter of the present invention is to select on the basis of certain theory analysis, and experimental result shows respond well.This embodiment experimental result shows, antenna is that 3.6GHz place working frequency range is 3.51GHz to 3.67GHz in central task frequency, S
11return loss is-18.49dB, S
22return loss is-19.96dB, in central task frequency, is that 5.8GHz place working frequency range is 5.71GHz to 5.86GHz, S
11return loss is-18.53dB, S
22return loss is-18.45dB, therefore, in 3.6GHz frequency range and 5.8GHz frequency range, all can either receive the signal from multiple directions simultaneously, also can to multiple directions, transmit simultaneously, realize low-loss, omni-directional, can be used for the wireless communication fields such as bluetooth and WLAN (wireless local area network).
By reference to the accompanying drawings embodiments of the present invention are explained in detail above, but the present invention is not limited to above-mentioned execution mode, in the ken possessing those of ordinary skills, can also under the prerequisite that does not depart from aim of the present invention, makes a variety of changes.