JPS5846562Y2 - Koshuyuuhahasatsushinki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high frequency oscillator that generates an oscillation output at a high frequency of, for example, 1 to 100 MHz.

Some conventional devices of this type control a high frequency oscillation circuit so that the DC voltage obtained by detecting the output of the high frequency oscillation circuit is equal to a reference DC voltage.

However, this conventional device has the disadvantage that when the characteristics of the detection circuit change due to temperature changes, the amplitude of the output of the device as a whole also changes.

An object of the present invention is to provide a high frequency oscillator that solves the problems of the conventional device.

The present invention will be explained below with reference to the drawings.

The figure is an electrical connection diagram showing the device of the present invention.

In the figure, HO is the oscillation output e of high frequency f1.

Lo is the oscillation output e of the high frequency oscillation circuit Ho at a low frequency f, for example 1 to 10 kHz.

A low frequency oscillation circuit outputs a signal er with a waveform similar to ol, and Dl and D2 are outputs e of a high frequency oscillation circuit HO1 and a low frequency oscillation circuit Lo, respectively.

This is a detection circuit in which ut and er are manually operated.

Here, as the detection circuits DI and D2, field effect transistors FET1. The one using FET2 is shown.

In this detection circuit D1, the gate terminal of FET1 is connected to the output terminal of high frequency oscillation circuit Ho, and the drain terminal is connected to power supply V.

Further, the source terminal is grounded via a parallel circuit consisting of a capacitor C1 and a resistor R1.

In the detection circuit D2, the gate terminal of FET2 is connected to the output terminal of the low frequency oscillation circuit Lo, and the drain terminal is connected to the power supply ■
is grounded.

Further, the source terminal is grounded via a parallel circuit consisting of a capacitor C2 and a resistor R2.

AMP is an amplification circuit with large gain, and FET, , FET
The difference e between the output voltages of the detection circuits D2 appearing at the source terminals of the detector circuits , , and D2 is inputted, and the output amplitude of the high-frequency oscillation circuit Ho is controlled so that this difference voltage ed becomes zero. .

Tm is an output terminal, and this output terminal Tm receives the output e of the high frequency oscillation circuit Ho.

ut now appears.

In the device of the present invention configured as described above, the output e of the high frequency oscillation circuit Ho.

ut and ゛this e. The output er of the low frequency oscillation circuit Lo having a waveform similar to uo is expressed as, for example, eour = E 1sm 2 yr f ter =
E 2s1n 27r f t However, if t is time El and E2 is oscillation amplitude, then as is clear from the above configuration, in the state ed:O where the device is balanced, E is the main E2.

That is, the oscillation amplitude E1. of the high frequency oscillation circuit Ho and the low frequency oscillation circuit Lo. The device of the present invention operates so that E2 is equal.

Output e. To change the oscillation amplitude E1 of ut, it is sufficient to change the oscillation amplitude E2 of the low frequency oscillation circuit LO.

Here, the detection circuit D1. FET1 with the same characteristics as D2
．． FET2 (for example, the well-known dual (pair) FET
etc.), the detection circuits D2 have almost the same temperature characteristics.

In addition, a voltage e having a similar waveform is applied to the detection circuit D2.

ut and er have been added.

This is because, for example, when a sine wave (the most common) is used as a high-frequency output and a square wave is used as the low-frequency side, the following problem will occur.

That is, as is well known, FETs tend to generate spikes due to internal parasitic capacitance between electrodes in response to square wave power on the low frequency side.

On the other hand, since the high frequency side is a sine wave, almost no spikes occur in the FET.

This results in an imbalance between the two, and this imbalance is influenced by temperature.

As mentioned above, this unbalance can be prevented by making the waveform on the low frequency side the same sine wave as the waveform on the high frequency side (a triangular wave or the like is also possible, but it will be a little more complicated).

Therefore, even if there is a temperature change, the detection circuit DI.

The output of D2 changes similarly, and the output voltage e is such that the differential voltage e becomes zero.

The size of ut remains unchanged. That is, even if there is a temperature change, the oscillation amplitude E1 accurately corresponds to the oscillation amplitude E2.

Generally, a stable low-frequency oscillation circuit can be easily obtained, so the low-frequency oscillation circuit of the device of the present invention is suitable.

If such a device is used, the entire device of the present invention will be extremely stable.

In addition, in the above embodiment, in the detection circuit, F is connected to D2.
Although an example using ET, FET2 is shown, the present invention is not limited to this.

Furthermore, a waveform other than that in the embodiment may be obtained as the waveform of the oscillation output eOUTt.

As explained above, according to the present invention, it is possible to obtain a high frequency oscillator that is extremely stable against temperature changes, and its practical effects are great.

[Brief explanation of the drawing]

The figure is an electrical connection diagram showing an embodiment of the present invention. Ho...High frequency oscillation circuit, Lo...Low frequency oscillation circuit, D, D2...Detection circuit, AM
P...Amplification circuit.

Claims (1)

[Scope of utility model registration request] a high-frequency oscillation circuit, a first detection circuit that uses the output signal of this high-frequency oscillation circuit as human power; a low-frequency oscillation circuit that generates an output signal with a waveform substantially similar to that of the high-frequency oscillation circuit; L includes a second detection circuit having almost the same temperature characteristics as the first detection circuit;
The high frequency oscillator is configured to control the high frequency oscillation circuit so that the output signal of the detection circuit and the output signal of the second detection circuit have a constant relationship.