JP3402186B2 - Transmitter / receiver circuit for dual band wireless communication device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission / reception circuit for a dual band radio communication device, and more particularly to a GSM (Global
System for Mobile communications) and DCS (Digital
The present invention relates to a transmitter / receiver circuit for a dual band wireless communication device capable of communicating by both different communication systems such as Cellular System).

[0002]

2. Description of the Related Art In Europe, there are a 900 MHz band GSM and a 1.8 GHz band DCS as communication systems for mobile phones. And this 900MHz band and 1.
There is a demand for a compatible mobile phone capable of communicating by connecting to both bands including the 8 GHz band. This compatible mobile phone is technically a dual-band wireless communication device.

FIG. 7 shows a conventional transmitter / receiver circuit for a dual band radio communication device. The transmission / reception circuit 50 is an antenna 5 that transmits / receives GSM and DCS transmission signals and reception signals.
1. The GSM transmission signal and the DCS transmission signal are combined to form the main transmission signal transmitted from the antenna 51, or the main reception signal received by the antenna 51 is GS
A diplexer 52 for demultiplexing the received signal of M and a received signal of DCS, low pass filters 53, 54 for cutting off the second and third harmonics of the transmitted signals of GSM and DCS,
And first and second high frequency switches 55 and 56 for switching between a transmission signal and a reception signal in GSM and DCS
Composed of. The first terminal of the diplexer 52 is connected to the antenna ANT, and the second and third terminals of the diplexer 52 are connected to each other.
Through the low-pass filters 53 and 54 to the first terminals of the first and second high-frequency switches 55 and 56, and the second terminals of the first and second high-frequency switches 55 and 56 to GSM. And DCS modulators MODgsm, MODdcs
In addition, the third terminals of the first and second high-frequency switches 55 and 56 have the GSM and DCS demodulation units DEgsm and DEdc.
s, respectively.

[0004]

However, in the above-mentioned conventional transmitter / receiver circuit for a dual-band wireless communication device, first, the diplexer is used to divide into GSM and DCS, and a high frequency switch is used to switch between a transmission signal and a reception signal.
In the GSM and DCS, when the modulation unit and the demodulation unit are shared, the wirings cross each other as shown in FIG. Therefore, there has been a problem that the design is complicated and the design becomes complicated.

On the contrary, in order to facilitate the design, G
In the SM and the DCS, when the modulation unit and the demodulation unit are separately provided, the number of parts increases, and there is also a problem that the dual band wireless communication device mounting the transmission / reception circuit becomes large.

The present invention has been made to solve the above problems, and is easy to design, and the dual band wireless communication device for transmitting and receiving can be miniaturized. The purpose is to provide a circuit.

[0007]

In order to solve the above-mentioned problems, a transceiver circuit for a dual band radio communication apparatus of the present invention includes an antenna for transmitting and receiving a main transmission signal and a main reception signal, a transmission signal of a first band, A first diplexer for multiplexing the transmission signal of the second band into the main transmission signal to the antenna, a first switch for turning on / off the main transmission signal to the antenna, and A second diplexer for demultiplexing the main reception signal into a reception signal of a first band and a reception signal of a second band, and turning on the reception signal of the first band and the reception signal of the second band A second switch that is turned off, the first terminal of the first switch and the second diplexer is the antenna, and the second terminal of the first switch is the first dip A first terminal of the first diplexer, second and third terminals of the first diplexer to a modulator of the first and second bands, and second and third terminals of the second diplexer to the first terminal of the second diplexer. The second and third terminals of the second switch are respectively connected to the first and second terminals of the second switch, and the demodulators of the first and second bands are connected to the second and third terminals, respectively .
When transmitting the transmission signals of the first and second bands, the first
Turn on the switch, turn off the second switch,
When receiving the reception signals of the first and second bands, the first
Is turned off and the second switch is turned on .

A low pass filter is arranged between the first switch and the first diplexer, and a second terminal of the first switch is a first terminal of the low pass filter. , The second terminal of the low-pass filter is connected to the first terminal of the first diplexer, respectively.

According to the transmitter / receiver circuit for a dual band radio communication device of the present invention, the first diplexer multiplexes the transmission signal of the first band and the transmission signal of the second band, and transmits the main transmission signal to the antenna. The main transmission signal to the antenna is turned on / off by turning on / off the first switch, and the main reception signal from the antenna is turned on / off by the second diplexer. Since the received signal is demultiplexed and the second switch is turned on / off to turn on / off the received signal of the first band and the received signal of the second band, the first and second Even in the case where the modulation section and the demodulation section are shared in the band, the wiring does not intersect and the design can be facilitated.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of an embodiment of a transceiver circuit for a dual band wireless communication apparatus according to the present invention.

The transmission / reception circuit 10 includes an antenna 11 for transmitting / receiving a main transmission signal and a main reception signal, and an antenna 11 for multiplexing the transmission signal of the first band and the transmission signal of the second band.
First diplexer 12 as a main transmission signal to the antenna, a low-pass filter 13 that blocks second and third harmonics of the main transmission signal to the antenna 11, and on / off of the main transmission signal to the antenna 11. First switch 14, antenna 1
A second diplexer 1 for demultiplexing a main reception signal from the first reception signal into a reception signal of a first band and a reception signal of a second band.
5, and a second switch 16 for turning on / off the reception signal of the first band and the reception signal of the second band.

The first terminals 141 and 151 of the first switch 14 and the second diplexer 15 are connected to the antenna 11, and the second terminal 142 of the first switch 14 is connected to the first terminal of the low-pass filter 13. The second terminal 132 of the low pass filter 13 is connected to the terminal 131 by the first diplexer 12
To the first terminal 121 of the second diplexer 12 of the first diplexer 12.
And the third terminals 122 and 123 are connected to the modulation section MOD1 of the first band and the modulation section MOD2 of the second band, and the second and third terminals 152 and 153 of the second diplexer 15 are connected.
Is the first and second terminals 161, 1 of the second switch 16.
62 to the third and fourth terminals 16 of the second switch 16
3, 164 are connected to the demodulation unit DE1 for the first band and the demodulation unit DE2 for the second band, respectively.

FIG. 2 shows a specific circuit diagram of the transmission / reception circuit for the dual band radio communication device of FIG. First and second
The diplexers 12 and 15 have the same structure and are composed of inductors L11 and L12 and capacitors C11 to C15. Then, the first and second terminals 121 (15
1) and 122 (152), a parallel circuit including an inductor L11 and a capacitor C11 is connected, and the second terminal 122 (152) side of the inductor L11 is grounded via the capacitor C12.

The first and third terminals 121 (15)
1) and 143 (153) between capacitors C13 and C14
Connected in series circuit, and capacitors C13, C1
The connection point of 4 is grounded via an inductor L12 and a capacitor C15.

The low pass filter 13 is an inductor L2.
1, L22 and capacitors C21 to C25,
An inductor L2 is provided between the first and second terminals 131 and 132.
A series circuit composed of 1 and L22 is connected. Both ends of the inductors L21 and L22 have capacitors C21 to C21.
The capacitors C24 and C25 are connected in parallel to the inductors L21 and L22, respectively.

The first switch 14 is a diode D31,
Inductors L31 to L34, capacitors C31 to C34
And a resistor R31, and the first and second terminals 14
1 and 142, the anode of the diode D31 is connected so as to be on the first terminal 141 side. The anode of the diode D31 is grounded via the inductor L31 and the capacitor C31, and the cathode of the diode D31 is the resistor R31, the inductor L32 and the capacitor C32.
Grounded through.

Further, the inductor L31 and the capacitor C3
1 connection point, inductor L32 and capacitor C3
Control terminals Vcc1 and Vcc2 for controlling ON / OFF of the diode D31 are provided at a connection point with 2.
Further, the diode D31 has inductors L33 and L3.
4 and a capacitor C33 are connected in parallel, and a capacitor C34 is connected in parallel to the inductor L33.

The second switch 16 is a diode D41,
D42, inductors L41 to L43 and capacitor C4
1 to C44, the first and third terminals 161 and 1
A capacitor C41 and a diode D41 are connected between 63 and the ground. Also, the second and fourth terminals 16
A capacitor C42 and a diode D42 are connected between 2, 164 and the ground, and a series circuit including an inductor L41 and a capacitor C43 is connected in parallel to the diode D42.

Further, a capacitor C41 and a diode D
41 connection point, capacitor C42 and diode D4
A control terminal Vcc3 for controlling on / off of the diodes D41 and D42 is provided at the connection point of 2 with the inductor L4.
2, L43. In addition, inductor L4
The control terminal Vcc3 side of 3 is grounded via a capacitor C44.

Here, regarding the operation of the transmission / reception circuit 10 having the above configuration, the first and second bands are set to GSM (900M).
Hz band) and DCS (1.8 GHz band).

First, when transmitting GSM or DCS, the diodes D31, D41 and D42 of the first and second switches 14 and 16 are turned on (Vcc1 = 3V, V).
cc2 = 0V, Vcc3 = 3V), and the first switch 14 is turned on and the second switch 16 is turned off. Therefore, GSM or DCS modulators MOD1 and MOD
The transmission signal from 2 flows only to the antenna 11. At this time, the GSM and DCS second and third harmonics are blocked by the low-pass filter 13.

Here, the reason why the second switch 16 is turned off will be described. Since the diodes D41 and D42 become an inductance component when turned on, the capacitor C41
And the diode D41, and the capacitor C42 and the diode D42 form an LC series resonance circuit. Therefore, if the resonance frequency of this LC series resonance circuit is set to be the same as the frequencies of the GSM transmission signal and the DCS transmission signal, the second
Switch 16 turns off when transmitting GSM or DCS.

3 and 4 show the insertion loss of the transmission / reception circuit 10 when transmitting GSM and DCS. The solid line shows the insertion loss between the antenna and the modulation unit (ANT-MOD), and the broken line shows the insertion loss between the antenna and the demodulation unit (ANT-DE).

From FIG. 3, between the antenna and the modulator, the insertion loss near 900 MHz is about -1 dB, and the insertion loss near the second harmonic of 1.8 GHz is -25.
The insertion loss near 2.7 dB, which is about 3 dB as the third harmonic, is about −53 dB, and the insertion loss near 900 MHz between the antenna and the demodulation unit is about −20 dB, which is the second harmonic thereof. The insertion loss around 8 GHz is about -44 dB, which is the third harmonic of 2.7 GHz.
It can be seen that the insertion loss in the vicinity is about -56 dB.

This is because between the antenna and the modulator,
The GSM transmission signal is passed, and the second harmonic and the third harmonic of the GSM transmission signal are completely cut off.
It indicates that the third harmonic and the third harmonic are completely cut off.

From FIG. 4, between the antenna and the modulator, the insertion loss near 1.8 GHz is about -1 dB,
The insertion loss near 3.6 GHz, which is the second harmonic, is −
About 30 dB, the insertion loss near 5.4 GHz, which is the third harmonic, is about -38 dB, and the insertion loss near 1.8 GHz is -20 d between the antenna and the demodulator.
B, the insertion loss near 3.6 GHz, which is the second harmonic, is about -35 dB, 5.4 G, which is the third harmonic.
It can be seen that the insertion loss around Hz is about -42 dB.

This is because between the antenna and the modulator,
The DCS transmission signal is allowed to pass through, and the second and third harmonics of the DCS transmission signal are completely cut off, and the DCS transmission signal, 2
It indicates that the third harmonic and the third harmonic are completely cut off.

Next, when receiving GSM or DCS, the diodes D31, D41, D42 of the first and second switches 14, 16 are turned off (Vcc1 = 0V,
(Vcc2 = 3V, Vcc3 = 0V), and the first switch 14 is turned off and the second switch 16 is turned on. Therefore, the received signal from the antenna 11 flows only to the GSM or DCS demodulation units DE1 and DE2.

Here, in the second switch 16, a method of turning on between the first and third terminals 161 and 163 or between the second and fourth terminals 162 and 164 will be described. Since the diodes D41 and D42 become a capacitance component when turned off, the third terminal 163 side serves as a low pass filter, and the fourth terminal 164 side serves as a high pass filter for LC parallel resonance between the inductor L41 and the diode D41. Become. Therefore, the low-pass filter on the third terminal 163 side can block the DCS received signal, and the high-pass filter on the fourth terminal 164 side can block the GSM received signal. When the pass band is set, the first and third terminals 161 and 163 are turned on when receiving DCS, and the second and fourth terminals 162 and 164 are turned on when receiving GSM. Become.

5 and 6 show the insertion loss of the transmission / reception circuit 10 when receiving GSM and DCS. The solid line indicates the insertion loss between the antenna and the demodulation unit (ANT-DE),
The broken line shows the insertion loss between the antenna and the modulator (ANT-MOD).

From FIG. 5, between the antenna and the demodulator, the insertion loss around 900 MHz which is the frequency of the received signal of GSM is about -1 dB, and the insertion loss near the frequency of 1.8 GHz which is the frequency of the received signal of DCS is-. It can be seen that the insertion loss is about 35 dB, and the insertion loss near 900 MHz is about -24 dB between the antenna and the modulator, and the insertion loss near 1.8 GHz is about -13 dB.

This is because, when receiving GSM, the reception signal of GSM is passed between the antenna and the demodulation section, and the reception signal of DCS is completely cut off, and the GSM reception section between the antenna and the modulation section. It indicates that the reception signal of 1 and the DCS reception signal are completely cut off.

Further, from FIG. 6, between the antenna and the demodulation unit, the frequency of the received signal of GSM is 900 MHz.
The insertion loss in the vicinity is about -38 dB, the insertion loss in the vicinity of 1.8 GHz, which is the frequency of the received signal of DCS, is about -1 dB, and the frequency between the antenna and the modulator is 900
It can be seen that the insertion loss near z is about -30 dB and the insertion loss near 1.8 GHz is about -22 dB.

This is because when the DCS is received, the reception signal of DCS is allowed to pass between the antenna and the demodulation section, and the reception signal of GSM is completely cut off, and the GSM is received between the antenna and the modulation section. It indicates that the reception signal of 1 and the DCS reception signal are completely cut off.

According to the transmitter / receiver circuit for a dual band radio communication device of the above-mentioned embodiment, the first diplexer multiplexes the transmission signal of the first band and the transmission signal of the second band to the antenna. The main transmission signal to the antenna is turned on / off by turning on / off the first switch, and the main reception signal from the antenna is turned on / off by the second diplexer. The first band received signal and the second band received signal are turned on / off by demultiplexing into the second band received signal and turning on / off the second switch. And the second
Even in the case where the modulation section and the demodulation section are shared in the band, the wirings do not intersect with each other and the design can be facilitated.

In addition, since the wirings do not intersect, the first and second modulators and demodulators can be shared. Therefore, it is possible to reduce the size of the dual-band wireless communication device equipped with this transmission / reception circuit.

Further, since all the diodes constituting the first and second switches are grounded, all the diodes can be turned off at the time of reception, and as a result, the first and second switches can be turned off. Current consumption can be reduced to zero. In addition, since the received signal does not pass through the diode, the loss in the second switch can be zero.

Further, since the low-pass filter is arranged on the transmitting side, it is possible to block the second harmonic and the third harmonic of the main transmission signal. As a result, unnecessary signals are completely removed from the main transmission signal, the transmission characteristics are remarkably improved, and the transmission / reception circuit for a dual-band wireless communication device is extremely effective.

In the above embodiment, the case where the transceiver circuit for the dual band radio communication device is used for the combination of GSM and DCS has been described, but the use is limited to the combination of GSM and DCS. However, for example, GSM and DCS (Digital Cellular Sy)
stem), GSM and PCS (Personal Commu
nication services), AMPS (Advance
d Mobile Phone Services) and PCS, G
SM and DECT (Digital European Cordless Telephon
e), PDC and PHS (Personal Handy-ph)
can be used in combination with one System), etc.

Further, if at least two of the first and second switches, the first and second diplexers, and the low-pass filter are integrated and integrated in one laminated body, the transmission / reception circuit is further downsized, It is possible to further reduce the size of a dual band wireless communication device equipped with this transmission / reception circuit. This effect is enhanced by incorporating and integrating more components into one laminated body.

[0041]

According to the transmitter / receiver circuit for a dual band radio communication device of the first aspect, the first diplexer multiplexes the transmission signal of the first band and the transmission signal of the second band to the antenna. Set the first switch as the main transmission signal.
The main transmission signal to the antenna is turned on / off by turning it off, and the main reception signal from the antenna is demultiplexed into the reception signal of the first band and the reception signal of the second band by the second diplexer, Since the configuration is such that the reception signal of the first band and the reception signal of the second band are turned on / off by turning on / off the switch of No. 2, the modulation unit and the demodulation unit are provided in the first and second bands. In the case of sharing the same, the wirings do not cross each other and the design can be facilitated.

In addition, since the wiring does not intersect, the first and second modulators and demodulators can be shared. Therefore, it is possible to reduce the size of the dual-band wireless communication device equipped with this transmission / reception circuit.

Further, since all the diodes forming the first and second switches are grounded, all the diodes can be turned off at the time of reception, and as a result, the first and second switches can be turned off. Current consumption can be reduced to zero. In addition, since the received signal does not pass through the diode, the loss in the second switch can be zero.

According to the transmitter / receiver circuit for a dual-band wireless communication device of claim 2, since the low-pass filter is arranged on the transmitting side, the second harmonic wave and the third harmonic wave of the main transmission signal are cut off. be able to. As a result, unnecessary signals are completely removed from the main transmission signal, the transmission characteristics are remarkably improved, and the transmission / reception circuit for a dual-band wireless communication device is extremely effective.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a transceiver circuit for a dual band wireless communication device of the present invention.

FIG. 2 is a specific circuit diagram of the transmission / reception circuit of FIG.

FIG. 3 is a diagram showing insertion loss between an antenna and a modulation unit and between an antenna and a demodulation unit when transmitting the first band (GSM).

FIG. 4 is a diagram showing insertion loss between the antenna and the modulation unit and between the antenna and the demodulation unit when transmitting the second band (DCS).

FIG. 5 is a diagram showing insertion loss between the antenna and the demodulation unit and between the antenna and the modulation unit when transmitting the first band (GSM).

FIG. 6 is a diagram showing insertion loss between the antenna and the demodulation unit and between the antenna and the modulation unit when transmitting the second band (DCS).

FIG. 7 is a block diagram showing a conventional transceiver circuit for a dual band wireless communication device.

[Explanation of symbols]

10 Transmitter / receiver circuit 11 antenna 12 First Diplexer 13 Low pass filter 14 First switch 15 Second Diplexer 16 Second switch

Claims (2)

(57) [Claims] 1. An antenna for transmitting / receiving a main transmission signal and a main reception signal, a first band transmission signal for multiplexing a first band transmission signal and a second band transmission signal for the main transmission signal to the antenna. Diplexer, a first switch that turns on / off the main transmission signal to the antenna, and demultiplexes the main reception signal from the antenna into a reception signal of a first band and a reception signal of a second band. A second diplexer, and a second switch for turning on / off the reception signal of the first band and the reception signal of the second band, and the first switch and the first diplexer
To the antenna, the second terminal of the first switch to the first terminal of the first diplexer, and the second and third terminals of the first diplexer to the first and second terminals. In the band modulator, the second and third terminals of the second diplexer are connected to the first and second terminals of the second switch, and the third and fourth terminals of the second switch are connected to the first and second terminals of the second switch. the demodulator of the first and second bands are connected respectively, when transmitting a transmission signal of the first, second band
When the first switch is turned on, the second switch is turned off, and the reception signals of the first and second bands are received.
A transmitter / receiver circuit for a dual-band wireless communication device, characterized in that the first switch is turned off and the second switch is turned on . 2. A low-pass filter is disposed between the first switch and the first diplexer, and the first pass filter is disposed between the first switch and the first diplexer.
The second terminal of the switch is the first of the low pass filter
And a second terminal of the low-pass filter is connected to a first terminal of the first diplexer, respectively. .