US3154755A - Electrical device - Google Patents

Description

Oct. 27, 1964 R. WEGENER ELECTRICAL DEVICE Filed March 9, 1962 Jn venlor: Rokf \Oegener United States Patent "ice 3,154,755 ELECTRICAL DEVICE Rolf Wegener, Bielefeld, Germany, assignor to Telefunken Patentverwertungs-G.m.b.I-I., Ulrn (Danube), Germany Filed Mar. 9, 1962, Ser. No. 178,719

Claims priority, application Germany Mar. 14, 1%1

1 Claim. (iii. 334-43) The present invention relates to ultrahigh frequency (UHF) devices, and, more particularly, to such devices wherein the inductances of oscillator circuits associated therewith are disposed in sealed chambers and may be tuned for matching purposes.

Matching devices of the above-mentioned type often contain inductance elements which are arcuate or in the shape of bows and which are arranged in sealed chambers and used for tuning purposes. In order to provide for tuning, the effective length of this how member may be adjusted by means of a short circuit slide bar which is movable between a wall of the sealed chamber and the bow member. Due to the fact that the waveguide tubes which are used have inductances and capacitances which do not permit an exact initial determination of the resonant frequency of the bow, it has been the custom to carry out matching by bending a conductor which is disposed between the bow member and a contact on the waveguide tube.

However, such an arrangement presents a disadvantage because bending this conductor changes not only the total inductance, but also the inductance and capacitance of the bow itself. They are changed to an extent which cannot be previously determined and which cannot be produced, and therefore the matching is impaired. Furthermore, such matching may not be carried out exteriorly of the device and the device must be opened in order to bend the conductor. Therefore, the known type arrangements presented great difficulties in the mass production of these UHF devices.

With these defects of the prior art in mind, it is a main object of the present invention to provide a matching arrangement for UHF devices which may be adjusted exteriorly and without opening the device.

Another object of the invention is to provide means for adjusting the inductance of the conductor in a simple and accurate manner.

These objects and others ancillary thereto are accomplished according to preferred embodiments of the invention wherein the connecting line which is connected between the bow member and the waveguide tube contact, or another suitable stationary contact, is so dimensioned that it may not be deformed at all or only with difficulty by outside influences. This connecting line or conductor is arcuate and defines a portion of a circle. An electrically conductive body or core is movably positioned within this are whereby the inductance of the conductor may be adjustably and selectively varied.

Additional objects and advantages of the present invention will become apparent upon consideration of the following description when taken in conjunction with the accompanying drawing in which the single figure is a perspective view illustrating the bow and the conductor constructed of one piece, with the conductor bent away from the bow.

With more particular reference to the drawing, an ultrahigh frequency arrangement 1 is provided with walls and the like in order to define a plurality of chambers 2 which are independent and separate from one another, but which may be coupled together. To form the oscillator circuits, Lecher wires are arranged in these chambers. The Lecher wires are formed with one conductor 3,154,755 Patented Oct. 27, 1964 being defined by the wall 3 and the other conductor being formed by the bow member 4. One end of this bow member may be conductively connected with the bottom and/ or with the walls of the chamber. The other end of the bow member is connected to a conductor 5 which is connected to a contact or terminal 7 of a waveguide tube 8, and may be connected directly thereto or by means of a capacitor 6.

Also, a trimmer capacitor 9 may be used as an anchoring point for the free end of conductor 5 and this capacitor is arranged at this point for matching purposes. In order to tune the oscillator circuit of the chamber, a short circuit slide bar it? is arranged between the conductors of the Lecher wire, that is, between the bow 4 and the wall 3. The slide bar is connected to a shaft 11 and is movable therewith. The shaft 11 preferably extends through all of the chambers and may be used in an advantageous manner for also tuning the Lecher wires and/or oscillator circuits arranged in the other chambers.

In order to compensate for deviations of the oscillator circuit from the desired values of resonant frequency, the connecting line or conductor 5 is formed as an arc of a circle or as a spiral between the free end of bow member 4 and the terminal 7 of the waveguide tube 8. These deviations are caused by operating or working tolerances as well as the inherent inductances and inherent capacitances of the waveguide tube and its conductors. Within the are formed by conductor 5, a threaded body 12 is axially displaceably mounted, this body being formed of a conductive material. Preferably, the body 12 is silver-plated. Due to these factors, the inductance of conductor 5 is varied in order to be closer to or at the point which matches the resonant frequency.

In order to provide for uniform manufacture of the device with values which may be reproduced for all devices of the same type, the conductor 5 is constructed to be self-holding so that it cannot be displaced or deformed by smaller forces, e.g., during the matching operation. Preferably, conductor 5 is constructed of one piece with bow member 4, as, for example, by punching. Thus, the conductor 5 when mounted with the other components defines the arc of a circle which arc is especially determined for this part. The conductor 5 may be constructed of difierent length depending upon the use of the bow member in the different chambers of such a tuning arrangement and it may be shaped to be the arc of a circle or in the shape of a spiral.

The screw body 12 may be arranged to be displaceable either through the bottom plate of the chamber, in which case it may be done externally, or it may be done internally from the inside of the chamber after removing the cover. Preferably, this body 12 is mounted so that it has no conductive connection with the casing or chassis although such a conductive connection is permissible.

As an example the bow member 4 and the conductor 5 may have a thickness of 1 mm. The width of the bow member 4 may be 3 mm. and that of the conductor 1.5 mm. in this example.

The frequency range, in which the device is to be used may be from 450 to 1000 mcs.

it will be understood that the above description of the present invention is susceptible to various modifications, changes, and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claim.

What is claimed is:

In a matching device for ultra high frequency devices in which oscillator circuits contained in chambers are formed by Lecher wires of a chamber wall and a bow, a short circuit slide bar movable between such wall and the bow for tuning purposes and in which a connecting line between the bow and a connecting contact pertaining thereto may be influenced for changing the total inductivity of the bow, the improvement wherein the connecting line and the bow are one piece, the bow is disposed in a plane, the connecting line is displaced from the plane of the bow and forms only part of an arc and an electrically conductive core is disposed Within the arc of said connecting line, said electrically conductive core including a metal screw threaded from the exterior through a wall of the chamber into the interior of the chamber.

References Cited in the file of this patent UNITED STATES PATENTS Wallin Mar.

Osborn Nov.

Murakami et a1. Apr

Gossard July Reiches Jan.

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