JPH03141730A - Portable radio equipment - Google Patents

Abstract

PURPOSE:To obtain enough gain when a radio equipment is used while being carried with a human body by providing a switching means for the tuned or untuned state of a loop antenna and increasing the coupling degree of the loop antenna to the human body. CONSTITUTION:A switching means 12 connected to the both ends of a loop antenna 11 is composed of a choke coil L and diode. When a current (i) flows through the coil L to the diode, the impedance of the diode is decreased and a loop is formed by the antenna 11 and the diode. Next, when tuning is executed by a capacitor C for tuning in the loop and the inductance of the loop, an operation as an antenna is obtained. When the diode is not electrified, the loop is not formed and the antenna 11 is not operated as the antenna. The area of a close part 11c to the human body in the antenna 11 is enlarged and the antenna 11 is arranged almost parallelly to the mounting surface of the human body. Then, the metal part of an equipment is used for the part 11c. Thus, when the radio equipment is used while being carried with the human body, the enough gain can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a portable radio device that transmits and receives radio signals and performs control and notification.

[Conventional technology]

2. Description of the Related Art Personal calling devices (commonly known as pagers) are conventionally known as portable radio devices. Generally, this type of device is used in the form shown in FIG. Users M, M2 carry receiving devices R1 and R2, receive radio waves emitted from base station K, and obtain necessary information such as ID code information and control information from data included in the received signal. It is. As shown in FIG.
, a receiving circuit 2, a data identification section 3, a signal processing section 4, a notification display section 5, a power supply section 6, etc., and these are housed in a housing C. Here, the receiving circuit 2 includes the antenna 1
It amplifies and demodulates the radio signal received by
The data identification unit 3 identifies multiple types of information and sends identification data to the signal processing unit 4. In the signal processing section 4,
A signal is generated based on the above data, and the notification display section 5 notifies or displays the signal to the outside using the output signal from the signal processing section 4. The power supply circuit 6 supplies operating voltage to each part.

The example shown in FIG. 7 is a portable wireless device for remote control.

A controlled device E connected to a receiving device M is controlled by a human operating a transmitting device T. As shown in FIG. 8, the transmitting device T includes an operating section 7, a control section 8, a transmitting circuit 9, an antenna 1, and a power supply section 6, which are housed in a housing C. Here, the operation section 7 accepts and accepts operations using operation buttons, etc., and transmits them to the control section 8. The control section 8 generates transmission data based on signals from the operation section 7, and transmits the data to the transmission circuit. It is intended to supply
The transmission circuit 9 modulates and amplifies the transmission data to generate a radio signal and sends it to the antenna l. The power supply circuit 6 supplies operating voltage to each part.

[Problems to be Solved by the Invention] However, in the conventional example described above, a loop antenna is disposed inside the housing A as a transmitting and receiving antenna, and is connected to the transmitting circuit 9 and the receiving circuit 2. When such a radio is placed in close contact with the human body, it is strongly influenced by the human body, and the gain of the antenna may vary depending on how the radio is placed in close contact with the human body, that is, the positional relationship between the radio and the human body. There have been problems in that the directivity may drop or the directivity may change drastically.

The present invention has been made in view of the above points, and an object of the present invention is to provide a portable radio device that can obtain sufficient gain when carried and used on the human body.

[Means to solve the problem]

The present invention provides a portable radio device for wear on the human body which includes a radio circuit and a loop antenna connected to the radio circuit housed in a housing, and includes a switching means for switching the loop antenna between a tuned state and an untuned state. It is characterized by the following:

Furthermore, in the conductor constituting the loop antenna,
The width of the conductor in a portion close to the human body is made wider than other portions and is arranged approximately parallel to the mounting surface of the human body. It is characterized by the use of metal parts of equipment built into the machine.

[Effect]

In the portable radio device of the present invention, the tuning state of the loop antenna can be changed by switching between the case where the loop antenna installed inside the housing is equivalently formed and the case where it is not formed using the switching means. It is possible to switch the synchronization state. In other words, when the gain of the loop antenna decreases due to the positional relationship between the loop antenna and the human body, the switching means makes the loop antenna out of tune and effectively uses the human body as an antenna to compensate for the decrease in gain. be.

Furthermore, in the conductor constituting the loop antenna, the width of the conductor in the part close to the human body is made wider than the other part, and by arranging it so that it is approximately parallel to the surface on which the human body is attached, the conductor and the human body are This strengthens the degree of coupling, allowing the human body to be more effective as an antenna.

Further, by using a metal part of a device built into the radio, especially a relatively wide part, as the conductor part close to the human body, more effective coupling with the human body can be achieved.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. 1st
The figure is a schematic configuration diagram showing an embodiment of the present invention. 11
is a loop antenna, which is formed by forming a band-shaped conductor into a loop. Reference numeral 12 denotes a switching means, which is connected to both ends of the loop antenna 1, and by switching between the two ends to make it conductive or non-conductive, it can make the loop antenna 1 into a tuned state or a non-tuned state. This is a switch. 13 is a transmitting/receiving section;
It consists of a transmitting/receiving circuit 2.9 as shown in the conventional example of FIG. 8, and has a function of comparing data and signal levels in addition to transmitting and receiving data.

FIG. 2 shows an example of the switching means 12. It consists of a choke coil L and a diode D, one end of the choke coil L and the anode of the diode D are connected to one end 11a of the loop antenna 11, and the cathode of the diode D is connected to the other end 11b of the loop antenna 11. Note that a capacitor C with a variable capacitance for tuning is connected within the loop antenna 11. Here, when a current i is passed through the diode D through the choke coil L, the impedance of the diode D becomes low, a loop is formed between the loop antenna 11 and the diode D, and the tuning capacitor C in the loop is
If it is tuned with the loop inductance, it works as an antenna.

On the other hand, when diode D is not energized, diode D
Since the impedance of the antenna becomes high, a loop is not formed and it does not function as an antenna. In other words, the loop antenna 11 is simply connected to the transmitting/receiving section 13,
It does not work as an antenna.

Therefore, depending on whether or not a current flows through the choke coil L to the diode D, the loop antenna 11 can be operated as an antenna or not operated.

Here, as shown in FIG. 3, the area of the portion 11c of the loop antenna 11 that is close to the human body is made large. As described above, when the loop antenna 11 is not operating as an antenna, the proximal portion 11c is capacitively coupled to the human body, and the human body and the loop antenna 11 function as a type of dipole antenna.

If the area of the proximal portion 11C to the human body, which is arranged substantially parallel to the human body, is larger, the coupling between the proximal portion 11c and the human body will be stronger, and the antenna efficiency will be higher.

Therefore, by the switching means 12, the loop antenna 11
By making the antenna function as a loop antenna, or by combining it with the human body to function as a dipole antenna, and selecting the one with the larger gain using the transmitting/receiving section 13, deterioration of the transmitted/received signal level and directivity can be reduced. .

FIG. 4(a) shows the proximal portion 11c of the loop antenna 11.
The outer frame 1 of a battery or sounding body whose outer frame is made of metal
This is an example using 4. FIG. 4(b) shows a metal diaphragm 15 of a sounding body as a proximal portion 11c of the loop antenna 11.
This is an example using .

In this case, it is sufficient to insert the outer frame 14 and the metal diaphragm 15 in the middle of the loop antenna 11.

If the outer frame 14 and the metal diaphragm 15 are used, the area close to the human body is large, making it easier to connect to the human body.

[Effects of the Invention] As described above, according to the present invention, the switching means
By switching the loop antenna installed inside the housing between forming a loop and not forming a loop, the loop antenna can be switched between a tuned state and an untuned state.

In other words, when the gain of the loop antenna decreases due to the positional relationship between the loop antenna and the human body, the switching means puts the loop antenna into a detuned state and effectively uses the human body as an antenna. We have been able to provide a portable radio that provides sufficient gain when used in

Furthermore, in the conductor constituting the loop antenna, the width of the conductor in the part close to the human body is made wider than the other part, and by arranging it so that it is approximately parallel to the surface on which the human body is attached, the conductor and the human body are The degree of coupling becomes stronger, further improving the gain.

Further, by using a metal part of a device built into the radio, especially a relatively wide part, as the conductor part close to the human body, more effective coupling with the human body can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing a specific example of the switching means according to the above, FIG. 3 is an explanatory diagram of the operation of the above embodiment, and FIG. 5 is a schematic diagram showing a conventional portable wireless device in use; FIG. 6 is a schematic diagram showing a receiving device according to the above; and FIG.
FIG. 8 is a schematic diagram showing another conventional example, and FIG. 8 is a schematic configuration diagram showing the same transmitting device as above. 11-Loop antenna 12-...Switching means 13
-Transmission/reception section 11cm...Proximity part A housing

Claims (3)

[Claims] (1) A portable radio device for wear on the human body, which includes a radio circuit and a loop antenna connected to the radio circuit housed in a housing, including a switching means for switching the loop antenna between a tuned state and an untuned state. A portable radio device characterized by: (2) A claim characterized in that, in the conductor constituting the loop antenna, the width of the conductor in a portion close to the human body is wider than in other portions, and is arranged so as to be substantially parallel to the surface on which the human body is attached. The portable radio device according to item 1. (3) The portable radio device according to claim 2, wherein a metal part of a device built into the radio device is used as the portion of the conductor that is close to the human body.