JP3146187U - Chip antenna - Google Patents

Abstract

Provided is a chip antenna that is small in size and retains a necessary frequency band and can obtain an ideal radiation effect.
A substrate including a first surface, a second surface, a first end surface and a second end surface located between both surfaces, and the first surface of the substrate is formed. A chip antenna including a radiating metal piece 2 extending to the side surface and a ground metal piece 3 formed in the substrate body, wherein the first surface 11 and the second surface 12 face each other, and the first end face 13 and the first antenna 13 The two end faces are also opposite, and both ends of the radiant metal piece 2 are connected to the signal input terminal and the ground terminal to form a circuit, and the ground metal piece 3 is opposite to the radiant metal piece 2 and has a coupling effect between them. The frequency, frequency band, and impedance matching are adjusted by adjusting the distance between the ground metal piece 3 and the radiant metal piece 2.
[Selection] Figure 1

Description

  The present invention forms a loop type antenna using one terminal of the radiating metal piece as a signal input terminal and a grounding terminal, and utilizes a grounding metal piece provided in an antenna substrate capable of adjusting a relative distance from the radiating metal piece, The present invention relates to a coupling loop type chip antenna that obtains a coupling effect with a radiating metal piece.

  Impedance Matching is one of the elements that should be emphasized in antenna design. When the impedance of the system and the impedance of the antenna match, the signal is efficiently transmitted without being reflected from the system side to the antenna side, and the signal transmission efficiency is maximized. This state is called “impedance matching”. If the impedance of the system and the impedance of the antenna do not match, a part of the signal is reflected on the antenna side and returned to the system side. This state is referred to as “impedance matching is not achieved”. The greater the difference in impedance between the two, the greater the energy of the reflected signal. When the impedance is set to 500 ohms when designing the antenna, the impedance matching becomes better as the impedance between the system and the antenna becomes closer to 500 ohms.

  Since a small antenna is affected by its own volume, gain and radiation efficiency are not so good. Further, in order to improve the shortage of the frequency band of the small antenna, as shown in Patent Document 1 below, a technique called “a microstrip structure capable of increasing the frequency band” has been filed (see FIG. 10). In this structure, a metal ground plate is attached to one side in the form of a metal microstrip on one substrate, and a radiating metal piece is attached to the other side in the form of a metal microstrip. The sizes of the metal ground plate and the radiating metal piece are both smaller than the substrate. One micro strip is extended along the edge of the substrate from a position close to the center of the edge of the one side surface to serve as a radio signal input line of the micro strip antenna. Adjacent to the connection point with the microstrip line on the radiating metal piece, one slit is formed on one side along the microstrip line, and the route of the current passing over the microstrip antenna is directed in this one direction. As long as detour.

  This microstrip line system is intended to improve the coupling and frequency band by adjusting the impedance capacitively or inductively, but it does not provide the ideal effect that is technically satisfactory. The manufacturing process is also complicated.

Also, Patent Documents 2 and 3 below disclose technologies related to chip antennas. These techniques achieve the “coupling” effect of an antenna with one dielectric substrate and two radiation electrode layers separated by a gap formed on the substrate surface. The degree of coupling is determined by the size of the gap between the radiation electrode layers, and the degree of impedance matching and the frequency band are determined. In order to obtain an ideal frequency and frequency band, the gap between the radiation electrode layers cannot be made too large, and if it is too small, the manufacture becomes difficult. In addition, the size of both radiation electrode layers is also related to the frequency, and in order to obtain a general commercial frequency, the area of the radiation electrode layer must be increased. The purpose of making it light, thin, short and small will not match.
Taiwan Patent Publication No. 1256751 Specification US Pat. No. 6,323,811 US Patent Application Publication No. 2007/0152885

  In light of the above-mentioned drawbacks, the inventor of the present application has succeeded in developing the chip antenna according to the present invention as a result of further hard work based on many years of technical experience in order to improve this drawback. It came to.

  The main object of the present invention is to provide a chip antenna that can achieve an ideal radiation effect while a miniaturized antenna maintains its required frequency band.

  Further, a short circuit is formed on the radiating metal piece of the chip antenna with the signal input terminal and the ground terminal, and the radiating surface of the antenna is not limited to the surface of the antenna itself, and the radiating metal piece, the grounding surface in the vicinity thereof, and the grounding metal surface 3 The present invention provides a chip antenna that can be expected to improve the radiation efficiency by expanding the radiation surface, not only the antenna itself, but also extending the radiation surface of the antenna to the ground surface. Another purpose.

  In addition, a grounding metal piece that can be coupled to the radiating metal piece is provided. When the grounding metal piece is parallel to the radiating metal piece, a capacitive coupling is performed between them, and the impedance of the slightly inductive antenna is reduced to about 500 ohms. It is still another object of the present invention to provide a chip antenna that can obtain a desired frequency band even if the antenna is adjusted and downsized.

  In order to achieve the above object, the present invention uses a non-conductive substrate or air as the material interposed between the radiating metal piece and the ground metal piece of the chip antenna, and appropriately modifies the dielectric constant of the substrate. Then, by adjusting the area where the radiating metal piece and the ground metal piece overlap and the distance between them, the degree of coupling of the chip antenna is changed, the value of equivalent capacitance is determined, and the capacitance value related to this frequency is After the frequency is determined, a chip antenna that can be determined by size and thereby effectively reduce the size is provided.

  In light of the above configuration, the chip antenna according to the present invention reliably retains the necessary frequency band and can achieve ideal impedance matching and radiation effect. In addition to being creative in its form, it can add many functions as compared to conventional antennas, and sufficiently meets the requirements of the utility model registration claim having novelty and inventive step.

  Detailed features, advantages, and applications of the chip antenna according to the present invention will be described below as embodiments with reference to the drawings attached to the specification.

  An antenna according to the present invention is shown in FIG. The coupling loop type chip antenna includes a substrate 1, a radiating metal piece 2, and a ground metal piece 3. The substrate 1 includes a first surface 11, a second surface 12, a first end surface 13, and a second end surface 14. The first surface 11 and the second surface 12, and the first end surface 13 and the second end surface 14 are opposed to each other. ing. The first end surface 13 and the second end surface 14 form the side surface of the substrate 1.

  The radiating metal piece 2 is formed on the first surface 11 of the substrate 1 or the upper part in the substrate body, and the end thereof includes a signal input terminal F and a ground terminal G as shown in FIG. The ground metal piece 3 is formed in the main body of the substrate 1.

  As shown in FIG. 3, the radiating metal piece 2 and the ground metal piece 3 do not contact each other and hold an appropriate distance d in parallel. If the signal input terminal F of the radiating metal piece 2 and the ground terminal G are connected to the circuit board to form a closed loop circuit, a capacitive coupling effect is provided between the radiating metal piece 2 and the grounding metal piece 3. Occurs (ie C = εA / d). This effect is inversely proportional to the distance d between the two metal pieces and directly proportional to the size of the area A between the two metal pieces.

  The above state is shown in the graph of FIG. The curve represented by the slightly thin dotted line on the right side shows the relationship between the frequency and impedance when only the radiating metal piece 2 having the signal input terminal F and the ground terminal G is installed. In this case, the resonance frequency is as high as 2.75 GHz, indicating that the degree of impedance matching of the antenna is low. The curve represented by the thick solid line on the left shows the relationship between the frequency and the impedance when the ground metal piece 3 to be coupled to this is attached below the radiating metal piece 2. In this case, the resonant frequency effectively drops to 1.07 GHZ, indicating that the antenna impedance matching is better maintained.

  Referring to the graph showing the measurement results of FIG. 5, the radiant metal piece 2 and the ground metal piece 3 become smaller as the distance d becomes smaller due to the change in the distance d between the radiant metal piece 2 and the ground metal piece 3. The capacitance between and becomes larger, the resonance frequency becomes lower, and the impedance matching performance of the antenna becomes better.

  Referring to FIG. 6, when the chip antenna according to the present invention is attached to the circuit board 100, the radiating metal piece 2 above the first surface 11 is mainly extended to the first end face 13 of the substrate 1, and the signal input terminal F is connected to the circuit board 100. The ground terminal of the circuit board 100 is connected to the ground terminal G 1 of the radiating metal piece 2. The ground metal piece 3 is connected to the ground terminal G2 of the circuit board 100 and grounded.

  In the present embodiment, the radiating metal piece 2 is in the form of an L-shaped radiating metal piece 4 </ b> A and extends to the first end face 13 of the substrate 1 in addition to the horizontal radiating metal piece 41 formed on the first surface 11 of the substrate 1. When the radiating metal piece 4A is connected to the signal input terminal F and the ground terminal G1 of the circuit board 100 through the vertical radiating metal piece 42, the radiating metal piece 4A contacts the radiating surface. A loop antenna is formed by extending to the ground. The ground metal piece 4B is in the form of a flat piece formed in the substrate 1, and the end of the ground metal piece 4B extends downward along the substrate 1 and is connected to the ground terminal G2 of the circuit board 100. In this configuration, the distance between the radiating metal piece 4A and the ground metal piece 4B is changed to adjust the frequency band of the antenna and the degree of impedance matching.

  In addition, as shown in FIG. 6C, after the radiating metal piece 4A is formed on the top of the substrate 1, the vertical radiating metal piece extends to the side of the substrate 1, or in FIG. 6B. As shown, the antenna body part or all is covered with a protective layer 20 to prevent damage during manufacture of the antenna circuit. This configuration can also be applied to other embodiments.

  Still another embodiment will be described below with reference to the drawings.

  As shown in FIGS. 7A and 7B, the radiating metal piece of the coupling loop type chip antenna according to another embodiment of the present invention is divided into three-stage bent radiating metal pieces 5A, and is formed on the first surface of the substrate. The first horizontal radiating metal piece 51 formed, the vertical radiating metal piece 52 formed at one end of the first horizontal radiating metal piece 51, and the vertical radiating metal piece 52 in succession. 2nd horizontal radiation metal piece 53 formed in the lower end. A first horizontal radiating metal piece 51 is connected to one edge of the first surface of the substrate, and a signal input terminal F and a ground terminal G are provided at this connection point. The second horizontal radiating metal piece 53 and the first horizontal radiating metal piece 51 are parallel to each other, and the ground metal piece 5B provided on the second surface of the substrate is also parallel to each other. With this configuration, the radiating metal piece 5 </ b> A has a curved structure formed by the first horizontal radiating metal piece 51, the vertical radiating metal piece 52, and the second horizontal radiating metal piece 53, and its radiation surface can be extended to some extent. The frequency band and the degree of impedance matching can be adjusted by changing the distance between the second horizontal radiating metal piece 53 and the ground metal piece 5B.

  As shown in FIGS. 8A and 8B, the radiation metal piece in another embodiment of the chip antenna according to the present invention is a three-stage curved radiation metal piece 6A, and the first horizontal radiation metal piece 61 in the first stage. Is formed on the first surface 11 of the substrate, the second-stage vertical radiating metal piece 62 is formed on the side end surface 13 of the substrate, and the third-stage second horizontal radiating metal piece 63 is formed on the second surface 12 of the substrate. The ground metal piece 6 </ b> B is formed between the first horizontal radiating metal piece 61 and the second horizontal radiating metal piece 63. In this configuration, the distance between the ground metal piece 6B and the second horizontal radiating metal piece 63 is changed to change the frequency band of the antenna and the degree of impedance matching.

  As shown in FIGS. 9A, 9B, and 9C, the radiating metal piece 8A of the chip antenna body according to another embodiment of the present invention includes a first horizontal radiating metal piece 81 formed on the first surface of the substrate, and It includes a vertical radiating metal piece 82 formed on the side surface. The vertical radiating metal piece 82 is provided with a signal input terminal F and a grounding terminal G. The grounding metal piece 8B is located below the radiating metal piece 81 in an aerial state, and the grounding piece 83 is connected to the side surface of the substrate from one end thereof. The grounding piece 83 is separated without contacting the grounding terminal G of the radiating metal piece 8A.

  The above detailed description is a specific description of possible embodiments of the present invention. However, these embodiments do not limit the technical scope defined by the claims of the utility model of the present invention, and further, the same effects can be achieved without departing from the technical spirit of the present invention. All implementations or changes are included within the scope of the utility model registration claim of the present invention.

  The present invention can be applied to a small chip antenna.

FIG. 3 is an exploded view of a radiating metal piece and a ground metal piece formed on a substrate of a chip antenna according to the present invention. It is a top view of the radiation metal piece of the chip antenna which concerns on this invention. It is a schematic block diagram which shows the relative position of the radiation metal piece and ground metal piece of the chip antenna which concerns on this invention. It is a figure which shows the frequency fluctuate | varied by whether a grounding metal piece is provided below the radiation metal piece of the chip antenna which concerns on this invention. It is a figure which shows the frequency fluctuate | varied by the change of the relative distance of the radiation metal piece and grounding metal piece of the chip antenna which concerns on this invention. It is a schematic block diagram which shows embodiment of the radiation metal piece and ground metal piece which were formed on the board | substrate of the chip antenna which concerns on this invention. It is a schematic block diagram of the protection structure of the chip antenna which concerns on this invention. It is a schematic block diagram of the other protection structure of the chip antenna which concerns on this invention. It is a schematic block diagram in other embodiment of the chip antenna which concerns on this invention. It is a longitudinal cross-sectional view of FIG. 7A. It is a schematic block diagram of the other protection structure of the chip antenna which concerns on this invention. It is a longitudinal cross-sectional view of FIG. 8A. It is a schematic block diagram in other embodiment of the chip antenna which concerns on this invention. It is a longitudinal cross-sectional view of FIG. 9A. FIG. 9B is a side view of FIG. 9A. It is a figure where it uses for description of the prior art.

Explanation of symbols

1 substrate,
2 radiation metal pieces,
3 Ground metal piece,
11 first surface;
12 second surface,
F signal input terminal,
G Ground terminal,
100 circuit boards,
4A L-shaped radiation metal piece,
41 Horizontal radiation metal piece,
42 vertical radiating metal pieces,
4B Ground metal piece,
5A Three-stage curved radiation metal piece,
51 1st horizontal radiation metal piece,
52 vertical radiating metal pieces,
53 Second horizontal radiation metal piece,
5B Ground metal piece,
6A Three-stage curved radiation metal piece,
61 1st horizontal radiation metal piece,
62 vertical radiating metal pieces,
63 second horizontal radiation metal piece,
6B Ground metal piece,
8A radiation metal piece,
81 1st horizontal radiation metal piece,
82 vertical radiating metal pieces,
8B Ground metal piece,
83 Ground strip.

Claims (10)

A chip antenna,
The antenna body is
A substrate including a first surface, a second surface and a side surface;
A radiation metal piece formed on the first surface of the substrate;
A ground metal piece formed inside the substrate;
Including
The radiation metal piece has a signal input terminal for inputting a signal and a ground terminal for grounding,
The chip antenna according to claim 1, wherein the ground metal piece maintains a certain distance from the radiation metal piece to obtain a coupling effect.   2. The chip antenna according to claim 1, wherein the radiating metal piece is formed in a substrate, and at least a part of the antenna body is covered with a protective layer.   2. The chip according to claim 1, wherein the radiating metal piece of the antenna body is formed on the first surface and the side surface of the substrate at the same time, and constitutes a horizontal radiating metal piece and a vertical radiating metal piece, respectively. antenna.   4. The chip according to claim 3, wherein the horizontal radiating metal piece and the vertical radiating metal piece of the radiating metal piece are both formed in a substrate, and at least a part of the antenna body is covered with a protective layer. antenna.   The radiating metal piece of the antenna body is formed on the first surface, the side surface, and the second surface of the substrate at the same time, and the ground metal piece is composed of the radiating metal piece on the first surface and the radiating metal piece on the second surface. The antenna according to claim 1, wherein the antenna is provided in an aerial state between the antennas.   6. The chip antenna according to claim 5, wherein the radiating metal piece is formed in a substrate, and at least a part of the antenna body is covered with a protective layer.   The radiation metal piece of the antenna body includes a first horizontal radiation metal piece formed on a first surface of a substrate, a vertical radiation metal piece connected to one end of the first surface radiation metal piece, and the vertical radiation metal piece. The chip antenna according to claim 1, further comprising: a second horizontal radiating metal piece extending from one end of the chip antenna.   8. The chip antenna according to claim 7, wherein the radiating metal piece is formed in a substrate, and at least a part of the antenna body is covered with a protective layer. The radiating metal piece of the antenna body includes a first horizontal radiating metal piece formed on the first surface of the substrate, and a vertical radiating metal piece formed on the side surface of the substrate,
2. The chip antenna according to claim 1, wherein the ground terminal of the vertical radiating metal piece and the ground terminal of the ground metal piece are located on the side surface of the substrate without contacting each other.   The chip antenna according to claim 9, wherein the radiating metal piece is formed in a substrate, and at least a part of the antenna body is covered with a protective layer.