JPH02151130A - Antenna multicoupler - Google Patents

Abstract

PURPOSE:To attain simultaneous talking without using a large sized filter even if two radio waves used for transmission and reception are approached by providing a circulator between an antenna and a transmitter-receiver and providing a canceller comprising a level adjustment device and a phase shifter. CONSTITUTION:A transmitter 1 and a receiver 2 are connected to an antenna 6 used for transmission and reception in common via a circulator 7, a coupler 8 is connected between an output of the transmitter 1 and an input of a disturbing radio wave eliminating device (canceller) 5 and a coupler 9 is connected between an output of the canceller 5 and the receiver 2. The circulator 7 regulates a direction of the flowing of a high frequency current, a high frequency current inputted to a terminal A of the circulator 7 flows to a terminal B in a direction represented in the arrow D and the high frequency current inputted to the terminal B flows in the direction shown in the arrow E. The high frequency current outputted from the transmitter 1 is branched by the coupler 8 and inputted to the canceller 5, and the output is fed to transmission lines L6, L7 coupling the antenna 6 and the receiver 2 and inputted to the receiver 2 from the transmission line L5 via the coupler 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an antenna duplexer used in a wireless communication device capable of simultaneous calls, such as a telephone line.

[Conventional technology]

Wireless communication that allows simultaneous calls, like a telephone line, requires two radio waves with different frequencies for transmission and reception. If the frequency used for transmission is 150 MHz, 154 MHz is used for reception, and 60 M l (
The frequencies of the radio waves used for transmission and reception are slightly shifted, such that when 62MHz is used for transmission, 62MHz is used for reception.

In order to provide a large number of lines in the allocated frequency band, it is best to make the frequencies used for transmission and reception as close as possible, but if they are placed too close together, interference will occur on both sides, making simultaneous calls impossible.

[Problems with conventional technology]

The two frequencies used for transmission and reception are placed close to each other, and
In order to enable simultaneous reception and calls, it is necessary to install a filter with steep frequency characteristics in this receiver in order to prevent the output signal from the own transmitter from flowing into the own receiver. . However, filters must be made large enough to sharpen their frequency characteristics, and there is a natural limit to the size of the filter, making it difficult to narrow the interval between transmitting and receiving frequencies used in a single line any more than it currently does. It became.

[Purpose of the invention]

The present invention was made to eliminate the above-mentioned defects, and even if the two radio waves used for transmission and reception are placed in close proximity, simultaneous calls can be made without using a large filter. The purpose is to provide an antenna duplexer.

[Structure of the invention]

That is, the present invention provides an antenna duplexer for use in a transmitter/receiver capable of simultaneous calls, in which a circulator is provided between the antenna and the transmitter/receiver to regulate the direction in which high-frequency current flows. A configuration in which the output of a canceller formed by a level adjuster that adjusts the level of a partially extracted output signal and a phase shifter that inverts the phase of this partially extracted output signal is connected to the input circuit of the receiver. It is said that

[Embodiments of the invention]

Hereinafter, embodiments of the antenna duplexer according to the present invention will be described in detail using the drawings.

FIG. 1 is a block diagram of an antenna duplexer used in a transmitter/receiver capable of simultaneous calls, showing one embodiment of the present invention.

The transmitter AL and receiver 2 shown in FIG. A coupler or directional coupler 58 is connected between the input and the receiver 2, and a coupler or directional coupler 2S9 is connected between the output of the canceller ~5 and the receiver 2.

Hereinafter, the operation of the antenna duplexer shown in FIG. 1 will be explained. The circulator 7 regulates the direction in which the high-frequency current flows, and the high-frequency current input to the terminal A of the circulator 7 flows in the direction shown by the arrow and is output to the terminal B, and the high-frequency current input to the terminal B flows in the direction shown by the arrow. It flows in the direction shown by arrow E, and has the function of making it difficult to flow in the direction opposite to the direction shown by arrow E. Therefore, the output signal from the transmitter 1 passes through the transmission lines L1 and L2, is inputted to the circulator from the terminal A, flows in the direction indicated by the arrow, and flows through the transmission line L3.
is transmitted to the antenna 6, where it is converted into radio waves and radiated into space.

The radio wave sent to the other party is converted into a high frequency current by the antenna 6, is input to the terminal B of the circulator 7 via the transmission line L3, flows therein in the direction of the arrow E, and is transmitted to the transmission line L6. The signal is input to the receiver 2 through L7.

The high-frequency current output from the transmitter l mainly flows in the direction of the arrow in the circulator 7 and proceeds from terminal B to the antenna 6 via the transmission line L3. A part of the high frequency current is transmitted from terminal C of circulator 7! The signal flows into the receiver 2 via L6 and L7, and depending on its strength, may cause reception interference such as masking reception. Therefore, the high frequency current output from the transmitter 1 is branched by a coupler or directional coupler 8 and inputted to a canceller 5 consisting of a level adjuster 3 and a phase shifter 4, and this output is sent to an antenna 6 and a receiver. A coupler

The function of the canceller 5 will be explained in detail below.

The level of the high frequency current from the transmitter 1, which is input to the canceller 5, is adjusted by the level adjuster 3. Its level is adjusted to be the same level as the high frequency current flowing from the transmitter ml through the circulator 7 and into the receiver 2. The high frequency current adjusted by the level adjuster 3 has its phase inverted by the phase shifter 4, and this becomes the output of the canceller 5. This output is circulator 7
The two high-frequency currents flow into the receiver 2 and cause reception disturbances at the same level, but have a phase difference of 180 degrees, so when combined in the coupler or directional coupler 9, the two high-frequency currents cancel each other out and become zero. Therefore, the high frequency current flowing from the transmitter a1 to the receiver 2 via the circulator 7 disappears,
The high frequency current of the radio waves emitted from the transmitter of the other party is inputted smoothly to the receiver a2, and even without using a large filter, there will be no reception interference due to a mask or the like caused by the high frequency current of the transmitter l.

As explained in the prior art section, in a transmitter/receiver that can make simultaneous calls, if the frequencies of the radio waves used for transmitting and receiving are brought close together, the filter must be made larger, which naturally leads to a limit and making the image frequencies too close together. I couldn't do that. However, by providing the canceller 5 shown in FIG. 1, the high frequency current output from the transmitter 1 is always canceled out no matter what the frequency, and does not flow into the receiver 2. Therefore, even if the frequencies of the transmitter and receiver 5 are very close or the same, the high frequency current of the transmitter l will be
can be prevented from invading. Even if the transmitting and receiving frequencies are the same, they will always differ instantaneously, and the phases of both cannot always be the same, and there will always be a shift. If the frequency used for transmission changes, the canceller 5 will follow this and output a frequency that is 180 degrees different from this, so only the high frequency current flowing from the circulator 7 to the receiver 2 will be canceled out, and the other party's transmitter will be A high-frequency current is input to the receiver 2 manually. Therefore, even if the transmitter/receiver 1.2 shown in FIG. 1, which is capable of making simultaneous calls, uses the same frequency for transmitting and receiving, reception interference due to masks etc. does not occur.

Further, in the circulator 7, high-frequency current easily flows only from the transmitter 1 toward the antenna 6 and from the antenna 6 toward the receiver 2, and hardly flows in the opposite direction. Therefore, it becomes difficult for the other party's radio waves received by the antenna 6 to flow into the transmitter 1, and the problem of cross modulation becomes less likely to occur.

To explain using specific numbers, it is generally said that if the output signal from the transmitter 1 flowing into the receiver 2 is 80 dBμ or less, reception interference such as a mask will not occur. Even if the output signal level of the transmitter 1 is 153 dBμ, and the level of this signal flowing from the circulator 7 to the receiver 2 is 120d13μ, if 40 dBμ is canceled by the 4-Janceler-5, the signal will be transmitted to the receiver 2. The level of the incoming output signal from the transmitter 1 is 80 dBμ, and no reception interference occurs.

FIG. 1 shows the principle of operation of the antenna duplexer. The level adjuster 3 of the canceller 5 detects the output signal from the transmitter at which flows into the receiver 2, and must be operated manually.

Therefore, as shown in FIG. 2, a coupler or directional coupler 10 is provided in the input circuit of the receiver 2 to receive signals from the transmitter
Detecting the output signal flowing into the controller 11 and controlling the level adjuster 3 in accordance with the level of the output signal detected by the controller 11,
It automatically maintains the best condition at all times.

If the impedance matching between the antenna 6 and the circulator 7 is sufficient, the high frequency current of the transmitter l will flow through the antenna 6.
However, if the impedance of the antenna 6 changes due to changes in the environment such as weather, the impedance of the antenna 6
If the high-frequency current is reflected from the circulator, the amount of leakage from the circulator may deteriorate to 10 to 20 dBμ, and the receiver 2 may cause reception interference due to a mask or the like.

Therefore, as shown in FIG. 3, between the circulator 7 and the antenna 6, an antenna matching Hl 2 and a directional coupler
3, the controller 14 is manually supplied with information regarding the reflection from the antenna 6 from the directional coupling 2S13, and based on this information regarding the reflection, the controller 314 outputs information regarding matching, and the antenna matching device 12 outputs information regarding the circulator 7. and the antenna 6.

If the impedance on the output side of the circulator 7 is 50Ω and the impedance of the antenna 6 is 200Ω,
The controller 14 shown in FIG. 4 makes the standing wave ratio as seen from the output side of the circulator 7 approach 1.0 as shown in FIG. 5 when its output voltage is about 3 V based on the information regarding the reflection of the directional coupling 2Sl3. The antenna matching device 12 can absorb changes in the antenna 6 due to the environment, and can always operate in the best condition. Note that the controller 14 can be easily configured by using a microcomputer or the like.

〔Effect of the invention〕

By configuring the present invention as described above, the two frequencies used for transmission and reception can be brought very close to each other, or even if they are the same, the antenna can be shared at the same time without causing reception interference due to masks, etc. equipment can be provided. Therefore, the frequency band occupied by one line can be narrow, making it possible to increase the number of lines more than at present, and allowing a wideband receiver to arbitrarily select a frequency.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a diagram showing the principle of an antenna duplexer, and FIG. 2 is a diagram showing a level adjuster for the antenna duplexer shown in FIG. Figure 3 shows the antenna duplexer shown in Figure 2 equipped with an antenna matching device to match the circulator and antenna. Figure 4 shows the antenna matching device. FIG. 5 is a diagram showing the characteristics of the antenna matching device. (Oh, regarding the symbols used in the drawings, 1... transmitter
2. Receiver 3. Level adjuster 4. Phase shift 2S
5.Canceller 6.Antenna 7.Circulator 8.9.10.Coupler, directional coupler 11
14...Controller 12...Antenna matching device.

Claims (2)

[Claims] (1) In an antenna duplexer used for a transmitter/receiver capable of simultaneous calls, a circulator is provided between the antenna and these transmitters/receivers to regulate the direction in which high-frequency current flows, and An output of an interference radio wave removal device configured with a level adjuster that adjusts the level of a part of the output signal and a phase shifter that inverts the phase of this part of the output signal is connected to the input circuit of the receiver. An antenna duplexer characterized by: (2) An antenna duplexer used in a transmitter/receiver capable of simultaneous calls includes an antenna matching device that matches the antenna and a circulator that regulates the direction in which high-frequency current flows, and an antenna matching device that matches the output signal from the transmitter. An antenna duplexer characterized in that it is provided with a controller for controlling a jamming wave removal device comprising a level adjuster from which a portion is taken out and a phase shifter for inverting the phase of this output signal. .