JPH05102777A - Distributer or synthesizer - Google Patents

Abstract

PURPOSE:To provide the distributer or the synthesizer whose matching is taken by an impedance matching circuit even when number of the distributers of the synthesizers is changed with respect to the distributer or the synthesizer used when plural power amplifiers are employed for a radio transmitter. CONSTITUTION:The distributer or the synthesizer is provided with cables of number of distribution or synthesis whose length is lambda/2 (lambda is wave length) and whose one terminals are connected together at a connecting point 10 and with an impedance matching circuit comprising lines whose length is lambda/4 used to match the impedance between the point 10 and an input point of distributed signals or an output point 11 of synthesized signals. Through the constitution of the distributer or synthesizer as above, the impedance matching circuit is made up of the plural cables 1, 2, 3,...N whose length is lambda/4, and number of the cables 1, 2, 3,...N whose length is lambda/4 is used selectively to match the impedance depending on the distributed number or the synthesized number.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a distributor or combiner used when a plurality of power amplifiers are used in a wireless transmitter.

FIG. 5 is a block diagram showing a usage example of a distributor and a combiner when a plurality of power amplifiers are used. FIG. 5 shows an example of using four power amplifiers 20 to 23 to increase the output power. The input signal is divided into four by the distributor 30 and input to the power amplifiers 20 to 23 to be amplified. The outputs are combined by the combiner 31 and output.

The distributor 30 and the combiner 31 have the same structure, and the power amplifiers 20 to 2 at the output of the combiner 31.
The phases of 3 must be matched. As a method of using the distributor and the combiner, they are mostly used in pairs as shown in FIG.

Since the distributor and the synthesizer have the same structure, the case of the synthesizer will be described below.

[0005]

2. Description of the Related Art FIG. 6 is a block diagram of a conventional combiner.
In the figure, 60 to 64 are terminals, and 60 to 63 are cables 40.
Up to 43 are respectively wound, and a wire 80 is connected to the terminal 63. Reference numeral 90 denotes a substrate.

FIG. 6 shows a combiner for combining four signals. Since the impedance of the device connected to the four input sides and the output point 11 is usually 50Ω, the four input sides have impedances. The cable 40 and the pattern 50, the cable 41 and the pattern 51, the cable 42 and the pattern 52, and the cable 43 and the pattern 53 of 50Ω each have λ /.
The length is 2 and the connection is made at the connection point 10.

The length of the cable and the pattern is set to λ / 2, for example, when the power amplifier connected to the input point of the cable 43 is removed and the cable is opened, the connection point 1
This is because the pattern 53 at 0 is also open and is not connected.

Assuming that the impedance at the connection point 10 is Z ₁ and the impedance at the output point 11 is Z ₂ , an impedance matching circuit is a λ / 4 long line whose characteristic impedance is Z ₀ of the square root of Z ₁ × Z _2. It is necessary to be.

In this case, the impedance of the connection point 10 is 5
Since 0Ω / 4 = 12.5Ω and the impedance at the output point 11 is 50Ω, the characteristic impedance Z ₀ of the line 80 is 25Ω which is the square root of 12.5 × 50 and has a λ / 4 length.

[0010]

However, for example, when the power amplifier connected to the input terminal is disconnected due to a failure or the like, or in the mobile radio system, the area used is large and the transmission output must be increased. For example, when a combiner is shared between the case where four power amplifiers are used and the case where three power amplifiers are used because the area used is small and the transmission output must be made small, impedance changes when the combined number changes. There is a problem in that the matching circuit does not perform sufficient matching, resulting in loss.

An object of the present invention is to provide a distributor or combiner which can be matched by an impedance matching circuit even if the number of distributions or the number of combination changes.

[0012]

FIG. 1 shows the principle of the present invention. As shown in FIG. 1, a cable having a λ / 2 (λ is a wavelength) length of the number of distributions or the number of composites connected to one end, a connection point 10 to which the one end is connected, an input point of a signal to be distributed or a signal Λ / to match the impedance between output points 11
In a distributor or combiner having an impedance matching circuit composed of four-length wires, the impedance matching circuit is composed of a plurality of λ / 4-length cables 1, 2, 3, ... , Λ / 4 length cables 1, 2, 3, ... N are selected and used to match impedance.

[0013]

According to the present invention, when the composite number changes, for example, the λ / 4 length cables 1, 2,
Since the impedances are matched by selectively using 3, ..., N, even if the composite number changes, the impedance can be matched and no loss occurs.

[0014]

2 is a block diagram of a synthesizer of another embodiment of the present invention, FIG. 4 is a schematic diagram of a synthesizer of another embodiment of the present invention, and FIG. It is a block diagram.

2 and 3 are different from the conventional example of FIG. 6 in that one line 80 having a characteristic impedance of 25Ω is used in FIG. 6 as an impedance matching circuit. Cable 1 with impedance 50Ω
2 and a cable 3 having a characteristic impedance of 75Ω, and connecting or disconnecting the cables 1 to 3 between the connection point 10 and the output point 11. Therefore, the different points will be mainly described below. ..

In the case of FIG. 2, the cables 1 to 3 are connected to the connection point 1.
It is possible to connect or disconnect between 0 and the output point 11 by using the U-link.
In the case of FIG. 3, connect the cables 1 to 3 to the connection point 10 and the output point 1.
The connection and disconnection between 1 are performed by turning on / off the switches SW1 and SW4, SW2 and SW5, and SW3 and SW6, respectively.

2 and 3, the impedance of the connection point 10 in the case of the composite number 4 in which four power amplifiers are connected is 12.5Ω, so that the cables 1 and 2 are connected. The characteristic impedance of the impedance matching circuit when cables 1 and 2 are connected is 12.5 x 50
It becomes 25Ω of the square root of, and impedance matching can be achieved.

When the combined number becomes 3 due to a failure of one power amplifier or the like, the impedance at the connection point 10 becomes 17Ω. Therefore, the cables 1 and 3 should be connected, but when the cables 1 and 3 are connected. The characteristic impedance of the impedance matching circuit of 2 is 29Ω, which is the square root of 17 × 50, and impedance matching can be achieved.

That is, even if the composite number changes, impedance matching can be achieved in the impedance matching circuit. In the case of FIG. 4, the power amplifiers 20 to 23 are connected to the other ends of the switches SW10 to SW13, one ends of which are connected to the connection point 10 via the cables 70 to 73 of λ / 2 length, and the connection points. The switch SW14 is provided between 10 and the output point 11.
And SW18, SW15 and SW19, SW16 and SW20
Connect the cables 1, 2 and 3 via each of them,
The control unit 81 detects normality / abnormality of the power amplifiers 20 to 23, and when normal, controls the control unit 81 to turn on the switches SW10 to SW13, and to turn on the switches SW14 and SW18, SW15 and SW19, When one power amplifier, for example 23, becomes abnormal, switch SW13 is turned off, switches SW15 and SW19 are turned off, and SW1
6 and SW20 are turned on so that the impedance matching circuit can achieve impedance matching.

Although the above description has been made in the case of the combiner, even if the number of distribution changes in the case of the distributor, the impedance matching circuit can similarly perform impedance matching. Although the above description has been made in the case of using the cables having the impedances of 50Ω and 75Ω, when a plurality of cables having various impedances are used and the distribution number and the composite number are changed, the cable to be used is selected according to the impedance in this case. However, impedance matching can be achieved by the impedance matching circuit.

[0021]

As described in detail above, according to the present invention, there is an effect that a distributor or combiner can be obtained in which impedance matching can be achieved by an impedance matching circuit even if the combination number and distribution number change.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention,

FIG. 2 is a configuration diagram of a combiner according to an embodiment of the present invention,

FIG. 3 is a block diagram of a combiner of another embodiment of the present invention,

FIG. 4 is a block diagram of a combiner of another embodiment of the present invention,

FIG. 5 is a block diagram showing a usage example of a distributor and a combiner when a plurality of power amplifiers are used,

FIG. 6 is a configuration diagram of a conventional combiner.

[Explanation of symbols]

1 to N, 40 to 43, 70 to 73 are cables, 10 is a connection point, 11 is an input point or an output point, 20 to 23 are power amplifiers, 30 is a distributor, 31 is a combiner, 50 to 53 are patterns, 60 to 64 are terminals, SW1 to SW6, SW13 to S
W20 is a switch, 80 is a line, 81 is a control unit, and 90 is a substrate.

Claims (1)

[Claims] 1. A distribution number or composite number λ / having one end connected.
Λ / matches impedance between a cable having a length of 2 (λ is a wavelength), a connection point (10) connecting the one end, and an input point of a signal to be distributed or an output point (11) of a signal to be combined.
In a distributor or combiner having an impedance matching circuit composed of four-length wires, the impedance matching circuit is composed of a plurality of λ / 4-length cables (1, 2, 3, ... The λ / 4 length cable (1, 2, 3, ... N) depending on the number of composites
Distributor or combiner characterized in that impedances can be matched by selectively using.