CN2465339Y - Plane spiral double-frequency antenna - Google Patents

Abstract

The utility model relates to a plane spiral double-frequency antenna, which mainly comprises a circuit board. The plane spiral double-frequency antenna is characterized in that the upper and the lower surfaces of the circuit board are respectively provided with a plurality of microstrip line sections divided by set space; opposite endpoints of the microstrip line sections arranged on the upper and the lower surfaces of the circuit board in an opposite oblique shape form electric connection by filling holes; loading is carried out on the upmost end of one side of a plurality of microstrip line sections, and the undermost end of the other side becomes a feed outlet point. According to the same plane, the microstrip line sections are coupled to form high frequency resonant points, and positive and negative surfaces are connected to form low frequency resonant points in total length. A plane and miniaturization double-frequency effect antenna with excellent functions is formed by the variation of line section spacing and antenna loading.

Description

The snail dual-band antenna

The utility model relates to a kind of spiral dual-band antenna, particularly a kind of snail dual-band antenna of reaching double frequency function with the complanation helical structure.

Generally establishing the helical coil that forms with the metal wire silver lap is main antenna form, and this type of helical antenna (helix antenna) all can have influence on the function that sets in each side such as coil diameter, coil method, circle distance and total lengths.But anyway, helical antenna is still and is widely adopted and the transmitting-receiving Iflytech line structure of quite stable.Communication Equipment is required and cooperate now, and this type of helical antenna more can constitute different resonance frequency (resonance frequency) by various different structure designs.As Japan Patent 1997-320748 number, promptly be provided with helical coil, and can be by the outer adjustment part (adjusting member) that stretch into of pipe in an outer tube inside, determine its resonance frequency with the different built-in lengths of this adjustment part.In addition, British patent the 2nd, 206 then stretches into a linear conductor (linearconductor) and constitutes double frequency (dual-frequeney) antenna for No. 243 in a helical coil.But the shortcoming of this type of helical antenna then is to occupy larger volume with three-dimensional, for the maybe essential Communication Equipment (as mobile phone or portable computer) that uses built-in antenna of miniaturization in modern age, is difficult to definite being suitable for.

At this point, be that the microplate antenna (microstrip antenna) that various miniaturizations and complanation are arranged is developed gradually.But early stage microplate antenna, as be disclosed in United States Patent (USP) the 3rd, 921, No. 177 and 3,810, No. 183, normally formed by circle or rectangle foil, fill dielectric material between itself and ground connection, this type of microplate antenna is generally only allowed narrower frequency range.Application No. then provides a kind of multiangle spiral type microplate antenna that improves early stage microplate antenna for No. 07/695686, and its frequency range can approach general constant impedance helical antenna.But this kind microplate antenna shortcoming then is when low frequency, and it is quite big that antenna diameter will become, and on the Communication Equipment of the uncomfortable carried type that is used in modern age.

At this point, U. S. application number No. 07/798700 (Taiwan patent the 81108896th) number then provides a kind of and has dwindled and be the microplate antenna of wideband, but its helical antenna element is located on the ground plate that separates, and therebetween be provided with the dielectric material and the support materials of specific thicknesses, except the entire antenna size still was difficult to further dwindle, its transmitting-receiving communication function also was inferior to helical antenna.

The purpose of this utility model is that a kind of snail dual-band antenna will be provided, and can reach the dual-band antenna function with the complanation helical structure.

The purpose of this utility model is achieved in that

A kind of snail dual-band antenna, mainly comprise a circuit board, it is characterized in that: this circuit board upper and lower surface is respectively equipped with a plurality of microstrip line sections that are arranged with setting spacing branch each other, and these are electrically connected with grout formation with the microstrip line section opposite endpoint that oblique relatively shape is arranged at the circuit board upper and lower surface; The one side of these a plurality of microstrip line sections is topmost in cutting to add, and face then becomes bottom and feeds out a little in addition.

The live width of this microstrip line section is the width of 50 ohm microstrip tracks, and to make the intersegmental spacing of microstrip line in twos be four times of microstrip line section width.

This flat helical antenna is 1/2 λ design, and its total electrical length meets following formula: $\mathrm{\λe}=\frac{\mathrm{\λ}}{\sqrt{{\∈}_{\mathrm{\γ}}}}$ 。

The width that this antenna loads is the twice of microstrip line section width, and length then is 1/20 λ.

The utility model is respectively equipped with corresponding microstrip line section in the upper and lower surface of a circuit board, these positive and negative microstrip line sections can be arranged in pairs or groups each other constitute a helical antenna, its each formation line segment opposite endpoint then can be electrically connected with grout (through hole); Load (top loading) topmost simultaneously and in its microstrip line section, line of engagement is intersegmental apart from setting, and can make same planar microstrip line form the high-frequency resonant point with coupled modes, joining of tow sides microstrip line section then can form the low-frequency resonant point with its total electrical length, thereby reaches the purpose that the complanation helical structure is reached the dual-band antenna function.

The utility model is simple in structure, is a kind of snail dual-band antenna, loads the double-frequency effect antenna that changes with formation function excellence, plane and miniaturization by line segment spacing and antenna, and the tool practicality.

Further specify the technical solution of the utility model and embodiment below in conjunction with accompanying drawing.

Description of drawings:

Fig. 1 is the utility model preferred embodiment stereogram;

Fig. 2 is the front elevation of Fig. 1;

Fig. 3 is the reverse side figure of Fig. 1;

Fig. 4 is the enlarged section cutaway view of Fig. 1 grout part.

See also shown in Fig. 1,2,3, in preferred embodiment as figure, the utility model is provided with the circuit board 10 of a suitably big small size and thickness, it contains upper surface 11 (promptly positive) and lower surface 12 (being reverse side), and can be in this upper and lower surperficial 11,12 common formation one plane helical microstrip antenna.

In illustrated embodiment, circuit board 10 fronts 11 have three to set the right tiltedly microstrip line section 22,24,26 that spacing is separated, its reverse side 12 then is provided with three oblique microstrip line sections 21,23,25 in a left side corresponding with it, the common plane helical microstrip antenna of forming of this microstrip line section.The connected mode of this front microstrip line section 22,24,26 and reverse side microstrip line section 21,23,25 then is that its relative line end is connected with a plurality of grouts 30 (through hole).For example, the bottom right line end 220 of positive first line segment 22 is electrically connected with grout 30 formation with the upper right line end 210 of reverse side first line segment 21; Upper left line end 222 that should front first line segment 22 then is electrically connected with another grout 30 with the bottom right line end 230 of reverse side second line segment 23, so constantly is connected and constitutes this plane helical microstrip antenna jointly.

As shown in Figure 4, according in the existing feasible fabrication schedule, above-mentioned grout 30 is can be after making through hole on the circuit board 10, carry out metal coating with plating or application pattern in this through hole, be electrically connected and the microstrip line section 21 and 22,22 and 23,23 and 24,24 and 25,25 and 26 of circuit board 10 positive and negative 11,12 can be formed.

The live width A of above-mentioned flat plane antenna (front and reverse side) is based on the width of 50 ohm microstrip tracks, same plane (promptly positive 11 or reverse side 12) in twos microstrip line intersegmental be that four times of microstrip line section 21,22,23,24,25,26 width are optimum apart from B.

The utility model is with the helical antenna complanation, and the electrical length of antenna itself will change to some extent because of dielectric constant is different.When the utility model adopts 1/2 λ design, its total electrical length can be shorter than general helical antenna, mainly be because:

Because medium is an air between the line of general helical antenna, the utility model then is a circuit board 10, and the dielectric constant of air makes total electrical length of the present utility model can be shorter than total electrical length of general helical antenna less than circuit board.

Top according to above-mentioned flat helical antenna can be loaded 90 (top loading), and its bottom 91 then conduct feeds out a little.This loading 90 is located at the left upper end of front microstrip line section 26 according to illustrated embodiment, and it feeds out a little the 91 lower-left ends of then being located at reverse side microstrip line section 21.This antenna loads can cause capacity effect, to reduce the inductive of antenna itself, the frequency range of antenna is increased, and reduce the electrical length of antenna.The width of above-mentioned antenna loading 90 is the twice of microstrip line section width A, and its length then can be 1/20 λ.

Each microstrip line section 22,24,26 and 21,23,25 on the same plane of the utility model (front 11 or reverse side 12) can form the high-frequency resonant point with coupled modes; And join in positive and negative two sides 11,12 microstrip line sections, then can form the low-frequency resonant point with total length.The variation that loads by spacing and antenna between this kind microstrip line section line can form this kind function excellence, the double-frequency effect antenna of plane and miniaturization.

Above illustrated embodiment is only with for conveniently illustrating the utility model, not from the novel spiritual category of this reality, be familiar with the dealer of this delegation various simple and easy distortion and the modification that can do, all must include in the utility model claim the existing utility application that in accordance with the law proposes.

Claims (4)

1, a kind of snail dual-band antenna, mainly comprise a circuit board, it is characterized in that: this circuit board upper and lower surface is respectively equipped with a plurality of microstrip line sections that are arranged with setting spacing branch each other, and these are electrically connected with grout formation with the microstrip line section opposite endpoint that oblique relatively shape is arranged at the circuit board upper and lower surface; The one side of these a plurality of microstrip line sections is topmost in cutting to add, and face then becomes bottom and feeds out a little in addition.

2, snail dual-band antenna as claimed in claim 1, it is characterized in that: the live width of this microstrip line section is the width of 50 ohm microstrip tracks, and to make the intersegmental spacing of microstrip line in twos be four times of microstrip line section width.

3, snail dual-band antenna as claimed in claim 1 is characterized in that: this flat helical antenna is 1/2 λ design, and its total electrical length meets following formula: $\mathrm{\λe}=\frac{\mathrm{\λ}}{\sqrt{{\∈}_{\mathrm{\γ}}}}$ 。

4, snail dual-band antenna as claimed in claim 1 is characterized in that: the width that this antenna loads is the twice of microstrip line section width, and length then is 1/20 λ.

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