JP2002330082A - Radiocommunication adaptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiocommunication adaptor which materializes the downsizing and weight reduction by operating the ground of a connected portable communication terminal as an antenna. SOLUTION: The radiocommunication adaptor 1 performs the radiocommunication, using the case ground G of the portable telephone 10 as an antenna. Moreover, the radiocommunication adaptor 1 is equipped with a high frequency checking circuit 3 which interrupts high frequency components out of the input signal sent from the portable telephone 10 prior to output, a radio section 5 which converts the signal into the one capable of radiocommunication wit an external apparatus, and a matching circuit 6 which matches the impedance of the radio section 5 and that of the case ground G.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication adapter for performing wireless communication with an external device while being connected to a portable communication terminal.

[0002]

2. Description of the Related Art In recent years, with the development of communication technology, wireless LA
N (Local Area Network) and Bluetooth (Bluetoot
Wireless communication adapters capable of high-speed and high-density wireless communication with external devices using radio waves conforming to various wireless communication standards such as h) have been developed and used. The wireless communication adapter
In order to respond to a wider frequency band, by mounting an antenna inside or outside the main unit, it can radiate radio waves to external devices or receive radio waves from external devices,
Transmission and reception of various signals and data are possible.

[0003] On the other hand, with the spread of portable communication terminals such as cellular phones and PDAs and their personal use, an increasing number of users are using data transmission / reception functions with external devices such as PCs.
Therefore, development and provision of portable communication terminals and peripheral devices excellent in portability and portability have been desired, and reduction in size and weight of these devices has been an important issue for promoting demand.

[0004]

However, in the conventional wireless communication adapter, as shown in FIG. 11, since an external antenna is mounted or the antenna is built in the adapter body, the mounting space of the antenna is reduced. For this reason, the wireless communication adapter has become large and heavy, which has been a factor that hinders portability and portability.

An object of the present invention is to operate a ground of a portable communication terminal to be connected as an antenna,
An object of the present invention is to provide a wireless communication adapter that realizes reduction in size and weight.

[0006]

The present invention has the following features to solve the above-mentioned problems. In the following description of the means, the names of components corresponding to the embodiments and reference numerals in the drawings are exemplified in parentheses.

[0007] The first aspect of the present invention provides a wireless communication adapter (for example, a wireless communication adapter for performing wireless communication with an external device while being connected to a mobile communication terminal (for example, the mobile phone 10 in FIG. 1)).
The wireless communication adapter 1) of FIG. 1 is characterized in that wireless communication is performed using a ground of the portable communication terminal (for example, a housing ground G including a ground pattern of the printed circuit board of FIG. 1) as an antenna.

According to a second aspect of the present invention, in the first aspect of the present invention, a high-frequency blocking circuit (for example, as shown in FIG. 1) for blocking and outputting a high-frequency component in an input signal transmitted from the portable communication terminal. A high-frequency blocking circuit 3), a wireless unit that converts the signal into a signal capable of wireless communication with the external device, and a ground connected to the portable communication terminal without the intermediation of the high-frequency blocking circuit. Matching circuit for matching the impedance of the ground (for example, matching circuit 6 in FIG. 1)
And, it is characterized by having.

According to a third aspect of the present invention, in the second aspect of the present invention, a level detector (for example, a directional coupler shown in FIG. 4) for detecting an incident wave level and / or a reflected wave level of the signal to the ground. 7), wherein the matching circuit is connected to at least one control terminal, and by appropriately changing a control voltage (for example, control terminal 1 or 2 in FIG. 5) at the control terminal, the level detector The incident rate is automatically adjusted so that the incidence rate of the signal to the ground, which is calculated based on the incident wave level and / or the reflected wave level detected by the method, becomes maximum.

The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the ground is a metal constituting a part of the portable communication terminal, a ground pattern of a printed circuit board, and metal deposition. And metal plating. The part of the portable communication terminal is, for example, a housing of the portable communication terminal, a shield case inside the portable communication terminal, a printed circuit board, or the like. The ground is not necessarily the ground itself, but may be a metal part such as an antenna feed unit connected to the ground.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of a wireless communication adapter 1 according to an embodiment of the present invention will be described below with reference to the drawings.

First, the configuration will be described. The internal configuration of the wireless communication adapter 1 will be described with reference to FIG. FIG. 1 is a block diagram illustrating a circuit configuration of the wireless communication adapter 1. FIG.
As shown in (1), the wireless communication adapter 1 is configured by housing a connector 2, a high-frequency blocking circuit 3, a digital unit 4, a wireless unit 5, and a matching circuit 6 inside a housing, and each block is unidirectional via a bus. Alternatively, they are connected so that various signals can be transmitted and received in both directions.

The connector 2 has a plurality of electric wires inside, and is electrically connected to a mobile phone 10 described later, and transmits and receives various signals between the wireless communication adapter 1 and the mobile phone 10.

The high-frequency blocking circuit 3 is located at the subsequent stage of the connector 2 and, as shown in FIG. 2, an LPF (for example, an LPF) having a plurality of (for example, six) coils having a predetermined inductance L ₁ connected in parallel. Low Pass Filter) circuit.

The digital section 4 is a digital circuit located downstream of the high frequency blocking circuit 3 and having a low frequency signal passed through the high frequency blocking circuit 3 as an input signal. That is, the digital unit 4 transmits and receives data and audio signals to and from the digital unit 11 of the mobile phone 10 via the high-frequency blocking circuit 3.

The radio unit 5 is located further downstream of the digital unit 4 and transmits and receives various signals necessary for wireless communication with the digital unit 4 and transmits and receives high-frequency signals to and from the matching circuit 6. Do.

The matching circuit 6 is located between the radio unit 5 and a housing ground G of the mobile phone 10 to be described later, and as shown in FIG. 3, a coil having a predetermined inductance L ₂ is connected in series. , Two capacitors having a predetermined capacitance C are connected in parallel with the other end grounded. Note that the housing ground G includes a ground pattern (earth pattern) of the printed circuit board.

The portable telephone 10 also includes a digital unit 11 for transmitting and receiving data and audio signals to and from the wireless communication adapter 1 via the connector 2, and a digital signal received from the digital unit 11 as an external wireless signal. A radio unit 12 that transmits to the base station B to transmit and receive data and voice signals to and from another mobile phone, and a power supply unit that supplies power required for operation of the digital unit 11, the radio unit 12, and the wireless communication adapter 1. 13
At least.

Next, the operation will be described. When data to be transmitted is transmitted from the digital unit 11 to the high-frequency blocking circuit 3 via the connector 2, the high-frequency blocking circuit 3 sets the housing ground G that functions as the ground of the mobile phone 10 and the wireless communication adapter 1. Among the signals flowing from the input / output lines including the input / output lines, high frequency components are cut off and transmitted to the digital unit 4.

The digital section 4 converts the signal received from the high frequency blocking circuit 3 into a signal capable of wireless communication with an external device via the radio section 5 and transmits the signal to the matching circuit 6 as a high frequency radio signal. I do. The matching circuit 6 outputs (feeds) the wireless signal input from the wireless unit 5 to the housing ground G without passing through the high-frequency blocking circuit 3, and (the power supply unit of the wireless unit 5 and the housing ground G). By matching the impedances of the above, the housing ground G is operated as an antenna.

The operation when data is transmitted from the wireless communication adapter 1 to an external device has been described above.
As shown in (1), each signal can be transmitted and received in both directions, and it is of course possible to receive data from an external device by following the above steps in the reverse direction.

As described above, according to the wireless communication adapter 1 of the present embodiment, the housing ground G of the mobile phone 10 can be made to function as an antenna. There is no need to mount an antenna. Therefore, the size and weight of the wireless communication adapter 1 can be reduced without changing the circuit configuration of the mobile phone 10. Further, even at a low frequency of, for example, about 300 MHz, the function of an antenna having a desired length can be obtained without using an external antenna. Furthermore, the electrical length of the antenna is
Basically, it is almost determined by the size of the housing, and the size of the housing may be (5/8) λ at the operating frequency.

[Other Embodiments] As an application example of the above embodiment, a wireless communication adapter 1 to which the present invention can be applied to a general-purpose mobile phone 10 will be described in detail. Note that the configuration of the wireless communication adapter 1 in the other embodiments is similar to the configuration of the wireless communication adapter 1 in the above embodiment, so that the same components are denoted by the same reference symbols and detailed description thereof is omitted. The components specific to the other embodiments are given new reference numerals, and will be described in detail.

First, the configuration will be described. FIG. 5 is a circuit configuration diagram illustrating an example of the matching circuit 6 according to another embodiment. As shown in FIG. 5, the matching circuit 6, the coil having a predetermined inductance L ₂ is connected in series with a capacitor across portions of the coil are connected in parallel. Each capacitor is configured such that two capacitors having predetermined capacitances C ₁ and C ₂ are connected in series, and the other end is grounded. However, capacitance C
Reference numeral ₂ denotes a varactor diode (variable capacitance diode), which changes according to a voltage applied to the control terminals 1 and 2. Further, between the two capacitors, resistors having a predetermined impedance R ₁ are connected in parallel.

FIG. 6 is a circuit diagram showing an example of the directional coupler 7 according to another embodiment. As shown in FIG. 6, the directional coupler 7 has a diode D ₁ for detecting an incident wave and a diode D ₂ for detecting a reflected wave in parallel at _two conductor portions connecting the radio unit 5 and the matching circuit 6. It is connected, further in the central portion thereof one place, and resistor having a predetermined impedance R ₂ whose other end is grounded is connected in parallel.

The memory 8 is, for example, an EPROM (Erasable and Programmable ROROM) capable of storing and updating data.
M) etc. The memory 8 sequentially stores the levels of the incident wave and the reflected wave detected by the directional coupler 7 and the control voltages 1 and 2 applied to the matching circuit 6 from the digital unit 4. Further, the memory 8 has a control program necessary for executing an incident rate automatic adjustment process to be described later, and a threshold used as a criterion for determining a level difference between an incident wave and a reflected wave (hereinafter referred to as “incident rate”). Values 1 and 2 are stored in advance.

Next, the operation of another embodiment will be described. Hereinafter, the incident rate automatic adjustment process executed and controlled by the wireless communication adapter 1 will be described with reference to the flowchart of FIG.

When the connector 2 of the wireless communication adapter 1 is connected to the mobile phone 10, the digital section 4 reads out the incident rate automatic adjustment processing program from the memory 8 and starts the incident rate automatic adjustment processing. First, the digital unit 4 measures the incident wave level and the reflected wave level detected by the directional coupler 7 (Step S1). Next, the digital unit 4
The incident rate is obtained by subtracting the reflected wave level from the incident wave level, and the incident rate is compared with the threshold value 1 stored in the memory 8 (step S2).

As a result of the comparison, when the incidence rate is less than the threshold value 1 (step S2; N), the digital section 4 generates a sawtooth wave having a period T ₁ and a maximum voltage E, and matches the control voltage 1 as the control voltage 1. The voltage is applied to the control terminal 1 of the circuit 6 and the period T
_2. A sawtooth wave having the maximum voltage E is generated and applied to the control terminal 2 as the control voltage 2 (step S3). FIG. 8 shows a time series change of the control voltage 1 and the control voltage 2 applied at this time.
8 (a) and 8 (b).

Subsequently, the digital section 4 includes a directional coupler 7
Then, the time-series changes of the incident wave level and the reflected wave level, and the values of the control voltages 1 and 2 detected are measured, and the measurement results are sequentially stored in a predetermined area in the memory 8 (step S4). At the same time, the digital unit 4 calculates the incidence rate based on the incident wave level and the reflected wave level stored in the memory 8 (Step S5). FIG. 8C shows the step S.
FIG. 9 is a diagram showing a correspondence relationship between a time-series change in the incidence rate calculated in 5 and control voltages 1 and 2;

The digital unit 4 calculates the calculated incidence rate and the threshold
When the incident rate is greater than or equal to the threshold 2
(Step S6; Y), the control voltage 2
To E _TwoIs stored in a predetermined area of the memory 8. one
On the other hand, as a result of the above comparison, the incidence rate is still lower than the threshold 2
If it is full (step S6; N), the threshold is 2 or less.
Repeat steps S3 to S5 until it is up
I do.

Next, as shown in FIGS. 9A and 9B, the digital section 4 keeps the control voltage 2 at E ₂ ,
Only the control voltage 1 is changed proportionally from 0 to E (V) (step S7). At the same time, the digital section 4 calculates the incidence rate based on the incident wave level and the reflected wave level detected by the directional coupler 7, and sequentially stores the calculation result in a predetermined area in the memory 8. The control when the voltage 1 has reached the maximum voltage E, is stored in a predetermined area of the memory 8 the control voltage 1 when the incidence rate was recorded maximum value as E ₁ (step S8). For example, as shown in FIG.
In the case where the incident rate was recorded maximum time t _1, the time t ₁
The value E ₁ of the control voltage 1 at is stored in the memory 8.

Further, the digital section 4 executes the processing of steps S7 to S8 by reversing the control voltages 1 and 2. That is, as shown in FIGS. 10A and 10B, the digital unit 4 controls the control voltage 2 with the control voltage ₁ fixed at E1.
Only from 0 to E (V) (step S
9). At the same time, the digital section 4 calculates the incidence rate and sequentially stores the calculation result in a predetermined area in the memory 8.
The control when the voltage 2 has reached the maximum voltage E, is stored in a predetermined area of the memory 8 the control voltage 2 when the incidence rate was recorded maximum value as E ₃ (step S10). For example, FIG. 10 as shown in (c), when the incidence rate is recorded the maximum value at time t _2, the control at time t ₂ Voltage 2
Values E ₃ are stored in the memory 8.

After the end of step S10, the digital section 4
Compares the incidence rate at time t ₂ with a threshold of 1,
If the incidence rate is equal to or greater than the threshold value 1 (step S11;
Y), a series of incident rate automatic adjustment processing ends. On the other hand, as a result of the comparison, if the incidence rate is still less than the threshold value 1 (step S11; N), the processes of steps S7 to S10 are repeatedly executed until the incidence rate becomes equal to or more than the threshold value 1. However, during the second and subsequent execution uses E ₂ rather than E ₃ as the value of the control voltage 2 for fixing.

As a result of the comparison in step S2,
When the incidence rate is equal to or higher than the threshold value 1 (step S2;
In Y), the digital unit 4 determines that adjustment is unnecessary because the incidence rate is a value sufficient for the antenna operation of the housing ground G,
A series of incident rate automatic adjustment processing ends.

As described above, according to the wireless communication adapter 1 of another embodiment, the wireless communication adapter 1 of the above embodiment has a matching circuit 6 with an automatic incident rate adjustment function, and an incident wave and a reflected wave. A directional coupler 7 for level detection is newly provided. Thereby, the control voltages 1 and 2 applied to the matching circuit 6 are changed while detecting the incident wave and the reflected wave, and the control voltages 1 and 2 are determined so that the incident wave is maximum and the reflected wave is minimum. Fix it.

Therefore, even if the connected mobile phone 10 is not a genuine product dedicated to the wireless communication adapter 1, it is possible to obtain a wireless signal having an incident rate with a minimum attenuation. Therefore, a signal having a high gain can be supplied to the housing ground G of the mobile phone 10 even for a wireless signal having a long wavelength, and the housing ground G can function as a highly sensitive antenna. As a result, the versatility can be improved while maintaining the small and light weight of the wireless communication adapter 1. That is, when the wireless communication adapter 1 is small, it is difficult to realize an antenna function having a high gain when an antenna for a wireless signal having a long wavelength is to be built therein. Therefore, an antenna having a high gain can be manufactured by using the housing ground G of the mobile phone 10 as an antenna.

The description in each of the above embodiments is a preferred example of the wireless communication adapter 1 according to the present invention, and the present invention is not limited to this. For example, in the other embodiments described above, both the incident wave level and the reflected wave level are detected to control the incidence rate, but only one of them may be used. Further, the directional coupler 7 may be a circulator. Furthermore, in each of the above embodiments, the mobile phone 10 has been described as an example of the mobile communication terminal. However, the present invention is not limited to the mobile phone, and for example, a PDA (Personal Digital Assis
tance) or a PC. Also, the external device may be any communication terminal that can transmit and receive data to and from the wireless communication adapter 1 such as a mobile phone.

The signal output from the high frequency blocking circuit 3 does not always pass through the digital section 4 and may be directly input from the high frequency blocking circuit 3 to the radio section 5. In addition, the detailed configuration and detailed operation of the wireless communication adapter 1 can be appropriately changed without departing from the spirit of the present invention.

[0040]

According to the present invention, it is possible to reduce the size and weight of the wireless communication adapter by operating the ground of the portable communication terminal to be connected as an antenna.
Therefore, a wireless communication adapter excellent in portability and portability can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a circuit configuration of a wireless communication adapter 1 according to the present invention.

FIG. 2 is a circuit diagram showing an example of a high-frequency blocking circuit 3 of FIG.

FIG. 3 is a circuit configuration diagram showing an example of a matching circuit 6 of FIG.

FIG. 4 is a block diagram showing a circuit configuration of a wireless communication adapter 1 according to another embodiment.

FIG. 5 is a circuit configuration diagram showing an example of a matching circuit 6 of FIG.

FIG. 6 is a circuit configuration diagram illustrating an example of a directional coupler 7 in FIG. 4;

FIG. 7 is a flowchart showing an incident rate automatic adjustment process executed by the wireless communication adapter 1 of FIG. 4;

FIGS. 8A and 8B are characteristic diagrams in a preceding stage of the incident rate automatic adjustment process of FIG. 7, in which FIG. 8A is a graph showing a time series change of a control voltage 1, and FIG. 7C is a graph showing a time-series change of the incidence rate in the matching circuit 6.

9A and 9B are characteristic diagrams in the middle part of the incident rate automatic adjustment process of FIG. 7, in which FIG. 9A is a graph showing a time series change of the control voltage 1, and FIG. 7C is a graph showing a time-series change of the incidence rate in the matching circuit 6.

10A and 10B are characteristic diagrams in the latter part of the incident rate automatic adjustment process of FIG. 7, where FIG. 10A is a graph showing a time series change of the control voltage 1, and FIG. 7C is a graph showing a time-series change of the incidence rate in the matching circuit 6.

FIG. 11 is a schematic external view of a wireless communication adapter 20 connected to a mobile phone 10 in a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wireless communication adapter 2 connector 3 high frequency blocking circuit 4 digital unit 5 wireless unit 6 matching circuit 7 directional coupler 8 memory 10 mobile phone 11 digital unit 12 wireless unit 13 power supply unit G housing ground

Claims (4)

[Claims] 1. A wireless communication adapter for performing wireless communication with an external device while being connected to a portable communication terminal, wherein the wireless communication adapter performs wireless communication using a ground of the portable communication terminal as an antenna. . 2. A high-frequency blocking circuit for blocking and outputting a high-frequency component in an input signal transmitted from the portable communication terminal; a wireless unit for converting the input signal into a signal capable of wireless communication with the external device; The wireless communication according to claim 1, further comprising: a matching circuit connected to a ground of the portable communication terminal without passing through the high-frequency blocking circuit to match impedance of the wireless unit and the ground. adapter. 3. A level detector for detecting an incident wave level and / or a reflected wave level of the signal to the ground, wherein the matching circuit is connected to at least one control terminal, and controls the control terminal. By appropriately changing the voltage, the incidence rate of the signal to the ground calculated based on the incident wave level and / or the reflected wave level detected by the level detector is maximized,
The wireless communication adapter according to claim 2, wherein the incident rate is automatically adjusted. 4. The ground according to claim 1, wherein the ground is formed of one of a metal constituting a part of the portable communication terminal, a ground pattern of a printed circuit board, metal deposition, and metal plating. The wireless communication adapter according to any one of the above.