JP2001177432A - Portable wireless device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite portable wireless device that suppress a transmission loss of a signal and simplifies its configuration so as to reduce the cost and save the space. SOLUTION: The portable wireless device has at least an antenna, a common unit (caption 7 in Figure 1) that employs a low pass filter (caption 7a in Figure 1) and a high pass filter (caption 7b in Figure 1) to separate a signal received by the antenna into signals with different frequency bands, a PDC wireless section (caption 2 in Figure 1) that sends/receives a signal passing through the low pass filter, a PHS wireless section (caption 3 in Figure 1) that sends/ receives a signal passing through the high pass filter. The low pass filter of the common unit and a high pass filter (caption 5 in Figure 1) provided to the PDC wireless section configure a band pass filter, and the high pass filter of the common unit and a low pass filter (caption 9 in Figure 1) provided to the PHS wireless section configure a band pass filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable radio, and more particularly, to a filter structure of a composite portable radio in which a PDC (Personal Digital Cellular) radio section and a PHS (Personal Handy-phone System) radio section are combined.

[0002]

2. Description of the Related Art In recent years, portable telephones (hereinafter referred to as PDCs) have been developed.
And PHS, a composite portable radio that handles two transmission / reception systems has come to be used. In such a composite portable radio, when a dedicated circuit is configured for each transmission / reception system, the size of the device becomes large, To increase the cost, antennas are commonly used to simplify the system configuration and reduce the price. In this case, PDC /
A duplexer for combining and distributing transmission / reception signals of both PHS systems is required.

In such a composite portable radio, P
In each DC / PHS system, it is necessary to limit each frequency band, so that a filter is inserted at an appropriate place to limit the band. Here, conventional PDC and PH
The configuration of the composite portable wireless device using the two transmission / reception systems of S will be described with reference to FIG. FIG. 3 is a configuration diagram schematically showing a schematic configuration of a conventional composite portable wireless device.

[0004] As shown in FIG. 3, a conventional composite portable radio device comprises a PDC radio unit 2 using one frequency band, a PHS radio unit 3 using another frequency band, a PDC frequency band and a PHS radio frequency band. Antenna 1 for receiving signals in both frequency bands for use, and a signal received by common antenna 1 for P
It is composed of a duplexer 7 for allocating a frequency band for DC and a frequency band for PHS.

The PDC radio section 2 includes a switch 8 for switching between transmission and reception, a transmission circuit 4, a reception circuit 6,
And a band-pass filter 13 for transmitting only a signal in a band necessary for PDC to the receiving circuit 6 out of the frequency band passing through the duplexer 7. A band-pass filter 14 for transmitting only a signal in a band necessary for the PHS to a transmitting / receiving circuit,
Switch 10 for switching between transmission and reception, and transmission circuit 11
And a receiving circuit 12.

[0006]

In such a conventional composite portable radio, the signal distributed by the duplexer 7 is P
Since a signal in a frequency band unnecessary for the DC radio unit 2 or the PHS radio unit 3 is included, a bandpass filter is installed in each radio unit to remove the unnecessary signal. Only signals that have passed through both the low-pass / high-pass transmission filter of the duplexer 7 and the band-pass filters of each radio unit are transmitted to the unit.

Here, as is well known, in a band-pass filter, when the pass band width is constant and the attenuation gradient is steep, the number of resonance elements increases, and the signal transmission loss increases in proportion to the number of resonance elements. I do. Therefore, when the attenuation slope is steep and the amount of attenuation outside the band is set to a desired value, transmission loss increases. On the other hand, when the number of stages of the resonance elements is reduced to reduce the transmission loss, the amount of attenuation outside the band does not become a desired value. .

When the low-pass / high-pass transmission filter and the band-pass filter are combined as described above, the signal transmission loss increases in each stage filter, especially in the band-pass filter, and many components are required. Therefore, there is a problem that the cost and the mounting area increase.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its main objects to reduce cost and space by suppressing signal transmission loss and simplifying the configuration. An object of the present invention is to provide a composite portable wireless device that can be achieved.

[0010]

In order to achieve the above object, according to a first aspect of the present invention, there is provided an antenna, a duplexer for dividing a signal received by the antenna into a plurality of frequency bands, And a plurality of radio units for transmitting and receiving signals of each frequency band passed through the duplexer, wherein the duplexer is provided with a low-pass filter and a high-pass filter. A high-pass filter is provided in the first wireless unit through which the signal passing through the low-pass filter of the duplexer is transmitted, and the signal passing through the high-pass filter of the duplexer is transmitted. The second radio section is provided with a low-pass filter.

According to a second aspect of the present invention, in a second aspect, an antenna, a duplexer for dividing a signal received by the antenna into a plurality of frequency band signals, and a signal of each frequency band passing through the divider are provided. A plurality of wireless units for transmitting and receiving
And a low-pass filter and a band-pass filter are provided in the duplexer, and a first radio through which a signal passing through the low-pass filter of the duplexer is transmitted. The unit is provided with a high-pass filter.

In the present invention, it is preferable that a band-pass filter is constituted by a high-pass filter provided in the first radio section and the low-pass filter of the duplexer.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A composite portable wireless device according to the present invention comprises:
In a preferred embodiment, the antenna and a signal received by the antenna are subjected to a low-pass filter (7a in FIG. 1).
And a high-pass filter (7b in FIG. 1), a duplexer (7 in FIG. 1) for dividing the signal into signals in different frequency bands, and a PDC radio unit (FIG. 1) for transmitting and receiving signals passing through the low-pass filter
2) and a PHS radio unit (3 in FIG. 1) for transmitting and receiving signals passing through the high-pass filter, and a low-pass filter of the duplexer and a high-pass filter provided in the PDC radio unit ( A band-pass filter is configured with 5) in FIG. 1, and a band-pass filter is configured with the high-pass filter of the duplexer and the low-pass filter (9 in FIG. 1) provided in the PHS radio unit.

With this configuration, it is possible to reduce the transmission loss of the band for the PDC radio unit and the band for the PHS radio unit distributed by the duplexer connected to the shared antenna of the composite portable radio.

That is, as a filter on the side of the PHS radio section, the conventional transmission / reception circuit band-pass filter is replaced with a low-pass filter, so that the total transmission loss can be reduced and the high-frequency transmission of the duplexer can be reduced. By combining with a filter, a conventional bandpass filter can be configured.

Further, as a filter on the PDC radio side,
By using a high-pass filter as the conventional bandpass filter for the receiving circuit, it is possible to reduce the total loss of reception, and configure a conventional bandpass by combining with the low-pass filter of the duplexer. Can be.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention;

[First Embodiment] First, referring to FIG. 1, a composite portable wireless device according to a first embodiment of the present invention will be described. FIG. 1 is a diagram schematically showing a schematic configuration of a composite portable wireless device according to a first embodiment, in which a duplexer 7 is provided with a low-pass filter 7a on the PDC side and a high-pass filter 7b on the PHS side.
FIG. 3 is a configuration diagram in a case where a filter in the PDC radio unit 2 is a high-pass filter 5 and a filter in the PHS radio unit 3 is a low-pass filter.

As shown in FIG. 1, the composite portable radio device according to the first embodiment includes a PDC radio unit 2 using one frequency band, a PHS radio unit 3 using another frequency band,
It comprises a shared antenna 1 for receiving both the PDC frequency band and the PHS frequency band, and a duplexer 7 for distributing a signal received by the shared antenna 1 into a PDC frequency band and a PHS frequency band.

The PDC radio unit 2 includes a switch 8 for switching between transmission and reception, a transmission circuit 4, a reception circuit 6,
And a high-pass filter 5 that transmits only a signal in a band necessary for the PDC to a receiving circuit among the frequency bands that have passed through the low-pass filter 7a of the duplexer 7. The PHS radio unit 3 Low-pass filter 9 for transmitting only a signal in a band necessary for PHS to a transmitting / receiving circuit
And a switch 10 for switching between transmission and reception, a transmission circuit 11, and a reception circuit 12.

Here, conventionally, the receiving circuit 6 of the PDC radio unit 2 and the transmitting / receiving circuit of the PHS radio unit 3 are each provided with a band-pass filter for transmitting a signal of a predetermined band. Is characterized in that a high-pass transmission filter 5 is provided on the PDC radio unit 2 side and a low-pass transmission filter 9 is provided on the PHS radio unit 3 side.

As described above, the PDC radio section 2 constitutes a bandpass filter by combining the low-pass filter 7a and the high-pass transmission filter 5 of the duplexer 7, and the PHS radio section 3 constitutes a bandpass filter. By combining the high-pass filter 7b and the low-pass filter 9 to form a band-pass filter, the total transmission loss can be reduced, and only the signal in the desired band can be transmitted to the PDC radio unit 2. P
It can be transmitted to the HS radio unit 3.

That is, since the band was limited by combining the low-pass / high-pass transmission filter and the band-pass filter in the past, the total transmission loss increased.
In the configuration of the present embodiment, the same band limitation as that of the band-pass filter can be performed by the low-pass filter and the high-pass filter having small transmission loss, and the transmission loss can be reduced.

[Second Embodiment] Next, with reference to FIG. 2, a composite portable radio device according to a second embodiment of the present invention will be described. FIG. 2 is a diagram schematically showing a schematic configuration of a composite portable wireless device according to a second embodiment, in which a duplexer 7 includes a low-pass filter 7a on the PDC side and a band-pass filter 7 on the PHS side.
c is a configuration diagram when the filter of the receiving circuit 6 of the PDC radio unit 2 is not provided with the high-pass filter 5 and the transmitting / receiving circuit of the PHS radio unit 3 is not provided with the filter. That is,
In the second embodiment, three filters, PDC and PHS, are used.
This is to limit the band of one transmission / reception system.

As shown in FIG. 2, the composite portable radio device according to the second embodiment includes a PDC radio unit 2 using one frequency band and another frequency band, similarly to the first embodiment. The PHS radio unit 3 uses a band, a shared antenna 1 for receiving signals in both bands, and a duplexer 7 for distributing a signal received by the shared antenna 1 into a PDC frequency band and a PHS frequency band. .

The PDC radio unit 2 includes a switch 8 for switching between transmission and reception, a transmission circuit 4, a reception circuit 6,
The PHS radio unit 3 includes a switch 10 that switches between transmission and reception, and a high-band transmission filter 5 that cuts a signal in a band unnecessary for the PDC radio unit 2 out of the received frequency band and transmits the signal to the reception circuit 6. , A transmission circuit 11 and a reception circuit 12 only.

That is, the PDC radio unit 2 side is
The band is limited by the low-pass filter 7a and the high-pass filter 5 in the PDC radio unit 2.
In the first embodiment, the band is limited by the high-pass transmission filter 7b of the duplexer 7 and the low-pass transmission filter 9 in the PHS radio unit 3, whereas in the present embodiment, the band is limited by the duplexer 7. The band is limited only by the provided band pass filter 7c.

Therefore, conventionally, the band was limited by the high-pass transmission filter 7b and the band-pass filter 14 provided in the PHS radio section 3 for cutting unnecessary band signals. Although the signal transmission loss has occurred, in the present embodiment, the PHS radio unit 3 uses only one of the band-pass filters 7 c provided in the duplexer 7.
Since the band on the side is restricted, signal transmission loss can be suppressed.

The PDC radio unit 2 limits the band by the low-pass filter 7a of the duplexer 7 and the high-pass filter 5 in the PDC radio unit 2, as in the first embodiment. It is not necessary to install a bandpass filter 5 having a large transmission loss unlike the related art, and the total loss of reception can be reduced.

As described above, in this embodiment, PDC and PH
For each of the two transmission / reception systems of S, each filter can be limited by three filters, so that the number of components can be reduced and the mounting area can be reduced.

[0031]

As described above, according to the filter structure of the composite portable radio of the present invention, it is possible to reduce the total signal transmission loss and to reduce the size of parts. It works.

The reason is that the filter on the side of the PDC radio section is made to be a high-pass filter, and is combined with the low-pass filter of the duplexer to function as a band-pass filter. This is because the filter functions as a bandpass filter by being combined with the high-pass filter of the duplexer.

Further, by using a bandpass filter on the PHS side filter of the duplexer, it is possible to omit the filter in the PHS radio section.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a schematic configuration of a composite portable wireless device according to a first embodiment of the present invention.

FIG. 2 is a diagram schematically illustrating a schematic configuration of a composite portable wireless device according to a second embodiment of the present invention.

FIG. 3 is a diagram schematically illustrating a schematic configuration of a conventional composite portable wireless device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 shared antenna 2 PDC radio unit 3 PHS radio unit 4 transmission circuit (PDC side) 5 high-pass transmission filter (PDC side) 6 reception circuit (PDC side) 7 duplexer 7 a low-pass transmission filter 7 b high-pass transmission filter 7 c bandpass Filter 8 Switch (PDC side) 9 Low-pass filter (PHS side) 10 Switch (PHS side) 11 Transmitter circuit (PHS side) 12 Receiver circuit (PHS side) 13 Bandpass filter (PDC side) 14 Bandpass filter (PHS) side)

Claims (4)

[Claims] An antenna, a duplexer that divides a signal received by the antenna into a plurality of frequency band signals, and a plurality of radio units that transmit and receive signals of each frequency band that have passed through the duplexer. A composite portable wireless device having at least a low-pass filter and a high-pass filter provided in the duplexer, and a first radio to which a signal passing through the low-pass filter of the duplexer is transmitted. A high-pass filter is provided in the unit, and a low-pass filter is provided in the second wireless unit of the duplexer, through which a signal passing through the high-pass filter is transmitted. And a composite portable radio. 2. A band-pass filter comprising a high-pass transmission filter provided in the first radio unit and the low-pass transmission filter of the duplexer, wherein the band-pass filter is provided in the second radio unit. 2. The composite portable wireless device according to claim 1, wherein a band-pass filter is formed by the low-pass filter and the high-pass filter of the duplexer. 3. An antenna, a duplexer for dividing a signal received by the antenna into signals of a plurality of frequency bands, and a plurality of radio units for transmitting and receiving signals of the respective frequency bands passing through the divider. A composite portable wireless device having at least a low-pass filter and a band-pass filter provided in the duplexer, and a first wireless unit to which a signal passing through the low-pass filter of the duplexer is transmitted. Wherein a high-pass filter is provided. 4. A band-pass filter comprising a high-pass filter disposed in the first radio section and the low-pass filter of the duplexer.
The composite portable wireless device as described.