JP3261628B2 - antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna suitable for use in radio equipment used for portable telephones, automobile telephones, etc., and more particularly to an antenna combining a quarter-wave radiation element and a half-wave radiation element. It is.

[0002]

2. Description of the Related Art FIG. 6 is a diagram showing an example of a helical half-wavelength radiation element 103 using a conventional matching circuit 101. As shown in FIG.

FIG. 7 shows a conventional 波長 wavelength radiating element 10.
5 and the extendable 波長 wavelength radiating element 107 are combined.
FIG. 1 is a diagram illustrating an example of an antenna that feeds power to a two-wavelength radiation element 107 (Japanese Patent Application Laid-Open No. 54-52450). However, a plastic mold portion surrounding the helical conductor is omitted.

[0004] In the case of this antenna, the expansion process of the 1/2-wavelength radiating element 107 (the state in FIG. 7 (b)), the 1
Power is supplied to the 素 子 wavelength radiating element 107 by capacitive coupling via the 波長 wavelength radiating element 105. At this time, the 波長 wavelength radiating element 105 is made to function as a resonance circuit and a matching circuit, so that Broadband frequency characteristics due to double resonance of the radiating element 105 and the half-wavelength radiating element 107 and high radiation efficiency due to a matching circuit with small matching loss are realized.

On the other hand, in the case of this antenna, the electrical length of the 波長 wavelength radiating element 105 is approximately １ ／ wavelength with respect to the wavelength corresponding to the frequency to be used. Also one
The 波長 wavelength radiating element 107 is fed by electric field coupling from the 波長 wavelength radiating element 105 as described above.
At this time, as described above, when the electrical length of the 波長 wavelength radiating element 105 is approximately １ ／ wavelength with respect to the wavelength corresponding to the frequency to be used, 、 wavelength as viewed from the feeding point In order to match the input impedance of the entire antenna composed of the radiating element and the 波長 wavelength radiating element to a desired value, the electrical length of the 波長 wavelength radiating element 107 is
About 1/2 wavelength was required for the wavelength corresponding to the frequency to be used.

[0006]

In the conventional example as shown in FIG. 6 , an LC resonance circuit 101 is generally used as a matching circuit, but the LC resonance circuit 101 has an electrical length of about 1/2 wavelength.
Since the input impedance of the two-wavelength radiating element 103 is very high at several hundreds of ohms, a resonance circuit having a considerably high Q must be formed in order to match a feed line of, for example, 50 ohms. In addition to the narrow band, there is a problem that the radiation efficiency of the antenna is significantly deteriorated due to an increase in matching loss.

In the antenna as shown in FIG. 7 invented to solve the above problem, the １ ／ wavelength radiating element 107 is pulled into the housing 108 and the 波長 wavelength radiating element
7 (a), a certain amount of gain is required over the operating frequency band.
The physical length of the half-wave radiating element 107 is required when the dimensions of the entire wireless device including the antenna at the time of extension are to be kept constant. However, there is a problem that is necessarily limited. Therefore, the resonance frequency bandwidth of the 波長 wavelength radiating element 107 becomes narrower, for example, when the operating frequency band of a 800 MHz band mobile phone or the like is wide, and when the human body inherent to the 波長 wavelength radiating element 107 comes close. There is a problem in that it is difficult to obtain a feature that the radiation characteristic is less deteriorated over the entire use frequency band.

[0008] 1/4 wavelength emission element shown in FIG. 7 105
In the antenna in which the と wavelength radiating element 107 is combined with the 波長 wavelength radiating element 107, the electrical length of the ４ wavelength radiating element 105 is approximately １ ／ wavelength with respect to the wavelength corresponding to the frequency to be used. In this case, when a human body approaches when using this antenna, the peak frequency of resonance of the 波長 wavelength radiating element 105 becomes slightly lower, so that matching cannot be achieved and radiation efficiency is significantly reduced. .

The electrical length of the quarter-wavelength radiating element 105 is approximately 1 to the wavelength corresponding to the frequency used.
In the case of 波長 wavelength, in order to match the input impedance of the entire antenna composed of the ４ wavelength radiating element 105 and the 波長 wavelength radiating element 107 from the feed point to a desired value, 1 / Since the electrical length of the two-wavelength radiating element 107 is required to be about １ ／ wavelength with respect to the wavelength corresponding to the frequency to be used, the external dimensions of the antenna become large, which is inconvenient to carry. there were.

[0010] The present invention has been made in view of the above points, and an object of the present invention is to use it for a wireless device such as a mobile phone or a car phone, which has a wide-band frequency characteristic and has little deterioration of characteristics due to a human body. It is to provide an optimal antenna.

[0011]

[0012]

In order to solve the above-mentioned problems, an antenna according to the first aspect of the present invention comprises a half-wavelength radiating element having an electrical length of about half a wavelength and a housing for a radio device. The half-wavelength radiating element is provided so as to protrude from the body, and power is supplied to the half-wavelength radiating element by electromagnetic coupling from a planar resonant circuit having an electrical length of 波長 wavelength spirally wound,
Further, the resonance circuit is provided on a lower surface of a portion of the housing of the wireless device where the half-wavelength radiating element protrudes, and a spiral surface thereof is parallel to a surface where the half-wavelength radiating element protrudes from the wireless device. And a part of the resonance circuit.
A cover member is provided so as to cover the wireless communication device, and a shielding material for shielding an internal circuit of the wireless device is formed on a lower surface of the cover portion.

Further, the antenna according to the first invention of the present application has the following configuration.
1/2 wavelength radiating element having an electrical length of around 1/2 wavelength
Is provided protruding from the housing of the wireless device, and the half-wavelength radiation
The power supply to the element is a 1/4 wavelength spiral wound coil.
Electromagnetic field coupling from a planar resonant circuit
Therefore, the spiral resonance circuit was further formed.
A substrate, the half-wavelength radiating element of the housing of the wireless device;
The spiral surface is on the lower surface side of the protruding part
For the surface where the half-wavelength radiating element protrudes from the wireless device
Install it so that it is parallel to
Metal material and a ground conductor provided on the back surface of the substrate.
It is characterized by being connected by a material.

[0014]

According to the first aspect of the present invention, the high-frequency power applied to the spiral resonant circuit resonates in the resonant circuit and is supplied to the half-wavelength radiating element coupled by electromagnetic coupling. . At this time, by adjusting the positional relationship and distance between the two, the impedance characteristics of the double resonance of the resonance circuit and the half-wavelength radiating element viewed from the feeding point can be adjusted. Therefore, a wide-band frequency characteristic by the double resonance and a high radiation efficiency by a matching circuit with a small matching loss can be obtained. Also, since the resonance circuit is formed in a spiral and planar shape, the height dimension can be made very small, and the physical length of the half-wavelength radiating element can be made relatively long, so that the resonance frequency bandwidth is increased. The radiation characteristics can be reduced when the human body approaches over a wide frequency band.

[0015]

[0016]

[First invention]

FIG. 1 is a view showing one embodiment of an antenna according to the first invention of the present application. As shown in FIG.
A 波長 -wavelength radiation element 11 wound in a helical shape and a 波長 -wavelength spiral element (resonance circuit) 13 having an electric length of １ ／ -wavelength wound in a spiral shape are provided. It is composed by combining them.

Here, the 1/4 wavelength spiral element 13
Is disposed at a position where the spirally wound plane is perpendicular to the longitudinal direction of the half-wavelength radiation element 11. In other words, the quarter-wave spiral element 13
Are arranged in parallel to the plane where the half-wavelength radiating element 11 protrudes from the radio.

At this time, the 1/4 wavelength spiral element 1
The high frequency power applied to 3 resonates in the 1/4 wavelength spiral element 13 and is coupled to the 1/2 wavelength radiating element 11 placed at an appropriate distance by electromagnetic field coupling and supplied. At this time, the 1/4 wavelength spiral element 13
By adjusting the positional relationship and the distance between the 波長 wavelength radiating element 11 and the 波長 wavelength radiating element 11, it is possible to adjust the impedance characteristic of the double resonance of the 波長 wavelength spiral element 13 and the み wavelength radiating element 11 from the feed point. it can.

Therefore, with the above-described configuration, a wide-band frequency characteristic due to double resonance of the quarter-wave spiral element 13 and the half-wave radiation element 11, and a high radiation efficiency due to a matching circuit with a small matching loss are obtained. Is obtained.

Further, since the quarter-wave spiral element 13 is formed in a planar shape, the height dimension can be made very small, so that the physical length of the half-wave radiation element 11 is relatively reduced. Therefore, the resonance frequency bandwidth of the 波長 wavelength radiating element 11 is widened, and deterioration of radiation characteristics when a human body approaches over a wide frequency band can be reduced.

FIG. 2 is a view showing another embodiment of the first invention of the present application. This embodiment differs from the first embodiment in that the １ ／ wavelength spiral element 13 shown in FIG.
The point is that the spirally wound surface of the 波長 wavelength spiral element 23 having the same structure as that of と is disposed at a position parallel to the longitudinal direction of the 波長 wavelength radiation element 11. In other words, the quarter-wave spiral element 13 is arranged so that its surface is perpendicular to the surface where the half-wave radiation element 11 protrudes from the radio.

FIGS. 3A and 3B are views showing one specific configuration example of the quarter-wave spiral element 33 used in the present invention. FIG. 3A is a plan view, and FIG. It is AA sectional drawing of. As shown in FIG.
The four-wavelength spiral element 33 is provided on a dielectric substrate 35. In the figure, the feed point to the quarter-wave spiral element 33 may be the end point 37 at the outer peripheral portion of the spiral, the end point 37 'at the center, or a point between them. This is the same in other embodiments. If the quarter-wave spiral element 33 is provided on the dielectric substrate 35 as described above, it is not necessary to wind a coil, so that the manufacture thereof becomes easy.

FIG. 4 is a view showing still another embodiment of the first invention of the present application. In this embodiment, a quarter-wave spiral element 43 is formed on the lower surface of a molding material 41 constituting a casing of a wireless device, and a cover 45 integrated with the molding material 41 is provided so as to cover the portion. A shield material 47 is applied to the lower surface, and a helical half-wave radiation element 42 is disposed on the upper surface of the mold material 41.

FIG. 5 is a view showing still another embodiment of the first invention of the present application, in which a quarter-wave spiral element 49 is formed on a flexible printed board or dielectric substrate 51 and applied to the back surface of a molding material 53. The shield member 55 and the ground conductor 57 provided on the back surface of the flexible printed board or the dielectric substrate 51 are connected by a metal member 59. The half-wave radiation element 52 is provided on the upper surface of the molding material 53.

In each of the above-described embodiments, a helical element is used as the radiating element having a wavelength of about 1/2 wavelength. However, the present invention is not limited to a linear element or an element formed by combining a helical and a straight line. It goes without saying that the present invention can be applied to an element.

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

As described above in detail, the antenna according to the present invention has the following excellent effects. A 1 / 2-wavelength radiating element is wound spirally.
When power is supplied from a resonance circuit having an electrical length of four wavelengths by electromagnetic field coupling, a spirally wound 1
Since a resonance circuit having an electrical length of 波長 wavelength functions as a resonance circuit and a matching circuit,
Broadband frequency characteristics due to double resonance of wavelength radiating element,
High radiation efficiency can be obtained by a matching circuit with a small matching loss.

Further, since the resonance circuit is formed in a spiral and planar shape, the height dimension can be made very small, so that the physical length of the half-wavelength radiation element is made relatively long. Therefore, the resonance frequency bandwidth of the 波長 wavelength radiating element is widened, and deterioration of the radiation characteristics when a human body approaches over a wide frequency band can be reduced.

Further, since power is supplied from the resonance circuit having an electrical length of １ ／ wavelength to the 波長 wavelength radiating element by electromagnetic field coupling, a positional relationship between the resonance circuit and the 波長 wavelength radiating element is provided. If the distance is adjusted, the degree of freedom of the configuration is high and the restrictions on other components of the wireless device such as a mobile phone or a car phone are reduced, so that the design of the wireless device such as a mobile phone or a car phone is easy. become.

[0036]

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of an antenna according to a first invention of the present application.

FIG. 2 is a diagram showing another embodiment of the first invention.

FIG. 3 is a quarter-wave spiral element 3 used in the first invention.
FIG. 3 is a diagram showing one specific configuration example of No. 3;

FIG. 4 is a diagram showing still another embodiment of the first invention.

FIG. 5 is a view showing still another embodiment of the first invention.

FIG. 6 shows a helical 1 using a conventional matching circuit 101;
FIG. 3 is a diagram illustrating an example of a half-wavelength radiation element 103.

FIG. 7 is expandable and contractible with a conventional quarter-wave radiation element 105.
One of the antennas combining the half-wavelength radiation element 107
It is a figure showing an example.

[Explanation of symbols]

11, 42, 52 1/2 wavelength radiation element 13, 23, 33, 43, 49 Resonant circuit (1/4 wavelength spiral element)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-271701 (JP, A) JP-A-54-52450 (JP, A) JP-A-5-275919 (JP, A) JP-A 53-524 84546 (JP, A) Japanese Utility Model Application Hei 4-85841 (JP, U) Japanese Utility Model Publication No. 51-39470 (JP, Y1) European Patent Application Publication 511577 (EP, A1) (58) Fields investigated (Int. ⁷ , DB name) H01Q 11/08 H01Q 9/30

Claims (2)

(57) [Claims] 1. An electric device having an electrical length of about 1/2 wavelength.
A half-wave radiation element is provided protruding from the housing of the wireless device,
The power supply to the 波長 wavelength radiating element is performed by electromagnetic field coupling from a planar resonant circuit having an electrical length of １ ／ wavelength spirally wound, It formed so as to be parallel to the plane in which the said resonant circuit half-wavelength radiating element to the lower surface of the portion projecting its spiral face the half-wave radiating element protrudes from the wireless device, wherein Resonant circuit part
Antenna, characterized in that minute a cover portion to cover by forming a shielding member to shield the internal circuit of the wireless device to the underside of the cover portion. 2. An element having an electrical length of about 1/2 wavelength.
A half-wave radiation element is provided protruding from the housing of the wireless device,
The power supply to the 波長 wavelength radiating element is performed by electromagnetic field coupling from a planar resonant circuit having an electrical length of １ ／ wavelength spirally wound, and a substrate on which the resonant circuit is formed. On the lower surface side of the portion of the housing of the wireless device where the half-wavelength radiation element protrudes, the spiral surface is parallel to the surface where the half-wavelength radiation element protrudes from the wireless device. And a shield member formed on the back surface of the housing and a ground conductor provided on the back surface of the substrate are connected by a metal member.