JPH0635533Y2 - Magnetostatic wave delay linear oscillator - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is, for example, a VOC (voltage-controlled oscillator):
Magnetostatic wave (MSW… magne) used for voltage controlled oscillators, etc.
tostatic wave) is related to the improvement of the delay linear oscillator.

<Prior Art> FIG. 6 shows a configuration example in which a signal from a conventional magnetostatic wave delay linear oscillator (hereinafter, simply referred to as an oscillator) 1 is input to a spectrum analyzer 2 and its characteristics are measured.
The oscillator 1 includes a magnetostatic wave generating element 3 having an input transducer 3a and an output transducer 3b, an amplifier 4, a coupler 5,
It is composed of an attenuator 6. The output transducer 3b side formed in the magnetostatic wave generating element 3 is connected to the input side of the amplifier 4 connected to the latter stage, the output side of this amplifier is connected to one end of the coupler 5, and the other end of this coupler is an attenuator. Is connected to the input side of. Furthermore, the output side of this attenuator is connected to the input transducer 3a of the magnetostatic wave generating element 3 to form a closed loop.

In the above configuration, a magnetic field is applied to the magnetostatic wave generating element 3 from a magnetic field generator (not shown) to generate a magnetostatic wave according to the applied magnetic field, and the amplifier gain and The loop gain is adjusted with the attenuator.

<Problems to be Solved by the Invention> FIG. 7 shows a prototype of the oscillator having the configuration shown in FIG. 6 by the present applicant, and the relationship between the oscillation frequency and the power is displayed by a spectrum analyzer. In such a state, the magnetostatic wave generating element is saturated, and spurious noises indicated by a and b are generated on both sides of the peak, resulting in large noise. Especially in the case of magnetostatic surface waves (MSSW), the saturation input level is as low as -25 dBm, so it is difficult to adjust the oscillator so that it does not saturate by only adjusting the attenuator (there is no oscillation when the attenuation is large). It was

The present invention has been made in view of the above problems of the prior art.
The purpose is to insert a limiter between the coupler and the attenuator to oscillate the magnetostatic wave generating element without saturating it and obtain a good oscillation spectrum.

<Means for Solving the Problems> In the configuration of the present invention for solving the above problems, a magnetostatic wave generating element, an amplifier, a coupler, and an attenuator are sequentially coupled in a loop, and a magnetic field is applied to the magnetostatic wave generating element. Thus, in the magnetostatic wave delay linear oscillator in which the magnetostatic wave generated in the input / output transducer of the magnetostatic wave generating element is taken out through the coupler, it is determined in advance by the physical characteristic of the magnetostatic wave generating element. The saturation level is measured in advance, and a limiter having the saturation level as an upper limit of output is inserted between the coupler and the attenuator.

<Embodiment> The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. The same elements as those of the conventional example are designated by the same reference numerals, and a duplicate description will be omitted.
The present invention is different only in that a limiter is inserted between the attenuator and the coupler of the conventional device. As the limiter, for example, a clamp circuit using a diode as shown in FIG. 2 can be used.

FIG. 3 shows the ideal characteristics of the limiter, and is used for the purpose of limiting the output power with respect to the input power (PL represents the limiter limit level).

Returning to FIG. 1, in this embodiment, the saturation input level of the magnetostatic wave generating element is -25 dBm, the insertion loss of the magnetostatic wave generating element is 5 dB,
Amplifier gain 40 dB, attenuator insertion loss 30 dB,
The limiter insertion loss is 0 dB and the limit level is 0 dBm to form a loop.
Can oscillate at dBm.

Figure 4 shows the relationship between frequency and power by oscillating the above loop under the same conditions as the conventional CRT of a spectrum ram analyzer.
This shows the state indicated by, and it can be seen that the spurious that has been generated in the past is decreasing.

In this embodiment, an example in which the limiter limit level is 0 dBm is used. However, if a limiter having a limit level of −30 dBm is used as shown in FIG. 5, an attenuator may be unnecessary. I can.

<Effect of the Invention> As described above in detail with the embodiments, according to the present invention, by applying a magnetic field to the magnetostatic wave generating element,
In a magnetostatic wave delay line oscillator in which a magnetostatic wave generated in an input / output transducer of the magnetostatic wave generating element is taken out through the coupler, a limiter is inserted between the coupler and an attenuator so that the oscillator is oscillated without being saturated. It is possible to obtain a clear oscillation spectrum without spurious.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the magnetostatic wave delay line oscillator of the present invention, FIG. 2 is a view showing an example of a limiter, FIG. 3 is a view showing the characteristics of the limiter, and FIG. 4 is this embodiment. FIG. 5 is a diagram showing an oscillation spectrum obtained by the magnetostatic wave delay line oscillator, FIG. 5 is a diagram showing a state in which the limiter characteristics are changed, and FIG. 6 is a configuration diagram of a conventional magnetostatic wave delay line oscillator, FIG. FIG. 4 is a diagram showing an oscillation spectrum obtained by a conventional oscillator. 1 ... Magnetostatic wave delay line oscillator, 2 ... Spectrum analyzer, 3 ... Magnetostatic wave generator, 4 ... Amplifier, 5 ... Coupler, 6 ...
… Attenuator, 7 …… Limiter.

Claims (1)

[Scope of utility model registration request] 1. A magnetostatic wave generating element, an amplifier, a coupler and an attenuator are sequentially coupled in a loop shape, and a magnetostatic wave is generated in an input / output transducer of the magnetostatic wave generating element by applying a magnetic field to the magnetostatic wave generating element. In the magnetostatic wave delay line type oscillating device configured to take out through the coupler, the saturation level determined in advance by the physical characteristics of the magnetostatic wave generating element is measured, and the saturation level is set between the coupler and the attenuator. A magnetostatic wave delay line type oscillator having a limiter inserted as an upper limit of output.