JPH01314435A - Hot standby system in multiple radio device - Google Patents

Abstract

PURPOSE:To prevent the interference of a transmitting wave due to leak in a high frequency switch part with simple constitution by providing a variable attenuator to an intermediate frequency signal in respective transmitting unit, which is presently used, and auxiliary transmitting unit and holding the attenuation degree of the variable attenuator in the auxiliary side transmitting unit to a high level. CONSTITUTION:A detector 11 detects a signal level in the output side of a high output power amplifier 8 and a control circuit 12 controls a variable attenuator 6 in correspondence to a detecting output. When a high frequency switch part 3 selects an output from a transmitting unit 1-0, an output from the high output power amplifier 8 (HPA) in a transmitting unit 1-1 is full reflected in the high frequency switch part 3. Thus, an output from the detector 11 (DET) goes to be large and the attenuation degree of the variable attenuator 6 (VATT) is controlled to the high level. As a result, the output level of the HPA 8 is held to a low level and the interference is erased. On the other hand, in the transmitting unit 1-0 side, there is no reflection and the attenuation degree of the variable attenuator 6 is kept to 0 level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a hot standby system in a multiplex radio device equipped with a high frequency switch section that selectively switches between the output of a working transmitting unit and the output of a protection transmitting unit.

The object of the present invention is to simplify the configuration for preventing interference of transmitted waves due to leakage in the high frequency switch section, or to further reduce the interference.

A variable attenuator for the intermediate frequency signal is provided in each of the above transmitting units, and focusing on the fact that total reflection occurs from the above high frequency switch section in the output of the standby side transmitting unit, the attenuation of the above variable attenuator is It has a structure that maintains the temperature at a high level.

[Industrial application field]

The present invention relates to a hot standby method in a multiplex radio device, and particularly to a hot standby method in a multiplex radio device equipped with a high frequency switch section that selectively switches between the output of a working transmitting unit and the output of a protection transmitting unit.

In the multiplex radio device, in the high frequency switch section, the output from the active transmitting unit may be undesirably interfered with due to leakage from the multiple transmitting unit. Measures for this are required.

[Conventional technology]

FIG. 4 shows a general configuration in which the hot standby system is adopted, and FIG. 5 shows the configuration of the high frequency switch section in FIG. 4.

The symbols +-0 and 1-1 in the figure are transmitting units, respectively.

2 is a hybrid circuit, and 3 is a high frequency switch section.

4 represents an antenna, and 13 represents a switch control section. Further, in FIG. 5, the input l is, for example, the transmitting unit 1-0.
Input 2 is the signal from transmitting unit 1-1,
Di to D6 are PIN diodes for attenuating the signal on the standby side, CI to C4 are DC cut capacitors, and Ll and L2 are choke coils, respectively.

The base hand input signal is passed through the hybrid circuit 2'
ζ is supplied to two transmitting units l-0 and 1-1, respectively. The high frequency switch section 3 selects the output from, for example, the active transmitting unit l-0 under the control of the switch control section 13 and supplies it to the antenna 4. and,
When a failure or the like occurs in the working transmitting unit 1-0, the high frequency switch section 3 is controlled to select the output from the P-side transmitting unit 1-1.

The high frequency switch unit 3 has a configuration as shown in FIG.
When the input is input from the diodes D4 to D6, a DC voltage is applied through the choke coil L2 to turn on the diodes D4 to D6. That is, the signal at input 2 is antagonized across diodes D4 to D6. On the other hand, the signal of human power l is generated when diodes DI or D3 are turned off.
It is supplied to the antenna 4.

[Problem to be solved by the invention]

In the case of the above configuration, the PIN diode provided in the high frequency switch section 3 has an attenuation capacity of, for example, about 1 OdB.If attenuation of 30 dB or more is required to eliminate the above interference, the PIN diode provided in the high frequency switch section 3 has an attenuation capacity of, for example, about 1 OdB. As shown in Figure 5, three or more PIN diodes are required on one side.
The high frequency switch section 3 becomes expensive.

The present invention aims to simplify the configuration for preventing interference of transmitted waves due to leakage in the high frequency switch section 3, or to further reduce the interference.

[Means to solve the problem]

FIG. 1 shows a basic configuration diagram of the present invention. Code +-o in the diagram
, t and t are respectively transmitting units; 2 is a hybrid circuit;
3 is a high frequency switch section, 4 is an antenna, 13 is a switch control section, 5 is a modulation circuit, 6 is a variable attenuator provided in the present invention, 7 is a mixer, and 8 is a high output power amplifier.

9 represents a local oscillator, 10 represents a circulator, 11 represents a detector, and 12 represents a control circuit.

The detector 11 detects the signal level on the output side of the high output power amplifier 8. The variable attenuator 6 attenuates the signal level of the intermediate frequency signal supplied to the mikina 7 under control from the control circuit 12 . As the mixer 7, a low power cancellation type mixer is used which handles the signal level of the intermediate frequency signal input by one person as needed.

The switch control unit 13 sends an instruction for the high-frequency switch 3 to select, for example, the output from the transmitting unit 1-0, and if a failure occurs on the transmitting unit 1-0 side, the high-frequency switch 3 selects the output from the transmitting unit l-1. 1 younger to select the output from the side.

[Effect]

Even in the case of the present invention, it is not excluded that a predetermined number of the above-mentioned PIN diodes that attenuate the input signal on the non-select side are arranged in the high-frequency switch section 3; Unit 1. −
The output level from 1 is suppressed.

That is, it is assumed that the high frequency switch section 3 selects the output from the transmitting unit l-0.

High output power amplifier 8 (HP
The output from A) is totally reflected at the high frequency switch section 3. For this reason, the output from the detector 11 (DET) is large, and as a result, the variable attenuator 6 (VA
TT) is controlled to a high level. As a result, the output level of the high output power amplifier 8 (11PΔ) is maintained at a lower level than before the variable attenuator 6 (VATT) was activated. That is, there is less interference. on the other hand,
On the transmitting unit l-0 side, there is no reflection, and the attenuation degree of the variable attenuator (6) is maintained at O level.

〔Example〕

FIG. 2 shows the configuration of an embodiment of the present invention. Code 3 in the figure,
4.5...12 correspond to FIG. 1, respectively.

When the degree of attenuation of the variable attenuator 6 is maintained at the O level, the output (0 point) of the -curator lO is, for example, +
30dB-, and the output at this time (+39dB+a
) is reflected and goes from the circulator IO to the detector 11. The "input end return loss when passing through the high frequency switch section" is selected to be, for example, 27 dB. The edge return loss is chosen to be, for example, OdB.

By doing this, the transmitter unit 1 on the active side
Regarding −〇, the ■ point shown in the figure is at most +3 dBII,
If the potential at the 0 point at this time is approximately IV, the control circuit 1
The voltage input to 2 is about 1V at most. Control part l5
12 is a variable attenuator 6 corresponding to such an input.
maintain the attenuation level at O level.

On the other hand, regarding the transmission unit 1-1 on the backup side.

The 0 point is at a high level such as +30dBm, and the control unit IN
I 24 The voltage applied by two people will be a sufficiently higher value than in 1 above. For this reason, the control unit 912.

The degree of attenuation of the variable attenuator 6 is controlled to, for example, 20 dB or more.

FIG. 3 shows the configuration of an embodiment of the transmitting/receiving terminal station. Reference numerals 1.2 and 3.4 in the figure correspond to those in Fig. 1, 14 is a hybrid circuit, 15-0.15 1 is a receiving unit, 16 is a Heath-Hunt switch, and 17 is a circulator. There is.

The illustrated configuration 14.15-0.15-1.16 corresponds to the receiving section. For example, the transmitting unit 1-O and the receiving unit 15-O are on the active side, and the transmitting unit 1-1 and the receiving unit 15-1 are on the standby side. and,
Transmitting unit l-0 and/or receiving unit 15-
If a failure occurs in 0, the transmitting unit 11 and/or the receiving unit 15-1 are switched accordingly.

[Effects of the Invention] As explained above, according to the two aspects of the present invention, there is no need to use a very expensive high frequency switch section.

Furthermore, it is possible to reduce undesired interference.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the basic configuration of the present invention, Fig. 2 is a configuration of an embodiment of the present invention, Fig. 3 is a configuration of an embodiment of a transmitting/receiving terminal station, and Fig. 4 is a diagram in which a hot standby system is adopted. Figure 5 shows the configuration of the high frequency switch section in Figure 4. In the figure, l is a transmitting unit, 2 is a hybrid circuit 53, a high frequency switch section, 4 is an antenna, 5 is a modulation circuit, 6 is a variable attenuator, and 7 is a mixer. 8 is a high output power amplifier, 9 is a local oscillator, 10 is a circulator, II is a wave detector, and 12 is a control circuit.

Claims (1)

Claims: At least two baseband input signals each provided with a baseband input signal.
A high-frequency switch section that includes two transmitting units (1-0, 1-1) and selectively switches the output from each of the transmitting units (1-0, 1-1) and supplies it to the antenna (4). (3), and the transmitting unit on the active side (
In response to a failure in the transmission unit (1-0), the backup transmitting unit (1-0)
In a hot standby system in a multiplex radio device in which the output from 1) is supplied to the antenna (4), a high output power amplifier (8) is installed in each of the transmitting units (1-0, 1-1). A detector that detects the output level (
11), a variable attenuator (6) that attenuates the level of an intermediate frequency signal obtained by modulating the baseband input signal, and a variable attenuator (6) that adjusts the degree of attenuation of the variable attenuator (6) in response to the output of the detector (11). In the multiplex radio device, the attenuation degree of the variable attenuator (6) is maintained at a high level in the standby side transmitting unit (1-1). Hot standby method.