CN1705164A

CN1705164A - Broad band paster antenna with double L shaped probes

Info

Publication number: CN1705164A
Application number: CN 200410042927
Authority: CN
Inventors: 陆贵文; 黄行; 麦志伦
Original assignee: City University of Hong Kong CityU
Current assignee: City University of Hong Kong CityU
Priority date: 2004-06-01
Filing date: 2004-06-01
Publication date: 2005-12-07
Anticipated expiration: 2024-06-01
Also published as: CN100428564C; HK1089564A1

Abstract

An antenna containing an adhered piece located on and separated with grounding board, a pair of L-shaped probes in adhered piece and grounding board, each probe containing a part parallel with the adhered piece and grounding board and a part vertical with the adhered piece and grounding board, said invention has the method for exciting two probes in same power and phase.

Description

Broadband paster antenna with double L-shaped probe

Technical field

The present invention relates to paster antenna, particularly relate to broadband paster antenna by double L-shaped probe feed.The present invention can further expand to the antenna array that comprises a plurality of paster antennas.

Background technology

In recent years, micro-strip paster antenna is used widely in various fields.Micro-strip paster antenna has lot of advantages, comprises that cost is low, size is little and in light weight, and this makes them be well suited for being applied to as in PCS Personal Communications System etc.

Traditional little band (microstrip) paster antenna comprises a paster with geometry in particular (as circle, rectangle, triangle), and this paster and ground plate are separated from each other, and with dielectric it are separated mutually.Usually the method for using coaxial feed is carried out feed to paster.

Yet micro-strip paster antenna has a shortcoming, and promptly their bandwidth is less relatively, generally is unsuitable for using under the bigger condition of bandwidth.In recent years, taked certain methods to attempt increasing the bandwidth of micro-strip paster antenna.For example, existing proposal comprises, increases a parasitic patch (parasitic patch) so that passive paster (driven patch) is carried out electromagnetic coupled (R.O.Lee, K.F.Lee, J, Bobinchak Electronics Letters, 9,24,1987, Vol.23, No.20,1017-1072); In capacitance gap (capacitive gap), use thicker substrate, by this capacitance gap with the inductance of eliminating probe (P.S.Hall Electronics Letters, 5,21,1987, Vol.23, No.11,606-607); And in paster antenna, use U-lag IEEProc.Microw.Antennas Propag. such as (, Vol.144 No.5,10,1997) K.F.Lee.

Yet, all undesirable at the art methods that the problems referred to above are all.Lay the thickness that parasitic patch can increase antenna on passive paster, this does not also meet people's hope.Capacitance gap very high accuracy is made.Introduce U-lag and can make antenna cross-polarization higher, and can not be applied to circular polarization radiation.

Another example of prior art is as shown in US472443 (Nysen).Nysen has described a kind of paster antenna, and wherein strip line electricity supply element and paster carry out electromagnetic coupled, and wherein an end of little band (paralleling with paster) is connected with the inner wire of coaxial cable (perpendicular with paster).In this design, have only little band and paster to be coupled, and the bandwidth of antenna and little.

US6593887 (incorporating this paper into the form of reference here) has described a kind of paster antenna, and this paster antenna is driven by the L shaped probe that is placed between paster and the ground plate.The part of this probe is vertical with paster and ground plate, and another part is parallel with paster and ground plate.Two-part length is through selecting meticulously, so that the induction reactance of first is offset by second one capacitive reactance.This design is very effective, yet the described antenna of US6593887 can obtain only to be the gain of about 7.5dBi, and antenna cross-polarization approximately-still very high during 15dB.Thereby be necessary to design a kind of novel paster antenna, in the hope of alleviating above-mentioned problem at least, and when cross polarization is relatively low, provide higher gain.

Summary of the invention

According to the invention provides a kind of antenna, this antenna comprises a paster, this paster is placed on the ground plate and with ground plate to be separated mutually, and pair of L-shaped probe, probe is placed between above-mentioned paster and the above-mentioned ground plate, each above-mentioned probe all comprises a part parallel with paster and ground plate, with a part vertical with paster and ground plate; And with power and same-phase to above-mentioned two methods that probe encourages.

Even more ideal is, these probes are connected with transmission line, and loop is connected with the center of transmission line the latter, and probe is connected in the relative two ends of transmission line, and two probes are identical with the distance of loop.In a preferred embodiment, each probe is connected on the transmission line, and itself and the transmission line distance of an end separately are λ/4, and the separation distance of two loops is λ/2, and wherein λ is the central task wavelength of antenna expection.

Transmission line can be a microstrip line (microstrip line), separates just even more ideally mutually with ground plate, for example can use metal or dielectric spacers to separate.

In a preferred embodiment, probe is directed, and their parallel parts meet at right angles with the edge of paster like this.Even more ideal is, probe is symmetrical with respect to paster, and whereby, each probe all is placed in the position with the patch edges same distance.

Paster can be any suitable shape, for example circle or triangle, but rectangle is the most suitable.When paster was rectangle, the size on its long limit can be 0.7 λ to 1.1 λ, and the length of minor face can be about 0.4 λ, and wherein λ is the central task wavelength of antenna expection.

Description of drawings

With example and method with reference to the accompanying drawings some embodiments of the present invention are described herein, wherein:

Figure 1 shows that: the perspective view of the basic geometry of She Ji antenna according to one embodiment of present invention,

Figure 2 shows that the vertical view of the antenna among Fig. 1,

Fig. 3 (a) and 3 (b) are depicted as the end view of the antenna among Fig. 2,

Fig. 4 has shown the gain (a) of the antenna of making according to the embodiment of Fig. 1 to Fig. 3 and the experimental result of standing-wave ratio (b),

Fig. 5 (a) to (c) is depicted as other possible direction of feed probes,

Fig. 6 (a) to (c) is depicted as other possible shape of paster,

Fig. 7 (a) to (c) has shown an embodiment of application stack paster with schematic diagram.

Embodiment

Referring to Fig. 1, can see that at first according to one embodiment of the invention, paster 1 separates mutually with ground plate 2, but parallel with it.Paster is a rectangle, the scope of its width W (see figure 2) be 0.7 λ to 1.1 λ, the length L (see figure 2) is approximately 0.4 λ, wherein λ is the central task wavelength of antenna.Paster 1 can as a pair of plastic support 3, support being placed on the ground plate 2 by dielectric substance, and the spacing of paster and ground plate is approximately 0.1 λ.

Paster 1 is presented by two identical L shaped probes 4, and each probe is some vertical with paster and ground plate (" vertical component ") all, another part parallel with paster and ground plate (" parallel portion ").For each probe 4, vertical component and parallel portion form an integral body, and vertical component and parallel portion all are coupled with paster 1.That the cross section of probe 4 can be is square, rectangle, circle or any other suitable shape.L shaped probe 4 is vertical orientations, and like this, its vertical component arrives shown in Figure 3 to the radiating side vertical extent of paster 1 as Fig. 1.The vertical component of probe 4 is laid near the radiating side of paster 1; Power divider 5 by a two-way homophase constant amplitude presents input signal to two probes 4.

Yet, to shown in (c), also might carry out orientation by other direction to feed probes 4 as Fig. 5 (a).Referring to Fig. 5 (a), feed probes 4 is carried out orientation with vertical direction by angle theta; If this angle is about tens degree, as long as probe is positioned under the paster and probe does not contact with each other, antenna still can be worked effectively so.Probe 4 can be shown in Fig. 5 (a) such mutual sensing the other side, also can be mutually the other side dorsad, perhaps also can point to another probe by a probe, and second probe first probe dorsad.Probe 4 is straight then more suitable, and they are other shape also, as (Fig. 5 (c)) of (as Fig. 5 (b)) or arc at an angle.

Get back to the embodiment of Fig. 1 to Fig. 3 now, power divider 5 is straight microstrip lines, and this microstrip line is supported on the ground plate 2 by two metal derbies 6, and these two metal derbies lay respectively at the two ends of microstrip line, but antenna DC earthing just like this.Power divider also can be selected to support with dielectric material, and in fact be installed on the ground plate or under all can.Microstrip line is by coaxial feeder 7 (coaxial launcher feed) receiving inputted signal, and this coaxial feeder is positioned at the mid point of microstrip line.Distance between the nearest end of each L shaped probe 4 and microstrip line is λ/4.In order to obtain higher gain and lower cross polarization, the distance that two probes 4 separate should be about λ/2.

According to the geometric figure of Fig. 1 to Fig. 3, (referring to Fig. 2 and Fig. 3) made antenna by following size:

Parameter size (mm) size (λ)

a 5.8 0.07λ

b 15.5 0.18λ

c 2 0.02λ

d 2 0.02λ

e 2 0.02λ

f 3.8 0.04λ

g 10 0.12λ

Gw 100 1.16λ

G _L 100 1.16λ

H 8.4 0.1λ

L 30.5 0.35λ

S ₀ 43 0.5λ

S ₁ 20.1 0.25λ

W 55 0.64λ

Except above-mentioned parameter, the thickness of microstrip line 5 is 0.3mm, and the thickness of paster 1 also is 0.3mm.Microstrip line and paster all can surpass this thickness, for example thickly reach 1 to 2mm.And the H value is 0.1 λ in this example, can between 0.05 λ and 0.15 λ, change, and Gw and G _LCan be respectively arbitrary value greater than W and L.The height of the vertical component of each probe can be according to the height H of paster, and the distance of the width W of paster and probe and patch edges is determined, but the height of the vertical component of probe is 0.05 λ to 0.1 λ usually.

Fig. 4 (a) and Fig. 4 (b) have shown the gain and the standing-wave ratio result of the antenna of making by above parameter respectively, can see that this antenna gains above 9dBi in 3.4 to 3.7GHz scopes, and cross polarization are lower.

To Fig. 6 (c), just notice that paster might not be square or rectangle referring to Fig. 6 (a), also can be other possible shape, as triangle (Fig. 6 (a)), trapezoidal (Fig. 6 (b)) or oval (Fig. 6 (c)).

So just can see, at least in the preferred case, by two identical L shaped probes are provided to antenna, and these two probes be encouraged, just can obtain higher gain and lower cross polarization with same-phase with power.Also note that this design also can combine to the geometric figure of the storehouse paster shown in Fig. 7 (c) with Fig. 7 (a).In this embodiment, lay second paster 1 ' above first paster 1, the height of first paster 1 above ground plate is H ₁, and the height of second paster 1 ' above ground plate is H ₂Common H ₁Be 0.05 λ to 0.08 λ, and H ₂Be 0.1 λ to 0.15 λ.Second comparable first patch size of paster is little or size is big, or identical with first patch size.Another kind may be to use a plurality of pairs of L coupling probe pasters to form a high-gain aerial battle array.

Claims

1, a kind of antenna, it comprises a paster, this paster is placed on the ground plate and with ground plate to be separated mutually, and pair of L-shaped probe, this probe is placed between above-mentioned paster and the above-mentioned ground plate, each above-mentioned probe all comprises a part parallel with paster and ground plate, with a part vertical with paster and ground plate, and to encourage the method for above-mentioned two probes with power and same-phase.

2, antenna according to claim 1, its middle probe is connected with transmission line, and loop is put therein with above-mentioned transmission line and is connected, and above-mentioned probe is connected in the relative two ends of above-mentioned transmission line, and equates with above-mentioned loop distance.

3, antenna according to claim 2, wherein each above-mentioned probe is connected with above-mentioned transmission line, probe is λ/4 apart from the distance of a corresponding separately end of transmission line, and wherein between two loops standoff distance be λ/2, λ is the central task wavelength of antenna expection here.

4, antenna according to claim 2, wherein above-mentioned transmission line is a microstrip line.

5, antenna according to claim 4, wherein above-mentioned microstrip line is separated mutually with ground plate.

6, antenna according to claim 5, wherein microstrip line is separated by metal spacer mutually with ground plate.

7, antenna according to claim 1, wherein above-mentioned probe is directed, their parallel portion meets at right angles and extends to the edge of paster like this.

8, antenna according to claim 7, wherein above-mentioned probe are symmetrical with respect to paster, and by this, each probe all is placed in and the identical position of paster side distance.

9, antenna according to claim 1, wherein paster is a rectangle.

10, antenna according to claim 9, wherein the size on the long limit of paster be 0.7 λ to 1.1 λ, and the size of minor face is about 0.4 λ, λ is the central task wavelength of antenna expection here.

11, antenna according to claim 1, wherein paster is leg-of-mutton.

12, antenna according to claim 1, wherein paster is trapezoidal.

13, antenna according to claim 1, wherein paster is oval-shaped.

14, antenna according to claim 1, it further comprises second paster, this second paster is positioned on above-mentioned first paster also parallel with it.