Патент USA US2403657код для вставки
July 21946@ ' ‘ 'RLH'AàvEY ‘2,403,657uw :s_sumnne :um m-mgczn'zc u_nsnxns ' Y6WYEE Filed .n_n. 2s. 1943 PEVOLYZ FRIEMQU'GNHCYBES *1oz 6 -. b'Q‘zgl n N gcmb‘ob'q» 'n n gcaqswwç 'n Q *t N ` ~ ' q. u _ _ Jnx‘cnlm’ Robert L. Harvey m f1. ' L AV f’ìll _ . Ima. ' ` (mamey ‘ Patented ¿Joly 9,„1946__ o e PATENT ^ AUNITED STATES OFFICE ~ ‘ macs-1 INSULATING. -AND DIELECTRIC MATERIAL Robert L. Harvey. Princeton, N. J.. lssignor to Radio Corporation of of Delaware _ „ , » America. a con»- cration""""` " Application January 29, Masern! no. 413.931 1 lliialn‘i- (Cl. S60-41) l , My present invention relates to insulating and dielectric materials for radio currents and has for its general object to provide an improved insulat-~ Accordingly. a speciflc-obiect of my invention ' ing and dielectric material having lßertain unique properties which render it especially suitable. for use in electrical apparatus of the type designed ' t0 handle currents of ultra-high-frequencies', in cluding so~called “centimeter waves”. l My invention will be described in connection with the accompanying drawing wherein the sin- ' glefigure comprises a group of comparative curves showing how the Q . _ is to provide an improved insulating and dielec tric material> for currents of radio frequencies, and one which shall exhibit a ilat “Q” or. alter- > natively. a rising "Q” with an increase in frequency. and this, too. at frequencies of upwards of nve million cycles (5 megacycles) per second. A'Another and important object of my present invention is to achieve the aforesaid highly de airable and unique characteristics in a material having satisfactory heat resisting properties. (QT-_“ ' 2 tuned circuits in a desired manner. with fre» fluency; reactan The foregoing and other objects are achieved resistance - of certain materials changes with frequency. It is known to those skilled in the art to which my invention appertains that the Q of the usual insulating materials. including the common ther~ in accordance with my invention by the addition, to moldable types of insulating compounds. prior to the molding operation, of a metal of low spe cific resistance. such for example. as copper or silver.' in o. finely divided state. The speciilcl re mo«plastic and thermo-setting resins. decreases with an increase in frequency. Thus. as shown by the curve which is designated "A” in _the ac companying chart, polystyrene (or "styroi," as it is sometimes called) exhibits a Q which decreases 25 from a high value of approximately 6,000 at fre quencies _of the order of l rncgacycle to a value of In m1571118 my invention into eil'ect I prefer to employ polystyrene as the basic insulating ingre dient because of its relatively high "Q" value. though I may employ other thermoplastic or thermosetting insulating materials. such for ex ample as the phenol aldehyde, urea. ‘aldehyde and. less than 2.000 when subjected to frequencies in furfural resins, and to use copper particles of, 'x the 60G-1.000 megacycie range. sa?. 300 mesh as the metallic mier. The mixing 80 It is also known that if two dielectric materials. _may be carried out with' the insulating material :such. for example, as polystyrene and Asilica. di either in the powder or liquid form. ' oxide (see- curve “B”). are mixed together, the As shown by curve C of the drawing, the ad ¿ resulting compound will possess a Q lower than dition of» substantially 10% by weight of copper - either of its constituents at any given frequency I and. like _its separate constituents. will exhibit >a 35 j decrease in Q with an increase in frequency. There are numerous applications in radio and ' analogous communication systems of> the type utilizing ultra-high-frequencies for an insulating particles to polystyrene results in a moldabie non conductive compound which exhibits a suhstan- . tially constant Q over a frequency range of from. say. 5 to 400 megacycles. In order to achieve a Q ~~ which increases with frequency I employ a greater Percentage of powdered metal.` Thus, referring to or dielectric material which will exhibit a con- 40l curve D.‘I have -found that the addition of 35 %. etant Q or a rising Q. with an increase in freby weight. of powdered copper to polystyrene re quency. By way of example: in a transmission sults in a compound which exhibits o. uniformly line wherein losœs normally increase with fr@ Q in the 5 to 400 megacycle band. Curves _ quency due to redistribution of the current il. e.. E and F' show that over the same frequency range "skin efiect”) _a material having 'a Q which in 45. o. somewhat lower Q, but one which nevertheless creases with frequency could bc employed as dielectric and/or insulating material to compen sate for such losses. A material which exhibits inflatQorarisingQ.withanincreaseinfreé'V increases with frequency, is achieved when the percentage of copper in- the compound is ln creased to 50% and 70% respectively. I have found that the addition of the powdered quen'cy can also be used to advantage. either 5° lr'netal to the conventional insulating materials in alone or in combination with other materials, as creases the usable temperature range of such the dielectric medium' in electric capacitors .of materials. Thus, in the case of polystyrene the various types and ratings._ By way of example. usable temperature range is increased from 75° -auch capacitors could be used in installations Cito, say. 90° C. ' wherein it is desired-to vary the selectivity ofthe As a result ci' my work with these dielectric / / 8,403,657 consisting ot polystyrene and distributed there~ compounds over a. iride frequency range I have reason to believe that the slope oi' the curves C, through a ñneiy divided meta! selected from the group consisting of _copper and silver in the proportion of from 10 percent to 35 percent by weight o! the polystyrene. said medium exhibiting n ratio o! œactance to resistance within the fre D. E and F xemaìn substantially the same as indi-A cated m the drawing at irequencies of the order of several thousand megacycies._ but owingto the possibility of error in making the necessary :new _'urement; at these frequencies with present day ` npparatus and technique. I _have omitted such - representation from the drawing. _ I claim: ' _ '_ quency range o! from 5 megacycies per second to 1.000 megacycles per second which has a. value at least. as great at the higher of said frequencies „_ as at the lower of said frequencies. ‘ An eiearioai insulating and dielectric medium ROBERT L HARVEY.