JPH0865199A - Antenna changeover device - Google Patents

Abstract

PURPOSE: To realize the antenna changeover device to monitor whether or not other station makes transmission by other carrier even during the transmission of a concerned station in the transmitter-receiver using the same carrier in time division through changeover. CONSTITUTION: When a transmitter 1 makes transmission, each contact of electronic switches 3, 4 connects respectively to connecting points 25, 26 and when a receiver 2 makes reception, each contact of the electronic switches 3, 4 connects respectively to connecting points 27, 28. In this state, when each contact of the electronic switches 3, 4 connects respectively to the connecting points 25, 27, an antenna 11 is selected and when each contact of the electronic switches 3, 4 connects respectively to the connecting points 26, 28, an antenna 12 is selected to attain diversity control. When each contact of the electronic switches 3, 5 connects respectively to the connecting point 25 and each contact of electronic switches 4, 6 connects to a connecting point 28, an output terminal 21 of the transmitter 1 connects to the antenna 11 and an input terminal 22 of the receiver 2 connects to the antenna 12 and even when the transmitter makes transmission, whether or not a transmitter of other station makes transmission by other carrier is monitored.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna switch for switching the antenna between the transmitter and the receiver in a personal communication system in which the same carrier is used by switching the same carrier in a time division manner. It is about.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram of an antenna switching device generally adopted in a personal communication system in which a transmitter and a receiver switch and use the same carrier in a time division manner. Is a time division simultaneous transmission / reception type transmitter,
2 is a receiver of the time division simultaneous transmission / reception system, 3 is an electronic switch, 11 is an antenna, 21 is an output terminal of the transmitter 1, 22
Is an input terminal of the receiver, and 23 is a connection terminal of the antenna 11. Next, the operation will be described. Since the transmitter and the receiver operating in the time division simultaneous transmission / reception system are not in the operating state at the same time, one antenna is alternately switched by the antenna switching unit 3 and used. That is, while the transmitter 1 is transmitting, the contact of the antenna switching device 3 is connected to the output terminal 21 of the transmitter 1 in synchronization with this, and while the receiver 2 is receiving, the contact of the antenna switching device 3 is synchronized with this. To the input terminal of the receiver 2. Thus, one antenna 11 can be shared by the transmitter 1 and the receiver 2.

[0003]

The conventional antenna switching device is provided to switch and use one antenna in a time division manner between a transmitter and a receiver. There is a problem that the receiver of the own station cannot be connected to the antenna when monitoring whether or not it is transmitting on another carrier. The present invention has been made in order to solve the above-mentioned problems, and is provided with two antennas having a coupling loss necessary for the receiver not to be desensitized by the transmitter of its own station, By switching these two antennas, it is possible to monitor whether or not the transmitter of another station is transmitting even when the transmitter of the own station is transmitting.

[004]

SUMMARY OF THE INVENTION An antenna switching device according to the present invention is provided with two antennas having a coupling loss necessary for a receiver not to be desensitized by a transmitter of its own station. The antennas are switched so that the transmitter and the receiver can be connected to separate antennas at the same time.

[0005]

According to the present invention, the two antennas having the coupling loss necessary for the receiver not to be desensitized by the transmitter of the own station are transmitted by the transmitters of other stations while the transmitter of the own station is transmitting. It acts as a monitor antenna for monitoring whether it is inside or not, and also acts as a diversity antenna.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a transmitter of the time division simultaneous transmission / reception system, 2 is a receiver of the time division simultaneous transmission / reception system, 3, 4, 5,
6 is an electronic switch, 11 and 12 are antennas, 21 is an output terminal of the transmitter 1, 22 is an input terminal of the receiver, 23 is a connection terminal of the antenna 11, 24 is a connection terminal of the antenna 12,
25, 26, 27, 28 are electronic switches 3, 4 and 5, 6
It is a connection point between. The electronic switches 3 and 4 are first switching means for switching the transmitter and the receiver in a time division manner, and the electronic switches 5 and 6 are second switching means for switching the antennas 11 and 12. First, the operation will be described in a normal case other than during monitoring. The contacts of the electronic switches 3 and 4 are connected to the connection points 25 and 26 while the transmitter 1 is transmitting, and the contacts of the electronic switches 3 and 4 are connected to the connection point 2 when the receiver 2 is receiving.
Connect to 7, 28. In this state, the electronic switches 5 and 6
Is connected to the connection points 25 and 27, the antenna 11 is selected, and when connected to the connection points 26 and 28, the antenna 12 is selected to enable diversity control. Next, the operation will be described for the case of monitoring. Electronic switches 3, 5
To the connection point 25 and connect the electronic switches 4 and 6 to the connection point 2
8 is connected to the output terminal 21 of the transmitter 1 antenna 1
1, the input terminal 22 of the receiver 2 is connected to the antenna 12
Connected to. In this state, the isolation between the output terminal 21 of the transmitter 1 and the input terminal 22 of the receiver 2 is
The one to which the isolation between the OFF of the electronic switches 3 and 6 is added and the one to which the isolation between the OFF of the electronic switches 4 and 5 is added are connected in parallel, and usually 50 dB or more can be secured, and the antenna 11 and If the isolation between 12 is sufficient, it becomes possible to attenuate the output of the transmitter 1 of its own station to the extent that the receiver 2 is not subjected to sensitivity suppression. Thus, it is possible to monitor whether or not the transmitter of another station is transmitting on another carrier even when the transmitter of the own station is transmitting. FIG. 2 shows another embodiment of the present invention, in which circulators 5 and 6 are used as the first switching means instead of the electronic switches. With this connection, it is not necessary to switch the transmitter 1 and the receiver 2 in a time division manner, and there is an advantage that control is simplified. Although the electronic switch or the circulator is used as the switching means in the above description, the same effect can be obtained by using a hybrid circuit or a branch circuit. Further, the electronic switch can be miniaturized by forming it on the same wafer or a ceramic substrate.

[0007]

Since the antenna switching device of the present invention is configured as described above, diversity control of the transmitter and the receiver is possible, and at the same time, the transmitter and the receiver can be connected to separate antennas. There is an advantage that it is possible to monitor whether or not another station is transmitting on another carrier while the transmitter of the station is transmitting.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an antenna switching device of the present invention.

FIG. 2 is a diagram showing another embodiment of the antenna switching device of the present invention.

FIG. 3 is a diagram showing an example of a conventional antenna switching device.

[Explanation of symbols]

1 Time division simultaneous transmission / reception type transmitter 2 Time division simultaneous transmission / reception type receiver 3, 4 First switching means 5, 6 Second switching means 11, 12 Antenna 21 Output terminal of transmitter 1 22 Receiver 2 Input terminals 23, 24 Antenna connection terminals 25, 26, 27, 28 Connection point between first switching means and second switching means

Claims (3)

[Claims] 1. In a personal communication system in which a transmitter and a receiver switch and use the same carrier in a time division manner, a first switching means for switching the transmitter and the receiver, an A antenna and a B antenna. Antenna switching device characterized by having a second switching means for switching between the transmitter and the receiver, and being able to simultaneously connect individual antennas to each other. 2. The antenna switching device according to claim 1, wherein the switching means is composed of an electronic switch, a circulator, a hybrid circuit, a branch circuit, or a combination thereof. 3. The antenna switching device according to claim 1, wherein the switching means is formed on a common semiconductor wafer, a ceramic substrate, or a plastic substrate.