JPH06260961A - Digital mobile telephone set - Google Patents

Abstract

PURPOSE:To provide a compact digital mobile telephone set with low power consumption by sharing the circuits, in a digital mobile telephone set which can share two different frequency bands (800MHz band and 1.5MHz band). CONSTITUTION:In the digital mobile telephone set which can share the 800MHz band and 1.5MHz band, the means by which an antenna 1, a receiving circuit (amplifier 7, a band pass filter 8, a mixer 9, band pass filter 10, an amplifier 11, mixer 16, and an I/F circuit 17), and a quadrature modulator 20 are shared in the two frequency bands and a frequency-divider, etc., are used to phase the oscillators, so that the number of the oscillators can be reduced. Thus, the equipment can be made small in size and low in power consumption 1.

Description

Detailed Description of the Invention

[0001]

The present invention relates to the 800 MHz band and 1.
The present invention relates to a digital car telephone that can be shared in the 5 GHz band.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a configuration example of a conventional digital car telephone. As shown in the figure, the conventional digital mobile phone has an 800 MHz band processing unit 9
1, 1.5 GHz band processing unit 92, switch 93 for switching between both frequency bands, IF circuit 9 for processing an intermediate frequency signal
4 and a baseband signal processing unit 95.

The 800 MHz band processing unit 91 includes an antenna 91-1 for transmitting and receiving radio waves, an antenna duplexer 91-2 for sharing one antenna during transmission and reception, an amplifier 91-3, and a bandpass filter 91. -4, mixers 91-5 and 91 for down converting received signals
-8, bandpass filter 91-6, amplifier 91-7,
Power amplifier 91-9, bandpass filter 91-10,
It is composed of a quadrature modulator 91-11, a first local oscillator 91-12, and a second local oscillator 91-13.

The 1.5 GHz band processing section 92 includes an antenna 92-1 for transmitting and receiving radio waves, an antenna duplexer 92-2 for sharing one antenna during transmission and reception, an amplifier 92-3, a band pass. Filter 92-4, mixers 92-5, 92 for down converting received signals
-8, bandpass filter 92-6, amplifier 92-7,
Power amplifier 92-9, bandpass filter 92-10,
It is composed of a quadrature modulator 92-11, a first local oscillator 92-12, and a second local oscillator 92-13.

800 MH received by antenna 91-1
The reception signal of z passes through the reception side by the antenna duplexer 91-2 and is then sent to the amplifier 91-3 and amplified. After the unnecessary signal is removed by the bandpass filter 91-4, the amplified signal is down-converted (frequency conversion) by the mixer 91-5 at the frequency of the first local oscillator 91-12 to generate the first intermediate frequency. (1stIF). This signal is subjected to bandpass filter 91-6 to remove unnecessary waves, then amplified by amplifier 91-7, and further amplified by second local oscillator 91-1.
Down-conversion (frequency conversion) is performed by the mixer 91-8 at the frequency of 3 to obtain the second intermediate frequency (2ndIF), which is selectively switched by the switch 93 and then via the IF circuit 94, the baseband signal processing unit. It is sent to 95 and demodulated.

The transmission signal generated by the base band signal processing unit 95 is selectively switched by the switch 93 and then orthogonally modulated by the quadrature modulator 91-11 to be band-pass filter 91.
After the unnecessary wave is removed at -10, it is amplified to the specified power by the power amplifier 91-9, and further supplied to the antenna 91-1 via the antenna duplexer 91-2 and transmitted.

Although the above description has been made with respect to the 800 MHz band, the 1.5 GHz band processing unit 92 processes the 1.5 GHz band in exactly the same manner. The quadrature modulator 91-1 of FIG.
1 and 92-11 adopt the direct modulation method, but FIG.
There is also a method in which the mixer 6-2 performs up-conversion (frequency conversion) after performing quadrature modulation at the frequency of the second local oscillator 6-5 as shown in FIG.

[0008]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention In the above-mentioned conventional digital car telephone, the 800 MHz band and 1.
5 GHz band and after the first intermediate frequency (mixer-91-5 and after and mixer-92-5 and after) and quadrature modulator 91-11
And 92-11 have two systems of exactly the same circuit, the circuit becomes large in scale, and the power consumption increases.

The present invention has been made in view of the above points, and an object of the present invention is to eliminate the above-mentioned problems and to provide a small size and low power consumption digital car telephone by sharing a used circuit. To do.

[0010]

In order to solve the above-mentioned problems, the first invention of the present invention is 800 MHz band and 1.5 GHz.
In a digital type mobile phone that can be shared by the bands, as shown in FIG. 1, the antenna 1 and the receiving circuit (amplifier 7, bandpass filter 8, mixer 9,
Band pass filter 10, amplifier 11, mixer-16,
(Composed of IF circuit 17) and quadrature modulator 20 and N for dividing the output frequency of oscillation circuit 12 by N
Frequency divider 13 and means for setting the frequency obtained by dividing the output frequency of oscillation circuit 12 by N to become the second local frequency of the receiving circuit (input to mixer 16), and further a transmission / reception switching signal The output frequency of the oscillation circuit 6 for switching the frequency is supplied to the mixer -21 for frequency conversion of the transmission frequency and to the mixer -4 for frequency conversion of the reception frequency.

The second invention is the 800 MHz band and 1.5 G
In a digital type mobile phone that can be shared in the Hz band, the antenna 3 is used in the above two frequency bands as shown in FIG.
1 and the receiving circuit (amplifier 37, bandpass filter 38,
Mixer 39, bandpass filter 40, amplifier 41,
(Composed of a mixer 46, an IF circuit 47) and a quadrature modulator 50, and a frequency divider 43 for dividing the output frequency of the oscillation circuit 42 by N and a frequency divider for dividing the output frequency of the N frequency divider by M. The output frequency of the frequency divider 44 and the oscillation circuit 42 is (N
XM) A means for setting the divided frequency to be the second local frequency of the receiving circuit (input to the mixer 46) is provided, and the output frequency of the oscillation circuit 42 is used for the quadrature modulator 50. The frequency divided by N is supplied to the mixer 34 for frequency conversion of the reception frequency, and the frequency divided by N × M is supplied to the mixer 46 as the second local frequency.

A third invention is the 800 MHz band and 1.5 G
In a digital type mobile phone that can be shared in the Hz band, the antenna 6 is used in the above two frequency bands as shown in FIG.
1 and the receiving circuit (amplifier 67, bandpass filter 68,
Mixer 69, bandpass filter 70, amplifier 71,
The output frequency of the oscillation circuit 72 is used for the mixer 81 for frequency conversion of the transmission frequency, and the output frequency of the oscillation circuit 86 is used. Is supplied to the mixer 64 for frequency conversion of the reception frequency, and the frequency divided by N is set so as to become the second local frequency (input to the mixer 76) of the reception circuit.

[0013]

According to the first aspect of the present invention, in the digital type mobile telephone which can be commonly used in the 800 MHz band and the 1.5 GHz band, as shown in FIG.
In the Hz band, the antenna 1, the receiving circuit (amplifier 7, bandpass filter 8, mixer-9, bandpass filter 10, amplifier 11, mixer-16, IF circuit 17) and quadrature modulator 20 are shared, and the oscillation circuit 12 is also used. Fixed oscillator 12-1
By setting the frequency obtained by dividing the output frequency of (see FIG. 2) by N to be the second local frequency of the receiving circuit, the second local oscillator of the conventional receiving circuit is deleted, and the transmission / reception switching signal is further deleted. By using the output signal of the oscillator 6 for switching the frequency with, the mixer-21 up-converts the transmission frequency (frequency conversion), and the mixer-4 down-converts the reception frequency (frequency conversion). It is possible to reduce the number of fixed oscillators used, reduce the size of equipment, and reduce power consumption.

Similarly, the second and third inventions are also 800 MHz.
By using an antenna, a receiving circuit and a quadrature modulator in the band and the 1.5 GHz band and using a frequency divider, it is possible to reduce the number of oscillators, downsize the device, and reduce power consumption.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment of the Invention] FIG. 1 is a block diagram showing a configuration example of a digital car telephone of the first invention. As shown in the figure, this mobile phone has 800MHz band and 1.5G
An antenna 1 for sharing the Hz band, an antenna matching circuit 2 for sharing both frequency bands, a transmission / reception switch 3 for switching between transmission and reception, a mixer-4 for frequency-converting a 1.5 GHz band received signal into an 800 MHz band, 1.5GHz band and 8
The output signal of the frequency band switching device 5 for switching the 00 MHz band, the amplifier 7, the band pass filter 8, the mixer 9 for the first intermediate frequency conversion, the band pass filter 10, the amplifier 11, the oscillation circuit 12, and the oscillation circuit 12 is N. N frequency divider 13 for frequency division, low-pass filter 15, mixer 16 for second intermediate frequency conversion, IF circuit 17 for processing intermediate frequency signal, baseband signal processing unit 18 for processing signal, transmission signal A quadrature modulator 20, a mixer-21 that frequency-converts an 800 MHz band signal into a 1.5 GHz band, a band pass filter 22, a power amplifier 23 that amplifies the 1.5 GHz band signal to a specified power, a band pass filter 24,
It is composed of a power amplifier 25 that amplifies an 800 MHz band signal to a specified power.

In the digital car telephone having the above-mentioned structure, the reception signal received by the antenna 1 passes through the receiving side of the antenna matching circuit 2 and the transmission / reception switch 3 and has a frequency of 1.5 GHz.
In the case of z, it is input to the mixer-4. In the mixer-4, the signal oscillated by the oscillation circuit 6 down-converts the 1.5 GHz band signal into the 800 MHz band (frequency conversion).
Then, the output signal is amplified by the amplifier 7, passes through the band pass filter 8, and is input to the mixer 9.

The oscillator circuit 6 is an oscillating circuit used for down-conversion at the time of receiving a 1.5 GHz signal and up-conversion at the time of transmitting 1.5 GHz, and has a frequency band of the received signal (1477 to 1513 MHz). Since the frequency band (1429 to 1465 MHz) of the transmission signal is different, the frequency of the output signal is switched according to the transmission / reception switching signal.

In the mixer 9, the input signal is down-converted by the output signal of the oscillation circuit 12, and the output signal is amplified by the amplifier 11 through the band pass filter 10 and input to the mixer 16.

In the mixer 16, the signal oscillated by the oscillating circuit 12 is divided by N by the N frequency divider 13 to obtain the signal from the amplifier 1.
The signal from 1 is down-converted. The output signal passes through an IF circuit (intermediate frequency circuit) 17 and is output to the base.
It is input to the band signal processing unit 18 and demodulated.

On the other hand, the transmission signal output from the base band signal processing section 18 is modulated by the quadrature modulator 20 and, when further transmitted in the 1.5 GHz band, it is 1.5 in the mixer-21.
It is up-converted to the GHz band, passes through the band pass filter 22, is power-amplified to the specified power by the power amplifier 23, and is transmitted from the antenna 1 through the frequency band switch 5, the transmission / reception switch 3, and the antenna matching circuit 2. It 800
When transmitting at MHz, the power is amplified up to the specified power by the power amplifier 25 through the band pass filter 24, and is transmitted from the antenna 1 through the frequency band switch 5, the transmission / reception switch 3, and the antenna matching circuit 2.

FIG. 2 is a block diagram showing a configuration example of a frequency synthesizer used as the oscillation circuit 12 of FIG.
As shown in the figure, the oscillator circuit 12 includes a fixed oscillator 12-1 that outputs a signal of a fixed frequency, and the fixed oscillator 12-1.
Output signal and PLL (Phase Locked Lo)
op) mixer 12 for mixing the output signals of circuit 12-4
-2, low-pass filter (or band-pass filter) 1
2-3, PLL circuit 12-4, fixed oscillator 1
The output of 2-1 is supplied to the N frequency divider 13, and the output signal of the PLL circuit 12-4 is supplied to the mixer 9 for frequency conversion and the modulator 20. The frequency synthesizer of the oscillator circuit 12 is
In order to speed up the lock-up time, down-conversion is performed by a fixed oscillator and the frequency is lowered to form a loop of the PLL.

With the above configuration, the antenna 1, the receiving circuit (amplifier 7, bandpass filter 8, mixer 9, bandpass filter 10) in two frequency bands are provided.
The amplifier 11, the mixer 16 and the IF circuit 17) and the quadrature modulator 20 are shared. Further, the output frequency of the fixed oscillator 12-1 of the oscillation circuit 12 is divided by the N frequency divider 13
Since the frequency divided by N is set so as to become the second local frequency of the receiving circuit, the second local oscillator of the conventional receiving circuit can be deleted, and the output signal of the oscillator 6 is used.
By up-converting the transmission frequency via 1 and down-converting the reception frequency via the mixer 4, the number of fixed oscillators used conventionally can be reduced.

[Embodiment of the Second Invention] FIG. 3 is a block diagram showing an example of the configuration of a digital car telephone of the second invention. As shown, the car telephone of the present invention is 800 MH
An antenna 31 for both z band and 1.5 GHz band, an antenna matching circuit 32 for sharing both frequency bands, a transmission / reception switch 33 for switching between transmission and reception, for frequency conversion of a reception signal of 1.5 GHz band to 800 MHz band Mixer
34, frequency band switch 35 for switching between 1.5 GHz band and 800 MHz band, amplifier 37, band pass filter 3
8, mixer 39 for first intermediate frequency conversion, bandpass filter 40, amplifier 41, oscillation circuit 42, N frequency divider 43 for dividing the output signal of the oscillation circuit 42, and further divides the output signal M divider 44, low-pass filter 45,
Second intermediate frequency conversion mixer 46, IF circuit 47 for processing the intermediate frequency signal, baseband signal processing unit 48 for demodulating the signal, quadrature modulator 5 for modulating the transmission signal
A mixer 51 and an oscillator 56 that frequency-convert a 0, 800 MHz band signal into a 1.5 GHz band, a bandpass filter 52, a power amplifier 53 that amplifies the 1.5 GHz band signal to a specified power, a bandpass filter 54, and an 800 MHz band signal. It is composed of a power amplifier 55 that amplifies to a specified power.

In the digital car telephone having the above-mentioned configuration, the received signal received by the antenna 31 passes through the receiving side of the antenna matching circuit 32 and the transmission / reception switch 33.
In the case of 5 GHz band, it is input to the mixer-34. In the mixer 34, the signal oscillated by the oscillator circuit 42 is divided by the N divider 4
The signal in the 1.5 GHz band is divided into 80 by the signal divided by N in 3
Down conversion (frequency conversion) to 0MHz band,
The output signal is amplified by the amplifier 37, passed through the bandpass filter 38, and input to the mixer 39.

In the mixer 39, the input signal is down-converted by the output signal of the oscillation circuit 42, and the output signal is amplified by the amplifier 41 through the bandpass filter 40 and input to the mixer 46.

In the mixer 46, the signal oscillated by the oscillating circuit 42 is frequency-divided by the N frequency divider 43 and further divided by M by the M frequency divider 44 to downconvert the signal from the amplifier 41. John. The output signal passes through an IF circuit (intermediate frequency circuit) 47 and a baseband signal processing section 48.
Is input to and demodulated.

On the other hand, the transmission signal output from the baseband signal processing unit 48 is modulated by the quadrature modulator 50, and when further transmitted in the 1.5 GHz band, the mixer 51 outputs 1.5.
It is up-converted to the GHz band, passes through a band pass filter 52, is power-amplified to a specified power by a power amplifier 53, and is transmitted from an antenna 31 through a frequency band switch 35, a transmission / reception switch 33, and an antenna matching circuit 32. It When transmitting in the 800 MHz band, the power is amplified up to the specified power by the power amplifier 55 through the band pass filter 54, and transmitted from the antenna 31 through the frequency band switch 35, the transmission / reception switch 33, and the antenna matching circuit 32.

The oscillation circuit 42 is the frequency synthesizer described with reference to FIG.
The output of -1 is to the N frequency divider 43, and the output signal of the PLL circuit 12-4 is the mixer 39 for frequency conversion and the quadrature modulator 50.
Is supplied to.

The oscillating circuit 56 is an oscillating circuit used for up-conversion when transmitting a 1.5 GHz band signal.
Transmitting 800MHz band transmission signal with mixer 51 to 1.5GHz
The frequency is converted to the frequency band (1429 to 1465 MHz).

With the above configuration, the antenna 31, the receiving circuit (amplifier 37, bandpass filter 38, mixer 39, bandpass filter 40, amplifier 41, mixer 46, and IF circuit 47) are used in two frequency bands. ) And the quadrature modulator 50 are shared. Also,
By using the N frequency divider 43 and the M frequency divider 44, the number of oscillators can be reduced as compared with the conventional one.

[Embodiment of Third Invention] FIG. 4 is a block diagram showing an example of the configuration of a digital car telephone of the third invention. As shown, the car telephone of the present invention is 800 MH
An antenna 61 for both z band and 1.5 GHz band, an antenna matching circuit 62 for sharing both frequency bands, a transmission / reception switch 63 for switching between transmission and reception, for frequency conversion of a reception signal of 1.5 GHz band to 800 MHz band Mixer
Frequency band switch 65, amplifier 67, band pass filter 6 for switching between 64, 1.5 GHz band and 800 MHz band
8, mixer 69 for converting the first intermediate frequency, bandpass filter 70, amplifier 71, oscillator circuit 72, oscillator circuit 8
6. N divider 7 for dividing the output frequency of the oscillation circuit 86
3, a low-pass filter 75, a second intermediate frequency conversion mixer 76, an IF circuit 77 for processing the intermediate frequency signal,
A base band signal processing unit 78 that demodulates a signal, a quadrature modulator 80 that modulates a transmission signal, a mixer 81 that frequency-converts an 800 MHz band signal into a 1.5 GHz band, a band pass filter 82, and a 1.5 GHz band signal. Power amplifier 83 and band pass filters 84, 8 for amplifying to a specified power
Power amplifier 8 that amplifies 00MHz band signal to the specified power
It is composed of 5.

In the digital car telephone having the above structure, the reception signal received by the antenna 61 passes through the receiving side of the antenna matching circuit 62 and the transmission / reception switch 63.
In the case of 5 GHz, it is input to the mixer-64. Mixer
In 64, the signal oscillated by the oscillating circuit 86 is used to
The Hz band signal is down-converted to 800 MHz band (frequency conversion), and the output signal is amplified by the amplifier 67 and is input to the mixer 69 through the band pass filter 68.

In the mixer 69, the input signal is down-converted by the output signal of the oscillation circuit 72, and the output signal is amplified by the amplifier 71 through the band pass filter 70 and input to the mixer 76.

In the mixer 76, the signal oscillated by the oscillating circuit 86 is divided by N by the N frequency divider 73 to obtain the signal from the amplifier 7.
The signal from 1 is down-converted. The output signal passes through an IF circuit (intermediate frequency circuit) 77 and is output to the base.
It is input to the band signal processing unit 78 and demodulated.

On the other hand, the transmission signal output from the base band signal processing unit 78 is modulated by the quadrature modulator 80, and when further transmitted in the 1.5 GHz band, the mixer 81 outputs 1.5.
It is up-converted to the GHz band, passes through a band pass filter 82, is power-amplified to a specified power by a power amplifier 83, and is transmitted from an antenna 61 via a frequency band switch 65, a transmission / reception switch 63, and an antenna matching circuit 62. It When transmitting at 800 MHz, the power is amplified to a specified power by the power amplifier 85 through the bandpass filter 84, and is transmitted from the antenna 61 via the frequency band switch 65, the transmission / reception switch 63, and the antenna matching circuit 62.

The oscillator circuit 72 is the frequency synthesizer described with reference to FIG.
The output of -1 goes to the mixer 81, and the output signal of the PLL circuit 12-4 goes to the mixer 69 for frequency conversion and the quadrature modulator 80.
Is supplied to.

With the above configuration, the antenna 61 and the receiving circuit (amplifier 67, bandpass filter 68, mixer 69, bandpass filter 70, amplifier 71, mixer 76 and IF circuit 77) are used in two frequency bands. ) And the orthogonal transformer 80 are shared. Also,
By using the N frequency divider 43, the number of oscillators can be reduced as compared with the conventional one.

[0038]

As described above in detail, according to the present invention, different frequency bands (for example, 1.5 GHz band and 800 GHz band) are used.
By sharing the antenna, the receiving circuit, and the quadrature modulator in the (MHz band), the number of antennas used is one, the number of quadrature modulators is one, the receiver circuit is one, and the oscillator is An excellent effect that the number of devices used can be reduced to three and the device can be downsized and the power consumption can be reduced can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a digital car telephone according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a frequency synthesizer used as the oscillation circuit of FIG.

FIG. 3 is a block diagram showing a configuration example of a digital car telephone according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration example of a digital car telephone according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration example of a conventional digital car telephone.

FIG. 6 is a block diagram showing a configuration example of an up-conversion jaw.

[Explanation of symbols]

 1 Antenna 2 Antenna Matching Circuit 3 Transmit / Receive Switcher 4 Mixer 5 Frequency Band Switcher 6 Oscillation Circuit 7 Amplifier 8 Bandpass Filter 9 Mixer 10 Bandpass Filter 11 Amplifier 12 Oscillation Circuit 12-1 Fixed Oscillator 12-2 Mixer 12 -3 Low-pass filter 12-4 PLL (Phase Locked Loop) circuit 13 N divider 15 Low-pass filter 16 Mixer 17 IF circuit 18 Baseband signal processing unit 20 Quadrature modulator 21 Mixer 22 Bandpass filter 23 Power Amplifier 24 Band Pass Filter 25 Power Amplifier 31 Antenna 32 Antenna Matching Circuit 33 Transmit / Receive Switch 34 Mixer 35 Frequency Band Switch 37 Amplifier 38 Band Pass Filter 39 Mixer 40 Band Pass Filter 41 Amplifier 42 Oscillation Circuit 43 N Dividing Bowl 44 M Frequency divider 45 Low pass filter 46 Mixer 47 IF circuit 48 Base band signal processing unit 50 Quadrature modulator 51 Mixer 52 Band pass filter 53 Power amplifier 54 Band pass filter 55 Power amplifier 56 Oscillation circuit 61 Antenna 62 Antenna matching circuit 63 Transmitter / receiver switcher 64 Mixer 65 Frequency band switcher 67 Amplifier 68 Bandpass filter 69 Mixer 70 Bandpass filter 71 Amplifier 72 Oscillation circuit 73 N divider 75 Low-pass filter 76 Mixer 77 IF circuit 78 Baseband Signal processing unit 80 Quadrature modulator 81 Mixer 82 Bandpass filter 83 Power amplifier 84 Bandpass filter 85 Power amplifier 86 Oscillation circuit

Claims (3)

[Claims] 1. A digital mobile telephone that can be shared by two different frequency bands, in which the antenna, the receiving circuit and the modulator are shared by the two different frequency bands, and the output frequency of the first local oscillation circuit. A frequency divider that divides the output frequency of the first local oscillator circuit by N, and a unit that sets the frequency obtained by dividing the output frequency of the first local oscillator circuit by the second local frequency of the receiver circuit. A digital type mobile telephone, comprising an oscillator for switching, and means for sharing an output frequency of the oscillator for frequency conversion of a transmission frequency and frequency conversion of a reception frequency. 2. A digital mobile telephone that can be shared by two different frequency bands, a means for sharing an antenna, a receiving circuit and a modulator in the two different frequency bands, and an output frequency of the first local oscillation circuit. Frequency divider that divides N by N
A divider for dividing the output frequency of the divider by M, means for setting the frequency obtained by dividing the output frequency of the oscillator circuit by (N × M) to be the second local frequency of the receiver circuit, A digital type car telephone, characterized in that the output frequency of the first local oscillation circuit is shared for the modulator, and means for using the frequency divided by N for converting the reception frequency is provided. 3. A digital type mobile telephone that can be shared by two different frequency bands, a means for sharing an antenna, a receiving circuit and a modulator in the two different frequency bands, and an output frequency of a first local oscillation circuit. Is used for the modulator and for converting the transmission frequency, an oscillation circuit is separately provided, and a frequency divider for dividing the output frequency of the oscillation circuit by N is provided, and the output frequency of the oscillation circuit is used for conversion of the reception frequency. And a means for using the frequency divided by N as the second local frequency is provided.