JPS6089108A - Field effect transistor amplifier device - Google Patents

Abstract

PURPOSE:To simplify the bias voltage supply circuit by converting directly a trigger signal to a gate bias voltage in FET amplifiers connected in cascade amplifying a pulse microwave signal. CONSTITUTION:The pulse microwave signal is fed to the FET amplifiers 1-4 connected in cascade. On the other hand, a trigger signal inputted in a TTL level is converted into a negative voltage by a voltage shift circuit 15. Then an output voltage of the voltage shift circuit 15 is fed to resistance voltage dividing circuits 16-19, and the divided voltage is fed respectively as a gate bias voltage of the FET amplifiers 1-4. The voltage dividing ratio of the voltage dividing circuits 16-19 is set respectively so as to generate an optimum gate bias voltage when the amplifiers 1-4 are operated for amplification. The bias voltage supply circuit is simplified in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention amplifies pulsed microwave signals. Field effect transistor (hereinafter referred to as FKT) amplifier device,
In particular, it is characterized by the way the bias voltage is supplied.

- [Prior art] FIG. 1 amplifies a pulsed microwave signal.

This is a block diagram showing an example of the configuration of a conventional FIT amplifier, and in Figure 1, (1) to (4) are cascade-connected FF1T amplifiers, and (5) is a voltage that generates a voltage vc that turns the FF1T amplifiers into a non-operating state. The cutoff voltage generator (6) to (9) is the bias voltage vG1 for each of the FET amplifiers (1) to (4) to perform optimal amplification operation.
From V. Bias tortoise pressure generator for generating 4, (1
The switch circuit supplies the bias voltage from VGl to vG4 to the gate terminal of the (11 to +4) Q FIT amplifier during the time when the microwave signal is present.

During the time when the microwave signal is not present, the cutoff voltage vc is (I+ to (4) F"Tjfffi'iA
is supplied to the gate terminal of the device. u4) is a switch driver.

The above (from IQ to
Normally, the bias IME of the FF1T amplifier that amplifies the pulsed microwave signal as shown in Figure 2 (a) is set to the power source and the drain bias 1 [(voltage) for the purpose of reducing the amount of heat generated. Alternatively, the gate bias voltage is applied in a curve shape (in FIG. 1, the gate bias voltage is applied in a Harune shape).

Here, FF! The bias characteristics of the FEiT used in the T amplifier are shown in Figure 3, and the drain current of the FIT is controlled by the gate voltage, so during the time when the microwave signal is present, the gate voltage and drain current are The voltage vG is set to be a droplet state, and during the time when there is no microwave signal, no drain current flows through the gate voltage, and F
The voltage vc is set at which KT becomes inactive.

Note c should be at least the pinch-off voltage Vp of the '1-FEiT shown in FIG. 3 and at most the maximum rated voltage VGSO between the gate and source of the PET.

This (5R element is shown in Figure 2 (a) and (b), and the gate bias voltage in Figure 2 (b) is +
It is applied to the gate terminals of FEiT amplifiers 11 to (4).

On the other hand, from the switch circuit 111 in FIG. A signal is applied from the outside.The trigger signal used for the interface with the outside is usually a TTL level signal as shown in Figure 2 (C) or a microwave signal. The time when the signal exists 9 For example, the trigger signal is at TTLH level, and the time when the microwave signal is not present, the trigger signal d is at TTL level.
If the settings are set such as E level, the output voltages vGo1 to vGo4 of the switch circuit u(1) will change from FET amplifier (1) to (4) in synchronization with the presence or absence of the microwave signal.
) to the jijj operation state from bias voltage VG1 to VO
2 and the magnetic pressure vc to set it to the non-operating state Jπ.

The FF1T amplifier device as described above needs to be small due to its application constraints (although the microwave part of the device such as the FET amplifier can be made smaller to some extent by using MMIO technology etc.

The bias voltage supply circuit that handles DC and pulses is H.
Even if IG technology or the like is used, the actual situation is that the part is larger than the microwave part, and this is one of the factors that hinders miniaturization of the device.

[1lj (I4) of the invention] This invention was made for the purpose of simplifying the gate bias voltage supply circuit and improving the above drawbacks. The problem is that the polarity of the trigger signal is used to switch the gate bias voltage that changes the state, without using a conventional switch circuit, and the trigger signal is directly converted into the gate bias voltage.

[Embodiment 1 of the Invention Fig. 4 is a block diagram showing an embodiment of the invention (
1) to (4) and the microwave signal and trigger signal input to the device are exactly the same as in the conventional device.

'Voltage shift circuit n-subtraction! The T T L level trigger signal is converted into a negative rb1 pressure pulse signal, and the resistance voltage divider circuit (1 (from D to (19) is the above magnetic pressure shift circuit f1
Divide the output voltage of ω and calculate F of (1) to (4) respectively.
The output voltage is supplied to the gate terminal of the ET amplifier.

In FIG. 4, the trigger signal input at the TTL level is converted into a negative magnetic pressure by the magnetic pressure shift circuit (11) as shown in FIG. 5(c).

The purpose of this is to ensure that the gate bias voltage is a negative voltage, and to use the emissivity of the trigger signal as it is for the polarity of the gate bias voltage.

The output voltage of the voltage shift circuit 119 is transmitted through four resistance voltage divider circuits f1. It is sent from G to (11, but resistor voltage divider circuit Ilυ
The voltage division ratio is set so that the optimum gate bias voltage vG1 is generated when the FET amplifier (1) performs an amplification operation. Similarly, the resistance voltage divider circuit (from 1η to flI is FE
Depending on the characteristics of each of the T amplifiers (2) to (3),
The partial pressure ratio is set for each. On the other hand, resistor voltage divider circuit 1
1Q to (11 voltage division ratio is FET amplifier +11 to (4
) is set to give priority to the state in which the amplification works, but this is.

As mentioned above, the voltage vc for disabling the FET amplifier is calculated from Vp to ■Gso・lii'' in Figure 3.
This is because a magnetic pressure of 4 is sufficient.

Incidentally, the voltage shift circuit Its can be easily constructed from an L-transistor (1), a Zener diode (A), a resistor (T), etc., as an example of which is shown in FIG.

In addition, in Block 1 Zo 1, which explains the present invention in detail, an example is shown in which four FF1T amplifiers are connected in cascade for the sake of explanation, but the present invention can be applied to any FInT amplifier device having any number of FE'T amplifiers. It is clear that there is a similar effect.

[Effects of the Invention] As described above, this invention converts the trigger signal directly into the gate bias tV voltage, so the bias voltage supply circuit is greatly simplified compared to the conventional configuration, and the device This has the effect of greatly contributing to the miniaturization of.

[Brief explanation of the drawing]

41 Simple explanation of each figure Figure 1 shows a conventional F for amplifying pulsed microwave signals.
A block diagram of the Iiii T amplifier device, FIG. 2 is a waveform diagram of each part to explain FIG. 1, FIG. 3 is an explanatory diagram of the operation of FET, and FIG. Block diagram, Figure 5 is a waveform diagram of each part to explain Figure 4,
FIG. 6 is a connection diagram showing an example of a voltage shift circuit. In the figure, (11 to (4) are FET amplifiers, (5) is a cut-off voltage generator, (6) to (9) are bias voltage generators. (10 to (1) are switch circuits, and Oa is a switch driver. (151 is the voltage shift circuit, and 11e to 11 are the resistor voltage divider circuits. The numbers in the middle of Figure 9 indicate the same or equivalent parts. Agent Masuo Oiwa No. 1 [/, 1 Figure 2, 3F15 te) - Figure 4 Figure 5 'A> rj diagram

Claims (1)

[Claims] A plurality of cascade-connected field effect transistors for amplifying a pulsed microwave signal, and a voltage for level-converting a TTL level trigger signal synchronized with the microwave signal to a negative voltage. The shift circuit is connected to the gate terminal of each of the amplifiers formed by the plurality of field effect transistors. A field-effect transistor amplifier comprising a plurality of resistor voltage divider circuits that divide the output voltage of the voltage shift circuit.