CN2901607Y

CN2901607Y - Small double frequency MLA built-in antenna for cell phone

Info

Publication number: CN2901607Y
Application number: CN 200620002298
Authority: CN
Inventors: 陈骊; 金列锋
Original assignee: SKYCROSS ELECTRONIC (SHENZHEN) CO Ltd
Current assignee: SKYCROSS ELECTRONIC (SHENZHEN) CO Ltd
Priority date: 2006-02-24
Filing date: 2006-02-24
Publication date: 2007-05-16
Anticipated expiration: 2016-02-24

Abstract

A pocketed bi-frequency built-in antenna for mobile phones is provided with a sheet-like antenna main block (A) which is arranged upside down at the periphery end of a reference floor and kept a certain distance with the reference floor. The antenna main block is electrically connected with the reference floor (13) through a feed point (1). The two longitudinal sides of the sheet-like antenna main block are respectively provided with an open groove (6, 8) and a (3, 2), which are in alternate permutation so that the antenna main block forms an alternative crease antenna structure. The longitudinal side of the antenna main block is a folded surface (5, 7, 9), and the feed point (1) is provided at the initial end of the crease antenna and electrically connected with the reference floor thorough the corresponded circuit. The utility model has the advantages of single feed point, simple structure, and small volume. Besides, it has the multiple frequency band function.

Description

The small-sized double frequency MLA built-in aerial that is used for mobile phone

Technical field

The utility model belongs to a kind of antenna that is used for mobile phone, especially for the broken line type built-in aerial of mobile phone.

Background technology

In the application of antenna for mobile phone, mostly be small size antenna.The Dipole type is generally arranged, or claim Monopole type, PIFA (Planar Inverted-F Antenna) etc.For the Dipole type, modal is helical antenna.This type of antenna can only be used for the external big line of mobile phone owing to the reason of its size.Nearly one or two years is because the popular mobile phone that requires in market then requires built-in aerial to dispose.The PIFA antenna has just obtained being extensive use of.But classical PIFA needs bigger space to realize usually, and the antenna volume space that often can not satisfy the proposition of mobile phone manufacturer is little relatively, and is the requirement that multifrequency (double frequency, three frequencies or four are frequently) is used.

Summary of the invention

The technical problems to be solved in the utility model provide a kind of simple in structure, volume is little, and has the small-sized double frequency MLA built-in aerial that is used for mobile phone of multiband function.

The technical scheme that addresses the above problem is (referring to implementing illustration): the utility model is provided with and places with reference to floor (13) one marginal ends, and draw back the antenna body (A) of certain distance (D) with the reference floor, antenna body passes through distributing point (1) and is electrically connected with reference to floor (13), it is characterized in that: described chip aerial main body two vertical sides have slot (6,8) and (3,2), the slot of dual-side is staggered in a longitudinal direction, make antenna body form circuitous broken line shape antenna structure, vertical side position of described antenna body is a bending side (5,7,9), described distributing point (1) is located at broken line shape antenna head end, and by by inductive element (L1, L2) and the match circuit of capacitive element (C1) composition be electrically connected with radiofrequency signal input/output port with reference to the floor.

Further scheme of the present utility model is: the broken line shape antenna tail end of described antenna body is provided with ennation (4) backward.

Common antenna always designs on desired frequency, if do not accomplish, also design as much as possible in its vicinity.Both be that multifrequency also is like this.According to this design, locate as designing at low frequency (for example being 800MHz), the length of antenna must extend and much just can reach resonance in the 800MHz place, for reduced volume, antenna will very carefully just can reach effective length makes resonance frequency reach 800MHz, and the reason that this elongated structure makes the beamwidth of antenna narrow down just.

The utility model antenna has then adopted the way different with routine: design frequency is being higher than low frequency and is being lower than high frequency treatment, antenna body is circuitous broken line shape antenna structure, broken line shape sky line width with broad, with the bandwidth that obtains broad than short antenna length, dwindled antenna volume, the bending side at the vertical side of antenna body position can further dwindle and take up room.The utility model can by match circuit with antenna resonance in 800MHz and 1900MHz band, and suitably adjust the distance D of antenna to the floor, can gently obtain double frequency: 800MHz, 1900MHz frequency band.

The utlity model has single feed point, simple in structure, advantage that volume is extra small, and have the multiband function.

Description of drawings

Fig. 1, the utility model embodiment antenna body A and reference ground board connecting structure schematic diagram

Fig. 2, the utility model embodiment antenna body A structural representation

The characteristic echo ratio of Fig. 3, the utility model embodiment antenna function

The Smith chart of Fig. 4, common antenna

Smith chart after Fig. 5, the utility model embodiment antenna body W widen

Fig. 6, the utility model embodiment match circuit figure

1-distributing point 2,3,6,8-slot 4-extension 5,7,9-bending side

10,11,12-location hole 13-floor

Specific embodiments

This routine chip aerial main body A places with reference to floor 13 1 ends, and big to parallel with the reference floor, the projection on antenna body longitudinal medial limit is positioned at the position near corresponding end floor edge line.The length L of antenna body is approximately 28mm, and width W is approximately 8.6mm, and liftoff plate distance is about 5.5mm

The vertical dual-side of antenna body A has two slots 6,8 and 3,2, the slot of both sides is staggered at longitudinal direction, form circuitous broken line shape antenna (being two S shapes that head and the tail connect), described distributing point 1 is located at broken line shape antenna head end on the feed leg that direction bending in floor is extended, broken line shape antenna tail end is provided with ennation 4 backward, the vertical outer side edges of antenna body position is a bending side, bending side 9 near vertical two-end part, 5 bend towards the floor direction, cross section roughly is  shape, the bending side 7 at middle part is towards the floor direction, bend inwards, cross section roughly is Contraband shape again.

Described distributing point 1 is positioned at antenna body longitudinal medial limit one end, and broken line shape antenna tail end is positioned at the vertical outer side edges other end of antenna body, tail end extend back body 4 in the form of sheets, and with bending side 5 bending at this position, the antenna body face bends 90 degree approximately relatively.

Position at close broken line shape antenna head end of antenna body and tail end is respectively equipped with location hole 10,12, be provided with location hole 11 on the broken line body near antenna body longitudinal center axis position, described location hole 10,11,12 all is positioned at the position of the close Width central point of the local broken line body in place.

The position of above-mentioned location hole is beneficial to the fixing of distributing point, and can reduce the harmful effect of perforate to feed current.

The distributing point 1 of antenna body is electrically connected with radiofrequency signal input/output port with reference to the floor by match circuit, and described match circuit also is arranged on the floor, is made up of the inductive element L1 and inductive element L2, the capacitive element C1 in parallel of series connection.Concrete structure is distributing point 1 first shunt capacitance C1, series inductance L1, opens connection inductance L 2 again.

Shown in Figure 6 is the match circuit that this antenna adopts.For different antenna sizes, the form of match circuit and capacitor C 1 and inductance L 1, the value of L2 is all different.The distance on antenna and ground not simultaneously, the form of match circuit and capacitor C 1 and inductance L 1, the value of L2 also can be different.

This antenna trend is: from distributing point 1, circuitous to tail end ennation 4 along broken line shape antenna.

Antenna performance as shown in Figure 3, from Fig. 3 as seen, it is a lot of that lowest resonant frequency is higher than 900MHz, but the non-constant width of bandwidth.If L increases, then resonance frequency will be moved to low side, otherwise if L reduces, then resonance frequency will be moved to high-end.If increase W on the direction of leaving the PCB floor, then bandwidth will increase (especially low frequency end), and resonance is offset to low frequency, especially low frequency end.

The bending side of the vertical outer side edges of antenna body can reduce to take up room under the situation that increases antenna electrical length as far as possible.

The Smith chart of the utility model antenna that Fig. 4 does not widen for W (initial data when not using match circuit), Fig. 5 is the Smith chart (initial data when not using match circuit) of the present embodiment of W after widening, point mark 1 and 2 is low-frequency range 880MHz～960MHz, and some mark 3 and 4 is for being high band 1710MHz～1880MHz.As seen from the figure, widen W after, the capacitive of some mark 1 and some mark 2 reduces, promptly inductance value increases, some mark 1 and some mark 2 more close centers; Point mark 3 and some mark 4 are also close mutually, like this, through adopting matching technique, just can obtain than widening wideer bandwidth before the W.The width of antenna body bending part and the size of fluting also can influence bandwidth.

Select cheaply on this routine material that copper adds nickel plating for use, light and handy cheap.

This example adopts single feed point, is inverted MLA (Meander Line Antenna) Monopole type antenna, is used matching technique, can meet design requirement with extra small volume, and has good broadband and multifrequency characteristic.The comparable common similar antenna of this routine antenna volume is half as large to 1/3rd.

Claims

1, the small-sized double frequency MLA built-in aerial that is used for mobile phone, be provided with and place with reference to floor (13) one marginal ends, and draw back the antenna body (A) of certain distance (D) with the reference floor, antenna body passes through distributing point (1) and is electrically connected with reference to floor (13), it is characterized in that: described chip aerial main body two vertical sides have slot (6,8) and (3,2), the slot of dual-side is staggered in a longitudinal direction, make antenna body form circuitous broken line shape antenna structure, vertical side position of described antenna body is a bending side (5,7,9), described distributing point (1) is located at broken line shape antenna head end, and by by inductive element (L1, L2) and the match circuit of capacitive element (C1) composition be electrically connected with radiofrequency signal input/output port with reference to the floor.

2, the small-sized double frequency MLA built-in aerial that is used for mobile phone according to claim 1, it is characterized in that: the broken line shape antenna tail end of described antenna body is provided with ennation (4) backward.

3, the small-sized double frequency MLA built-in aerial that is used for mobile phone according to claim 2, it is characterized in that: described distributing point (1) is positioned at antenna body longitudinal medial limit one end, broken line shape antenna tail end is positioned at the vertical outer side edges other end of antenna body, the body that extends back (4) of tail end in the form of sheets, with the bending of the bending side (5) at this position.

4, the small-sized double frequency MLA built-in aerial that is used for mobile phone according to claim 2, it is characterized in that: described chip aerial main body (A) places with reference to floor (13) one ends, with reference floor almost parallel, the projection on antenna body longitudinal medial limit is positioned at the position near corresponding end floor edge line.

5, the small-sized double frequency MLA built-in aerial that is used for mobile phone according to claim 2, it is characterized in that: the length L of described antenna body is approximately 28mm, and width W is approximately 8.6mm, and liftoff plate distance is about 5.5mm.

6, the small-sized double frequency MLA built-in aerial that is used for mobile phone according to claim 2, it is characterized in that: the vertical dual-side of described antenna body A has two slots (6,8) and (3,2), the slot of both sides is staggered at longitudinal direction, forms circuitous broken line shape antenna.

7, according to the described small-sized double frequency MLA built-in aerial that is used for mobile phone of the arbitrary claim of claim 1-6, it is characterized in that: the vertical outer side edges of described antenna body position is a bending side, bending side (9,5) near vertical two-end part bends towards the floor direction, cross section roughly is  shape, the bending side (7) at middle part is towards the floor direction, bend inwards again, and cross section roughly is Contraband shape.

8, according to the described small-sized double frequency MLA built-in aerial that is used for mobile phone of the arbitrary claim of claim 1-6, it is characterized in that: described match circuit is arranged on the floor (13), inductive element (L1) by series connection, form with inductive element (L2), the capacitive element (C1) of parallel connection, be specially: the first shunt capacitance of described distributing point (1) (C1), series inductance (L1), shunt inductance (L2) again.

9, according to the described small-sized double frequency MLA built-in aerial that is used for mobile phone of the arbitrary claim of claim 1-6, it is characterized in that: the position at close broken line shape antenna head end of antenna body and tail end is respectively equipped with location hole (10,12), be provided with location hole (11) on the broken line body near antenna body longitudinal center axis position, described location hole (10,11,12) all is positioned at the position of the close Width central point of the local broken line body in place.