CN101465476B - Built-in antenna - Google Patents

Abstract

A built-in antenna, applied to a DVB-H system, comprises a first monopole radiating portion, a second monopole radiating portion and a signal feeding section. The first monopole radiating portion has a first end, a second end away from the first end, and a first meandering radiating section connecting the first end and the second end. The structure of the second monopole radiating portion is similar to that of the first monopole radiating portion, and is adjacent to and symmetrical to the first monopole radiating portion in a straight line. The second monopole radiating portion has a third end, a fourth end away from the third end, and a second meandering radiating section connecting the third end and the fourth end. The signal feeding section is connected to the first end and the third end. This antenna has the advantages of small size, ultra-wideband, good efficiency, simple design structure, etc.

Description

built-in antenna

technical field

The invention relates to a built-in antenna, in particular to a built-in antenna applied to handheld digital video broadcasting (DVB-H).

Background technique

Digital Video Broadcasting Project (DVB), in order to realize the future trend of mobile viewing, based on the original digital video terrestrial broadcasting (DVB-T; DVB-Terrestrial) transmission technology standard, proposed "handheld digital Video Broadcasting" (DVB-H; DVB-Handheld) technical specifications, and in February 2004, DVB Project officially announced the completion of the DVB-H specification work. This DVB-H technology can meet the functions of low power consumption, high mobility (easy to receive), shared platform, and uninterrupted network switching services required by handheld devices. In the future, mobile communication networks and DVB-H broadcasting Network integration provides users with more diverse content and interactive services.

Referring to Fig. 1, the antenna structure shown in the figure is the DVB-H antenna 10 proposed by the United States Patent Publication No. US20060214857A1, the antenna 10 has an inverted L-shaped antenna radiation part 11 and a feed-in wire 12 connected to the radiation part 11, and The other end of the feeding wire 12 is connected to a matching circuit 13 , and the rear end of the matching circuit 13 is connected to another RF circuit 14 . Except the radiation part 11 , the other three components are all disposed on the metal printed circuit board 15 .

The antenna 10 utilizes the inverted L-shaped radiating part 11 and the matching circuit 13 to resonate multiple frequencies to generate the bandwidth of DVB-H. However, the disadvantage is that the multi-frequency resonance will affect its gain; in addition, the coupling distance between the matching circuit 13 and the RF circuit 14 is not easy to control, which will cause frequency deviation.

Contents of the invention

Therefore, the purpose of the present invention is to provide a DVB-H built-in antenna with small size, good efficiency and simple design and structure.

The invention proposes a built-in antenna, which includes a first monopole radiation part, a second monopole radiation part and a signal feeding section.

The first monopole radiating portion has a first end, a second end away from the first end, and a first meandering radiating section connecting the first end and the second end.

The structure of the second monopole radiator is similar to that of the first monopole radiator, and it is adjacent to the first monopole radiator and symmetrical to a straight line. The second monopole radiator has a third end and a fourth end far away from the third end. , and the second meandering radiation section connecting the third end and the fourth end.

The signal feeding section is connected to the first end and the third end.

Description of drawings

Fig. 1 is a perspective view illustrating the structure of a conventional DVB-H antenna;

Fig. 2 is a perspective view illustrating that the first preferred embodiment of the built-in antenna of the present invention is arranged in an insulating casing;

Fig. 3 is a perspective view illustrating that the first preferred embodiment is disposed on the insulating housing;

Fig. 4 is the front view of the built-in antenna of the present embodiment unfolded into a plane, illustrating the structure of the preferred embodiment;

Fig. 5 is a schematic diagram illustrating the structure of an impedance matching circuit;

Fig. 6 is a schematic diagram illustrating that the impedance matching circuit is arranged on a microwave substrate and its connection with a signal feed-in section;

Fig. 7 is the measurement result figure of the voltage standing wave ratio (VSWR) of the present preferred embodiment;

Fig. 8 is the Smith chart of present preferred embodiment;

Fig. 9 is the measurement result figure of the gain (GAIN) of present preferred embodiment;

Fig. 10 is the radiation pattern (Radiation Pattern) figure when frequency is 650MHz of present preferred embodiment; And

Fig. 11 is a front view of the built-in antenna of the second preferred embodiment unfolded into a plane, illustrating the structure of the preferred embodiment.

Description of main component symbols

2 built-in antenna

3 first monopole radiating part

31 first end

32 second end

4 second monopole radiating part

41 third end

42 fourth end

5 signal feed-in section

6 The first meander radiating section

61 first line segment

62 second line segment

63 third segment

64 fourth line segment

65 fifth line segment

7 The second meander radial section

71 sixth line segment

72 seventh line segment

73 Eighth segment

74 ninth line segment

75 Tenth Line Segment

8 impedance matching circuit

81 capacitance

82 inductance

83 signal line

84 microwave substrate

91 insulating matrix

92 first side

93 second side

94 The third side

95 fourth side

L straight line

Detailed ways

The foregoing and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of two preferred embodiments with reference to the accompanying drawings.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to Fig. 2 and Fig. 3, the first preferred embodiment of the built-in antenna 2 of the present invention is built in hand-held electronic devices such as mobile phones and PDAs, and its working frequency band is 470MHz～862MHz meeting the requirements of DVB-H, and for To reduce the occupied area, in this embodiment, the built-in antenna 2 is designed in a three-dimensional form, however, it can also exist in a planar form, as shown in Figure 4, and in order to facilitate the description of its structure, the following first uses The plane type is used for illustration.

Referring to FIG. 4 , the built-in antenna 2 includes a first monopole radiating portion 3 , a second monopole radiating portion 4 and a signal feeding section 5 .

The first monopole radiating portion 3 has a first end 31 , a second end 32 and a first meandering radiating section 6 connected to the two ends.

The first meander radiating section 6 comprises a first line segment 61 extending leftward from the first end 31, a second line segment 62 extending downwards following the end of the first line segment 61, and extending rightwards following the end of the second line segment 62 The third line segment 63 , the fourth line segment 64 extending downward following the end of the third line segment 63 , and the fifth line segment 65 extending leftward to the second end 32 following the end of the fourth line segment 64 .

Similar to the structure of the above-mentioned first monopole radiating part 3 , the second monopole radiating part 4 also has a third end 41 , a fourth end 42 and a second meandering radiating section 7 connected to these two ends. It is worth mentioning that the second monopole radiating portion 4 is adjacent to the first monopole radiating portion 3 and is symmetrical to the straight line L. As shown in FIG.

The structure of the second meandering radiating section 7 is also similar to that of the first meandering radiating section 6, including a sixth line segment 71 extending leftward from the third end 41, a seventh line segment 72 extending from the end of the sixth line segment 71 toward the straight line L, The eighth line segment 73 extending from the end of the seventh line segment 72 to the right, the ninth line segment 74 extending from the end of the eighth line segment 73 in the direction of the straight line L, and the tenth line segment 75 extending from the end of the ninth line segment 74 to the fourth end 42 .

It should be further explained that the second end 32 and the fourth end 42 are adjacent to the straight line L, the first end 31 and the third end 41 are away from the straight line L, and the signal feed-in section 5 is connected to the first end 31 and the second end. Three-terminal 41.

Preferably, the first, third, fifth, sixth, eighth, and tenth line segments 61, 63, 65, 71, 73, and 75 are parallel to the straight line L; the second, fourth, seventh, and ninth line segments 62, 64, 72, 74 and the signal feeding section 5 are perpendicular to the straight line L. The third, fifth, eighth, and tenth line segments 63, 65, 73, and 75 are equal in length to each other, the second, fourth, seventh, and ninth line segments 62, 64, 72, and 74 are equal in length and width to each other, and the first line segment 61 is equal in length to that of the first line segment. Six line segments 71; it is worth noting that the width of both the fifth line segment 65 and the tenth line segment 75 is wider than the other line segments, and when the distance between them is less than 3 mm, the effect of improving the gain is preferred.

Referring to FIG. 2 and FIG. 3 together, as shown in the figures, the first monopole radiating portion 3 , the second monopole radiating portion 4 and the signal feeding section 5 are bent and arranged on the surface of a rectangular parallelepiped insulating base 91 . Among them, the first and third line segments 61, 63 are located on the first surface 92 of the insulating matrix 91, the fifth line segment 65 extends from the first surface 92 to the second surface 93 of the insulating matrix 91, the tenth line segment 75 and the fifth line segment The line segments 65 are located on the second surface 93 at intervals, and the signal feed-in section 5 is extended from the third surface 94 to the fourth surface 95 of the insulating matrix 91; the second surface 93 and the third surface 94 are separated from each other by the first surface 92 They are parallel and vertically connected to the first surface 92, while the fourth surface 95 is vertically connected to the other three surfaces. (due to the consideration of setting convenience, some line segments are not straight as shown in Fig. 4, but slightly more tortuous, such as the first line segment 61, signal feed-in section 5, this does not deviate from the concept of the present invention, on the contrary Set off the design diversity provided by the present invention)

Referring to Fig. 2, Fig. 3, Fig. 4, Fig. 5 and Fig. 6, when designing this built-in antenna 2, the first monopole radiation part 3 with a center frequency of about 600 MHz and a wavelength of 1/4 can be designed first, and then the The second monopole radiating part 4, which is similar in structure to the first monopole radiating part 3, is adjusted with the impedance matching circuit 8 connected to the signal feeding section 5, so that the built-in antenna 2 can work in DVB- H-band. The impedance matching circuit 8 includes a capacitor 81 and an inductor 82. The capacitor 81 is connected between the positive end of the signal line 83 and the signal feeding section 5, and the inductor 82 is connected between the signal feeding section 5 and a ground. In the preferred embodiment, the capacitor has a value of 4.7pF and the inductor has a value of 15nH. As shown in Figure 6, the impedance matching circuit 8 is arranged on the microwave substrate 84 (it is FR4 material), the microwave substrate 84 is long 90mm, wide 40mm, high 0.8mm, and the insulating matrix 91 that is provided with for antenna is long 40mm, wide 8mm, 15mm high.

Referring to Fig. 7, this figure is the voltage standing wave ratio (VSWR) measurement value of built-in antenna 2, can find out from the figure, can improve voltage standing wave ratio by impedance matching circuit 8, improves from (a) curve to (b) Curve. It can also be seen from the Smith diagram of FIG. 8 that the measurement result of diagram (b) with impedance matching circuit 8 is better than that of diagram (a) without impedance matching circuit 8 .

In addition, FIG. 9 is a gain diagram of the built-in antenna 2. It can be seen from the figure that the gain curve (a) improved by the built-in antenna 2 through the impedance matching circuit 8 conforms to the European Information and Communication Technology Association (European Information and Technology Association). Communication Technology Association (EICTA) for gain specification (b). FIG. 10 is a radiation pattern graph of the built-in antenna 2 , and the frequency in FIG. 10 is 650 MHz.

Fig. 11 is the second preferred embodiment of built-in antenna 2 of the present invention, and it is similar to first preferred embodiment (Fig. 4) structure, difference is that the end of its fifth line segment 65 is first end 31, and the tenth line segment The end of 75 is the third end 41, and the second end 32 is located at the first line segment 61, and the fourth end 42 is located at the sixth line segment 71, so the first end 31 and the third end 41 are adjacent to the straight line L, and the second end 32 is located at the sixth line segment 71. 32 and the fourth end 42 are away from the straight line L. Therefore, the signal feeding section 5 of the second preferred embodiment is shorter and slightly T-shaped; in addition, the lengths of the first line segment 61 and the sixth line segment 71 are also shorter than those of the first preferred embodiment. The rest of the impedance matching circuit 8 and the insulating base 91 are generally similar to those of the first preferred embodiment, so they will not be repeated here.

Finally, it should be further explained that the line segments (including the signal feeding section 5) of the built-in antenna 2 of the present invention are all parallel or perpendicular to each other, but those skilled in the art can deflect one of the line segments without Parallel or perpendicular to achieve the same effect, this should still fall within the scope of the present invention.

In summary, the present invention reduces the volume of the antenna by means of bending, so that the antenna can be applied to electronic devices such as mobile phones and PDAs, and utilizes the symmetrical structure of the first monopole radiation part 3 and the second monopole radiation part 4 Design, and the modulation of the impedance matching circuit 8 enable the built-in antenna 2 to work in the DVB-H frequency band, and has the advantages of ultra-wide bandwidth, good efficiency, and simple design structure, so the purpose of the present invention can indeed be achieved.

The above are only preferred embodiments of the present invention, and should not limit the scope of the present invention, that is, all simple equivalent changes and modifications made according to the contents of the present invention still fall within the scope of the present invention .

Claims (11)

1. built-in antenna comprises:

One first monopole radiation section, have a first end, away from one second end of this first end, and connect one first tortuous radiant section of this first end and this second end;

One second monopole radiation section, structural similarity is in this first monopole radiation section, and section is close to and is symmetrical in a straight line with this first monopole radiation, has one the 3rd end, away from one the 4th end of the 3rd end, and connects one second tortuous radiant section of the 3rd end and the 4th end; And

One signal feed-in section is connected in this first end and the 3rd end,

Contiguous this straight line of this second end and the 4th end wherein, this first end and the 3rd end be away from this straight line,

Wherein this first tortuous radiant section comprises one second line segment that extends towards this rectilinear direction by outward extending one first line segment of this first end, by this first line segment end, one the 3rd line segment that extended towards this first end direction by this second line segment end, one the 4th line segment that is extended towards this rectilinear direction by the 3rd line segment end, and is extended to one the 5th line segment of this second end by the 4th line segment end.

2. built-in antenna according to claim 1, wherein this second tortuous radiant section comprises one the 7th line segment that extends towards this rectilinear direction by outward extending one the 6th line segment of the 3rd end, by the 6th line segment end, one the 8th line segment that extended towards the 3rd extreme direction by the 7th line segment end, one the 9th line segment that is extended towards this rectilinear direction by the 8th line segment end, and is extended to 1 the tenth line segment of the 4th end by the 9th line segment end.

3. built-in antenna according to claim 2, wherein this first and third, five, six, eight, ten line segment is parallel to each other or make one of them deflection not be parallel; And this second, four, seven, nine line segment is vertical with this straight line or make one of them deflection not be vertical.

4. built-in antenna according to claim 3, wherein, the 5th line segment and the tenth line segment spacing each other are less than 3mm.

5. built-in antenna comprises:

One first monopole radiation section, have a first end, away from one second end of this first end, and connect one first tortuous radiant section of this first end and this second end;

One second monopole radiation section, structural similarity is in this first monopole radiation section, and section is close to and is symmetrical in a straight line with this first monopole radiation, has one the 3rd end, away from one the 4th end of the 3rd end, and connects one second tortuous radiant section of the 3rd end and the 4th end; And

One signal feed-in section is connected in this first end and the 3rd end,

Wherein, contiguous this straight line of this first end and the 3rd end, this second end and the 4th end be away from this straight line,

Wherein this first tortuous radiant section comprises one second line segment that extends towards this rectilinear direction by outward extending one first line segment of this first end, by this first line segment end, one the 3rd line segment that extended towards this first end direction by this second line segment end, one the 4th line segment that is extended towards this rectilinear direction by the 3rd line segment end, and is extended to one the 5th line segment of this second end by the 4th line segment end.

6. built-in antenna according to claim 5, wherein this second tortuous radiant section comprises one the 7th line segment that extends towards this rectilinear direction by outward extending one the 6th line segment of the 3rd end, by the 6th line segment end, one the 8th line segment that extended towards the 3rd extreme direction by the 7th line segment end, one the 9th line segment that is extended towards this rectilinear direction by the 8th line segment end, and is extended to 1 the tenth line segment of the 4th end by the 9th line segment end.

7. built-in antenna according to claim 6, wherein this first and third, five, six, eight, ten line segment is parallel to each other or make one of them deflection not be parallel; This second, four, seven, nine line segment is vertical with this straight line or make one of them deflection not be vertical.

8. built-in antenna according to claim 1, more comprise an impedance matching circuit that is connected in this signal feed-in section, in order to match with this second monopole radiation section with this first monopole radiation section, so that built-in antenna can be operated in the DVB-H frequency band.

9. built-in antenna according to claim 8, wherein this impedance matching circuit comprises an electric capacity and an inductance, one end of this electric capacity is connected to the anode of a holding wire, the other end of this electric capacity is connected to this signal feed-in section, one end of this inductance connects this signal feed-in section, the other end ground connection of this inductance.

10. built-in antenna according to claim 1, wherein this first monopole radiation section, this second monopole radiation section and this signal feed-in section are arranged at the insulating body surface of a solid bendingly.

11. built-in antenna according to claim 1, this built-in antenna is applied to handheld electronic device.

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