JPS61123303A - Antenna of small-sized radio equipment - Google Patents

Abstract

PURPOSE:To attain miniaturization by isolating a power battery of a radio equipment section in terms of high frequency from ground of the radio equipment section so as to use the battery case as an antenna element thereby eliminating the need for an exclusive use antenna element. CONSTITUTION:A case bottom 2b of a battery 2 is connected to the ground of a radio receiver 7a via a high frequency blocking choke coil 6 via a connecting metal fixture 5a and a lead wire 5. On the other hand, a voltage terminal 2a of the battery 2 is connected to a power switch 3c via a connecting metal fixture 3a and a high frequency blocking choke coil 3, grounded through a bypass capacitor 3b to supply power. A cylindrical case 2c of the battery 2 and the voltage terminal are coupled by a low resistance in the inside of the battery and short-circuited by a load resistor when the switch 3c is turned on, and the case 3c is isolated in terms of a high frequency by means of the coil 3 to act like an antenna element.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a small radio device, and particularly to an antenna for a small radio device used in a small pager, a small wireless communication device, and the like.

Conventional configuration and problems thereof Figure 1B shows the type of antenna used in a small radio device. FIG. 1(A) shows a small radio device whose casing is shielded with metal, FIG. 1(A) shows the metal casing, and FIG. 1(B) shows an external linear antenna. FIG. 1(b) shows a radio receiver whose main part is shielded and a small antenna is built into a part of the casing, and the main part of the radio device is metal shielded. (C) is a housing shield part, and (D) is a small antenna. Figure 1 (a) shows an externally attached linear antenna.If you carry it in your pocket like a wireless pager, this external antenna not only gets in the way;
There was a drawback that the gain varied greatly due to changes in the antenna position during use.

In FIG. 1(b), when the loop antenna is built into the radio case, it is necessary to separate it from the shield of the radio by an appropriate distance, which has the disadvantage of increasing the volume.

Purpose of the Invention The present invention eliminates the above-mentioned problems of the prior art, and shields the radio unit to eliminate the influence of interference, and in the case of a transmitter, prevents unnecessary radiation from the housing. Another object of the present invention is to provide an antenna for a small radio device that can obtain an appropriate antenna gain without the need for an antenna.

Structure of the Invention In order to achieve the above object, the present invention isolates a power supply battery that supplies operating power to a radio unit from the ground of the radio unit in terms of high frequency, and uses the battery case as an antenna element. By eliminating the need for a dedicated antenna element and eliminating the space required for the antenna, the wireless device can be made more compact.

DESCRIPTION OF EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows the portions of a small radio device, particularly a small pager used for radio calling, which are relevant to the present invention. Second
In the figure, (A) is a plastic case of a small radio device, 1 is a shield part that houses the radio receiver 7a, 2 is a small battery that supplies operating power to the radio receiver 72L, and connection fittings 3&, which will be described later.

6a and a wireless receiver 7& via a power switch 3C.

FIG. 3 shows a part of the above-mentioned FIG. 2 as an electric circuit.

In FIG. 3, reference numeral 3 denotes a choke coil for high frequency blocking to isolate the voltage terminal 2& of the battery from the radio receiver 7&, and exhibits an appropriate high impedance with respect to the reception frequency. 3& is a connection fitting with the voltage terminal 22L, and 3b is a bypass capacitor. Reference numeral 4 designates a side grounding plate of the shield portion 1 of the receiver, and reference numeral 5 designates a lead wire connecting the cylindrical case of the battery 2 to the receiver input side b, which is connected to the bottom portion 2b of the battery case at the arrow point 6 &. Reference numeral 6 denotes a choke coil for high frequency blocking, one end of which is connected to the ground of the radio receiver, and the contact point 5b with the lead wire 6 is connected to the receiver cuff b. 3C is a changeover switch that changes the power supply to the wireless receiver 7a from ON to 10FF.

Next, the operation will be explained. The case bottom 2b of the battery 2 is connected to the ground of the radio receiver T& by means of a connecting fitting 5a and a lead wire 5 via a high frequency blocking choke coil 6.

On the other hand, the voltage terminal 22L of the battery 2 is connected to the power switch 3C via the connecting fitting 3a and the high frequency blocking choke coil 3, and is also grounded by the bypass capacitor 3b, l'l! Supplies radio receiver TaVc power via J6L switch 3C. The cylindrical case 2C of battery 2 and the voltage terminal are connected with low resistance inside the battery, and when the power switch 3C is at 01, it is short-circuited by the load resistance, but the choke coil/L/3 is connected at high frequency. Since it exhibits high impedance, the cylindrical case 2C of the battery is isolated from the ground in terms of high frequency, becomes a single metal conductor separated from the ground, and operates as an antenna element.

Note that the bottom portion 2b of the cylindrical case 2C of the battery 2 is generally the (-) pole of the battery. The cylindrical case 2C can be one in which product label paper is simply wrapped around the outer periphery of the cylindrical part, or one in which a thin metal label is applied on top of a thin vinyl film, but in the latter case, the inner and outer cylindrical parts have a large capacity. are combined, so
In terms of high frequency, it operates as a single antenna element.

4(M) to (D) are diagrams showing specific configuration examples and modifications thereof corresponding to the equivalent circuit of FIG. 3, and FIG. 4(A) corresponds to almost the same configuration as FIG. 3. , Fig. 4(B) shows an example in which a Ti transformer is used instead of the choke coil 6, and the antenna output is tapped down and inputted to the input terminal 7b of the receiver 7, but of course other transformers may be used as necessary. A bond may also be used. FIG. 4(C) shows an example in which a pair of metal rings h, h2 are provided on the outside of the cylindrical case 2C with a minute interval between them, and a loop antenna is formed between them and the cylindrical case 2C by capacitive coupling.

Although the above description has been made regarding the case where the present invention is used as a radio receiver, the same effect can be obtained when the present invention is used as a radio transmitter such as a radio microphone or a wireless controller for a TV.

In addition, when using a battery as an antenna, the cylindrical case side of the battery is connected to the receiver input side, but this is done by connecting the voltage terminal side of the battery to the coupling capacitor C2 as shown in Figure 4 (F).
may be used to connect to the receiver input. In this case, if the voltage terminal 2a and the case gap 2a are coupled by a capacitor C3, characteristics equivalent to those in (A) and (B) above can be obtained.

As mentioned above, the voltage terminal 2a of the battery and the case bottom 2b
All you have to do is connect it as a power source for the iQ line machine, isolate it from the ground at high frequencies using a conductor such as an inductance, use the entire battery as an antenna element, perform appropriate impedance conversion, and couple it with the high frequency input/output of the radio. .

Effects of the Invention The present invention has the above-described configuration, and provides the following effects.

+a) Since the cylindrical case of the battery is used as the antenna element, no special space is required to install the antenna.

(b) According to the present invention, the wireless section can be completely shielded, which is advantageous in preventing the intrusion of unnecessary waves and unnecessary radiation.

[Brief explanation of the drawing]

Fig. 1 A1 is a diagram showing an antenna of a conventional small radio receiving device, and Fig. 2 is a diagram showing a receiving device incorporating an antenna of a small radio according to an embodiment of the present invention. Machine shield E12...Battery, 3...
・Choke coil, 4... Coupling capacitor, 5
... Choke coil, 6 ... Shield plate, 7 ... Radio receiving section, 8 ... Attached circuit.

Claims (1)

[Claims] When supplying operating power to a small radio from the built-in cylindrical battery for power supply, power is supplied from the battery case and the connection terminal that connects to one or both of the voltage terminals through a choke coil for high frequency blocking. The wires are connected to supply power to the small radio, and at least the connection terminal side that is coupled to the battery case side of the battery terminals is connected to the high frequency circuit of the small radio via a coupling circuit. A small radio antenna that uses a power supply battery as the antenna element.