JP2805555B2 - 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 duplex communication radio communication apparatus.

[0002]

2. Description of the Related Art A specific low-power wireless communication device is widely used in a wireless communication device, especially a vehicle-mounted type and a portable type, which are used in a duplex system. The duplex wireless communication apparatus can transmit and receive at the same time by separating the transmission frequency f1 and the reception frequency f2 at a certain interval (several MHz). Conventionally, when performing communication using this method, the relationship between the transmission frequency and the reception frequency of the pair of wireless communication devices on the near side and the opposite side is opposite to each other, and simultaneous duplex communication is possible. Becomes In other words, if the device on this side has the transmission frequency f1 and the reception frequency f2, the communicable device on the other side has the transmission frequency f2 and the reception frequency f1.

FIG. 2 shows a related circuit configuration of a conventional wireless communication apparatus using a duplex system. The contents will be described in detail with reference to the drawings. The reception band-pass filter 2 and the transmission band-pass filter 8 are branched and connected to the antenna 1, and constitute a duplexer there. The received signal from the antenna 1 is passed through a receiving bandpass filter 2 to an amplifier 3.
, And is input to the mixer 4 and mixed with the output of the local oscillator 5 to be converted to an intermediate frequency. It should be noted that those up to the audio path below this are omitted because they are known. Also,
For transmission, the output from the VCO 6 is amplified by the power amplifier 7, sent to the antenna 1 via the transmission band-pass filter 8, and a transmission signal is output from the antenna 1. The circuit configuration up to the VCO 6 and the like are omitted because they are known. In the above circuit configuration, the following must be considered. That is, the receiving bandpass filter 2 must have a characteristic having a sufficient amount of attenuation in its transmission frequency band so as not to be affected by its own transmission output. Further, the transmission band-pass filter 8 must have a characteristic of sufficiently attenuating the reception frequency band in the sideband of the transmission carrier.

Therefore, the frequency band in which transmission or reception is possible is determined by the characteristics of such a band-pass filter, and in a device on the other side of communication, the transmission and reception band-pass filters must be replaced. No. That is, two types of such models are required for a call, and if these two types of models are arranged for a large number of users, the parties with which they can talk are naturally limited. There are problems such as being limited to things.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems and the like, and enables a user to communicate with an unspecified number of wireless communication devices. It is an object of the present invention to provide a wireless communication device of a duplex communication method in which the above-mentioned communication can be performed with only one model.

In order to achieve the above object, the frequency f1
The first bandpass filter and the received signal from the antenna
A reception frequency received through the first band-pass filter
A first receiving circuit system of the number f1 and the first bandpass filter;
Transmission frequency to transmit the transmission signal from the antenna through the filter
The first transmitting circuit system of the number f1 and the second band pass of the frequency f2.
Filter and the received signal from the antenna
Of the reception frequency f2 received through the
Via the receiving circuit system and the second band-pass filter
A second transmission frequency f2 for transmitting a transmission signal from the antenna
A transmission circuit system and a reception frequency f of the first reception circuit system
1 and the transmission frequency f2 by the second transmission circuit system
Or the receiving frequency of the second receiving circuit system
f2 reception and transmission frequency f by the first transmission circuit system
Switching means for switching to any one of
And the switching means comprises a first reception circuit.
One of the path system and the first transmission circuit system
A second band-pass filter and the second reception
One of the circuit system and the second transmission circuit system
Connected to a second bandpass filter .

[0007]

With the above arrangement, transmission and reception can be performed in any frequency band of the duplex communication, and control can be performed to electrically switch the transmission and reception frequency band together with the operation of the call request.

[0008]

FIG. 1 is a circuit diagram showing an embodiment of the apparatus of the present invention. An antenna a is branched and connected to a bandpass filter b1 of a frequency band f1 and a bandpass filter b2 of a frequency band f2. , Which constitutes a duplexer.

The band-pass filter b1 has a branch connection via a switching circuit c, one of which is connected to a receiving circuit system such as a receiving amplifier d, a mixer h, and a switching circuit i, and the other is a transmission power amplifier e and a switching circuit f. , V
It is connected to a transmission circuit system such as a CO circuit g and constitutes a transmission / reception circuit of the frequency band f1 by switching. The bandpass filter b2 is connected as a branch connection via a switching circuit m, one of which is connected to a receiving circuit system such as a receiving amplifier o, a mixer p, and a switching circuit q, and the other is a transmission power amplifier n, a switching circuit f, and a VCO circuit. It is connected to a transmission circuit system such as g to constitute a transmission / reception circuit of the frequency band f2 by switching.

In the apparatus of the present invention, the transmission frequency band is defined as f
1. When talking on the reception frequency band of f2, V
The transmission signal of the CO circuit g is connected to the power amplifier e by the switching circuit f. The amplified transmission signal is sent to the band-pass filter b1 by the switching circuit c and supplied to the antenna a. Also, it is input from antenna a,
The reception signal that has passed through the band-pass filter b2 is sent to the reception amplifier o by the switching circuit m and amplified. The amplified reception signal is input to a mixer p, mixed with an output signal of a local oscillator k connected by a switching circuit j, converted to an intermediate frequency, and sent from a switching circuit q to a known next-stage circuit (not shown). .

At this time, power is not supplied to the receiving amplifier d, the mixer h, the switching circuit i, and the like on the frequency band f1 side, and is in a non-operating state. Thus, isolation of the input terminal of the receiving amplifier d is ensured. Also, VC
Since the transmission signal of the O circuit g is not connected to the power amplifier n on the frequency band f2 side by the switching circuit f, the power amplifier n is not supplied with power and is in an inactive state, and is further cut off by the switching circuit m. Isolation from the receiving amplifier o is ensured.

As will be understood from the above description, the output of the transmission signal of the own frequency band f1 is not affected by the suppression of the reception sensitivity of the frequency band f2.

Next, a description will be given of a case where a call is made with the transmission frequency band f2 and the reception frequency band f1 according to the apparatus of the present invention. The transmission signal of the VCO circuit g is sent to the power amplifier n by the switching circuit m. The amplified transmission signal is converted by a switching circuit m into a band-pass filter b2.
To the antenna a. The received signal input from the antenna a and passed through the band-pass filter b1 is sent to the receiving amplifier d by the switching circuit c and amplified. The amplified reception signal is input to a mixer h, mixed with an output signal of a local oscillator k connected by a switching circuit j, converted to an intermediate frequency, and sent from a switching circuit i to a known next-stage circuit (not shown). .

At this time, power is not supplied to the receiving amplifier o, the mixer p, the switching circuit q, etc. on the side of the frequency band f2, the power amplifier n is in an inactive state, and the switching circuit m further outputs the transmission signal output of the power amplifier n. Isolation between the end and the input end of the receiving amplifier o is ensured. Also, VC
The transmission signal of the O circuit g is not connected to the power amplifier e on the frequency band f1 side by the switching circuit f, and the power amplifier is not supplied with power and is in a non-operating state. Isolation from the amplifier d is ensured.

As is apparent from the above, the output of the transmission signal in the own frequency band f2 is not affected by the suppression of the reception sensitivity in the frequency band f1.

[0016]

As described above, the wireless communication apparatus according to the present invention enables transmission and reception of both frequency bands with one apparatus in a duplex communication, and the transmission and reception frequencies during standby and called communication. The control of exchanging the band and the transmission / reception frequency band for the outgoing call together with the call request of the user can be electrically performed, and the duplex call can be performed with only one type of device. The user of the device of the present invention does not need to place the device separately, and can talk with an unspecified number of parties, and since the transmission and reception frequency bands at the time of standby and at the time of calling are specified in advance, the same frequency is used. All the waiting stations can be contacted simultaneously. Also, for the producers and sellers of the apparatus, since only one model is sufficient, a great effect can be expected in terms of management and the like.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a device according to the present invention.

FIG. 2 is a related circuit diagram of a conventional wireless communication device using a duplex system.

[Explanation of symbols]

 a antenna b1 band-pass filter in frequency band f1 b2 band-pass filter in frequency band f2 c switching circuit d receiving amplifier e power amplifier f switching circuit g VCO circuit h mixer i switching circuit j switching circuit k local oscillator m switching circuit n power Amplifier o Receiver amplifier p Mixer q Switching circuit

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-1-309422 (JP, A) JP-A-62-65522 (JP, A) JP-A-62-295527 (JP, A) 35656 (JP, U) Japanese Utility Model Showa 60-37956 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04B 1/38-1/58

Claims (1)

(57) [Claims] 1. A first band-pass filter having a frequency f1.
And a first band pass filter for receiving a signal from an antenna.
And a first receiving circuit system having a reception frequency f1 received through the first band-pass filter from the antenna.
A first transmission circuit system at a transmission frequency f1 for transmitting a transmission signal, a second bandpass filter at a frequency f2, and a second bandpass filter for receiving a signal from an antenna.
And a second reception circuit system having a reception frequency f2 received through the second band-pass filter.
A second transmitting circuit system of a transmission frequency f2 for transmitting a communication signal, and a reception and reception of a reception frequency f1 by the first receiving circuit system.
The transmission of the transmission frequency f2 by the second transmission circuit system, and
Is the reception frequency f2 received by the second reception circuit system.
And transmission of the transmission frequency f1 by the first transmission circuit system.
Switching means for switching to either the first receiving circuit system or the first receiving circuit system.
One of the first transmitting circuit systems is connected to the first band pass.
Connected to a filter and the second receiving circuit system or
One of the second transmission circuit systems is connected to the second bandpass
A wireless communication device connected to the wireless communication device.