JP2544725B2 - Loading antenna - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a loading antenna, and more particularly to a loading antenna for a handset type wireless communication device.

[Background Art] Handset type wireless communication device 9 (hereinafter referred to as communication device 9)
As shown in FIG. 3, a main body case 6 having a communication circuit 5 is provided with a loading antenna 7, a receiving speaker 10, a transmitting microphone 11, a call switch 1, and a communication circuit 5. There is. The call switch 1 has a call position and a standby position, and a two-way call can be made at the call position, and a standby state is established while checking communication from other communication devices. Conventionally, the loading antenna 7 of such a communication device 9 is composed of a rod antenna 4 and a loading coil 2 (hereinafter referred to as coil 2), and the inductance value of the coil 2 is fixed. The inductance value of such a coil 2 is determined by the communication device 9
Was determined so that the gain of the loading antenna 7 is maximized when there is no object in close proximity. For example, this inductance value is set to L0. By the way, as shown in FIG. 4, when the communication device 9 is normally used, it is used in the vicinity of the human body of the user, and when it is far from the human body of the user, the communication device 9 is in a standby state. If the communication device 9 is in a standby state and separated from the human body, the gain of the loading antenna 7 becomes the maximum gain as shown in the curve (a) of FIG. The gain of the loading antenna 7 is influenced by the human body of the user as shown in the curve (b) of FIG. 2, and cannot be the maximum gain. That is, since the inductance value is fixed to the inductance value L0, the communication device 9
The gain of the loading antenna 7 becomes the maximum gain M at the inductance value L0 when the communication device 9 is in the stand-by state apart from the human body, but when the communication device 9 is in the communication state close to the human body, the curve (b) in FIG. The gain S corresponds to the inductance value L0. Here, the inductance value corresponding to the maximum gain in the communication state is L1. As described above, the conventional loading antenna 7 obtained the maximum gain in the standby state, but the gain was lowered due to the influence of the human body in the communication state.

Also, the electrolytic strength around the loading antenna 7 during transmission is also affected by the distance between the communication device 9 and the human body. For example, when the inductance value is set to L0 as described above, as shown in FIG. 5, the electric field strength when not held by hand is determined by the curve (c) in FIG. 5, and when held by hand. The electric field strength of is determined by the curve (d) in FIG. The difference between the electric field intensities in the two states is obtained from the electric field intensities of the respective curves (c) and (d) with respect to the inductance value L0, and becomes the difference dI. There is a problem in that the communication device 9 using the conventional loading antenna 7 cannot stabilize the output because the difference in the change in the electric field strength is large and the electric field strength varies.

[Object of the Invention] The present invention has been made in view of the above problems,
It is an object of the present invention to provide a loading antenna that can be carried and used with the maximum antenna gain.

DISCLOSURE OF THE INVENTION A loading antenna of the present invention includes an antenna attached to a body case of a handset type wireless communication device, a loading coil having one end connected to the antenna and the other end connected to a communication circuit, and an outer wall of the body case. Along with a call switch slidably held between the call position and the standby position, and a magnetic core fixed to the call switch and slidably moved together with the call switch into the loading coil , When the call switch is in the standby position, the antenna gain in the free space is maximized, and when the call switch is in the talk position, the antenna gain is maximized in the carrying and used state. It is set and interlocks with the call switch that switches between the call state and the standby state Then, the magnetic core is slid and moved, and the insertion amount of the core to the loading coil is adjusted.
It is possible to maximize the antenna gain both in the possession use state and the standby state placed in the free space.

Embodiment As shown in FIG. 1, a loading antenna 7 of the present invention is provided in a handset type wireless communication device 9 (hereinafter referred to as communication device 9), and is provided on an outer wall of a main body case 6 having a communication circuit 5. A call switch 1 inserted through a slit (not shown) and slidably held along the outer wall, and magnetism that is fixed to the inside of the body case 6 of the call switch 1 and slides with the operation handle of the call switch 1. A core 3 of the body, a rod antenna 4 fixed to the main body case 6 and having one end extending outside the main body case 6, one end electrically connected to the rod antenna 4, and the other end connected to an input end of the communication circuit 5. And the coil 2 provided inside the main body case 6. The communication device 9 is the same as that described in the conventional example except for the configuration of the call switch 1 and the loading antenna 7, and the same description will be omitted. The call switch 1 is slidable between a call position that allows the communication device 9 to perform a two-way call and a standby position that causes the communication device 9 to wait while checking transmission from other communication devices. Has become. One end of the core 3 is inserted into the coil 2, and the coil 2 is fixed such that its extension direction coincides with the moving direction of the core 3 and the call switch 1
One end of the core 3 fixed to the telephone is movable back and forth in the coil 2 along with the call switch 1, and the core 3 when the call switch 1 is in the standby position is the call switch 1
Is inserted deeper into the coil 2 than when it is in the talking position. Therefore, the inductance of the coil 2, that is, the inductance value when the communication switch 1 is in the communication position is smaller than the inductance value when the communication switch 1 is in the standby position.

As shown in the curve (a) of FIG. 2 explained in the conventional example,
The inductance value when the communication switch 1 is in the standby position and the communication device 9 is in the standby state is set to an inductance value L0 such that the antenna gain of the loading antenna 7 can obtain the maximum gain when there is no object near the communication device 9. Has become
The inductance value when the communication switch 1 is in the communication position and the communication device 9 is in the communication state is such that the antenna gain is the maximum gain when the communication device 9 is close to the human body as shown by the curve (b) in FIG. The inductance value L1 is such that That is, with such a configuration, the communication device 9
The loading antenna 7 can maintain the maximum gain regardless of the standby state or the communication state, that is, regardless of the distance between the communication device 9 and the human body.

Reference Example In the above-described embodiment, the inductance value is variable between the state where the hand is not held and the state where the hand is held.
The loading antenna 7 shown in FIG. 6 has a configuration in which a loading coil 2 (hereinafter abbreviated as coil 2) is inserted under a rod antenna 4 and has a fixed inductance value. Quantitatively, as an example, the length A of the loading antenna 7 is 300 mm, the coil has, for example, a winding diameter of 0.6 mm, the number of windings is 17 tightly wound, the coil inner diameter is 6.0 mm, and the operating frequency is 70 MHz. There is. By the way, FIG. 7 shows the result of measurement by changing the electric field strength of the loading antenna 7 by the number of turns of the coil 2. The curve (f) in FIG. 7 shows the electric field strength when the loading antenna 7 is located at a position affected by the human body, and the curve (e) in FIG. 7 shows the electric field strength when the loading antenna 7 is located at a position not affected by the human body. The electric field strength. Here, the numbers of coil turns corresponding to the maximum values of the curves (e) and (f) are 21 and 17, respectively. Number of turns
The 21-time coil has an inductance value that maximizes the antenna gain. In a coil with 21 turns, the difference in electric field strength between the two states is dS, and the number of turns is 17
The coil 2 at the time of rotation is almost equal to the inductance value that maximizes the antenna gain and slightly lower, but the difference in electric field strength is
It becomes ds and is less than dS. That is, with the above-described configuration, the antenna gain is substantially maximized by setting the inductance value below the value corresponding to the maximum gain, and the difference in electric field strength that changes according to the distance from the human body is reduced. It is something.

[Effects of the Invention] The loading antenna of the present invention includes an antenna attached to the body case of a handset type wireless communication device, a loading coil having one end connected to the antenna and the other end connected to a communication circuit, and an outer wall of the body case. Along with a call switch slidably held between the call position and the standby position, and a magnetic core fixed to the call switch and slidably moved together with the call switch into the loading coil , When the call switch is in the standby position, the antenna gain in the free space is maximized, and when the call switch is in the talk position, the antenna gain is maximized in the carrying and used state. It is set and is linked to the call switch that switches between the call state and the standby state. Then, the magnetic core is slid to adjust the amount of insertion of the core into the loading coil.
There is an advantage that the antenna gain can be maximized in both the possession use state and the standby state placed in the free space.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a loading antenna according to an embodiment of the present invention, FIG. 2 is a graph showing a relationship between an antenna gain and an inductance value of a conventional example, FIG. 3 is a schematic view of a handset type wireless communication device, and FIG. Is an explanatory view showing the usage state of the handset type wireless communication device, FIG. 5 is a graph showing the relationship between the electric field strength of the conventional antenna and the number of coil turns, and FIG. 6 is a schematic showing the configuration of the loading antenna of the reference example. Figure, 7th
The figure is a graph showing the relationship between the number of coil turns and the electric field strength in the reference example. Reference numeral 1 is a call switch, 2 is a loading coil, 3 is a core, 4 is a rod antenna, 5 is a communication circuit, 6 is a main body case, 7 is a loading antenna, and 9 is a communication device.

Claims (1)

(57) [Claims] 1. An antenna attached to a main body case of a handset type wireless communication device, a loading coil having one end connected to the antenna and the other end connected to a communication circuit, a call position and a standby position along the outer wall of the main body case. A call switch that is slidably held between the call switch and a magnetic core that is fixed to the call switch and that is slidably moved together with the call switch to be inserted into the loading coil so that the call switch can move forward and backward. The amount of insertion of the core into the loading coil is set so that the antenna gain is sometimes maximized in the free space and the antenna gain is maximized when the call switch is in the call position. And loading antenna.