JPH0583175A - Diversity transmitter-receiver - Google Patents

Abstract

(57) [Summary] [Purpose] To be able to receive radio waves from one receiving system and transmit radio waves from the other transmitting system, even if the frequency difference between the two systems of transmitted and received signals is slight. [Configuration] A transmission / reception system connected to the α-system antenna 31,
The analog switch 58 is used to select a voice signal of a system having high reception sensitivity among the transmission / reception systems connected to the β system antenna 61,
A transmission control circuit 59 applies a transmission command signal to a transmission system different from the selected reception system to form a transmission path of this transmission system so as to prevent each transmission / reception system from simultaneously transmitting and receiving. ..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diversity transmitter / receiver used mainly in a wireless intercom base station used in a broadcasting station, a hotel banquet hall and the like.

[0002]

2. Description of the Related Art Conventionally, an apparatus of this type is known as shown in FIG. This device comprises a transmission / reception system connected to the α system antenna 1 and a transmission / reception system connected to the β system antenna 12. The radio wave received by the α-system antenna 1 is demodulated by the demodulator 7 via the mixer 2, the reception filter 3, the reception amplifier 4, the mixer 5, and the intermediate amplifier 6.
On the other hand, the radio wave received by the β-system antenna 12 is a mixer 13, a reception filter 14, a reception amplifier 15, and a mixer 1.
6, demodulated by the demodulator 18 via the intermediate amplifier 17.
At this time, the antennas 1 and 12 are
A component (hereinafter referred to as an IFDC component), which is a value after the rectification of the intermediate amplifier, which is proportional to the electric field strength of, is taken out, and its level is compared by the comparator 21. Then, the analog switch 22 selects the audio signal of the received radio wave having the stronger electric field strength.

On the other hand, in the transmission system, when the transmission signal is amplified by the drive amplifier 11, this signal is distributed by the distributor 10 to the α system transmission signal and the β system transmission signal in the same phase, and the α system transmission signal is transmitted. The signal is transmitted from the α-system antenna 1 via the transmission power amplifier 9, the transmission filter 8 and the mixer 2, and β
The system transmission signal is transmitted from the β system antenna 12 via the transmission amplifier 20, the transmission filter 19, and the mixer 13.

As described above, in the conventional transmission / reception apparatus, the frequency difference between the transmission / reception signals is large and the reception filters 3, 1
4. By increasing the Q of the transmission filters 8 and 19, transmission and reception can be performed without sacrificing reception sensitivity.

[0005]

However, in the conventional transmitter / receiver, when used in a system in which the frequency difference between transmitted / received signals is within 5%, a transmitter / receiver filter having a high Q must be used, and the device is miniaturized. I can't. Further, since the transmitted radio waves are radiated from the antennas 1 and 12 in the same phase, the dead points due to reflection increase in a small room.

The present invention solves such a conventional problem, and provides a diversity transmitting / receiving apparatus capable of transmitting / receiving without increasing the size of a transmission / reception filter even if the frequency difference between transmission / reception signals is small. The purpose is to do.

[0007]

In order to achieve the above object, the present invention amplifies a pair of first and second transmitting / receiving antennas and a radio wave received by the first transmitting / receiving antennas. A first reception system for demodulation, a first transmission system for amplifying a transmission signal and transmitting it from the first transmitting / receiving antenna, and an electric wave received by the second transmitting / receiving antenna are amplified and demodulated. A second receiving system and a second receiving system for amplifying a transmission signal and transmitting the amplified signal from the second transmitting / receiving antenna
And the first transmission control means for receiving the transmission command signal and opening the transmission line of the first transmission system, and closing the transmission line of the first transmission system at other times. Second transmission control means for receiving and opening the transmission line of the second transmission system and closing the transmission line of the second transmission system otherwise, the first reception system and the second reception system Selecting means for comparing the levels of the received radio waves to select the receiving signal of the receiving system having the higher receiving level, and the first and second transmission controls corresponding to the receiving systems not selected by this selecting means. And a transmission command signal generating means for outputting the transmission command signal to either one of the means.

[0008]

Therefore, according to the present invention, when a system having a strong electric field strength of a received radio wave is selected from the two transmission / reception systems, the radio wave received by this reception system is demodulated and the transmission of a system different from this system is performed. The transmission command signal is output only to the system.
That is, when one receiving system is selected, the transmitting system paired with this receiving system is cut off, and transmission and reception are not performed simultaneously by one antenna, so the isolation of the duplexer that constitutes the transmitting and receiving filter is reduced. It can be set, which can contribute to downsizing of the device. Further, since the transmitted radio wave is radiated from one antenna, it is possible to reduce the dead point in a small room.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, the diversity transmitter / receiver is composed of two transmission / reception systems, the α transmission / reception system is connected to the α system antenna 31, and the β transmission / reception system is connected to the β system antenna 61. The α transmission / reception system includes a reception filter 32, reception amplifier 33, mixer 34, intermediate amplifier 35, demodulator 3
6, a transmission attenuator circuit 37, a transmission filter 38, a transmission amplifier 39, a matching circuit 40, and a transmission input attenuator circuit 41. The β transmission / reception system has a reception filter 62, a reception amplifier 63, a mixer 64, an intermediate amplifier 65, demodulation. Device 66, transmission attenuator circuit 67, transmission filter 68, transmission amplifier 69, matching circuit 70,
It is composed of a transmission input attenuator circuit 71. The outputs of the demodulators 36 and 66 are connected to the comparator 57 and the analog switch 58. The output of the comparator 57 is the transmission control circuit 59.
Are connected to the output terminals A and B of the transmission control circuit 59.
Are respectively connected to terminals A and B of each transmission system.

The comparator 57 inputs the IFDC components of the demodulators 36, 66 and outputs a comparison signal corresponding to these components. That is, a negative signal is output when the reception level of the α reception system is higher than the reception level of the β reception system, and a positive signal is output when the reception level is higher. As the analog signal 58, an audio signal of a system having a high reception level is selected according to the output signal of the comparator 57. On the other hand, the transmission control circuit 5
9 selects terminal B when the α receiving system is selected by the analog switch 58, and conversely the analog switch 5
When the β reception system is selected by 8, the terminal A is selected and the transmission command signal is output to the selected terminal.

Each transmission system can transmit the transmission signal only when the transmission command signal is input to the terminal A or B. That is, the transmission attenuator circuit 37 has the resistor 4
The transmission amplifier 39 includes a transistor 47, a capacitor 48, a resistor 49, a transistor 50, a diode 43, a coil 44, a capacitor 45, and a resistor 46.
A transmission input attenuator circuit 41 including a resistor 51.
Is composed of a resistor 52, a diode 53, a coil 54, a capacitor 55, and a resistor 56. The transmission attenuator circuit 67 includes a resistor 72, a diode 73, and a coil 7.
4, the transmission amplifier 69 includes a transistor 77, a capacitor 78, and a resistor 7.
9, a transistor 80, and a resistor 81, and the transmission attenuator circuit 71 includes a resistor 82, a diode 83, a coil 84, a capacitor 85, and a resistor 86. Only when the transmission command signal is input to the terminal A, the diode 43 and the diode 53 are turned on and the transistors 47 and 50 are turned on so that the α transmission system is formed. When a transmission command signal is input to the terminal B, the diodes 73 and 83 are turned on and the transistors 77 and 80 are turned on, so that the β transmission system is formed. On the other hand, each terminal A, B
When the transmission command signal is not input to the diode 4
3, 53, 73, 83 are cut off, and the transistors 47, 50, 77, 80 are turned off, and each transmission system is cut off.

Next, the operation of the above embodiment will be described.
First, when radio waves are received by the antennas 31 and 61 and the radio waves of the respective systems are demodulated into audio signals, if the electric field strength of the α receiving system is stronger than the electric field strength of the β receiving system, the output of the comparator 57 is output. Therefore, the analog switch 58 is actuated, and the α system audio signal output from the demodulator 36 is output. At this time, when the transmission control circuit 59 operates according to the output of the comparator 57, the terminal B is selected and the selection command signal is output to the terminal B of the transmission system. At this time, the diodes 43 and 53 of the α transmission system are both in the cut-off state and the transistors 47 and 50 are in the off state,
The α transmission system is cut off.

On the other hand, in the β transmission system, the diodes 73 and 84 are turned on and the transistors 77 and 80 are turned on, so that the transmission line of the β transmission system is formed. As a result, radio waves are radiated from the β system antenna 61 via the β transmission system.

As described above, according to this embodiment, the transmission / reception systems of the two systems out of the two transmission / reception systems do not operate simultaneously, so that the reception filters 32 and 62 and the transmission filters 38 and 68 are not operated.
The isolation of the duplexer can be set low, and the radio wave can be received by one of the reception systems and the radio wave can be transmitted by the other transmission system without increasing the size of these transmission / reception filters. Further, according to the above-mentioned embodiment, since the radio wave is radiated from only one antenna, it is possible to reduce the dead point in a small room.

[0015]

As is apparent from the above embodiment, the present invention has the following effects. (1) Since each transmission / reception system does not perform transmission / reception at the same time, the isolation of the duplexer by the transmission / reception filter can be set low, which can contribute to downsizing of the device. (2) The reception sensitivity can be increased without increasing the size of the transmission / reception filter. (3) Since the radio wave is radiated from only one antenna,
It is possible to reduce the dead point due to reflection in a small room.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a diversity transceiver device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional example

[Description of Codes] 31 α Antenna 32,62 Reception Filter 34,64 Mixer 36,66 Demodulator 37,67 Transmission Attenuator Circuit 38,68 Transmission Filter 39,69 Transmission Amplifier 40,70 Matching Circuit 41,71 Transmission Input Attenuator Circuit 57 Comparator 58 Analog switch 59 Transmission control circuit 61 β system antenna

Claims (1)

[Claims] 1. A pair of first and second transmitting / receiving antennas, a first receiving system for amplifying and demodulating a radio wave received by the first transmitting / receiving antenna, and a transmitting signal for amplifying the transmitted signal. A first transmission system that transmits from the first transmission / reception antenna, a second reception system that amplifies and demodulates radio waves received by the second transmission / reception antenna, and a first transmission system that amplifies a transmission signal. Second transmitting from the second transmitting / receiving antenna
And the first transmission control means for receiving the transmission command signal and opening the transmission line of the first transmission system, and closing the transmission line of the first transmission system at other times. Second transmission control means for receiving and opening the transmission line of the second transmission system and closing the transmission line of the second transmission system otherwise, the first reception system and the second reception system Selecting means for comparing the levels of the received radio waves to select the receiving signal of the receiving system having the higher receiving level, and the first and second transmission controls corresponding to the receiving systems not selected by this selecting means. A diversity transmitter / receiver comprising: a transmission command signal generating means for outputting the transmission command signal to either one of the means.