JPH0511574U - Antenna with filter - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an antenna capable of downsizing a radio device. [Structure] The filter 2 is connected directly below a feeding end of a rod-shaped radiation conductor 4 having a cylindrical dielectric 11 mounted on the outer peripheral surface.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention relates to the structure of a small antenna applied to, for example, a mobile phone. Is.

[0002]

[Prior art]

  As shown in FIG. 2, the conventional portable telephone has a pole antenna on the upper surface of the telephone body 6. 7 is provided so as to project from the pole antenna 7 inside the telephone body 6 near the feeding end. A plexer 8 is provided.

[0003]   The pole antenna 7 is a rod-shaped antenna having a length of about 15 cm. At first, it is made to project from the telephone body 6. Also, the duplexer 8 , A transmit band filter for the transmit signal and a receive band filter for the receive signal. Filter and the transmission signal output from the transmission band filter to the pole antenna 7. And guide the received signal from the pole antenna 7 to the receiving band filter. It is a three-terminal filter having a directional coupling circuit for guiding only. This duplexer -8 is a feeding end of the pole antenna 7 in order to remove unnecessary signals other than transmitted and received signals. It is provided in.

[0004]

[Problems to be solved by the device]

  The pole antenna 7 for a conventional mobile phone is a bar-shaped antenna from the phone body 6. Since it has a protruding structure, it is easily damaged and may injure people. Paul A It may be possible to reduce the size of the antenna 7 by shortening it, but the pole antenna 7 Since the reception sensitivity of is reduced, it cannot be said to be a suitable improvement measure.

[0005]   In addition, the pole antenna 7 should be projected from the telephone body 6 only when the telephone is used. This makes it inconvenient to handle.

[0006]   Moreover, since the pole antenna 7 is an electric field receiving antenna, it is close to a conductor such as a human body. If it is used nearby, there is also a problem that the reception sensitivity decreases.

[0007]   The present invention has been made in view of the above problems, and can reduce reception sensitivity. The antenna element is made smaller and the filter is integrated, which makes it portable. It is an object to provide an antenna with a filter that can reduce the size of a wire machine. It

[0008]

[Means for Solving the Problems]

  In order to solve the above problems, the present invention provides a rod having a cylindrical dielectric member mounted on the outer peripheral surface. A filter is connected just below the feeding end of a rectangular radiation conductor.

[0009]   A duplexer may be used as the filter.

[0010]

[Action]

  According to the present invention, by loading a cylindrical dielectric on the outer peripheral surface of a rod-shaped radiation conductor, The effective wavelength of the resonance frequency of the radiation conductor is shortened, and the dimensions of the antenna element are It will be shorter than the one without dielectric. Therefore, the dimensions of the antenna element The antenna element and the filter are integrally configured to reduce the Enables antenna with antenna.   In addition, the size of the wireless device main unit can be reduced by installing the filter outside the wireless device main unit. It will be possible.

[0011]   Also, by connecting a filter just below the feeding end of the radiation conductor, the antenna element The transmission line between the filter and the filter is the shortest. Also, make sure that the space between the radiating conductor and the The radiating conductor is placed apart from the main body of the radio, and the gain Contribute to improvement.

[0012]

【Example】   FIG. 1 is a perspective view of an essential part showing an embodiment of an antenna with a filter according to the present invention. .   In the figure, 1 is an antenna, 2 is a duplexer, 3 is the antenna 1 and a duplexer. Redo for protecting an antenna with a filter integrally formed with the plexer 2 It is. The antenna 1 has a conductor film 4 formed on the inner peripheral surface of a cylindrical dielectric 11. Of. For example, high-permittivity ceramics are molded into a cylindrical shape, and the inner surface of the silver sheet The antenna 1 is formed by applying a strike and baking. In this example, the cylinder The conductor film 4 formed on the inner peripheral surface of the dielectric body 11 forms a rod-shaped radiation conductor. However, a cylindrical dielectric may be attached to the outer peripheral surface of the rod-shaped conductor.

[0013]   The antenna 1 is fixed to the upper surface of the duplexer 2. Also, ante The power feeding line 5 connected to the conductor film 3 on the inner circumferential surface feeds the na 1 from a proper place on the outer circumferential surface. The power supply line 5 is connected to the input / output end 21 of the duplexer 2. Also , This feed line 5 is an impedance match between the antenna 1 and the duplexer 2. It has been set to an appropriate size in order to take a good measure.

[0014]   The antenna 1 supplies power to the conductor film 4 on the inner peripheral surface directly from the lower surface of the dielectric 11. You may do it. In this case, the feed line 5 is the antenna 1 and the duplexer 2 Since it does not go outside, the structure becomes simple.

[0015]   A transmission signal line 22 and a reception signal line 23 are provided on the lower surface of the duplexer 2. These signal lines 22 and 23 are connected to the receiving circuit (not shown) of the radio main body. It is like this.

[0016]   As described above, the antenna 1 has a rod-shaped radiating conductor, that is, a cylinder on the outer peripheral surface of the conductor film 4. The dielectric conductor 11 is loaded, and the dielectric 11 causes the resonance circumference of the radiation conductor 4 to The effective wavelength with respect to the wave number is shortened. Therefore, the same resonance frequency The size of the radiation conductor 4 is smaller than that of the unloaded dielectric body 11. .

[0017]   The shortening rate of the radiation conductor 4 is determined by the relative permittivity of the dielectric body 11 to be loaded. Realize an antenna 1 with a length of approximately 2 cm by using ceramics with a high dielectric constant. It is possible. Also, as a small duplexer 2, it is currently about 3 cm long. It is known that the duplexer 2 and the antenna 1 with a length of 2 cm are If combined, an antenna with a filter having a length of about 5 cm is possible.

[0018]   Conventionally, the monopole antenna of a mobile phone has a size of about 15 cm. Therefore, according to the present invention, it can be shortened to about 1/6 as compared with this.

[0019]   It should be noted that although the cylindrical dielectric 11 is used in the above-described embodiment, the dielectric 11 is cut off. The surface shape is not limited to this, and may be an ellipse, a polygon, or the like. Well Also, in the case of a reception-only radio, a normal filter is used instead of the duplexer 2. You may use.

[0020]

[Effect of device]

  As described above, according to the present invention, a dielectric is attached to the outer peripheral surface of a rod-shaped radiation conductor. Since the size of the radiation conductor is shortened by wearing the antenna, the antenna can be downsized. In addition, the antenna can be fixed to the main body of the radio, and There is no need to take in and out the tena.

[0021]   Also, since the filter is connected just below the feeding end of the radiation conductor, the filter is Since it is provided outside the body, the size of the wireless device main body can be reduced.

[0022]   In addition, the radiation conductor is placed away from the main body of the radio because of the presence of the filter. Therefore, the radiation gain is improved.

[0023]   Also, the one equipped with a duplexer can be used as a transceiver for both transmission and reception. Wear.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part showing an embodiment of an antenna with a filter according to the present invention.

FIG. 2 is a schematic configuration diagram of an antenna of a conventional mobile phone.

[Explanation of symbols]

1 antenna 2 duplexer 3 radome 4 Conductor film 5 power lines 11 Dielectric 21 Input / output end 22 Transmission signal line 23 Signal line for reception

Claims (2)

[Scope of utility model registration request] 1. An antenna with a filter, characterized in that a filter is connected directly below the feeding end of a rod-shaped radiation conductor having a cylindrical dielectric member mounted on the outer peripheral surface. 2. The antenna with a filter according to claim 1, wherein the filter is a duplexer.