JPH08340227A - Radio amplifier - Google Patents

Abstract

PURPOSE: To make it possible to repair a failed amplifier part out of two amplifi cation parts connected in parallel while driving the other amplifier part by reducing the reduction of gain. CONSTITUTION: High frequency signals inputted/outputted to/from high frequency amplifiers 11a, 11b having parallel constitution are branched/composed by Wilkinson hybrids 3, 4. The hybrids 3, 4 are divided into three units, i.e., amplifier parts 1a, 1b and a connection circuit part 2. When the amplifier part 1b is detached due to repairment or the like, a high frequency signal inputted to a coaxial jack J5 is amplified by the amplifier 11a through one branch transmission line T1a of the hybrid 3. The high frequency signal from the amplifier 11a is outputted from a coaxial jack J6 through one branch transition line T2a of the hybrid 4. The output level is reduced only by 1dB as compared with a case that both amplifier parts 1a, 1b are actuated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio amplifier for amplifying a high frequency signal with an amplifier having a parallel configuration, and more particularly to a radio amplifier which has a small gain reduction even if one of the amplifiers fails.

[0002]

2. Description of the Related Art A conventional wireless amplifier of this type is provided with a signal distributor and a signal combiner using a hybrid at the signal input end and the signal output end of two amplifiers arranged in parallel. In this parallel-configured amplifier, when one unit amplifier fails in the output signal disconnection, the gain and the output level are almost 6%.
It decreases by dB. A technique for avoiding such a reduction in gain and output level due to amplifier failure is disclosed in, for example, Japanese Patent Laid-Open No. 3-71.
No. 708 is disclosed. In this parallel configuration amplifier, switching means is provided between the unit amplifier and the signal synthesizer,
When the unit amplifier fails, the transmission line length between the signal synthesizer and the switching means is set to a predetermined electrical length so that the signal loss is less than 6 dB and the fault amplifier is used as the signal synthesizer. It is electrically separated from.

[0003]

Since the unitary amplifier and the signal distribution / combining circuit are integrally configured in the above-mentioned conventional parallel-configured amplifier, all the circuits are used even if one unit amplifier fails. It was necessary to remove it from the device and repair or replace it.

Therefore, an object of the present invention is to eliminate the drawbacks of the parallel-configured amplifier according to the prior art, and even if the unit amplifier fails during the operation of the apparatus, the signal output does not stop and the gain reduction can be performed with a small unit amplifier. It is to provide a wireless amplifier that can be easily removed and repaired or replaced.

[0005]

A wireless amplifier according to the present invention comprises a Wilkinson type first hybrid for branching a high frequency signal received at a signal input terminal to first and second branch terminals, and the first and second hybrid amplifiers. First and second high-frequency amplifiers having substantially the same characteristics for amplifying the high-frequency signal from the second branch terminal, respectively, and high-frequency signals from the first and second high-frequency amplifiers into third and fourth branches, respectively. A second Wilkinson-type hybrid that receives the respective high-frequency signals and combines the high-frequency signals with each other to generate a signal output terminal in the wireless amplifier, the wireless amplifier including the first transmission line and the first transmission line that constitutes the first hybrid; A first circuit of a first absorption resistor circuit whose one end is connected to a branch terminal of the first transmission line, the first high frequency amplifier, and the second high circuit. A first amplification section including a second transmission line forming a lid and a first circuit of a second absorption resistor circuit having one end connected to a branch terminal of the second transmission line; and the first hybrid. Forming a third transmission line and a second circuit of the first absorption resistor circuit having one end connected to a branch terminal of the third transmission line, the second high frequency amplifier, and the second hybrid The fourth that constitutes
Second amplifying section including the second transmission resistor and the second circuit of the second absorption resistor circuit, one end of which is connected to the branch terminal of the fourth transmission line, and the high-frequency signal received at the signal input terminal. A signal branching unit for branching and connecting to the first and second transmission lines, and the first absorption connecting the other end of the first circuit and the other end of the second circuit of the first absorption resistor circuit. A third circuit of the resistor circuit, a third circuit of the second absorption resistor circuit that connects the other end of the first circuit and the other end of the second circuit of the second absorption resistor circuit, and It is divided into three units, that is, a connection circuit unit including a signal combining unit that connects the third transmission line and the fourth transmission line and combines the high-frequency signal to generate a signal at the signal output terminal.

In one of the wireless amplifiers, each of the first circuit and the second circuit of the first and second absorption resistor circuits has a resistance value which is approximately ½ of the absorption resistance value of the hybrid. A first resistor and a second resistor, respectively.
Each of the third circuits of the absorption resistor circuit can be configured to be a simple connection line.

In another one of the wireless amplifiers, each of the first circuit and the second circuit of the first and second absorption resistor circuits is a simple connection line, and the first and second circuits are respectively connected to each other. Each of the third circuits of the absorption resistor circuit may be a resistor having an absorption resistance value of the hybrid.

[0008] In still another one of the wireless amplifiers, the first amplifying section includes an input end of the high frequency signal in the first transmission line, a first absorbing resistor circuit of the first and second absorbing resistor circuits. The other end of each of the one circuit and the output end of the high frequency signal in the second transmission line are respectively configured by the same type of coaxial connector, and the second amplifying unit is provided in the third transmission line. The input end of the high frequency signal, the other end of each of the second circuits of the first and second absorption resistor circuits, and the output end of the high frequency signal in the fourth transmission line are respectively connected to the first end. Of the same type of coaxial connector as that of the amplifier section, and the signal branch section of the connection circuit section, the third circuit of the first and second absorption resistor circuits,
Also, the signal connecting ends of the signal synthesizing unit to the first and second amplifying units may be configured by coaxial connectors of a type suitable for connection with the coaxial connector.

[0009]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a wireless amplifier according to the present invention. FIG. 2 is an equivalent circuit diagram of the Wilkinson type hybrid 3 used in this embodiment.

Referring to FIG. 1, this radio amplifier is a hybrid combination type high-frequency amplifier having a parallel configuration, and is composed of a strip circuit or the like. This wireless amplifier is divided into three units, which are amplification units 1a and 1b having substantially the same characteristics and a connection circuit unit 2. Amplifiers 1a and 1
b is a high-frequency amplifier 11a and 11 which are unit amplifiers.
b is included. High frequency amplifiers 11a and 1
Wilkinson type hybrids 3 and 4 are used for branching and synthesizing high-frequency signals input to and output from 1b. As shown in the figure, each of the hybrids 3 and 4 is configured to straddle three units of the amplification units 1a and 1b and the connection circuit unit 2. In this wireless amplifier, the coaxial jack J5 of the connection circuit unit 2 is connected to a signal input terminal for a high frequency signal,
The coaxial jack J6 is used as a signal output terminal. The transmission line characteristic impedance Z0 of this wireless amplifier will be 50
It will be explained as an Ω system.

To explain the operation of this radio amplifier, the high frequency signal supplied to the coaxial jack J5 is branched to the branch terminals Q1a and Q1b of the hybrid 3 at a level lower than the input level by 3 dB and in phase. These high frequency signals are respectively amplified by the high frequency amplifiers 11a and 11b and output to the branch terminals Q2a and Q2b of the hybrid 4 at the same level and the same phase. The hybrid 4 synthesizes these high frequency signals and outputs them to the coaxial jack J6 at a level higher than the input level by 3 dB.
Therefore, the gain of this wireless amplifier is almost the same as that of the high frequency amplifiers 11a and 11b.

Next, the hybrid 3 will be described in detail. The hybrid 3 circuit of the connection circuit unit 2 includes a coaxial jack J5, a transmission line L1 having one end connected to the coaxial jack J5 and a characteristic impedance Z0, and a coaxial plug P1a connected to the other end of the transmission line L1. P1b and coaxial plugs P2a and P2b connected to each other. The circuit for the hybrid 3 of the amplification unit 1a has a coaxial jack J to be connected to the coaxial plug P1a.
1a, a transmission line T1a having a characteristic impedance Z1 whose one end is connected to the coaxial jack J1a and which has a quarter wavelength of the high frequency signal at the route 2 · Z0, and a transmission line T1.
a resistor R1a, which is connected to the branch terminal Q1a of a and has a resistance value equal to the characteristic impedance Z0, and a resistor R1a, and a coaxial jack J2a to be connected to the other end of the resistor R1a and to the coaxial plug P2a. And.
The circuit for the hybrid 3 of the amplifier 1b is the coaxial plug P1.
b, a coaxial jack J1b to be connected to b, a transmission line T1b having a characteristic impedance Z1 whose one end is connected to the coaxial jack J1b is route 2 · Z0 and has a quarter wavelength of the high frequency signal, and a branch of the transmission line T1b. Terminal Q1b
A resistor R1b having a resistance value equal to that of the characteristic impedance Z0 and configured by a chip resistor or the like, and a coaxial jack J2b that is connected to the other end of the resistor R1b and should be connected to the coaxial plug P2b.

Referring to FIG. 2, the equivalent circuit of the Wilkinson type hybrid 3 has a characteristic impedance Z0.
(= 50Ω) transmission line L1 and characteristic impedance Z1
Is a coaxial jack J1a and a coaxial plug P1a between the transmission line T1a of the route 2 · Z0 (≈70.7Ω),
Transmission line L1 and characteristic impedance Z1 are route 2 · Z
Resistors R1a and R having a resistance value (50Ω) equal to the characteristic impedance Z0, such as the coaxial plug P1b and the coaxial jack J1b between the transmission line T1b of 0 (≈70.7Ω) and the like.
The length of the connecting elements such as the coaxial jacks J2a, J2b, P2a, and P2b with the 1a is set to a level that can be ignored with respect to the electrical length of the high-frequency signal (about 1/10 wavelength or less). Circuit. The condition that the length of the connecting element is about 1/10 wavelength or less is that the connecting element is a strip line formed on a dielectric (for example, Teflon) having a dielectric constant of about 2.5, and the frequency of the high frequency signal is 1 GHz. In this case, the wavelength on the line is about 19 mm or less, which is a value that can be sufficiently realized. The resistor R is a combined resistor of the resistors R1a and R1b, and has a resistance value (= 100Ω) twice the characteristic impedance Z0.

The high frequency signal received by the coaxial plug P5 is
The transmission line T1a and T1b are branched into two, and a branch terminal Q
Transmitted at levels and phases equal to 1a and Q1b. The resistor R absorbs the reflected signals from the high frequency amplifiers 11a and 11b which are loads.

Referring again to FIG. 1, the hybrid 4
Also, the input and output terminals of the high frequency signal are reversed, but the configuration is similar to that of the hybrid 3. That is, the hybrid 4 circuit of the connection circuit unit 2 has a coaxial jack J6 and a characteristic impedance Z0 whose one end is connected to the coaxial jack J6.
Transmission line L2, coaxial plugs P4a and P4b connected to the other end of the transmission line L2, and coaxial plugs P3a and P3b connected to each other. Amplifier 1
The hybrid 4 circuit of a includes a coaxial jack J4a to be connected to the coaxial plug P4a, and a coaxial jack J4a.
The characteristic impedance of which one end is connected to is route 2 ・ Z
0, the transmission line T having a quarter wavelength of the high frequency signal
2a, a resistor R2a having one end connected to the branch terminal Q2a of the transmission line T2a and having a resistance value equal to the characteristic impedance Z0, and a coaxial plug P connected to the other end of the resistor R2a.
3a and a coaxial jack J3a to be connected.
The circuit for the hybrid 4 of the amplification unit 1b is the coaxial plug P4.
b, a coaxial jack J4b, a transmission line T2b having one end connected to the coaxial jack J4b and having a characteristic impedance of route 2 · Z0 and having a ¼ wavelength of the high frequency signal, and a branch terminal of the transmission line T2b. A resistor R2b having a resistance value equal to the characteristic impedance Z0, one end of which is connected to Q2b, and a coaxial jack J3b, which is connected to the other end of the resistor R2b and should be connected to the coaxial plug P3b. When the hybrid 4 receives high-frequency signals having the same level and phase from the high-frequency amplifiers 11a and 11b at the branch terminals Q2a and Q2b, respectively, these high-frequency signals are synthesized without loss and the coaxial jack J6 is used.
Output to.

In the wireless amplifier consisting of three units of the amplification units 1a and 1b and the connection circuit unit 2 of FIG. 1, it is easy to assemble the amplification unit 1a and the connection circuit unit 2, and the connection circuit unit 2 and the amplification unit 1b, It is also configured to be easily separated (disassembled). The amplification units 1a and 1b and the connection circuit unit 2 are
Most of the functional elements are housed in a rectangular parallelepiped case, and only the connecting portion of a coaxial jack or a coaxial plug (coaxial connector) to another unit coaxial connector is projected from the case. In the amplification section 1a, coaxial jacks J1a, J2a, J
3a and J4a are sequentially arranged on one side surface of the case. In the connection circuit unit 2, the coaxial plugs P1a, P2a, P
3a and P4a are sequentially arranged on the opposing surface of the installation surface such as the coaxial jack J1a of the amplification unit 1a, and coaxial plugs P1b and P2
b, P3b and P4b are sequentially arranged on the opposite surface of the coaxial plug P1a and the like. Further, in the amplification section 1b, the coaxial jacks J1b, J2b, J3b and J4b are sequentially arranged on the surface opposite to the installation surface of the coaxial plug P1b of the connection circuit section 2 and the like.

As described above, in the wireless amplifier of this embodiment, each unit of the amplification units 1a and 1b and the connection circuit unit 2 has the same type of coaxial connector for connection with another unit to be connected. It consists of
Assembly and separation from this separate unit are easy.
The ease of assembling and separating these three units is the effect that, in the event that one of the amplifiers 1a or 1b fails, the amplifiers 1a and 1b can be repaired or replaced while the wireless amplifier remains active. Cause

Next, the reason why the amplification units 1a and 1b can be repaired or replaced while the wireless amplifier of this embodiment is active will be described.

Now, in the radio amplifier of FIG. 1, the amplification section 1b is separated from the connection circuit section 2 for repair or replacement. The high frequency signal supplied to the coaxial jack J5 has the tip of the coaxial plug P1b opened, but since the distance between the transmission line L1 and the coaxial plug P1b is short, the influence of this opening of the tip is very small and most of it is coaxial. It tries to flow into the plug P1a. The high frequency signal flowing from the coaxial plug P1a to the coaxial jack J1a is supplied to the high frequency amplifier 11a through the transmission line T1a and the branch terminal Q1a. The resistor R1 connected to the transmission line T1a
Since the distance a between the transmission line T1a and the coaxial jack J2a is short and the coaxial jack J2a is opened, a high frequency signal does not flow in these circuits and can be ignored.

When the input end of the high frequency amplifier 11a is matched with the characteristic impedance Z0 (50Ω), the input impedance Za of the high frequency amplifier 11a appearing on the coaxial jack J1a acts as an impedance conversion action by the transmission line T1a of ¼ wavelength. It is expressed by the received equation (1).

[0022] ^{Za = (Z1) 2 /Z0=(70.7)} 2/50 = 100Ω ... (1) voltage reflection coefficient in this case gamma, the reflection loss RL and mismatch loss Loss (2) equation (3 ) And (4).

Absolute value (Γ) = {Absolute value (Za−Z0) / Absolute value (Za + Z0)} = 0.33 (2) RL = 20Log {1 / Absolute value (Γ)} = 9.54 dB ((2) 3) Loss = 0.51 dB (4) As described above, the wireless amplifier in which the amplification unit 1b is separated causes a mismatch loss of 0.51 dB in the connection circuit unit 2 and the hybrid unit 2 of the amplification unit 1a. The mismatch loss Loss differs depending on the matching state of the high frequency amplifier 11a.

The high frequency amplifier 11a amplifies the high frequency signal generated at the branch terminal Q1a and outputs it to the branch terminal Q2a of the hybrid 4. The high frequency signal supplied to the branch terminal Q2a passes through the transmission line T2a, the coaxial jack J4a, the coaxial plug P4a, and the transmission line L2, and then the coaxial jack J2.
6 is output. Since the hybrid 4 has the same configuration as the hybrid 3 and is a similar reversible circuit, it outputs the high frequency signal from the branch terminal Q2a to the coaxial jack J6 with a mismatch loss of 0.51 dB.

Therefore, the radio amplifiers having the amplification section 1b separated are 0.5 at the two positions of the hybrids 3 and 4, respectively.
Since a mismatch loss of 1 dB is generated, the amplifier units 1a and 1a
The gain is reduced by 1.02 dB as compared with the parallel configuration of b. However, this gain reduction is a much smaller loss than the 6 dB reduction when using a single-sided amplifier according to the prior art, and is a value that can be sufficiently used for emergency operation in most communication systems.

In this embodiment, the absorbing resistors R1a and R2a in the hybrids 3 and 4 are arranged in the amplifying section 1a, and the resistors R1b and R2b are arranged in the amplifying section 1b. However, the resistors R1a and R1b are arranged. And resistor R2a
And R2b are connected to the coaxial plugs P2a and P2 of the connection circuit unit 2.
b and between the coaxial plugs P3a and P3b, they can be collectively arranged with a resistance of 100Ω. In this case, two resistors can be saved.

[0027]

As described above, according to the present invention, in a wireless amplifier in which a high frequency signal input to and output from two high frequency amplifiers arranged in parallel are branched and combined by a Wilkinson type hybrid, the hybrid is used as a first high frequency signal. Since it is divided into three units, a first amplification unit including an amplifier, a second amplification unit including a second high frequency amplifier, and a connection circuit unit connecting both amplification units, Even if there is a failure in the amplifier unit, the output of high-frequency signals is not stopped, and the gain reduction is very small. Further, this wireless amplifier has an effect that the amplifying portion for repair and replacement can be easily assembled and removed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a wireless amplifier according to the present invention.

FIG. 2 is an equivalent circuit diagram of a Wilkinson type hybrid 3 used in this embodiment.

[Explanation of symbols]

1a, 1b Amplification part 2 Connection circuit part 3,4 Hybrid 11a, 11b High frequency amplifier J1a-J4a, J1b-J4b, J5, J6 Coaxial jack L1, L2 Transmission line P1a-P4a, P1b-P4b Coaxial plug Q1a, Q1b, Q2a. , Q2b Branch terminals R, R1a, R1b, R2a, R2b Resistors T1a, T1b, T2a, T2b Transmission line

Claims (4)

[Claims] 1. A Wilkinson-type first hybrid for branching a high-frequency signal received at a signal input terminal to first and second branch terminals and the high-frequency signal from the first and second branch terminals. First and second high-frequency amplifiers having substantially the same characteristics for amplifying, and third and fourth high-frequency signals from the first and second high-frequency amplifiers, respectively.
A second Wilkinson-type hybrid that receives each of the high-frequency signals and generates the signal output terminal by combining the high-frequency signals with each other, the first amplifier constituting the first hybrid. Line and a first circuit of a first absorption resistor circuit whose one end is connected to a branch terminal of the first transmission line, the first high-frequency amplifier, and the second transmission line forming the second hybrid And a first amplification section including a first circuit of a second absorption resistor circuit whose one end is connected to a branch terminal of the second transmission line, and a third transmission line forming the first hybrid, A second terminal of the first absorption resistor circuit, one end of which is connected to a branch terminal of the third transmission line.
A circuit, the second high-frequency amplifier, a fourth transmission line forming the second hybrid, and a second absorption resistor circuit having one end connected to a branch terminal of the fourth transmission line. A second amplifying unit including a circuit, a signal branching unit branching and connecting the high-frequency signal received at the signal input terminal to the first and second transmission lines, and a first absorbing resistor circuit of the first absorbing resistor circuit. A third circuit of the first absorption resistor circuit that connects the other end of the one circuit and the other end of the second circuit, and the other end of the first circuit of the second absorption resistor circuit and the second circuit of the second absorption resistor circuit. A third circuit of the second absorption resistor circuit that connects to the other end, and the third transmission line and the fourth transmission line are connected to combine the high-frequency signal to the signal output terminal. It is divided into three units including a connection circuit unit including a signal combining unit that occurs and That radio amplifier. 2. Each of the first circuit and the second circuit of the first and second absorption resistor circuits is a resistor having a resistance value that is approximately ½ of an absorption resistance value of the hybrid. The wireless amplifier according to claim 1, wherein each of the third circuits of the first and second absorption resistor circuits is a simple connection line. 3. Each of the first circuit and the second circuit of the first and second absorption resistor circuits is a mere connection line, and the third circuit of the first and second absorption resistor circuits. The wireless amplifier according to claim 1, wherein each of the circuits is a resistor having an absorption resistance value of the hybrid. 4. The first amplifying section includes an input end of the high frequency signal in the first transmission line, the other end of each of the first circuits of the first and second absorption resistor circuits, And the output ends of the high frequency signals in the second transmission line are respectively configured by the same type of coaxial connector, and the second amplifying unit includes the input end of the high frequency signals in the third transmission line, The other end of each of the second circuits of the first and second absorption resistor circuits and the output end of the high frequency signal in the fourth transmission line are respectively the same type of coaxial connector as the first amplifying section. And the signal branch section of the connection circuit section, the first and second
The third circuit of the absorption resistor circuit and the signal connection end to the first and second amplification units in the signal synthesis unit are respectively configured by coaxial connectors of a type suitable for connection with the coaxial connector. The wireless amplifier according to claim 1, wherein: