CN201868575U

CN201868575U - Bluetooth antenna

Info

Publication number: CN201868575U
Application number: CN2010205240780U
Authority: CN
Inventors: 张莲
Original assignee: Huizhou TCL Mobile Communication Co Ltd
Current assignee: Huizhou TCL Mobile Communication Co Ltd
Priority date: 2010-09-08
Filing date: 2010-09-08
Publication date: 2011-06-15
Anticipated expiration: 2020-09-08

Abstract

The utility model provides a bluetooth antenna which comprises a printed circuit board, an annular antenna, a radio frequency transceiver and a capacity coupling and feeding part, wherein the annular antenna is arranged on the front side of the printed circuit board; the radio frequency transceiver and the capacity coupling and feeding part are arranged on the back side of the printed circuit board; and the capacity coupling and feeding part is connected with the radio frequency transceiver and is coincided with the annular antenna to form the coupling capacitor. The bluetooth antenna can excite the resonance with one fourth of wave length through the coupling and feeding of the annular antenna and the capacity coupling and feeding part; the size of the annular antenna is small, so that the annular antenna can be printed on the circuit board, and the cost is reduced; the radio frequency induction current of the annular antenna on the metal part of the product is reduced, and the anti-interference property is enhanced.

Description

A kind of Bluetooth antenna

Technical field

The utility model relates to a kind of Bluetooth antenna that is applied to portable equipment, particularly a kind of annular Bluetooth antenna of capacitive coupling feed.

Background technology

Bluetooth technology is a kind of low cost, low-power and short-range wireless communication technique, can be applied in widely on any personal mobile communication equipment.Antenna is the important important component that is used for transmitting and receiving electromagnetic wave energy in wireless telecommunication system.Because at present still can't be to semiconductor chip with aerial integration, thus in bluetooth module except the System on Chip/SoC of core, antenna is that another has the critical components that influences the bluetooth module transmission characteristic.In various bluetooth applications product, employed antenna design method also is not quite similar with the making material.Select suitable antenna for use except the external form of the product that helps to arrange in pairs or groups and promote the transmission characteristic of bluetooth module, can also further reduce the cost of whole bluetooth module.Present modal Bluetooth antenna kind includes dipole antenna (Dipole Antenna), PIFA (Planar Inverted F Antenna) antenna, monopole antenna (Monopole antenna) and microminiature ceramic antenna (Ceramic Antenna) etc.The length of dipole antenna is relevant with its frequency of operation, and general design commonly used is to use the length of half-wavelength as antenna.PIFA antenna and monopole antenna working length are quarter-wave, and wherein the PIFA antenna implements needs certain height, and monopole antenna needs certain clear space (not having the copper district of applying).Ceramic antenna is that another is suitable for the employed miniature antenna of blue-tooth device.The kind of ceramic antenna can be divided into bulk (Block) ceramic antenna and multilayer (Multilayer) ceramic antenna, and the former is to use high temperature (Celsius 1000 degree more than) metal of antenna partly to be imprinted on the surface of ceramic block after finishing the monolithic ceramic body is once sintered again; The mode that the latter then adopts low temperature co-fired (LoW Temperature Cofired) is repeatedly pressed after the contraposition temperature sintering with 800～900 degree with multi-layer ceramics again, so the metallic conductor of antenna can need be imprinted on each layer ceramic dielectric layer according to design, just can effectively dwindle the antenna required size thus, but cost is higher relatively.

From the product application point of view, above-mentioned four kinds of antennas all are the electric field type antennas, and are very responsive for peripheral grounding metal plane (Ground P1ane) and human body.Therefore, be necessary to provide a kind of cost low, the space is little and be not subject to the Bluetooth antenna of external environmental interference.

Summary of the invention

The purpose of this utility model is to provide a kind of cost low, and the space is little and be not subject to the Bluetooth antenna of external environmental interference, is intended to solve the Bluetooth antenna cost height that exists in the prior art, and problem big and that be subject to disturb takes up space.

The utility model is achieved in that a kind of Bluetooth antenna, comprising: printed circuit board (PCB), loop aerial, radio-frequency (RF) transceiver and capacitive coupling feed part.Loop aerial is arranged at the printed circuit board (PCB) front; Radio-frequency (RF) transceiver and capacitive coupling current feed department branch are arranged at the printed circuit board (PCB) reverse side, and capacitive coupling feed part links to each other with radio-frequency (RF) transceiver, and capacitive coupling feed part overlaps the formation coupling capacitance with loop aerial.

Loop aerial in the Bluetooth antenna comprises the earth point and the open end of ground connection, the earth point ground connection of loop aerial, and open end and capacitive coupling feed partially overlap; Printed circuit board (PCB) comprises empty regions, and loop aerial is arranged at the empty regions front, the non-headroom district in printed circuit board (PCB) front be printed circuit board (PCB) cover the copper district; The loop aerial earth point covers the copper zone with this and is connected; Capacitive coupling current feed department branch is arranged on the reverse side of printed circuit board (PCB) empty regions, and the one end is that input point is connected with radio-frequency (RF) transceiver, and the other end is an open end, and it overlaps with this loop aerial open end; The open end of capacitive coupling feed part is inverted L shape.

In the Bluetooth antenna, the width of printed circuit board (PCB) is 40 millimeters, length is 90 millimeters, and thickness is 1 millimeter, and dielectric constant is 3.6, empty regions length is 13 millimeters, 5 millimeters of width, the cabling live width of loop aerial 5 is 1 millimeter, total length is 23 millimeters, the input point of capacitive coupling feed part sees into that total input impedance is 50 ohm.

Bluetooth antenna of the present utility model is by the coupling feed of loop aerial 5 with capacitive coupling feed part 7, encouraged quarter-wave resonance, reduced the loop aerial size, be printed on the circuit board, reduce cost, loop aerial has reduced the radio frequency induction electric current in the resultant metal part simultaneously, and itself is not subject to the interference of peripheral grounding metal plane and human body, and anti-interference improves.

Description of drawings

Fig. 1 is the structural representation of the utility model Bluetooth antenna;

Fig. 2 is the return loss plot that Bluetooth antenna of the present utility model records on network analyzer.；

Fig. 3 is the antenna pattern of the Bluetooth antenna of present embodiment on the X-Z plane;

Fig. 4 is the antenna pattern of the Bluetooth antenna of present embodiment on the Y-Z plane;

Fig. 5 is the antenna pattern of the Bluetooth antenna of present embodiment at X-Y plane.

Embodiment

In order to make the purpose of this utility model, technical scheme and advantage clearer,, the utility model is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.

Seeing also Fig. 1, is the structural representation of the utility model Bluetooth antenna.This Bluetooth antenna comprises printed circuit board (PCB) 8, is arranged at the loop aerial 5 in printed circuit board (PCB) 8 fronts, is arranged at the capacitive coupling feed part 7 and the radio-frequency (RF) transceiver 2 of printed circuit board (PCB) 8 reverse side.

The width of this printed circuit board (PCB) 8 is 40 millimeters, and length is 90 millimeters, and thickness (i.e. height) is 1 millimeter, and the dielectric constant of circuit board is 3.6.In Fig. 1, indicated X, Y, three axis of orientations of Z provide three faces of the electromagnetic radiation directional diagram of presentation graphs 4 to Fig. 6, X-Z plane, Y-Z plane and X-Y plane.This printed circuit board (PCB) 8 is provided with printed circuit board (PCB) empty regions 6, this empty regions length is 13 millimeters, and 5 millimeters of width, its front and back are not placed electronic device and be need not to apply copper yet, copper is covered in the non-headroom district in printed circuit board (PCB) 8 fronts, and what form printed circuit board (PCB) covers copper district 1.

The cabling live width of this loop aerial 5 is 1 millimeter, and total length is 23 millimeters, is about 1/4th of bluetooth resonance wavelength, and it is printed on the front of printed circuit board (PCB) empty regions 6.This loop aerial 5 comprises earth point 4 and open end, and the earth point 4 of loop aerial 5 is connected with the positive copper zone 1 of applying of printed circuit board (PCB), plays the ground connection effect.Change the position of the earth point 4 of loop aerial, can play the purpose of regulating loop aerial 5 length, the resonance frequency of final adjustable collar shape antenna 5.

Capacitive coupling feed part 7 is arranged on the reverse side of printed circuit board (PCB) empty regions 6, and the one end is an input point 3, directly is connected with radio-frequency (RF) transceiver 2, plays the feed effect, need not to increase extra match circuit; The other end is an open end, be inverted L shape, partially overlap with the open end of loop aerial 5, the open end of capacitive coupling feed part 7 overlaps with the loop aerial open end, and intersection equivalence on electrical property is an electric capacity, and this equivalence electric capacity and loop aerial 5 self inductance equivalence is for connecting, adjusting coupling capacitance makes it to offset with loop aerial 5 self inductance, see into that from the input point 3 of capacitive coupling feed part total input impedance is near 50 ohm, loop aerial 5 reaches resonance.Adjust the intersection of the open end of capacitive coupling feed part 7 open ends and loop aerial 5, can change the appearance value of coupling capacitance, and then adjust the resonance degree of depth of loop aerial 5.Increase the length width of intersection metal level, coupling capacitance increases, otherwise coupling capacitance reduces.

Fig. 2 is the return loss plot that Bluetooth antenna of the present utility model records on network analyzer.The bandwidth of the return loss of this Bluetooth antenna satisfies the requirement of Bluetooth communication.

Fig. 3 to Fig. 5 be respectively the Bluetooth antenna of present embodiment on the X-Z plane, the antenna pattern of Y-Z plane and X-Y plane.The radiation of this Bluetooth antenna is approximate omnidirectional on X-Y plane, does not have blind spot on X-Z plane and Y-Z plane.

The loop aerial of coupling feed of the present utility model, by the coupling feed of loop aerial 5 with capacitive coupling feed part 7, encouraged quarter-wave resonance, the loop aerial size is less, be printed on the circuit board, reduce cost, loop aerial has reduced the radio frequency induction electric current in the resultant metal part simultaneously, itself be not subject to the interference of peripheral grounding metal plane (Ground Plane) and human body, anti-interference improves.

The above only is preferred embodiment of the present utility model; not in order to restriction the utility model; all any modifications of within spirit of the present utility model and principle, being done, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.

Claims

1. Bluetooth antenna comprises:

Printed circuit board (PCB); Loop aerial is arranged at the printed circuit board (PCB) front; Radio-frequency (RF) transceiver and capacitive coupling feed part, radio-frequency (RF) transceiver and capacitive coupling current feed department branch are arranged at the printed circuit board (PCB) reverse side, it is characterized in that: capacitive coupling feed part links to each other with radio-frequency (RF) transceiver, and capacitive coupling feed part overlaps the formation coupling capacitance with loop aerial.

2. Bluetooth antenna according to claim 1 is characterized in that, loop aerial comprises the earth point and the open end of ground connection, the earth point ground connection of loop aerial, and open end and capacitive coupling feed partially overlap.

3. Bluetooth antenna according to claim 2 is characterized in that this printed circuit board (PCB) comprises empty regions, and loop aerial is arranged at the empty regions front, the non-headroom district in printed circuit board (PCB) front be printed circuit board (PCB) cover the copper district.

4. Bluetooth antenna according to claim 3 is characterized in that, this loop aerial earth point covers the copper zone with this and is connected.

5. Bluetooth antenna according to claim 3, it is characterized in that capacitive coupling current feed department branch is arranged on the reverse side of printed circuit board (PCB) empty regions, the one end is that input point is connected with radio-frequency (RF) transceiver, the other end is an open end, and it overlaps with this loop aerial open end.

6. Bluetooth antenna according to claim 5 is characterized in that, the input point of capacitive coupling feed part sees into that total input impedance is 50 ohm.

7. Bluetooth antenna according to claim 5 is characterized in that, this empty regions length is 13 millimeters, 5 millimeters of width.

8. Bluetooth antenna according to claim 5 is characterized in that, the open end of capacitive coupling feed part is inverted L shape.

9. Bluetooth antenna according to claim 1 is characterized in that, the width of this printed circuit board (PCB) is 40 millimeters, and length is 90 millimeters, and thickness is 1 millimeter, and dielectric constant is 3.6.

10. Bluetooth antenna according to claim 1 is characterized in that, the cabling live width of this loop aerial 5 is 1 millimeter, and total length is 23 millimeters.