A kind of wideband bidirectional radiation antenna of integrated design
Technical field
The utility model relates to the mobile communication antenna field, relates in particular to a kind of wide frequency antenna that works in multiband.
Background technology
The characteristics of mobile communication and difficult point are the complexity of wireless channel, in wireless service areas, often there are many weak signal areas or blind area, as: the inside in underground parking, tunnel, large-scale hotel or the like, so indoor covering is mobile network's a important component part.Usually the antenna that uses in radio communication mostly is the antenna of unidirectional directed radiation and azimuth plane omnidirectional radiation, but under special environment, as the long and narrow environment of indoor covering, requires a kind of antenna with bidirectional radiation ability.In order to save the input of indoor covering, often require radiating antenna can be operated in multiband aerial simultaneously, promptly serve multiple standard.The method that method (as the binary battle array) that bilateral antenna now commonly used mainly is made up of gust omnidirectional antenna or two identical unidirectional orientation radiating antennas set up back-to-back realizes, these two kinds of methods all are to make up by machinery with identical antenna to realize, they all have bulky shortcoming, still can use at outdoor environment or to the occasion that spatial volume is not particularly limited, then usually can't use in indoor environment or limited space or occasions with limited space.
And, existing antenna product often is operated in more single frequency range, maybe can only take into account from CDMA800 to UMTS, but the WLAN frequency range that down can't take into account 700MHz and up can't expand to higher 2.4G and 3.5G, work simultaneously for a plurality of wave bands this moment, often need to use a plurality of antennas, both increased the cost of system layout, also make system layout become complicated, be unfavorable for the follow-up network optimization, therefore needing a kind of new method realizes that a kind of volume is little, but the bilateral antenna of multiple-frequency operation.
Summary of the invention
The purpose of this utility model is to provide a kind of compactness, wideband bidirectional radiation antenna that cost is low.
The wideband bidirectional radiation antenna of a kind of integrated design of the utility model design, include reflecting plate, it is characterized in that: dielectric substrate is installed on the reflecting plate, two surfaces at dielectric substrate are respectively equipped with the main transmission line of feed circuit and the symmetrical dipole of at least two different frequency ranges, two oscillator arms of each symmetrical dipole lay respectively at two surfaces of dielectric substrate and are connected with two lip-deep main transmission lines of dielectric substrate respectively, and each symmetrical dipole is about 1/2nd of this oscillator operation wavelength with respect to the reflecting plate height.
The feed circuit of above-mentioned antenna is provided with distributing point, and this distributing point is near an end of short oscillator arms.
As the further improvement of such scheme, it is characterized in that the short circuit through hole on dielectric substrate two lip-deep main transmission line tops is connected to form one section short circuit minor matters.
As the further improvement of such scheme, it is characterized in that oscillator passes through the open circuit section formation open circuit minor matters on dielectric substrate two lip-deep main transmission line tops.
Advantage of the present utility model is as follows:
1, highly all is taken as about half of its relevant work wavelength between each radiating doublet and reflecting plate.Like this, the utility model not only has good stationary wave characteristic in the wideband section very much, and has good bidirectional radiation characteristic in working frequency range, satisfies indoor covering demand.Utilize new technology herein, the frequency of can finishing the work is 700MHz-960MHz, 1710MHz-2700MHz, the example of the super wideband bilateral antenna of 3300-3500MHz, this antenna gains in whole working range and all can reach more than the 5dBi, has covered GSM, CDMA, WCDMA, the required frequency range of contemporary main flow mobile communication system such as CDMA2000.
2, adopt radiation and the incorporate technical scheme of feed structure, advantages of compact and light structure is convenient to produce in batches.Whole radiation and feed system can be finished by a double face copper (pcb board), and volume is little, and it is convenient to produce and debug; And assemble easyly, and reduced a large amount of welding jobs, shortened assembly period, good product consistency, very suitable production in enormous quantities the in enormous quantities.
Description of drawings
Fig. 1 is a front electrical block diagram on the dielectric substrate of the utility model embodiment one;
Fig. 2 is a back side electrical block diagram on the dielectric substrate of the utility model embodiment one;
Fig. 3 is the standing wave measured drawing of the utility model embodiment one.
Embodiment
Embodiment one, with reference to figure 1 and Fig. 2, a kind of wideband bidirectional radiation antenna of integrated design, pcb board 14 as dielectric substrate is installed on reflecting plate 13, be respectively equipped with the main transmission line 15 of feed circuit and the symmetrical dipole 1 (1 ') of 12 different frequency ranges on two surfaces of dielectric substrate, 2 (2 '), 3 (3 '), 4 (4 '), 5 (5 '), 6 (6 '), 7 (7 '), 8 (8 '), 9 (9 '), 10 (10 '), 11 (11 '), 12 (12 '), two oscillator arms of each symmetrical dipole lay respectively at two surfaces of dielectric substrate and respectively with two lip-deep main transmission lines 15 of dielectric substrate, 16 connect, each symmetrical dipole is about 1/2nd of this oscillator operation wavelength with respect to the reflecting plate height, each oscillator arms of each symmetrical dipole is about 1/4th of this this oscillator operation wavelength, dielectric substrate two lip-deep feed circuit main transmission lines 15, the 16 short circuit through holes by the top are connected to form one section short circuit minor matters, the feed circuit of antenna is provided with distributing point 17, and this distributing point 17 is near an end of the shortest oscillator arms 1 (1 ').
The inner wire of coaxial cable is connected with the main transmission line 15 in dielectric substrate front, and the outer conductor of coaxial cable is connected with metal earth point 18 with the main transmission line 16 at the dielectric substrate back side.
The design principle of embodiment one
A. oscillator arms is that benchmark is finely tuned with λ/4 of corresponding centre frequency, and according to end effect, physical length is slightly shorter than λ/4.Oscillator is about λ/2 of respective frequencies apart from the reflecting plate height, so can reach the effect of bidirectional radiation.If the effective dielectric constant of PCB is ε
r, then
B. main Reference Design formula
The length of definition adjacent vibration generators is than being τ, and it satisfies following relation:
Wherein d is the spacing of adjacent vibration generators; R is the distance that oscillator arrives antenna vertex; L is the length of oscillator one arm; N is the sum of oscillator unit.Define the subtended angle that α is an antenna array simultaneously, promptly
tgα=l
n/R
n (3)
The definition duty ratio is σ, closes between itself and α to be:
σ=d
n/4l
n=(1-τ)/4tgα (4)
With reference to above-mentioned design formula, and, finally obtain the desired broadband character of the design by adjusting the length of the terminal short circuit of first oscillator (i.e. the longest oscillator) (or open circuit) minor matters.
The test result of embodiment one, with reference to figure 3, the present embodiment frequency of can finishing the work is 700MHz-960MHz, 1710MHz-2700MHz, the example of the super wideband bilateral antenna of 3300-3500MHz, this antenna gain in whole working range and all can reach more than the 5dBi, covered GSM, CDMA, WCDMA, the required frequency range of contemporary main flow mobile communication system such as CDMA2000.At the operating frequency standing internal wave all less than 1.6.
Embodiment two, and a present embodiment and a last embodiment difference are that oscillator constitutes the open circuit minor matters by the open circuit section on microstrip transmission line and top, little band ground.