RU1780141C - Magnetic-returned uhf-resonator - Google Patents

Abstract

The invention relates to microwave technology, in particular to resonators for microwave generators. The purpose of the invention is to increase the efficiency of performing acoustic modes in a magnetically tunable microwave resonator containing a sound transducer made of a non-magnetic dielectric, on the working surface of which electrodes 4 and 6 are placed. The single-crystal ferrite film 7 is in direct electrodynamic contact with the electrode 4 at a certain length. The ratio of the contact length to the wavelength is given.

Description

The invention relates to microwave technology, D in particular to resonators for microwave generators,

A magnetically tunable acoustic microwave resonator is known, which consists of a sound duct made of an igrium iron garnet plate, metal electrodes, between which there is a zinc oxide plate - a pathogen, in which at small dimensions high-quality acoustic resonances are provided, the frequency of which is overlapped by the magnetic field.

At the same time, this structure has a number of significant drawbacks, the main ones of which are the low temperature stability of the parameters due to the temperature instability of the sound duct material (yttrium iron garnet - DZhO - as well as the lack of the possibility of selective tuning of one of the components of higher types of acoustic modes, t .e. the fundamental fundamental drawback of the resonators is not overcome - their multi-frequency.

Closest to the proposed one is a magnetoacoustic resonator containing a tunable magnetic system, between the poles of which there is a sound duct with a transducer of acoustic waves placed on its working face, made in the form of a layer of piezoelectric material, on the working surface of which electrodes are placed, at least one single-crystal ferrite film placed parallel to the working face of the sound duct with electrical contact with the plane at least one electrode, and the sound pipe is made of a non-magnetic dielectric.

However, the design considered does not always allow the acoustic mode to be effectively distinguished due to insufficient matching of the impedances of the resonant circuits arising in the resonator.

The purpose of the invention is to increase the efficiency of acoustic mode extraction.

This is achieved by the fact that in a magnetically tunable microwave resonator containing a sound pipe of a non-magnetic dielectric with a transducer of a volume acoustic wave on its working face, electrodes, a single-crystal ferrite film electrically in contact with one of the electrodes, and a tunable magnetic system, the free end of the resonator output electrode is closed shortly along the microwave at a distance of I from the short circuit point, an energy removal electrode is connected to the output electrode, and the ferrite film is in electrical contact with the output electrode at least at this length I, and the value of I is determined from the ratio b To I / 4,

. 2l: where

K is the wave number:

I-wavelength;

b is the width of the ferrite film when working on the 1st mode.

The essence of the claimed invention is that such a constructive solution provides the necessary matching of the impedances of the resonant circuits existing in the resonator.

In Figs. 1-3, a magnetically tunable microwave resonator is shown; Fig. 4 - experimental characteristics

the claimed microwave resonator; a) with a ferrite structure on the electrode (not optimized); b) optimized in connection with the gap between the electrode and the film, additional non-magnetic dielectric,

A magnetically tunable microwave resonator consists of a volumetric acoustic wave exciter formed by a piezoelectric film 1 (e.g. ZnO) located between electrodes made in the form of a microstrip line (MPL), one of which 2 is electromechanically connected to a sound guide 3 (e.g., a sapphire plate, gadolinium-gallium garnet, silicon, gallium arsenide), an output electrode 4 long, above it, A / 4, is shorted to ground 5, to which at a distance much less than I / 4 of the grounding point is connected an electrode 6 ui. Between it and the grounding location of the electrode 4 there is an IZH film 7, which is in direct electrodynamic contact with the electrode 4 or through a dielectric spacer 8 (Fig. 3), and in all cases the resonator is placed in a magnetic field.

The resonator operates as follows.

In the absence of a magnetic field, the segment of MPL 9, the length of which is a large change in R / 4 (between 5 and 6), is an effective short circuit for all frequencies of the working range.

When a magnetic field is applied in a ferroite film 7 with an MPL segment 9, magnetostatic waves (MB) (MSW) are excited. In this case, the input resistance of the MLP segment 9 is determined by the radiation resistance to the spin system

ferrite film. This radiation resistance is a complex quantity, and its active and reactive components can vary widely due to a change in the magnitude of the constant bias field. The MPL segment loaded on a ferrite film electrically acts as a controlled reactance. The resistance of this reactivity is close to zero at all frequencies except the frequency that is resonant for the ferrite film at a given magnetic field with a quality factor of 1000, resulting in the effective selection of one of the acoustic modes at a frequency corresponding to the resonance in the ferrite film.

Claims (2)

Thus, in the present design, one of the acoustic modes is effectively extracted. SUMMARY OF THE INVENTION A magnetically tunable microwave resonator comprising a tunable magnetic system, between the poles of which there is a sound pipe made of a non-magnetic dielectric with a transducer of acoustic waves placed on its working face, made in the form of a layer of piezoelectric material, on the working surface of which electrodes are placed, as well as a single-crystal ferrite film placed parallel to the working face of the sound duct with electrical contact with the plane of the output electric An electrode, characterized in that, in order to increase the efficiency of extraction of acoustic vibration modes, an energy pickup electrode is introduced into it, the free end of the output electrode is short-circuited in the microwave, and the energy pickup electrode is connected to the output electrode at the distance of the short circuit outflow, and single-crystal ferrite film is made to provide electrical contact with the plane of the output electrode along the length I, and the value of 1 0 is determined from the condition B- 2 b I / 4, b-. where K is the wave number, I am the wavelength 5 b is the width of the ferrite film when working on the first mode. I 2Z Z 2 ZZZZZZZZ ® FIG. 2 8( O XXXXXX S VSU6 ///////// ffl / ff fig.Z i 115 f .f20 2.E / a2 2, Ub S., 1/4 iO , 2 $ 2.5-, 3f 2.32 2, E2 I,