US2253379A - Ultra high frequency adjustable antenna - Google Patents

Description

Aug. 19, 1941. 'r. P. KINN ULTRA HIGH FREQUENCY ADJUSTABLE ANTENNA 2 Sheets-Sheet 1 Filed Nov. 13, 1940 INVENTOR ThevC/reF/V/hn.

ATTORN Au .19, 1941. P INN 2,253,379

ULTRA HIGH FREQUENCY ADJUSTABLE ANTENNA Filed Nov. 15, 1940 2 Sheets-Sheet 2 WITNESSES: INVENTOR Theodor A M/N7.

ATTORN Patented Aug. 19, 1941 j Application November 13, 1940, Serial Nb; $5,491

T-EeT-SrATEs My invention relates to radio antennae and, in particular, totantennae .of adjustable .Wave length for ultra high-frequency radiation.

Oneobject. of my invention. is to provide an- ;per second. One efiicient form of such anantenna comprises a compound external sheath item the end of which a central rod extends. "'Ihe compound external sheath consists 'of one con ducting cylinder surrounded by a second contennae whichcanbe adjusted as to radiant wave ducting cylinder bf slightly larger diameter and length from a remote point. t considerably shorterlepgth, the two cylinders be} Another object of my invention is to provide an ing connected together at the endof thesmalle'r adjustable Wave length antenna a particularly y inde and the internal rod extefid fi Ou adapted for use inconjunction with a concentric w r ly fr m his interconn cted end for a discarrier current transmission line. tance equal to the length of the outer cylinder. Still another object of my, invention is to pro- In ot r d t e Str ctu e s such a one as vlde an adjustable wave length antenna .of the Q' d e p cdu dif e ut r Sheath Offa be rconcentric line type-particularly, adapted for em- C t??? ne, 9 1 have: its and slight y pe d ployment of ultra high-frequency carrier curin diameter ahd peeled or folded back for alimrents. 1 a v ited distance upon itself, thereby leaving thec'en- Still another. object of my invention. is toprotrel r d i theycoiitcentfielifie p r a svide an antennaswhicht is adjustable as to Wave tim i e t0 the i wb w 'p of the length; butwhich maintainsa substantially consheath. Such an arrangemen wm be found to stant surgejxnpeda nc over a wide range of ad, constitute an. filcil'ltly radiating antenna havjustmentm p N i ta s wave 1en'gth equal to iourtiine's that er the Other objects of ,mvinventionwilibecome ap- KPPS erid ef'th tent'rl f parent upon readinglthehfollowmg description In Orde? to whesuch a a i f r n taken in connection withthe drawings, in which: e e i is obviolllfily necessary be able Figure 1 is a sideviewlin elevation of ananto vary at willnover a considerable range the tenna embodying the principles ofvmy invention; 1? g h 5f folddqoitk l b Of the Outer s eath- Fig. 2 is an enlarged View in cross-section mu In the arrangement aboiit to be described, I detratingadetail o1; thevstructure of myinvention; S i i s f emitting this result r Fig. 3 is an elevationalview taken at right an- Referring 'p rt a ly to Fi 1 d 2 Of t e gles to th det View m cross-section of drawings, I'provide an antenna having a central Fig. 2; w V L I, rodl which entendslongitudinally of substan- Fig, 4 i a tpp yiew logking down upon t tially the entire Fig. 1 and is supported by insuportion of t structure shown in cross section lator's 2, 3 in the axis of a metallictube 4. As is in Fig. 2; 1 l 4 t t shown in detail in Fig. 5, the tube 4 is supported Fig. 515 a view, partly in elevation andrpartly iPi the Walls Of a casing 5 W i is ad pted to in cross-section, illustrating in detail-the mechanbe r d d i fieSir-edrough an ap tu e in ical arrangements for varying the wave length of th W I'ld 0f thecasihg 5 a e t i li e my t n a d I t I having an outer sheath 6 and a central core 1 Fig. hi a view, partly in cross-section and transmits high-'irequencycurrents froma radiopartly in elevation; taken at right angles to a frequehey generator located at o t portion Fig. 5 a V i i point. The sheath 6 andthe central core 1 are t For radio transmission operations at ultra high electrically Connected, re p iv ly, to the tube 4 frequencies, that istto say, at frequencies of the and h red The tube 4jextends for ya po order of 50 to 200 million cyclesper second, it is iq Q the length b e and e its pp desirable to transmit current between the radio n is surrounded y a l i t be 8 which telefrequency generating andmodulating equipment s p s ve alild S d i y upon it. to the radiating antennae by transmission lines T lowi end of the tub-e 3 is'positioned at all of the concentric type; that is tot ay, by transtimes within the Gasihg 5 and bears a bracket 9 mission lines in which a central core comprises h wnin in ie tail in Figs. 5 and 6, which is one side of the line and a surrounding sheath adapted to elastically s pp rt on Spr ngs In a nut constitutes the other side. For many purposes it 9 12 carried by a threaded shaft l3 Whic sS p is desirable to have aradiating antenna supplied ported in s ta le rin s l4, l5 afiixed to the by such a line which can be tuned to any frecasing 5. A projection H on nut I2 is adapted to quency' within aconsiderable range, for example, contact a pair of insulate contact-fi gers ll between minim cycles and 200 million cycles which control the circuit ofthe motor l6 about to be described and thereby s'tbp rotation of shaft to the antenna,

l3 when adjustment of the antenna is complete, or when any part of the mechanism becomes jammed. The motor I6, adapted to be set in rotation in either direction desired by remote control is likewise supported upon the casing 5 and rotates the shaft it through a worm gear H. A second worm gear I8, engaging the shaft 13, drives a Selsyn indicator Is to register the position of the nut I2, and, consequently, of the tube 8 at any desired point.

As shown in more detail in Figs. 2 and 3, the upper end of the tube 8 carries an annular bracket 2| which supports six rollers 22 i'reely rotatable upon axis. Six thin ribbons 23 of highly conductive material, such, for example, as beryllium-copper, pass over the rollers 22 and have one of their ends connected to the metallic tube 4 on which the tube 8 slides. The other ends of the ribbons 23 are interconnected by a metallic ring 24 which is supported in concentric relation with the tube 8 by insulators 25 which make sliding engagement with the outer suri'ace of the tube 8. The arms or the bracket 2i likewise carry a set of three freely rotatable rollers 26 which engage and press downwardly upon the outer suriace of the ribbon 23 to hold it in position in contact with the surface of the rollers 22. Flat shields 21 are attached to each of the brackets 2| to aid in keeping the ribbon 23 in close contact with the periphery of the rollers 22.

It will be seen that when the rotation of shaft l3 moves the nut l2 longitudinally, the bracket 9 will move the tube 8 and its attached rollers 22 upwardly or downwardly relative to the sheath 4. when the rollers 22 move upwardly from the position shown in Fig. 2, the lower ends of the ribbons 23, together with their supports 24, 25, will be moved upwardly along the surface of the tube 8 and so will move in an upward direction relative to the sheath 4. The ribbons 23 thus constitute in electrical effect an extension of the sheath 4, and the length of the central rod l which is exposed beyond the upper end of this extended sheath (1. e.,' is exposed beyond the position of the rollers 22) is correspondingly decreased. The length of the ribbons 23 is made substantially equal to the length of the rod l which projects above the end of the sheath 4.

Correspondingly, when the shaft l3 in the opposite direction to that just described, the nut l2 moves the tube 8 and its attached rollers 22 downwardly, exposing a greater and greater length of the center rod I. The rollers 26, the shield 21 and the weight of the members 24 and 25 thus keep the portion of the ribbons 23 below the rollers 22 straight. Experiments have shown that the system of six ribbons 23, as just described, acts electrically as a satisfactory extension of the sheath 4 and constitutes an efficient radiating system.

I have found that when the above-described antenna is supplied with carrier current of such a frequency at any time that the exposed length of the center load I corresponds with a onequarter wave length, the surge impedance of the antenna is approximately 73 ohms. In order to insure eificient transmission of the radio current the concentric line should have the relative diameters of its core I and sheath 6 adjusted in accordance with principles well known in the radio art, so that this line likewise has a surge impedance of 7 3 ohms.

In accordance, with the patent statutes, I have described a particular embodiment of my invenis rotated tion, but the principles thereof are of broader application in ways that will be evident to those skilled in the art.

I claim as my invention:

1. A radiating antenna comprising a central rod of conducting material surrounded by a conducting sheath in stationary relationship thereto, means supported for longitudinal movement relative to said sheath and a flexible conducting body having one end attached to the end of said sheath passing over said means, and means for maintaining the portions of said body not in contact with said means in substantially parallel relationship to said sheath.

2. A radiating antenna comprising a central rod of conducting material surrounded by a conducting sheath in stationary relationship thereto, means supported for longitudinal movement relatlve to said sheath and a flexible conducting body having one end attached to the end of said sheath passing over said means, means for maintaining the portions of said body not in contact with said means in substantially parallel relationship to said sheath, and a concentric transmission line for radio-frequency current having its core electrically connected to said rod and its sheath electrically connected to the first-mentioned sheath.

3. A radiating antenna comprising a central rod of conducting material surrounded by a conducting sheath in stationary relationship thereto, a plurality of rollers supported for longitudinal movement relative to said sheath and a plurality of conducting ribbons each having one end attached to the end of said sheath passing over said rollers, means for maintaining the portions of said ribbons not in contact with said rollers in substantially parallel relationship to said sheath, and a concentric transmission line for radio-irequency current having its core electrically connected to said rod and its sheath electrically connected to the first-mentioned sheath, the surge impedance of said concentric transmission line being substantially 73 ohms.

4. A radiating antenna comprising a central rod of conducting material surrounded by a conducting sheath in stationary relationship thereto, a plurality of rollers supported for longitudinal movement relative to said sheath and a plurality of conducting ribbons each having one end attached to the end of said sheath passing over said rollers, and means for maintaining the portions of said ribbons not in contact with said rollers in substantially concentric relationship with said sheath.

5. A radiating antenna comprising a central rod of conducting material surrounded by a'conducting sheath in stationary relationship thereto, a plurality of rollers supported for longitudinal movement relative to said sheath and a plurality of conducting ribbons each having one end attached to the end of said'sheath passing over said rollers, means for maintaining the portions of said ribbons not in contact with said rollers in substantially concentric relationship with said sheath, and a concentric transmission line for radio-frequency current having its core electrically connected to said load and its sheath electrically connected to said sheath.

6. A radiating antenna comprising a central rod of conducting material surrunded by a conducting sheath in stationary concentric relationship thereto, a tubular sleeve adapted for slid ing engagement along said sheath and carrying a plurality of rollers at one end, a conducting ribbon passing over each roller and having one end connected to said sheath, means for maintaining said ribbons in engagement with the surface of said rollers, a metallic conducting ring interconnecting the other ends of said ribbons and supported on insulators which make a sliding engagement with the surface of said sleeve, and a remote-controlled motor-means arranged to slide said sleeve longitudinally along the surlace of said sheath.

A radiating antenna comprising a central rod of conducting material surrounded by a conducting sheath in stationary concentric relationship thereto, a tubular sleeve adapted for sliding engagement along said sheath and carrying a plurality of rollers at one end, a conducting ribbon passing over each roller and having one end connected to said sheath, means for maintaining said ribbons in engagement with the surface of said rollers, a metallic conducting ring interconnecting the other ends of said ribbons and supported on insulators which make a sliding engagement with the surface of said sleeve, a remote-controlled motor-means arranged to slide said sleeve longitudinally along the surface of said sheath, and means for indicating at a remote point the position of said sleeve relative to said sheath.

8. A radiating antenna comprising a central rod of conducting material surrounded by a conducting sheath in stationary concentric relationship thereto, a tubular sleeve adapted for sliding engagement along said sheath and carrying a plurality of rollers at one end, a conducting ribbon passing over each roller and havtransmitting current from a radio transmitter and having its core connected to said rod and its sheath connected to the first-mentioned sheath.

9. A radiating antenna comprising a central rod of conducting material surrounded by a conducting sheath in stationary concentric relationship thereto, a tubular sleeve adapted for sliding engagement along said sheath and carrying a plurality of rollers at one end, a conducting ribbon passing over each roller and having one end connected to said sheath, means for maintaining said ribbons in engagement with the surface of said rollers, a metallic conducting ring interconnecting the other ends of said ribbons and supported on insulators which make a sliding engagement with the surface of said sleeve, a remote-controlled motor-means arranged to slide said sleeve longitudinally along the surface of said sheath, and a concentric line transmitting current from a radio transmitter and having its core connected to said rod and its sheath connected to the first-mentioned sheath, said concentric line having a surge impedance of approximately 73 ohms.

THEODORE P. KINN.

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