JP6430122B2 - amplifier - Google Patents

Description

  Embodiments described herein relate generally to an amplifier.

  Conventionally, when the output of the amplifier is varied, the output is adjusted by varying the drain voltage of the amplifying element.

  However, when the drain voltage is varied, depending on the variable range of the power supply, a voltage higher than the allowable voltage of the amplifying element may be applied, possibly destroying the amplifying element.

  In particular, in the case of an amplifier that allows the user to change the drain voltage, this problem becomes apparent.

  More specifically, in the case of an amplifier used in a radar transmitter, when a user adjusts the output of the amplifier, the volume knob is turned so as to apply a voltage higher than the allowable voltage of the amplifying element by mistake in operation. May end up.

  If such an operation is allowed, the amplifier may be damaged.

JP 2011-109641 A

  Accordingly, there is a need for an amplifier that can change the drain voltage without destroying the amplifying element.

In order to solve the above problem, an amplifying element that connects a signal input terminal to a gate terminal, a first power supply unit that supplies power to the gate terminal of the amplifying element, a first variable resistor, a first variable resistor, A second variable resistor connected directly in parallel to the variable resistor, and a second variable resistor that applies an output voltage determined based on a combined resistance of the first variable resistor and the second variable resistor to the drain terminal of the amplifying element. A power supply unit , wherein the first variable resistor is installed inside the amplifying element, and the second variable resistor is installed on the operation panel of the amplifying element .

It is a figure which shows the structure of an amplifier. It is a figure which shows the example of the combination of desirable maximum resistance value. It is a figure which shows the example of the combination of the undesirable maximum resistance value. It is a figure which shows the example of a connection of the AC / DC converter which is a 2nd power supply part. It is a figure which shows the example of a connection in case a 2nd power supply part is a DC / DC converter. It is a figure which shows the amplifier which concerns on a modification.

  Hereinafter, an embodiment of an amplifier will be described in detail with reference to the drawings.

  The amplifier of this embodiment includes a first capacitor connected to a signal input terminal and removing a direct current component, an amplifying element connecting a gate terminal to the first capacitor, and a second capacitor connected to a drain terminal of the amplifying element. A first power supply unit that supplies power to the gate terminal of the amplification element; and a second power supply unit that includes a resistor that changes the output voltage and a variable resistor connected in parallel to the resistor. .

  FIG. 1 is a diagram illustrating a configuration of an amplifier. As shown in FIG. 1, the amplifier is connected to a signal input terminal 14, a first capacitor 15 that removes a DC component, an amplifying element 16 that connects a gate terminal to the first capacitor 15, and a drain of the amplifying element 16. A second capacitor 17 connected to the terminal, a DC / DC converter 13 which is a first power supply section for supplying power to the gate terminal of the amplifying element 16, a first variable resistor 22 for changing the output voltage, and a second The AC / DC converter 12 which is a 2nd power supply part provided with the 2nd variable resistance 21 connected in parallel with 1 variable resistance 22 and the signal output terminal 18 are provided.

  The first power supply unit applies a gate bias voltage to the gate terminal 20 </ b> A of the amplifying element 16.

  The second power supply unit applies a drain bias voltage determined by the combined resistance of the first variable resistor 22 and the second variable resistor 21 to the drain terminal 20 </ b> B of the amplifying element 16.

  The first variable resistor 22 is installed inside the housing of the amplifier. The second variable resistor 21 is provided on the operation panel surface of the amplifier.

  The first variable resistor 22 is set to be equal to or lower than the maximum voltage that can be applied to the drain terminal 20B of the amplifying element 16 when the second variable resistor 21 is set to the maximum resistance value at which the voltage is maximum. .

  Therefore, even if the user sets the second variable resistor 21 to the maximum resistance value, a voltage exceeding the allowable range is not applied to the drain terminal 20B of the amplifying element 16.

  It is desirable that the maximum resistance value of the first variable resistor 22 is equal to or greater than the maximum resistance value of the second variable resistor 21.

  FIG. 2 is a diagram illustrating an example of a combination of desirable maximum resistance values. In FIG. 2, the vertical axis represents the resistance value of the variable resistor and the resistance value of the combined resistor, and the horizontal axis represents the rotation angle of the knob of the variable resistor.

  As shown in FIG. 2, when the maximum resistance value of the first variable resistor 22 is 50 kΩ and the maximum resistance value of the second variable resistor 21 is 20 kΩ, the resistance value of the user's variable range is adjusted according to the rotation of the knob. Since the combined resistance gradually decreases, operability is good.

  FIG. 3 is a diagram illustrating an example of combinations of undesirable maximum resistance values. In FIG. 3, the vertical axis indicates the resistance value of the variable resistor and the resistance value of the combined resistor, and the horizontal axis indicates the rotation angle of the knob of the variable resistor.

  As shown in FIG. 3, when the maximum resistance value of the first variable resistor 22 is 20 kΩ and the maximum resistance value of the second variable resistor 21 is 50 kΩ, the resistance value of the user's variable range is adjusted according to the rotation of the knob. The operability is poor because the resistance decreases rapidly from where the combined resistance is.

  FIG. 4 is a diagram illustrating a connection example of the AC / DC converter 12 serving as the second power supply unit. As shown in FIG. 4, when the AC / DC converter 12 uses, for example, the PFE500 series manufactured by TDK Lambda Co., Ltd., the + output terminal + V, −output terminal −V, and wiring from the output terminal to the load terminal A + remote sensing terminal + S and −remote sensing terminal −S for compensating for a voltage drop, and an output voltage external variable terminal TRIM are provided.

  When changing the output voltage, the + remote sensing terminal + S and the + output terminal + V are connected by the first variable resistor 22.

  In the present embodiment, a second variable resistor 21 is provided in parallel with the first variable resistor 22.

  Power is supplied from the DC OUT terminal by a voltage determined by the combined resistance of the first variable resistor 22 and the second variable resistor 21 connected in parallel.

  FIG. 5 is a diagram illustrating a connection example when the second power supply unit is the DC / DC converter 12A. As shown in FIG. 5, when the DC / DC converter 12A uses, for example, CN100A24 series manufactured by TDK-Lambda Corporation, the + output terminal + V, the −output terminal −V, and the wiring from the output terminal to the load terminal A + remote sensing terminal + S and −remote sensing terminal −S for compensating for a voltage drop, and an output voltage external variable terminal TRIM are provided.

  When changing the output voltage, the + remote sensing terminal + S and the + output terminal + V are connected by the first variable resistor 22.

  In the present embodiment, a second variable resistor 21 is provided in parallel with the first variable resistor 22.

  Power is supplied from the DC OUT terminal by a voltage determined by the combined resistance of the first variable resistor 22 and the second variable resistor 21 connected in parallel.

  FIG. 6 is a diagram illustrating an amplifier according to a modification. As shown in FIG. 6, the amplifier is connected to the signal input terminal 14, a first capacitor 15 that removes a direct current component, an amplification element 16 that has a gate terminal connected to the first capacitor 15, and a drain of the amplification element 16. A second capacitor 17 connected to the terminal, a DC / DC converter 13 that is a first power supply unit that supplies power to the gate terminal of the amplifying element 16, and a fixed resistor 23 and a fixed resistor 23 that change the output voltage. An AC / DC converter 12 that is a second power supply unit including a second variable resistor 21 connected in parallel and a signal output terminal 18 are provided.

  The first power supply unit applies a gate bias voltage to the gate terminal 20 </ b> A of the amplifying element 16.

  The second power supply unit applies a drain bias voltage determined by the combined resistance of the fixed resistor 23 and the second variable resistor 21 to the drain terminal 20 </ b> B of the amplifying element 16.

  The fixed resistor 23 is installed inside the housing of the amplifier. The second variable resistor 21 is provided on the operation panel surface of the amplifier.

  The fixed resistor 23 is set to be equal to or less than the maximum voltage that can be applied to the drain terminal 20 </ b> B of the amplifying element 16 when the second variable resistor 21 is set to the maximum resistance value that maximizes the voltage.

  Therefore, even if the user sets the second variable resistor 21 to the maximum resistance value, a voltage exceeding the allowable range is not applied to the drain terminal 20B of the amplifying element 16.

  The resistance value of the fixed resistor 23 is preferably equal to or greater than the maximum resistance value of the second variable resistor 21.

  As described above, the amplifier of this embodiment includes the first capacitor 15 that is connected to the signal input terminal 14 and removes a DC component, the amplification element 16 that connects the gate terminal to the first capacitor 15, and the amplification element. A second capacitor 17 connected to the drain terminal 16, a DC / DC converter 13 which is a first power supply unit for supplying power to the gate terminal of the amplifying element 16, a resistor for changing the output voltage, and this resistor The AC / DC converter 12 which is a 2nd power supply part provided with the 2nd variable resistance 21 connected in parallel with a device, and the signal output terminal 18 are provided.

  Therefore, there is an effect that the drain voltage can be changed so as not to destroy the amplifying element.

  Although several embodiments have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

16: Amplifier 21: Second variable resistor 22: First variable resistor 23: Fixed resistor

Claims (2)

An amplifying element for connecting the signal input terminal to the gate terminal;
A first power supply for supplying power to the gate terminal of the amplifying element;
A first variable resistor and a second variable resistor connected in parallel directly to the first variable resistor, and is determined based on a combined resistance of the first variable resistor and the second variable resistor A second power supply unit for applying an output voltage to the drain terminal of the amplifying element;
Equipped with a,
The first variable resistor is installed inside the amplifying element;
The second variable resistor is installed on an operation panel of the amplification element.
amplifier.   The amplifier according to claim 1, wherein a maximum resistance value of the first variable resistor is equal to or greater than a maximum resistance value of the second variable resistor.

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