JP2591489Y2 - High frequency mobile radio transceiver - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention is applied to different frequencies, for example, 80.
In each frequency band of 0 MHz or 1500 MHz, a high frequency device in which a modulator can be shared by interlockingly switching a plurality of sets of wireless transceivers of a mobile communication device such as a digital car phone employing a heterodyne system for each frequency band. The present invention relates to a mobile radio transceiver.

[0002]

2. Description of the Related Art Conventionally, a heterodyne radio transmitting / receiving apparatus in a car telephone is, for example, a first transmitting / receiving apparatus shown in FIG.
For the 800 MHz band and the second transceiver B for 1500 MHz
Generally used for the Hz band. In FIG. 2, the first
The transceiver A receives the modulated carrier received by the antenna 1 via the duplexer 8, the RF amplifier 2, the bandpass filter 3, the mixer 4 of the frequency conversion unit offset by the first local oscillator 9, the bandpass filter 5, and the amplifier. 6. Mixer 7 of frequency conversion unit offset by second local oscillator 10
, A modulator 13 for modulating a signal from the signal processing unit 16, a band-pass filter 12, a power amplifier 11 for amplifying a transmission signal, and a path to the antenna via the duplexer 8. And a dedicated transmission stage, for example, for transmission and reception in the 800 MHz band.

[0003] The second transceiver B also includes the same transmission and reception stages provided in the first transceiver, for example, at 1500 MHz.
Dedicated for sending and receiving bands.

In order to correspond to the different frequency bands, each receiving stage and each transmitting stage of each of the first and second transceivers are movable so as to be switchable to each use frequency band A or B. A switch 1 provided with contacts A and B and having fixed contacts connected to a path from the receiving stage to a signal processing unit 16 through a final second intermediate frequency stage 15 including a detector and the like.
4-1 and a switch 14-2 in which a fixed contact is connected to a path from the signal processing unit 16 to the signal processing unit 16 included in each transmission stage.

[0005]

However, in the above-mentioned conventional configuration, since two systems of modulators are provided in each transmission stage for each different frequency band, the external dimensions and weight of the apparatus to be reduced in size and weight are increased. Alternatively, there is a problem in that power consumption during transport depending on battery power cannot be reduced.

[0006]

SUMMARY OF THE INVENTION In order to eliminate the above obstacles, the present invention aims at sharing a modulator provided in each of a plurality of transceivers dedicated to each frequency band, from a signal processing unit to each transmission stage. A switch for switching the output side of a single modulator for applying a modulation wave to the
A switch for switching between local oscillators and a switch for switching the output side of each frequency conversion unit mixed with the second local oscillator reaching the demodulation unit of each reception stage for each frequency band are provided so as to operate in conjunction with each other, and the wireless communication is performed. The transmitting and receiving device is constituted.

[0007]

FIG. 1 shows an embodiment of the present invention. In FIG. 1, the same parts as those in FIG. 2 are denoted by the same reference numerals, and frequency bands A,
B, in the circuit configuration of the first and second transceivers A and B respectively corresponding to each other, a portion surrounded by a two-dot chain line in the second transceiver B is a receiving stage Rx of the first transceiver A, 2 shows a circuit configuration corresponding to each of the transmission stages Tx. Further, a switch 14- for switching the receiving stage or the transmitting stage of the first and second transceivers.
The movable contacts A and B of 1, 14-2 and 14-3 are the first, respectively.
The switches correspond to the second transceivers A and B, and the switches are linked. The intermediate frequency stage 15 is a detector and other final stages of the second intermediate frequency which are not included in the receiving stage, and the modulator 13 is used alone for the first and second transceivers. A frequency suitable for frequency synthesis by a synthesizer (not shown) provided outside and capable of responding to transmission and reception of different frequencies can be taken out.

The signal from the signal processing unit 16 is transmitted to the modulator 13
The modulation is applied by the frequency of the first local oscillator 9 or 29 on either side A or B selected by the switch 14-3 linked with the above, and the band-pass filters remove the unnecessary waves, respectively, and are supplied to the respective power amplifiers. Sent through some duplexer.

[0009]

According to the present invention, it is possible to use a single modulator in the circuit configuration of each of the transmitting and receiving stages corresponding to different high-frequency bands. Just provide a switch to share a single modulator,
Reduce power consumption, size, and weight of the entire device.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of the high-frequency mobile radio transceiver of the present invention.

FIG. 2 is a circuit configuration diagram of a conventionally known high-frequency mobile radio transceiver.

[Explanation of symbols]

 1, 21 Antenna 2 RF amplifier 3, 5, 12 Band-pass filter 6 Amplifier 4, 7 Mixer 8, 28 Duplexer 9, 29 First local oscillator 10, 20 Second local oscillator 11 Power amplifier 13 Modulator 14-1, 14 -2, 14-3 Switch 15 Intermediate frequency stage 16 Signal processing unit A First transceiver B Second transceiver Rx reception stage Tx transmission stage

Claims (1)

(57) [Scope of request for utility model registration] 1. A heterodyne high-frequency mobile radio transmission / reception device in which two sets of mobile radio transmission / reception devices provided corresponding to different high-frequency bands are switched for each use frequency band. , A signal processing unit for processing a received signal from each receiver, a first switch for switching each of the receivers, and modulating a signal from the signal processing unit. A second path for switching to a path from the modulator to the high-frequency output section of each transmission stage corresponding to the frequency band;
And a third switch provided in each of the receivers for switching the frequency supplied from each of the first local oscillators, so that the modulators can be used irrespective of the frequency band used. A high-frequency mobile radio transmission / reception device characterized by the above-mentioned.