JPH11186921A - Multi-band mobile object communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leak-out of higher harmonics which becomes the cause of an interference fault by providing a variable attenuator to be set to a high attenuation rate state linked with the setting of a cut-off bias state on the input side of a high frequency power module. SOLUTION: A PIN diode P1 presents extremely low impedance by injecting conduction electrons and electron holes respectively from (p) and (n) regions at both ends to a (i) region and becoming a plasma shape at the time of forward bias. At the time of zero bias, the (i) region becomes a space charged region, and the impedance becomes high. Thus, by combining the PIN diode P1 and resistance elements R1 and R2, the variable attenuators 23 and 24 for microwaves capable of controlling a transmission attenuation rate by a voltage are easily constituted. In this case, to the variable attenuators 23 and 24, first and second bias control signals AP1 and AP2 for switching and setting first and second RF power modules 21 and 22 to the state of A class amplification or cut-off bias are supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology effective when applied to a multi-band mobile communication device, and more particularly to a portable telephone terminal connected (linked) to a wired general telephone network via a wireless transmission path. And for example PCN
(Personal Communications Network) or PC
S (Personal Communications Service), GSM
(Global System for Mobil Communications).

[0002]

2. Description of the Related Art A plurality of systems such as GSM and PCN have been put to practical use in a portable telephone system. Although the respective systems are common in that they can be connected to a general public network wirelessly, they are greatly different depending on the multiplexing system, the frequency band used, and the like, and there are aptitudes depending on applications.

For example, PCS or PHS (Perso)
nal Handyphone System)
The N-type mobile phone terminal uses a frequency band of 1.8 GHz, and realizes a two-way wireless communication (duplex communication) by a TDD (Time Division Duplex) method in which the same carrier frequency is time-divisionally used for transmission and reception. This method is effective for a system in which the service area covered by one base station, that is, a system with a small cell area, is not suitable for use during high-speed movement in which the frequency between cells is increased, but the cell area is small. Thus, there is an advantage that the number of terminals that can be used simultaneously per unit area can be increased, thereby improving the frequency use efficiency. In addition, although the cell area is small, the number of base stations per unit area is large, but the size of each base station is greatly reduced, for example, it can be easily installed in a building or underground mall without taking up space. can do. This greatly contributes to a reduction in communication costs (call charges).

[0004] On the other hand, the mobile phone terminal of the GSM system has a capacity of 0.0.
Transmit the carrier frequency using the 9 GHz frequency band (8
90MHz-915MHz) and reception (935MHz-9)
60MHz) and TDMA (Tim
Multiplexing is performed by the e Division Multiple Access method to realize two-way wireless communication. This method is inferior to the above-mentioned PCS in terms of the size of the base station and the frequency use efficiency, and the communication cost is correspondingly increased. However, there is an advantage that the system can be used during high-speed movement by widening the unit cell.

As described above, there are a plurality of types of mobile phone systems, but each type has advantages and disadvantages, and it was not possible to optimize all types of scenes by using one type. Thus, the present inventors have studied the integration of two systems in one device and the ability to selectively switch and use each system as needed.

FIG. 4 shows a schematic configuration of a mobile communication device studied by the present inventors prior to the present invention. The mobile communication device shown in FIG. 1 is configured as a mobile phone terminal, and includes a multi-band transmitting / receiving antenna 11 and a duplexer 1.
2, the first RF (high frequency) power module 21, the second
, An RF power module 22, a two-band two-mode wireless signal processing circuit unit (baseband unit) 3, a broadband driver amplifier 35, a handset 55, a microcomputer-based system control unit 61, an operation panel 62, a built-in battery 7, and the like. Have been.

Two-band two-mode radio signal processing circuit 3
Although not shown, has a modulation / demodulation processing unit, a transmission / reception IF (intermediate frequency amplification) unit, a frequency conversion unit (up / down converter), and the like. It is configured to generate and output a GSM radio transmission signal f1 in the band or a PCN radio transmission signal f2 in the 1.8 GHz band. The two kinds of wireless transmission signals f1 / f2 are amplified by the wideband driver amplifier 35, and then the first and second two RF power modules 21,
22 and distributed as it is.

The first RF power module 21 includes an RF power MOS field effect transistor T1 for final stage amplification,
Capacitive element C1 for input / output tuning and impedance matching
1, C21, inductance elements L11 and L21, bias resistance elements R3 and R4, and the like.
At this time, the transistor T1 is connected to the system control unit 6
In response to a first bias control signal AP1 supplied from the first control circuit 1, the bias state is switched and set to any of the bias states from the class A amplification to the cutoff.

Similarly, the second RF power module 22
Is the RF power field effect transistor T for final stage amplification
2. Capacitance elements C12 and C22 and inductance elements L12 and L22 for input / output tuning and impedance matching,
The transistor T2 is constituted by bias resistance elements R3, R4 and the like, and the transistor T2 is switched and set to one of the bias states from the class A amplification to the cutoff by the second bias control signal AP2 provided from the system control unit 61. It has become so.

[0010] At the same time, the first RF power module 21 transmits the frequency band (0.9) of the GSM radio transmission signal f1.
GHz) to efficiently class A power amplification.
21 and circuit constants such as L11 and L21 are optimized. Similarly, the second RF power module 22
Is the frequency band (1.8 GHz) of the PCN radio transmission signal f2.
z), C12, C22 and L1
2, circuit constants such as L22 are optimized.

When operating as a GSM mobile phone terminal, the first bias control signal AP1 is raised to the class A bias level while the second bias control signal A1 is raised.
By causing P2 to fall to the cutoff bias level, only the first RF power module 21 can be selectively operated to perform power amplification and transmission of the GSM radio signal f1 (0.9 GHz band).

When operating as a PCN type portable telephone terminal, the second bias control signal AP2 is raised to a class A bias level, while the first bias control signal AP1 is lowered to a cutoff bias level. By selectively operating only the second RF power module 22, the PCN radio signal f2 (1.8 GHz)
Band) power amplification and transmission.

As described above, if one terminal uses the PCN system and the GSM system as required, economical and efficient communication operation utilizing the advantages of both systems can be realized. .

[0014] GSM and PCN (PCS) are described in, for example, "Dictionary of PC Hardware and Data Communi" published by O'reilly & Associates, Inc.
cations Terms ”pages 206-208 and 334-337 are summarized.

[0015]

However, it has been clarified by the present inventors that the above-described technology has the following problems.

That is, in the above-described multi-band mobile communication device, the frequency difference between the GSM radio signal f1 and the PCN radio signal f2 is very large. For example, in the above example, the frequency difference is twice as large (0.9 GHz and 1.GHz). 8 GHz). Therefore, the two RF power modules 21 and 22
, A wide band amplifier is used so as to sufficiently cover (cover) the frequency difference (0.9 GHz and 1.8 GHz).

As described above, when the signals f1 and f2 having a frequency difference of twice or more are amplified by the wide-band driver amplifier 35, the GSM radio signal f of the lower frequency is used.
When the driver amplifies 1 (0.9 GHz), its second harmonic (2f1 = 1.9 GHz) is also driver-amplified.

At this time, the two RF power modules 2
Of A and B, the class A or class AB power amplifying operation is performed by the fundamental wave (0.9 GHz) of the GSM radio signal f1.
Of the first RF power module 21 configured to amplify the 1.9 GHz PCN radio signal, and the second RF power module 22 configured to amplify the 1.9 GHz PCN radio signal. The cutoff bias state is set by the signal AP2. According to this, even if the second harmonic (2f1) overlaps with the frequency range (1.9 GHz) of the PCN radio signal f2, the second harmonic (1.9 GHz) is transmitted to the second RF power module 22.
Should not have been amplified.

However, according to what the present inventor has learned, the second RF power module 22 in the cut-off bias state causes the peak of the second harmonic signal (2f1) amplified by the broadband driver amplifier 35 to be increased. It turned out to be driven near the level. That is, the second
Of the RF power module 22 is cut off by the low-level control signal AP2.
It has been found that the amplification operation in the class or the AB class is naturally stopped, but it may be driven in the class C or the D class in the cutoff bias state.

As a result, the second harmonic that would otherwise be suppressed by the second RF power module 22 in the cutoff bias state leaks from the output of the second RF power module 22. There is a problem that radiation is radiated from the antenna 11.

An object of the present invention is to provide a multi-mode mobile communication device having a communication function of a plurality of modes in which the frequency bands to be used are greatly different from each other, without using a large-scale configuration that impairs portability or mobility. It is an object of the present invention to provide a technique for surely preventing leakage of a harmonic that causes interference.

The above and other objects and features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0023]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, a broadband driver amplifier having frequency band characteristics so as to include both frequency bands of the first and second radio signals having different frequency bands, and the first radio signal amplified by the wideband driver amplifier A first high-frequency power module for power-amplifying the second radio signal and outputting the same to the antenna, a second high-frequency power module for power-amplifying the second radio signal amplified by the broadband driver amplifier and outputting the second radio signal to the antenna, Bias control means for selectively setting the high-frequency power module to a linear amplification operation state and setting the other to a non-operational cutoff bias state; and a high-frequency power module for power-amplifying at least a radio signal having a higher frequency band. Interposed on the input side, and linked to the setting of the cutoff bias state, the state of high attenuation Providing a variable attenuator to be constant, is that.

According to the above-described means, both the cutoff bias in the high-frequency power module and the high attenuation rate in the variable attenuator reliably prevent the non-selection type radio signal from being subjected to class C or class D amplification. be able to.

Thus, in a multi-mode mobile communication device having a communication function of a plurality of modes having greatly different frequency bands, a multi-mode mobile communication device can be provided without interference due to a large structure that impairs portability or mobility. The objective of reliably preventing leakage of the harmonics that cause the problem is achieved.

The variable attenuator may be configured using a PIN diode whose impedance is variably set by a bias voltage for controlling the operation of the high-frequency power module.

It is desirable that the frequency difference between the first and second radio signals is in the vicinity of an integral multiple of 2 or more.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a multi-band mobile communication apparatus to which the present invention is applied. The mobile communication device shown in FIG. 1 is configured as a mobile phone terminal, and includes a multi-band transmitting / receiving antenna 11, a duplexer 12, a first RF power module 21, and a second RF power module 22. 2 band 2 mode wireless signal processing circuit section (baseband section) 3, broadband driver amplifier 35, handset 5
5. System control unit 61 by microcomputer,
It is composed of an operation panel 62, a built-in battery 7, and the like.

2 band 2 mode radio signal processing circuit 3
Is composed of a transmitting part, a receiving part, and a common part. As the transmitting part, the QSPK modulator 3
1, transmission IF unit 32, frequency conversion unit (upverter) 3
3. A multi-band BPF (band pass filter) 34 is provided. As the reception side, a low noise amplifier 41, a multi-band BPF 42, a frequency conversion unit (downverter) 43, a reception IF unit 44, a QSPK demodulation unit 45, and the like are provided. The common parts include a frequency synthesizer 51 that generates a local signal for frequency conversion, a reference frequency oscillator 52, a multi-mode multiplexing circuit 53 that supports both GSM and PCN systems, and a code generator for audio signals and computer data. A codec unit 54 for performing a decoding process is provided.

The two-band two-mode radio signal processing circuit unit 3 operates at 0.9 based on the user's mode selection operation or the like.
GSM wireless transmission signal f1 in the GHz band or 1.8 GHz
A band PCN radio transmission signal f2 is generated and output. This 2
After being amplified by the broadband driver amplifier 35, the wireless transmission signals f1 and f2 are distributed to the respective inputs of the first and second RF power modules 21 and 22 as they are.

The wideband driver amplifier 35 converts both frequency bands (f1 to f2) of the first system GSM radio signal f1 (0.9 GHz band) and the second system PCN radio signal f2 (1.8 GHz band). It has sufficient broadband characteristics to be included in the amplification band (see FIG. 2).

The first RF power module 21 includes an RF power MOS field effect transistor T1 for final stage amplification,
Capacitive element C1 for input / output tuning and impedance matching
1, C21 and inductance elements L11 and L21, bias resistance elements R3 and R4, coupling capacitance elements C3 to C5,
It is composed of a high-frequency choke coil L3 and the like.
The transistor T1 is set to one of the bias states between the class A amplification and the cutoff in accordance with the binary logic level of the first bias control signal AP1 applied to the gate from the system control unit 61 via the resistance element R4. Switching is set. This first RF power module 2
1 is the frequency band of the GSM radio transmission signal f1 (0.9 GHz
In order to efficiently amplify z), C11, C21 and L1
Circuit constants such as 1 and L21 are optimized.

Similarly, the second RF power module 22
Is the RF power field effect transistor T for final stage amplification
2. Capacitance elements C12 and C22 and inductance elements L12 and L22 for input / output tuning and impedance matching,
Bias resistance elements R3, R4, coupling capacitance elements C3-C
5, the high frequency choke coil L3 and the like. In this case as well, the transistor T2 is connected to the second gate supplied from the system control unit 61 to the gate via the resistor R4.
According to the binary logic level of the bias control signal AP2 of
The bias state is switched to either the class A amplification or the cutoff. The second RF power module 22 includes C12 and C12 to efficiently amplify the frequency band (1.8 GHz) of the PCN wireless transmission signal f2.
22 and circuit constants such as L12 and L22 are optimized.

At the same time, a variable attenuator 2 comprising a PIN diode P1 and resistance elements R1 and R2 is provided on each input side of the RF power modules 21 and 22 respectively.
3, 24 are inserted.

The PIN diode P1 has a structure in which a p-type base of the step recovery diode is close to the intrinsic semiconductor, and an intrinsic semiconductor region, that is, an i-type region is interposed between the p-type region and the n-type region. I have. This P
The IN diode P1 exhibits a very low impedance when a forward bias is applied, in which conduction electrons and holes are respectively injected from the p and n regions at both ends into the i region to form a plasma. However, at zero bias, i
The impedance becomes higher when the region becomes a space electrification region. Therefore, by combining the PIN diode P1 with the resistance elements R1 and R2, the microwave variable attenuators 23 and 24 that can control the transmission attenuation rate by voltage can be easily configured.

Here, the variable attenuators 23, 24
Are supplied with bias control signals AP1 and AP2 for switching and setting the RF power modules 21 and 22 to a class A amplification or cutoff bias state.
As a result, the attenuator 23 or 24 interposed in the RF power module 21 or 22 in which the cutoff bias state is set by setting the bias control signal AP1 or AP2 to the zero level, and causing the attenuator 23 or 24 to operate in the zero bias state in conjunction with the cutoff bias state. As a result, a high attenuation rate state is set.

When the portable telephone terminal is used in the GSM system, the first bias control signal AP1 is raised to the class A bias level (AP1 = high level), while the second bias control signal AP2 is changed to the cutoff bias level. (A
(P2 = low level). As a result, only the first RF power module 21 is selectively operated, and
Power amplification and transmission of the GSM radio signal f1 (0.9 GHz band) can be performed.

When the portable telephone terminal is used in the PCN system, the second bias control signal AP2 is raised to the class A bias level while the first bias control signal A
P1 falls to the cutoff bias level. Thus, it is possible to selectively operate only the second RF power module 22 to perform power amplification and transmission of the PCN radio signal f2 (1.8 GHz band).

At this time, the RF power module 21 or 22 for which the cutoff bias level is set is
At the same time as the non-operation setting by the cutoff bias, the attenuator 23 or 24 interposed on the input side is set to a high attenuation state, and the input signal level is reduced. As a result, it is possible to reliably prevent the RF power module 21 or 22 set in the cutoff bias state from being subjected to class C or class D amplification.

FIG. 2 shows an example of the operating characteristics of the main part of the portable telephone terminal according to the present invention.

FIG. 7A shows an amplification band characteristic of the wide-band driver amplifier 35. As shown in the figure, the broadband driver amplifier 35 is connected to the GSM radio signal f1 and the PC.
It is configured such that a predetermined amplification performance can be obtained in a wide band extending outside both frequency bands (f1 to f2) of the N radio signal f2.

(B) shows the frequency spectrum state at the output side of the wide-band driver amplifier 35. The GSM radio signal f1 of 0.9 GHz is supplied to the broadband driver amplifier 35.
Is input to the amplified output, a second harmonic signal f1 ′ (f1 ′ = 2 × f1 = 1.8 GHz band) of the double frequency appears in addition to the normal GSM radio signal f1. If the second harmonic signal f1 'is directly input to the transistors T1 and T2 of the two RF power modules 21 and 22, the RF power modulator 22 on the side where the cutoff bias is set becomes a class C or a class D. Driven to the output side, that is, the antenna 11 side.
The second harmonic will leak.

However, as described above, the RF power module 22 on the side where the cutoff bias is set is
In addition to the cutoff bias, variable attenuator 2
Due to the attenuation of the input signal by 4, it is possible to reliably avoid driving in class C or class D.

As a result, as shown in (C), an RF power output (f1) with almost no leakage of the second harmonic signal f1 'can be obtained.

As described above, a multi-mode multi-band mobile communication device having a multi-mode communication function having greatly different frequency bands in use, particularly, the first and second radio signals f
In a multi-band mobile communication device having a frequency difference (f2 / f1) of 1, f2 which is twice or more, a multi-band mobile communication device causes an interference failure without a large-scale configuration that impairs portability or mobility. Leakage of harmonics can be reliably prevented.

FIG. 3 shows a second embodiment of the present invention.

In the embodiment shown in the figure, a variable attenuator 24 is interposed on the input side only of the second RF power module 22 that amplifies the PCN radio signal f2 in the higher frequency band, and the attenuator 24 Are set to the high attenuation rate state in conjunction with the setting of the cutoff bias state of the RF power module 22.

The first RF power module 21 for amplifying the power of the GSM radio signal f1 in the lower frequency band includes:
There is a possibility that a １ ／ subharmonic of the PCN radio signal f2 may be input, but the level of the subharmonic is much lower than the level of the harmonic. Or the likelihood of driving a D class is low. Therefore, as shown in the figure, even if the variable attenuator 24 is provided only on the side to which the second harmonic (f1 ') is input, a sufficient effect can be obtained for preventing leakage of the second harmonic.

As apparent from the above description, the present invention provides a broadband driver amplifier having a frequency band characteristic so as to include both frequency bands (f1 to f2) of first and second radio signals having different frequency bands. (35), a first high-frequency power module (21) for power-amplifying the first wireless signal (f1) amplified by the broadband driver amplifier (35) and outputting the amplified signal to the antenna (11); A second high-frequency power module (22) for power-amplifying the second radio signal (f2) amplified by the driver amplifier (35) and outputting the amplified signal to the antenna (11); and one high-frequency power module (21 or 22) And Bias control means (61) for selectively setting only the bias to the linear amplification operation state and setting the other to the non-operational cutoff bias state. It is interposed on the input side of the high-frequency power module (22) that amplifies the radio signal (f2) of the system with the higher frequency band, and is set to a high attenuation rate in conjunction with the setting of the cutoff bias state. By providing the variable attenuator (24), a multi-mode mobile communication device having a communication function of a plurality of modes in which frequency bands to be used are greatly different from each other is provided with a large-sized configuration that impairs portability or mobility. Without leakage, it is possible to reliably prevent the leakage of harmonics (f1 ') that cause interference.

Further, since a PIN diode (P1) having excellent characteristics in a microwave region is used as the variable impedance element constituting the variable attenuators 23 and 24, the variable attenuators 23 and 24 have a relatively simple configuration, and have a relatively simple structure of 0.9 KHz or Harmonic leakage in a quasi-microwave region such as 1.8 GHz can be reliably suppressed.

Although the invention made by the inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and can be variously modified without departing from the gist thereof. Needless to say. For example, the RF power module can be configured using a bipolar transistor or a GaAs transistor.

In the above description, the case where the invention made by the present inventor is applied to a two-mode two-band portable telephone terminal, which is the field of use as the background, has been mainly described. However, the present invention is not limited to this. For example, the present invention can be applied to a multi-band mobile communication device having three or more bands.

[0055]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

That is, in a multi-mode mobile communication device having a communication function of a plurality of modes which use greatly different frequency bands, there is no need for a large-scale configuration that impairs portability, and harmonics that cause interference may be generated. The effect of being able to reliably prevent the leakage of water is obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a multi-band mobile communication device to which the technology of the present invention is applied.

FIG. 2 is a frequency spectrum diagram illustrating an operation characteristic of a main part of the device of the present invention.

FIG. 3 is a circuit diagram showing a second embodiment of the present invention.

FIG. 4 is a circuit diagram showing an outline of a multi-band mobile communication device studied prior to the present invention.

[Explanation of symbols]

Reference Signs List 11 transmission / reception antenna 12 duplexer 21 first RF power module 22 second RF power module 23, 24 variable attenuator 3 2-band 2 mode wireless signal processing circuit section (baseband section) 31 QSPK modulation section 32 transmission IF section 33 Frequency converter (upverter) 34 Multi-band BPF (band-pass filter) 35 Wide-band driver amplifier 41 Low-noise amplifier 42 Multi-band BPF 43 Frequency converter (downverter) 44 Receive IF unit 45 QSPK demodulator 51 Frequency synthesizer 52 Reference frequency oscillator 53 Multi-mode multiplexing circuit 54 Codec unit 55 Handset 61 System control unit by microcomputer (bias control means) 62 Operation panel f1 GSM radio transmission signal in 0.9 GHz band f2 PCN radio transmission signal in 1.8 GHz band No. f1 ′ Second harmonic signal T1, T2 RF power MOS field effect transistor R3, R4 Bias resistance element AP1 First bias control signal AP2 Second bias control signal P1 PIN diode

Claims (3)

Claims: Multi-band mobile communication device 1. A broadband driver amplifier having frequency band characteristics so as to include both frequency bands of first and second radio signals having different frequency bands, and a first radio signal amplified by the wideband driver amplifier A first high-frequency power module for power-amplifying the second radio signal and outputting the same to the antenna, a second high-frequency power module for power-amplifying the second radio signal amplified by the broadband driver amplifier and outputting the second radio signal to the antenna, Bias control means for selectively setting the high-frequency power module to a linear amplification operation state and setting the other to a non-operational cutoff bias state; and a high-frequency power module for power-amplifying at least a radio signal having a higher frequency band. It is interposed on the input side, and is set to a high attenuation rate state in conjunction with the setting of the cutoff bias state. A mobile communication device comprising a variable attenuator. 2. The multi-band mobile communication device according to claim 1, wherein the variable attenuator is configured using a PIN diode whose impedance is variably set by a bias voltage for controlling the operation of the high-frequency power module. 3. The multi-band mobile communication device according to claim 1, wherein a frequency difference between the first and second wireless signals is near an integer multiple of two or more.