JPS6243926A - Relay amplifier - Google Patents

Abstract

PURPOSE:To miniaturize a relay amplifier by switching a reception amplifier into the operating state after a prescribed time after a transmission amplifier supplied with a threshold voltage is switched into the non-operating state to eliminate the need for plural band pass filters. CONSTITUTION:When an input signal having a determined amplifier is fed to a transmission amplifier 12 to be in the operating state to apply talking in the 2-frequency simplex system, a control circuit 13 detecting it makes a reception amplifier 7 into the nonoperating state. When the output of the transmission amplifier 12 reaches a predetermined value or below, it is detected and retarded by a time tau to switch the reception amplifier 7 into the operating state. This is because the prevention of state which may occur when the transmission/reception amplifier is brought into the operating state at the same time, a signal flows as shown in the arrow and there is a possibility that the relay amplifier is in the unstable operation. Thus, even when no filter is employed, the relay amplifier is operated normally, then the size is miniaturized.

Description

[Detailed Description of the Invention] [Summary] In a repeating amplifier used in a simplex system, after a transmitting amplifier to which a threshold voltage has been applied is switched to a non-operating state,
The receiving amplifier is switched to the operating state after a certain period of time. Therefore, the configuration of the repeater amplifier becomes simple and the size of the repeater amplifier can be reduced.

[Industrial application field]

The present invention relates to improvements in repeater amplifiers used in standalone wireless devices.

For example, if you place a 150Mtlz or 400Mtlz band portable wireless device outdoors and make a call to a base station, you can get good call quality, but if you place it indoors, the quality often deteriorates and you cannot make a good call. .

In such cases, a repeater amplifier is installed indoors to improve the quality.

FIG. 4 shows an explanatory diagram of the use of the repeater amplifier.

Note that the case of two frequencies will be explained.

As shown in the figure, for example, 10W from base station 1,
A radio wave of frequency F2 is received by an outdoor antenna 22 installed on the rooftop, amplified by a relay amplifier 2 installed indoors, and then transmitted to a portable radio device 3 at the same frequency from an indoor antenna 21 of this amplifier.

On the other hand, after the transmission from the base station is completed, the radio wave of, for example, 5-1 frequency F1 from the portable radio device 3 is amplified by the relay amplifier 2 and sent to the base station 1 via the outdoor antenna 22. You will be able to make calls with the same quality. At this time, it is necessary to downsize the repeater amplifier and reduce costs.

[Conventional technology]

FIG. 5 shows a block diagram of a conventional example of a repeater amplifier.

In the figure, the radio wave of frequency F1 from the portable radio device 3 inputted from the terminal 1 is transmitted to the hybrid 4. After passing through a band-pass filter 8 with a center frequency PI and amplified by a transmission amplifier 6, the filter passes through a band-pass filter 10. Hybrid 5. The signal is transmitted to the base station from the outdoor antenna through terminal 2.

On the other hand, the radio waves of frequency F2 from the base station are transmitted by an outdoor antenna.
Hybrid 5. Bandpass filters 11 and 9. Receive amplifier7. It is added to the portable radio device 3 through the hybrid 4.

Incidentally, since this relay amplifier uses a band-pass type filter, the wave of the frequency Fl, for example, does not pass through the receiving amplifier 7 and return to the transmitting amplifier N6, so that unstable operation does not occur.

[Problem that the invention seeks to solve]

Here, the transmitting amplifier and the receiving amplifier are constructed of integrated circuits, so they are miniaturized, but the bandpass filter allows only the pl or P2 waves to be treated, so, for example, the number
Since a Q of about 0.000 is required, it must be constructed from a plurality of semi-coaxial resonators, resulting in a large size. Therefore, there are problems in that the relay amplifier is large in size and expensive.

Means for Solving Problem C] The problem in item L is that, as shown in Figure 1, a threshold voltage is given so that the device enters the operating state when an input signal with a predetermined amplitude or more is applied. In addition, when the transmitting amplifier 12 becomes active, the receiving amplifier 7 becomes inactive, and the transmitting amplifier 1
This problem is solved by the repeating amplifier of the present invention, which is further equipped with a controller 13 for controlling the operation of the receiving amplifier 7 so that when the receiving amplifier 2 becomes inactive, the receiving amplifier 7 is delayed by r and brought into the active state.

[Effect]

In the present invention, since a call is made using a two-frequency single-channel system, when an input signal with an amplitude greater than a predetermined amplitude is applied to the transmitting amplifier 12 and the input signal becomes operational, the control circuit 13 detects this and immediately disables the receiving amplifier 7. Put it into working condition.

Next, when the output of the transmitting amplifier 12 becomes less than a predetermined value, this is detected and delayed by one hour, and the receiving amplifier 7
This is to prevent this, since if the transmitting and receiving amplifiers become active at the same time, there is a possibility that the signal will flow as shown by the arrow in Figure 1, causing unstable operation of this relay amplifier. It is. As a result, the repeater amplifier can operate normally even without a filter, resulting in a smaller size.

〔Example〕

The contents of the present invention will be specifically explained below with reference to illustrated embodiments. Note that the same reference numerals indicate the same objects throughout the figures.

FIG. 2 is a block diagram of the relay amplifier according to the present invention, and FIG. 3 is an explanatory diagram of the operation of FIG. 2. Therefore, the operation shown in FIG. 2 will be explained with reference to FIG.

In Fig. 2, first, when the transmitting amplifier 12 is in an inactive state, the receiving amplifier 7 is in an operating state, but the signal from the portable radio (see the first half of 〇 in Fig. 3) is transmitted through the hybrid 4. is applied to transmit amplifier 12, the amplitude of this signal is higher than the threshold voltage, so amplifier 12
becomes operational and sends the amplified output to the base station via the hybrid 5 (see the first half of Figure 3).

On the other hand, the output of the transmitting amplifier 12 is detected by the detector 133, and the obtained detected voltage (see the first half of FIG. The supplied voltage VC is cut off, and the amplifier 7 becomes inactive (see the first half of FIG. 3-■), but this state change is as shown in FIG. 3-■.

As shown in the first half of ①, this is done promptly.

Next, when the transmitter of the portable radio is turned off, the amplitude of the input signal gradually decreases as shown in the second half of Figure 3-■.
The output of the transmission amplifier 12 also changes accordingly, but when it becomes lower than the threshold voltage, it suddenly becomes inactive (see the second half of FIG. 3).

Further, the detector 133 detects that the output of the transmitting amplifier 12 is, for example, the third
When the voltage drops below 8 points in the figure, a detected voltage with a different state is output, but this voltage passes through the fast-acting slow-reply circuit 132 by 1 lfl and puts the receiving amplifier 7 into the operating state with a delay of τ, so that the transmitting and receiving amplifiers are activated at the same time. It never becomes operational. In addition, 13
indicates a control circuit.

This eliminates the need for a manual shaft type resonator, making it possible to downsize the device.

〔Effect of the invention〕

As described in detail above, according to the present invention, a plurality of band-pass filters are not required, so that the relay amplifier can be downsized and the cost can be reduced. It goes without saying that the present invention can also be applied to the single-frequency body system.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram of an embodiment of the invention, Fig. 3 is an explanatory diagram of the operation of Fig. 2, Fig. 4 is an explanatory diagram of the use of the repeater amplifier, Fig. 5 shows a block diagram of a conventional example. In the figure, 4.5 is a hybrid, 6.12 is a transmission amplifier, 7 is a reception amplifier, and 13 is a control circuit.

Claims (1)

[Claims] The input side of the transmitting amplifier and the output side of the receiving amplifier are connected to a common line via a hybrid, and the output side of the transmitting amplifier and the input side of the receiving amplifier are connected to a common line via another hybrid. In the single-pass relay amplifier connected to the common line, the transmitting amplifier (
12) becomes an active state, the receiving amplifier (7) becomes inactive, and when the transmitting amplifier (12) becomes inactive, the receiving amplifier (7) is delayed by τ and becomes active. A repeater amplifier characterized in that it further includes a controller (13) for controlling the operation of the receiving amplifier (7).