JP2723834B2 - Wireless amplifier - Google Patents

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 by 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 radio amplifier of this type is provided with a signal distributor and a signal combiner using a hybrid at a signal input terminal and a signal output terminal of two amplifiers arranged in parallel. In this parallel configuration amplifier, when one of the unit amplifiers has a failure of the output signal interruption, the gain and the output level become almost 6
Decrease by dB. A technique for avoiding a decrease in gain and output level due to such an amplifier failure is disclosed in, for example, JP-A-3-71.
No. 708. In this parallel configuration amplifier, switching means is provided between the unit amplifier and the signal combiner,
If the unit amplifier fails, the transmission line length between the signal combiner and the switching means is set to a predetermined electrical length so that the signal loss is less than 6 dB and the failed amplifier is replaced with the signal combiner. And is electrically disconnected.

[0003]

Since the unit amplifier and the signal distribution / combination circuit are integrally formed in the above-mentioned parallel configuration amplifier according to the prior art, all the circuits are used even when one unit amplifier fails. It had to be removed from the device and repaired or replaced.

Accordingly, an object of the present invention is to eliminate the drawbacks of the prior art parallel-structured amplifier, and to operate a unit amplifier which does not stop signal output even when the unit amplifier fails during operation and has a small decrease in gain. An object of the present invention is to provide a wireless amplifier that can be easily removed and repaired or replaced.

[0005]

SUMMARY OF THE INVENTION A wireless amplifier according to the present invention.
Converts the high frequency signal received at the signal input terminal
A first high of a Wilkinson type that branches into two branch terminals
A bridge and the first and second branch terminals.
The first and second amplifiers, which amplify high-frequency signals, have almost the same characteristics.
And a second high-frequency amplifier, and the first and second high-frequency amplifiers.
Third and fourth branch terminals for the high frequency signal from the amplifier
To each,These high-frequency signals are combined to produce a signal.
Wilkinson-type second hybrid generated at force terminal
And a wireless amplifier comprising:
Construct the first hybridThe first branch terminal,
And its endFirst absorption resistor circuit having one end connected to the first
The first circuit ofDepartmentThe first high-frequency amplifier; and the second high-frequency amplifier.
A hybridSaid third branch terminal, and
Its endTo one end of the second absorption resistor circuit
circuitDepartmentA first amplifying section comprising:
Configure the codeThe second branch terminal and its endNiichi
A second circuit of the first absorbing resistor circuit connecting endsDepartment
, The second high-frequency amplifier, and the second hybrid
Configure the codeThe third branch terminal and its endNiichi
A second circuit of the second absorbing resistor circuit connecting endsDepartmentWhen
And a high-frequency amplifier received at the signal input terminal.
Wave number signalThe first and second branch terminalsBranch to
And a first circuit of the first absorption resistor circuit
DepartmentAnd the other end ofThe first absorption resistor circuit2nd circuitDepartmentOther
A third circuit of the first absorption resistor circuit connecting an end thereofDepartment
And a first circuit of the second absorption resistor circuitDepartmentAnd the other end ofPrevious
The second absorption resistor circuit2nd circuitDepartmentTo the other end of
A third circuit of the second absorption resistor circuitDepartmentWhen,The third
Branch terminalWhenThe fourth branch terminalAnd connect with the high frequency
Several signalsCombined with the signal output terminalAriseThe second
HybridA connection circuit section including a signal synthesis section;No connection
Connectable3 unitsincluding.

In one of the wireless amplifiers, each of the first circuit portion and the second circuit portion of the first and second absorption resistor circuits has a resistance substantially half of the absorption resistance value of the hybrid. Each of the third circuit portions of the first and second absorption resistor circuits may be a simple connection line.

Another one of the wireless amplifiers is a first circuit section and a second circuit of the first and second absorption resistor circuits.
Each of the parts is merely a connection line, and the first
And each of the third circuit portions of the second absorption resistor circuit may be a resistor having the absorption resistance of the hybrid.

[0008] Still another of the wireless amplifiers is
The first amplification unit isConnected to the signal branch of the connection circuit
The other end of the first branch terminal,The first and second suction
The first circuit of the resistor resistor circuitDepartmentThe other end of each of theThe said
3 from the branch terminalThe output ends of the high-frequency signals
It comprises one kind of coaxial connector, and the second amplifying section comprises:
The second branch connected to a signal branch of the connection circuit unit
The other end of the terminal,The first and second absorption resistor circuits
2 circuitsDepartmentThe other end of each of theFrom the fourth branch terminal
ofThe output terminals of the high frequency signal are respectively referred to as the first amplifying unit.
The same type of coaxial connector, and the connection circuitBut,
Transmission line array connected to the first to fourth branch terminals
ToA third circuit of the first and second absorption resistor circuitsDepartment
, RespectivelyConnect to the corresponding circuitThe coaxial connectorTo
SuitableFor coaxial connectors that matchConnectionTake the configuration
be able to.

[0009]

Next, the present invention will be described with reference to the 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 the Wilkinson hybrid 3 used in the present embodiment.

Referring to FIG. 1, this radio amplifier is a high frequency amplifier of a hybrid combining type parallel configuration, and is constituted by a strip circuit or the like. This wireless amplifier is divided into three units: amplifier units 1a and 1b having substantially the same characteristics and a connection circuit unit 2. Amplifying sections 1a and 1
b denotes high-frequency amplifiers 11a and 11 forming unit amplifiers.
b. High frequency amplifiers 11a and 1
The Wilkinson hybrids 3 and 4 are used for branching and synthesizing the high frequency signal input / output to / from the 1b. As shown in the figure, each of the hybrids 3 and 4 is configured to straddle three units of the amplifiers 1a and 1b and the connection circuit 2. In this wireless amplifier, the coaxial jack J5 of the connection circuit unit 2 is connected to a signal input terminal of 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
Description will be given as an Ω system.

The operation of this radio amplifier will be described. 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 3 dB lower than the input level and at the same phase. These high frequency signals are amplified by the high frequency amplifiers 11a and 11b, respectively, and output to the branch terminals Q2a and Q2b of the hybrid 4 at the same level and the same phase. The hybrid 4 combines these high frequency signals and outputs them to the coaxial jack J6 at a level 3 dB higher than the input level.
Therefore, the gain of this wireless amplifier is almost the same as the gain of the high-frequency amplifiers 11a and 11b.

Next, the hybrid 3 will be described in detail. The circuit for the hybrid 3 of the connection circuit section 2 includes a coaxial jack J5, a transmission line L1 having a characteristic impedance Z0 having one end connected to the coaxial jack J5, 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 amplifying unit 1a includes a coaxial jack J to be connected to the coaxial plug P1a.
1a, a transmission line T1a having one end connected to the coaxial jack J1a, a characteristic impedance Z1 having a route 2 · Z0 and a quarter wavelength of the high frequency signal, and a transmission line T1.
a resistor R1a having one end connected to the branch terminal Q1a and having a resistance value equal to the characteristic impedance Z0 and a coaxial jack J2a connected to the other end of the resistor R1a and connected to the coaxial plug P2a. And
The circuit for the hybrid 3 of the amplifying unit 1b includes a coaxial plug P1.
b, a transmission line T1b having one end connected to the coaxial jack J1b and a characteristic impedance Z1 having a route 2 · Z0 and a quarter wavelength of the high frequency signal, and a branch of the transmission line T1b. Terminal Q1b
And a coaxial jack J2b connected to the other end of the resistor R1b and to be connected to the coaxial plug P2b.

Referring to FIG. 2, an equivalent circuit of the Wilkinson hybrid 3 has a characteristic impedance Z0.
(= 50Ω) transmission line L1 and characteristic impedance Z1
Are the coaxial jack J1a and the coaxial plug P1a between the transmission line T1a of the route 2 · Z0 (≒ 70.7Ω),
The transmission line L1 and the characteristic impedance Z1 are route 2 · Z
The resistors R1a and R1 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 and the transmission line T1b of 0 (≒ 70.7Ω).
The lengths of the connection elements such as the coaxial jacks J2a, J2b, P2a and P2b between the first and second coaxial cables 1a are set to be negligible with respect to the electrical length of the high-frequency signal (about 1/10 wavelength or less). Circuit. The condition that the connection element length is about 1/10 wavelength or less is that if the connection element is a strip line formed on a dielectric (for example, Teflon) having a dielectric constant of about 2.5, the frequency of the high-frequency signal is 1 GHz. In this case, the on-line wavelength 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 lines T1a and T1b are branched into two, and a branch terminal Q
Transmitted at a level and phase equal to 1a and Q1b. The resistor R absorbs reflected signals from the high-frequency amplifiers 11a and 11b which are loads.

Referring again to FIG. 1, the hybrid 4
Although the input / output terminals of the high frequency signal are reversed, they have the same configuration as the hybrid 3. That is, the circuit for the hybrid 4 of the connection circuit unit 2 includes a coaxial jack J6 and a characteristic impedance Z0 having one end connected to the coaxial jack J6.
, The coaxial plugs P4a and P4b connected to the other end of the transmission line L2, respectively, and the coaxial plugs P3a and P3b connected to each other. Amplifier 1
The circuit for hybrid 4a includes a coaxial jack J4a to be connected to the coaxial plug P4a and a coaxial jack J4a.
Characteristic impedance with one end connected to
0, a 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 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 section 1b is a coaxial plug P4.
b, a transmission line T2b having one end connected to the coaxial jack J4b and having a characteristic impedance of root 2 · Z0 and a quarter wavelength of the high frequency signal, and a branch terminal of the transmission line T2b. A resistor R2b having one end connected to Q2b and having a resistance equal to the characteristic impedance Z0, and a coaxial jack J3b connected to the other end of the resistor R2b and to be connected to the coaxial plug P3b. When the hybrid 4 receives high-frequency signals having the same level and the same phase from the high-frequency amplifiers 11a and 11b at the branch terminals Q2a and Q2b, respectively, the high-frequency signals are combined without loss to form a coaxial jack J6.
Output to

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

As described above, in the wireless amplifier of the present embodiment, each unit of the amplifying units 1a and 1b and the connection circuit unit 2 uses the same type of coaxial connector for connection with another unit to be connected. Since it consists of
Assembly and separation with this separate unit is easy.
The ease of assembling and separating these three units is such that when any one of the amplifiers 1a or 1b fails, the amplifiers 1a and 1b can be repaired and replaced due to the failure while the wireless amplifier remains active. Is generated.

Next, the reason why the amplifiers 1a and 1b can be repaired and replaced while the wireless amplifier of the present embodiment is active will be described.

Now, in the wireless amplifier of FIG. 1, the amplifier 1b is separated from the connection circuit 2 for repair or replacement. The high-frequency signal supplied to the coaxial jack J5 has the distal end of the coaxial plug P1b open, but since the distance between the transmission line L1 and the coaxial plug P1b is short, the effect of this distal end opening is very small and most of the high-frequency signals are coaxial. Attempts to flow to the plug P1a. A 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
In a, since the distance between the transmission line T1a and the coaxial jack J2a is shortened and the coaxial jack J2a is open, a high frequency signal does not flow through these circuits and can be ignored.

When the input terminal 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 is not affected by the impedance conversion effect of the 1/4 wavelength transmission line T1a. 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 = 20 LogＬ1 / absolute value (Γ)｝ = 9.54 dB ( 3) Loss = 0.51 dB (4) As described above, the wireless amplifier separated from the amplifier 1 b generates a mismatch loss of 0.51 dB in the connection circuit 2 and the hybrid 2 of the amplifier 1 a. 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 the amplified signal 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
6 is output. Since the hybrid 4 has the same configuration as the hybrid 3 and is a similar reversible circuit, it outputs a high-frequency signal from the branch terminal Q2a to the coaxial jack J6 with a mismatch loss of 0.51 dB.

Therefore, the wireless amplifiers separated from the amplifying unit 1b have 0.5
Since a mismatch loss of 1 dB occurs, the amplification 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 the present embodiment, the absorbing resistors R1a and R2a in the hybrids 3 and 4 are arranged in the amplifying unit 1a, and the resistors R1b and R2b are arranged in the amplifying unit 1b. And the 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 can be collectively arranged with a resistance of 100Ω. In this case, two resistors can be saved.

[0027]

As described above, the present invention relates to a radio amplifier in which a Wilkinson-type hybrid branches and combines high-frequency signals input and output to and from two high-frequency amplifiers configured in parallel. Since it is divided into three units, a first amplifying unit including an amplifier, a second amplifying unit including a second high-frequency amplifier, and a connection circuit unit connecting both amplifying units. Even if a failure occurs in the amplifying unit, there is an effect that the output of the high-frequency signal is not stopped and the decrease in gain is very small. Further, this wireless amplifier has an effect that it is easy to assemble and remove the amplifier for repair or replacement.

[Brief description of the 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 hybrid 3 used in the present embodiment.

[Explanation of symbols]

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

Continuation of the front page (56) References JP-A-5-110355 (JP, A) JP-A-6-112741 (JP, A) JP-A-1-162924 (JP, U)

Claims (4)

(57) [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 to be amplified, and high-frequency signals from the first and second high-frequency amplifiers being amplified by third and fourth high-frequency amplifiers.
Receiving the branch terminals respectively, in the radio amplifier and a second hybrid Wilkinson producing these high-frequency signals to the synthesis to the signal output terminal, the radio amplifier, constituting said first hybrid
Said first branch terminal, and the second constituting a first circuit portion of the first absorption resistor circuit connected at one end to the end portion, said first high-frequency amplifier, said second hybrid
A first amplifying unit including: a third branch terminal of the third amplifying circuit ; and a first circuit unit of a second absorbing resistor circuit having one end connected to the other end thereof ;
The second branch end constituting the first hybrid
A second circuit part of the first absorption resistor circuit, one end of which is connected to one end of the second high-frequency amplifier;
The third branch end constituting the second hybrid
A second amplifying section including a second circuit section of the second absorption resistor circuit having one end connected to one end thereof, and a high frequency signal received at the signal input terminal . 2
A signal branching section that branches connected to the branch terminal of said first absorption resistor first circuit portion and the other end to the first absorption resistance of the circuit
A third circuit portion of the first absorption resistor circuit that connects the other end of the second circuit portion of the vessel circuit, the first circuit portion of said second absorber resistor circuit and the other end to the second The second of the absorption resistor circuit
The third circuit portion and said third branch terminal and the fourth branch end of the second absorption resistor circuit that connects the other end of the circuit section
If the high-frequency signal to said signal output terminal connects the child
Three units connectable to a connection circuit unit including a signal synthesis unit of the second hybrid formed by the connection unit
A wireless amplifier comprising: 2. A resistor, wherein each of the first circuit portion and the second circuit portion of the first and second absorption resistor circuits has a resistance value that is approximately one half of the absorption resistance value of the hybrid. The wireless amplifier according to claim 1, wherein each of the third circuit portions of the first and second absorption resistor circuits is a simple connection line. 3. Each of the first circuit section and the second circuit section of the first and second absorption resistor circuits is merely a connection line, respectively. each respective third circuit unit of claim 1, wherein the radio amplifier, characterized in that the absorption resistance of the hybrid is a resistor having respectively. 4. The method according to claim 1, wherein the first amplifying unit is connected to the connection circuit unit.
The other end of the first branch terminal connected to the signal branch portion, the other end of each of the first circuit portions of the first and second absorption resistor circuits, and the high frequency from the third branch terminal. The output terminals of the signals are respectively constituted by coaxial connectors of the same type, and the second amplifying unit is connected to a signal branching unit of the connection circuit unit.
The other end of the second branch terminal, the first and second
Absorbing resistor second circuit section each respective other ends of the circuit, and before
The output terminals of the high-frequency signals from the fourth branch terminals are respectively constituted by coaxial connectors of the same type as the first amplifying unit, and the connection circuit unit is connected to the first to fourth branch terminals.
By connecting the third circuit portion of the transmission line and the first and second absorption resistor circuit to continue, to respectively conform before <br/> Symbol coaxial connector connected to the corresponding circuit type coaxial connectors The wireless amplifier according to claim 1, wherein