DE1027259B - Arrangement for the mechanical modulation of high frequency oscillations - Google Patents

Description

GERMAN

The invention relates to an arrangement for the mechanical modulation of high-frequency oscillations, in which a resonator for decimeter and centimeter waves (z. B. cavity resonator, cup circle, etc.) has a movable wall part (membrane), which in time with the modulating low frequency of a excitation system is vibrated and caused by the change of its position relative to the other wall parts of the resonator a \ ^r erstimmung the resonant frequency,

In the arrangements known up to now, the excitation usually takes place on electromagnetic, piezoelectric devices or magnetostrictive path; in doing so, however, the disadvantage arises that schwingungsgeneren.de Organ of the excitation system as a result of the temporal inconsistency of individual parts of the excitation system and especially as a result of temperature fluctuations is adjusted and this adjustment on the movable wall part (membrane) of the resonator transmits. This increases the resonance frequency of the Adjusted the resonator.

When using "the resonator as a frequency-determining organ of a high-frequency vibration generator, wherein the mechanical modulation results in a frequency modulation of the high-frequency carrier leads, as a result of the disadvantages described, the frequency constancy of the arrangement is considerably reduced.

According to the invention, the disadvantages of the known arrangements are avoided in that the vibration-generating surface of the excitation system with the movable wall part (membrane) of the resonator is firmly connected and the excitation system in the direction of movement of the movable Wall part is arranged freely movable and has such a large mass that the over A certain maximum frequency lying vibrations due to the inertia of the excitation system from the vibration-generating surface the movable wall part of the resonator are transmitted, while slow vibrations or Changes due to displacement of the excitation system in the direction of movement of the movable one Wall part (membrane) of the resonator are compensated.

It is therefore an essential advantage of an arrangement according to the present invention that unwanted, very slow vibrations or changes in the excitation system, the z. B. as a result of a change in time of components of the excitation system, in particular the premagnetization, do not occur on the movable ones Conversion part of the resonator are transmitted. It is thereby the frequency constancy of a such a modulation arrangement is significantly increased.

Arrangement for the mechanical modulation of high frequency vibrations

Applicant:

Siemens & Halske Aktiengesellschaft,

Berlin and Munich,
Munich 2, Witteisbacherplatz 2

Dipl.-Ing. Helmut Schröder

and Dipl.-Ing. Josef Gammel, Munich,
have been named as inventors

In the drawing, preferred embodiments of the arrangement according to the invention are described, whereby

Fig. 1 shows an application in an electromagnetic excitation system, while Fig. 2 shows an application in a piezoelectric excitation system and

Fig. 3 shows an embodiment in a magnetostrictive Represents the excitation system.

In Fig. 1, a pot circle 1 is shown, which for the oscillations in the decimeter and centimeter wave area represents a resonance circuit. Preferably at the point of the concentrated resonant circuit capacitance 2 is in the wall of the resonator 1, a movable wall part 3, z. B. a membrane inserted, the is actuated mechanically in time with the modulating low frequency and thus a frequency modulation which causes high frequency oscillations taken from the resonator. The electromagnetic excitation system 4 is preferably mounted on rails 5, so that easy displacement of the System is guaranteed in the direction of movement of the movable wall part 3 of the resonator.

The vibration-generating membrane 6 of the excitation system 4 is via a short connecting rod 7 with the movable wall part 3 of the Resonator 2 connected.

The arrangement described acts in such a way that vibrations of the excitation system 4, which over a certain cut-off frequency, due to the inertia ül> he the connecting rod 7 on the movable wall part 3 are transmitted and for the mechanical modulation of the resonator ent-

709 958/287

Assumed high frequency vibrations are used, while slow vibrations or changes in the excitation system 4, which z. B. as a result of temperature fluctuations or temporal inconsistency of individual components, e.g. B. the permanent magnets occur, be compensated for by shifting the entire system 4 along the rails 5. Owns that Excitation system does not have enough mass, so you can load the housing with additional mass.

Fig. 2 shows a resonator 1 with one for media, - ίο Niche modulation serving movable wall part 3, which is made of a piezoelectric crystal (Quartz) 10 is excited to vibrate. The piezoelectric crystal is in this case with a vibration generating Surface preferably attached to the movable wall part 3 in a cantilevered manner. At the the side of the piezoelectric crystal 10 facing away from the movable wall part 3 of the resonator 1 a mass layer 11 is applied. This has the task of increasing the mass inertia of the crystal to such an extent that that the vibrations lying above a certain limit frequency due to inertia be transmitted to the movable wall part 3, while the slow vibrations by a corresponding change in position of the crystal 10 can be compensated for.

An application example in the case of magnetostrictive oscillation generation is shown in FIG. 3. Here a rod 22 made of magnetostrictive material is cantilevered on the movable wall part 3 of a Resonator 1 attached. Due to the inertia of the rod 22, only those above a certain Limit frequency lying vibrations transmitted to the movable wall part 3 and serve to Detuning the resonance frequency of the pot circle 1.

Claims (4)

PATENT APPROACH: 1. Arrangement for the mechanical modulation of high-frequency vibrations in which a resonator for decimeter and centimeter waves (e.g. cavity resonator, cup circle, etc.) a movable one Wall part (membrane.) Possesses, which in time with the modulating low frequency of a Excitation system is set in oscillation perpendicular to its surface and by change its position relative to the other stationary wall parts of the resonator a detuning the resonance frequency, the vibration-emitting organ of the excitation system with the movable wall part (Membrane) of the resonator is firmly connected, characterized in that the excitation system in the direction of movement of the movable wall part that is elastically held in its rest position « Is arranged freely movable and opposite the movable wall part including the vibration-emitting organ has such a large mass that the over one certain limit frequency lying vibrations due to the inertia of the excitation system of the vibration-emitting organ be transmitted to the movable wall part of the resonator, while slow vibrations or changes in the case of a fixed vibration-emitting Organ by shifting the excitation system in the direction of movement of the movable wall part (membrane) of the resonator be balanced. 2. Arrangement according to claim 1, characterized in that that the membrane of the electromagnetic excitation system (4) has a short connecting rod (7) is firmly connected to your movable wall part (3) of the resonator (1) and the housing of the electromagnetic system (4) is mounted on rails (5) in such a way that it is in the Movement direction of the movable wall part (3) of the resonator is easily displaceable. 3. Arrangement according to claim 1, characterized in that a piezoelectric crystal (Quartz) (10) with an oscillation-generating surface on the movable wall part (3) of the Resonator (1) is attached and on the side surface facing away from the movable wall part (3) is occupied with such a large mass (11) that the above a certain fundamental frequency lying vibrations due to the inertia of the crystal (10) on the movable wall part (3) transmitted while slow vibrations by moving the with Mass occupied piezoelectric crystal (10) are compensated. 4. Arrangement according to claim 1, characterized in that a magnetostrictive rod (22) is attached in a cantilevered manner to the movable wall part (3j of the resonator (1), so> that the oscillations of the magnetostrictive rod (22) above a certain limit frequency due to inertia are transferred to the movable wall part (3) while slow vibrations are compensated for by movements of the rod (22). References considered: U.S. Patent No. 2,463,472. 1 sheet of drawings © 709 958/287 3.