Патент USA US2408199код для вставки
Sept. 24, 1946. '.1. w. coLTMAN - , 2,408,198 ULTRA HIGH-FREQUENCY POWER MEASUR'ING DEVICE v vF11-ed Fei». 5, 1945 » Jolm 001mm. Patented Sept. 24,> 1946 - 2,408,198 y UNITEDSTATES PATENT OFFICE ULTRA HIGH FREQUENCY POWER MEASURING DEVICE John W. Coltman, Forest Hills, Pa., assignor to Westinghouse Electric Corporation, East Pitts burgh, Pa., a corporation of Pennsylvania - ‘ f Application February 5, 1943, Serial No. 474,884 , 18 Claims. 1 (Cl. 171-95) . end of theguiae, causing the buib 1.0 glow. The brightness of the glow produced in the bulb is _This invention and discovery relates to a method and device for measuring ultra high frequency power, and has particular relation to an indication of the strength vof the ñeld produc l ing the ionization of the neon-gas. However, the ' use of a neon lbulb Aenables only a very rough apparatus for vmeasuring the ultra high-fre quency power delivered from a wave guide. In accordance with prior. art practices, ultra estimate of the power to be made for the visual impression Íof brightness is extremely diiîicultto high-'frequency lpower is measured by absorbing the energy in water and measuring the resulting increase in temperature of the water. rll‘he power output. of an ultra high-frequency generator is oftenV measured in this way. The wave guide is disconnected from the load adjacentfrtoV the gen erator and» a cap is mounted over the open end of the .wave guide.. The cap includes a quartz. retain. *Moreover, the glow'in a neon bulb is violently'affected by slight changes in the neigh boring electric ñeld, such as might be introduced . by reflection from nearby objects. It is„therefore, an object of my invention to provide a simple and inexpensive device for measuring ultra high-frequency power. ' plate extending directly across the waveguide 15 .'It -_is`another object of my invention to .pro vide novel apparatus for measuring ultra high opening and the remainder ofv the vcap cooperates immediately above the plate. A water reservoir, frequency power which enables a direct, instan taneous and accurate .reading of the power to pump. 'and :conduits are then arranged to pass a -be made. are such as to permit all ofthe energy incident high-frequency power. with the quartz plate to form a small chamber . constant’stream of water through the chamber. I.20 >AA further object of my invention is to provide a new and improved method of measuring ultra The position and form ofthe plate and chamber ' n It is still another object of my invention to to the plate to be absorbed in the water. Know ing the rate of iiow of the waterV and the tem provideY a novel methodA and apparatus for perature of the y,water before'and after it,v passes 25 measuring the ultra. high-frequency power de livered' from a wave guide.Y ~ throughthechamber, the average power may be Another object 'of my invention’ is to provide calculated. . . . ‘ . . a novel'device for measuring ultra high-frequency . ‘The water» temperature- arrangement. for de terminingthe power gives good results but also has certainobjectionable features. The appa peakîpower. 30 ratus is quite bulky and requires not only a water supply but certain supplementary equipment, in cluding pumps, conduits,Y valves, and .sensitive galvanometers. Consequently, it is impractical ' ' » vIt is a further'object of my invention to pro vide a simplified device for measuring ultra high frequency power which is not affected by slight changes in theY neighboring electric field. y Y More specifically, it is an object of my inven for use in the ñeld and inconvenient to handle 35 tion to provideY a compact, portable device for in the laboratory. In addition, the-,apparatus cannot show an erratic supply from the source because there is a time lag in the response of the. water Átemperature as>A indicated on the rvgal vanometers, to changes in the source. If tuning operationsare carried out ’to vary the output of the source, an appreciable time mustelapse, be cause of the slow response in the indicated water temperature, beforel the eiîect of the tuning op erations on the output cans-be determined. More over, the arrangement enables comparatively easy calculation of the average powerbut the Vduty cycle must be'lmown to calculate the peak power. Other difliculties encountered in theïuse of the water temperature arrangement involve the control of the rate of .water iiow and the positioning of (the cap on the end of vthe wave guide.V y , , , ` . . ` , measuring ultra high-frequency power which does 'not Vrequire any supplementary apparatus or supply sources. '.My invention arises from the discovery that upon introduction of an electric ñeld into an in ` sulated column of gas at a selected point thereon with the column of> a capillary cross-sectional area and the gas of the type which produces a . visible'glow in the presence of an electric ñeld above >a predetermined intensity, a portion of the column extending from the selected point pro duces a glow. There is a sharp line of demarca tion between the glowing and the non-glowing gas rand the length of the glowing column is a measure of; the intensity of the electric ñeld ' ' which isl introduced. into the column and of the '\ power absorbed thereby. ' . ` My discovery may be advantageously employed Vin the'provision of. a' measuring device compris delivered from a wave guide may be madeby. 55 ing an (elongated envelope of translucent in placing an ordinary neon bulb over the output 1 sulating material having a capillary bore therein f rA relatively quick estimate of the power being 3 4 ñlled with neon or other gas which produces a glow in the presence of an electric neld of a serted in the output end of the guide section and adjusted to eliminate wave reflections so that all the power is diverted into the capillary bore of the envelope. predetermined intensity. The device is adapted to have the electric field to` be measured intro duced at a selected point in the capillary bore. . 6 It then becomes apparent that the same cali If the intensity of the introduced field is suin brated measuring apparatus may be employed in ciently great, the gas is ionized at the `point of different systems of the same frequency and wave introduction and acts as a partial conductor along length. It is compact, portable and inexpensive. which the field travels. In addition it may be conveniently employed in As the field travels along the column of ionized lli the field and enables an instantaneous reading of gas contained within the capillary bore, its energy the peak'power. is dissipated in ionizing the gas, losses in. the The. features that I consider characteristic of material of which the envelope is formed, and in my invention are set forth with particularity in radiation. When the neld intensity decreases. the appended claims. The invention itself, how below the critical value necessary to- ioni‘ze the - ever, both as toits organization and its method gas, the glow ceases at that point. Thus a col of operation together with additional objects and umn of glowing gas extends along the» capillary advantages thereof viu‘ll best be understood from bore from the selected point for a distancev de the following description of specific embodiments pending upon the original intensity of the ñeld when read in connection with the accompanying introduced into the capillary bore and the dis drawing, in which: tance is a measure of the power absorbed by the Figure 1 is a View of the preferred embodiment device. l >t has been discovered that> the glow diminishes slightly in brightness along the capil lary bore but that it comes to a termination very suddenly. Moreover, it hasv been discovered that slight changes in neighboring electric fields as might be caused by wave reflections, do not affect of the measuring device, Fig, 2 illustrates an arrangement for measur ing the power in a system using a wave guide, and Figs. 3, 4 and 5> illustrate various arrangements for introducing the electric ñeld into the capil the length of the glowing column. A calibrated lary column of gas. scale> may be placed along the capillary bore to As shown in Fig. l, the preferred embodiment give a direct reading of the intensity of the elec' 30 of the measuring device consists of an elongated tric field introduced in the~ bore o_r the power ab envelope 3 of glass or other translucent insulat sorbed by the device. ing material. The envelope 3 has therein a capil The electric field- may be introduced into the lary bore 5 extending from a reservoir 1 at one capillary bore in various Ways. A satisfactory end to a small exciting chamber 9 at the other way-is to provi-de a small' exciting chamber at one end. The chamber 9 is of slightly larger cross end of the bore of larger diameter bul-I consider sectional area than the capillary bore 5 but is ably shorterin length than the bore, This cham considerably shorter in length. The capillary ber is also ñlled with gas and is adapted to be bore 5, reservoir 'l and' chamber 9 are filled with positioned to be exposed to the electric’ neld to be’ measured; The field then, ionizes the gas in neon or other gas of the type which produces a glow in the presence of an electric ñeld of a pre the chamber' which acts as a partial conductor to determined intensity. introduce the electric> neld into the’ bore. Other arrangements for introducing the ñeld into the bore may also be employed advantageously such The envelope 3 is adapted to be positioned with the chamber 9 exposed tothe electric field to be measured. The` ñeld causes the gas in the cham as- the use of' a conducting electrode or electrodes " ber to be ionized forming a partial conductor for y exposed to the electricîìel‘d.> It has'alsoY been dis the electric field to introduce it into the end of covered that anV electric yñeld of high intensity the capillary bore 5. The gas at the end of the may be introduced into the capillary bore by capillary bore is ionized by the electric ñeld which merely placing a portion thereof directly in the is> introduced therein and the ionized gas con path of the energy. An'exciting chamber isv pref 50 ducts the neld along the capillary bore. As .the erable, however, because the increased relation field is conducted along the bore, it dissipates between the volume of the gas and the area of itsV energy and the intensity of the field decreases the surface within which it is contained greatly gradually as it is conducted along the capillary facilitates the original'ionizati‘o’n of the gas. bore until it falls below the critical value neces Although the intensity of any ultra’hig’h-fre 55 sary to maintain ionization of the gas. The quency electric field may be measuredv by this length of the capillary bore is such that the ñeld‘ new method, apparatus is provided in accordancel intensity drops below the critical value inter with my invention for measuring power in. sys mediate the ends of the bore. Thus the ñeld tems in which the power is transmitted through causes only a portion of the gas in the capillary hollow wave guides. As the length of the column 60 bore to produce a glow, there being a sharp line of glowing gas in the envelope` is a measure of of demarcation between the ionized or glowing, the p_ower absorbed thereby, it is apparent that if gas andthe non-glowing gas. A calibrated scale a known percentage of the power in a wave l l` extends along. the capillary bore 5 to facilitater guide is diverted into the capillary bore of the measuring the length of the glowingy column and 65 to give a direct reading of the power absorbed envelope, a power reading may be taken. A simple way of diverting a known percentage by the device. of power from a wave guide into the capillary The reservoir 1 is used to replace gas losses bore of'anenvel'ope is to divert all of the power. and insure anadeduatesupply of gas' in theV capil The wave guide may be disconnected from the lary bore andv thereby extend the life of the de load anda small additional section of wave guide 70 vice. However, the reservoir isy not essential to connected thereto. A ñtting is provided to mount the operation of the device. the envelope on the wave guide section with the In Fig; 2, a wave guide I3 supplied from a source4 exciting chamber or electrode extending into the of ultra high-frequency power is shown in cross wave guidev so that it is` exposed to the electric> section with an open-ing l9`_in'.a wall of the guide field in the guide, A snorting stub is, then in ' which isA normal tdtheelectric field createdl in _2,408,198 5 6 . aware that many modifications thereof are pos sible. My invention, therefore, is not to be re-~ the guide when power is supplied thereto, the di rection of the yiield being indicated by an arrow 20.l The opening I9 is surroundedby an inter-f nally threaded boss 2| mounted on the outside ofl stricted except insofar as is necessitated by the prior art and the spirit of the appended claims. the guide.>` v The glass tube or envelope 3a with Ul the capillary bore 5 is similar to envelope 3 in I claim as my invention: ' 1. A device for measuring the intensity of an ultra high-frequency electric field comprising an elcngated'envelopeof translucent, insulating ma member 23 cementedabout the end thereof ad terial having a capillary bore therein ñlled with jacent to the chamber 9. The member 23 is threaded to screw into the boss 2|, and support 10' gas of the type Which produces a glow in the presence of an electrici'ield of a predetermined envelope 3a. with the chamber 9 within the wave intensity, said envelope being adapted to have the guide, as -shown, exposed to the electric field in electric ñeld to be measured introduced into said the guide. YA nut` 25 is then employed to hold the bore at a selected’place whereby said field travels member 2_3 in thedesired position.~ alo-ng said bore from said place, said bore being ' A shorting vstub 23 is provided in the output of such length that said ñeld decreases below said end of the wave guide. lThis stub, may be of anypredetermined intensity intermediate the ends of suitable shape, there being various designs in the bore. . . use at present, and serves to createl a short cir 2. A devi‘ce for measuring the intensityof an cuit across the end of the guide. The_position ultra, high-frequencyv electric ñeld comprising an of the` stub is adjustable so that byproper ad elongated envelope of translucent, insulating ma justment of the- stub 26 andthe position of the terial having a capillary ibore therein ñlled with exciting chamber 9, wave reflections may be gas of the type which produces a glow in the eliminated so that substantially al1 of the power presence of an electric iield of a predetermined is diverted into the capillary bore. HI have dis covered that the wave _reilections may be elimi 25 intensity, said envelope being adapted to have the Fig. 1 but does not have a reservoir and has a electric iield to be _measured introduced into said bore at a selected place whereby said ñeld travels along said bore from said place, said bore being 0f such length that said field decreases below said nated more-readily if the exciting chamberof the envelopeis inserted through a wall of the guide whichis normal to the electricrñeld Ain the guide. In Fig.v 3 is illustrated a device having the chamber 9 of Fig. 2 replaced byra conducting 30 predetermined intensity intermediate the ends of the bore, and a calibrated scale> extending along electrode 27. The envelope 3b is mounted _on a wave guide in the manner described in Fig. 2 with said bore. the guide.> The electrode 21 then serves to `intro ducelthe electric ñeld into the end of the capil lary bore 5. , , terialhaving a capillary bore thereinñlled with gas of the typeA which produces a glow in the presence of an electric ñeld above-a predeter - 40 i _ mined intensity„ and exciting means yassociated with >said bore which is effective when exposed to an electric ñeld ,to introduce that field into vsaid bore at aY selected place whereby said field travels along said :bore from said place, said bore being of such length that said field; decreases below said predetermined intensity intermediate the ends of the bore. 4. A device for measuring the `intensity of an ultra high-frequency electric ñeld comprising an ployedto direct substantially all of the power ,Y ' ultra high-«frequency electric i-leld comprising an bore `5 is connected to the center conductor 3l of the coaxial line. -AA shorting stub 33 is em into the'capillary bore; _ 35 elongated envelope of translucent, insulating ma In Fig. 4 is illustrated an arrangement for in troducing the electric-field into the capillary bore from a coaxial 4transmission line 2S. The len velope 3b its mounted on the outer conductor of the-coaxial line similarly to the mounting of the envelope onthe wave guide in Fig. 3, but the con ducting electrode 21 in the end ofthe capillary ' 3. A device `for measuring the intensity of an the electro-de 2l extending from the bore 5 into ' . ¿In measuring power above a predetermined magnitude the use of an igniting chamber or elec elongated envelope of translucent, insulatingma trode ymay be avoided. In'such a situation, a capillary tube 3c- sealed at both ends and ñlled with gas will be effective if a portion of the tube itself is placed across the wave guide as shown invFig. 5. Of course, if the tube 3c extends on terial having a capillary `bore therein filled with extends on both sides. If desired, the tube 3c may' field travels along said bore from said point, said gas `of the type which produces a glow in Athe presence of an electric field above a. predeter mined intensity, means` associated with said bore for introducing the electric ñeld to be measured both sides of the guide, the glowingcolumn also 55 into said bore at a selected point whereby said bore being'ofsuch length that said ñeld decreases below said predetermined intensity intermediate extend through the guide intermediate the ends and a snorting stub employed. the ends of the bore, and al calibrated scale ex It is Yto be noted that a capillary bore must ` Y be employed to support the gas column. If a 60 tending along said bore. 5. A device for measuring the intensity of an large bore is used, the glow tends to follow the ultra high-frequency electric ñeld comprising an surface of the bore producing glowing fingers elongated capillary tube of translucent, insulating and the line between glowing and non-glowing material, sealed at :both ends and ñlled with gas gas is extremely irregular and quite shadowy. In ultra high-frequency systems using a wave 65 of the type which produces a glow in the presence of an electric field of a predetermined intensity. length of 3 centimeters, I have found a bore of 6. A device for measuring the intensity of an approximately 3 millimeters or less in diameter is ultra high-frequency electric field comprising an satisfactory with a diameter of .5 millimeter pre elongated capillary tube of translucent, insulating ferred. Neon gas is also preferred at a pres sure of approximately '7 millimeters. The device 70 material, sealed at both ends and filled with gas may be calibrated in kilowatts with a peak power d of 5 kilowatts giving a glowing column over ten centimeters in length with a .5 millimeter bore. Although I have shown and described a pre ferred embodiment of my invention, I am fully of the type which produces aglow in the presence of an electric field of a predetermined intensity, and a calibrated scale extending along said tube. '7.V A device for measuring the intensity of an 75 ultra high-frequency electric field comprising an 7 elongated capillary tubelof translucent,v insulating material, said tube` having a bore of a diameter of the` order of .5- to 3 millimeters, sealed at both ends andy filled with gas of the type. which pro duces a glow in the presence of an electric íield of a, predetermined intensity. 8.. A device for measuring the intensityA of an ultralhi'gh-frequency electric ñeld comprising an elongated- envelope of translucent, insulating ma 8 terial having» therein a- bore ofy a- diameter of the order of .5 to 3.0i millimeters filled with gas ef the type which produces a- glow in the presence of an electric ñeld above a predetermined in tensity, exciting means associated with sai-d- bore for introducing the electric ñeld to be measured intoV said bore at a selected point' whereby said field travels along said borefrom said point, and a scale extending along- said bore. terialY having therein an exciting chamber at one l0 14. A device for measuring‘the intensity of an endl andy a reservoir at'the other end and a capil ultra high-frequency electric field comprising an lary bore interconnecting said chamber and res elongated envelope of translucent', insulating ma ervoir, said chamber, reservoir and bore being terial having therein a bore'- of a diameter' of the filled with gas of the type which` produces a glow order of .5 to 3.0 millimetersy ñlled with- gas of inthe presencelof an electric field of a predeter the .type which produces a glow in the presence mined intensity. of an electric ñ'eld above a predetermined in 9L A device- for measuring thev intensity of an tensity, and exciting means associated with said ultra high-frequency electric ñeld comprising an elongated envelope of translucent, insulating ma terial having therein an excitingl chamber atA one end’ and a reservoir at the other end and a capil lary bore of a diameter of the order of .5 to 3.0- millimeters interconnecting said chamber and reservoir, said chamber, reservoir and »bore being filled with gas ot the type which produces a glow in the presence of an- electric ñeld of a predeter mined intensity. 10. A device for measuring the intensity of an ultra high-frequency electric field comprising an elongated envelope of translucent, insulating ma terial having therein an exciting chamber at one end and a reservoir at the other end and' a` capil bore for introducing the electric' ñeldf to be measuredV into >said bore> at a selected poi-rit1'5. A device for measuring the intensityV ofV an ultra high-frequency'electric ñe'ld comprisingí an elongated envelope of translucent', insulating ma terial having thereinv an exciting'- chamberr and a capillary bore opening i'nt'o said: chamber with said bore .andi chamber being filled withA gas of the> type which produces a glow in the presence of an electric field of a- predetermined intensity. 16. A device for measuring the» intensity of ' an ultrahigh-»frequency electric ñeld comprising an elongated envelope of translucent, insulating ma terial having therein an exciting chamber and a capillary bore opening into> said chamber, said lary bore- interconnecting said chamber and res bore and chamber being ñlledï with gas- of the ervoir, said» chamber, .reservoir and bore being type which produces a glow-` in the presence of filled with gasA of the type Whichproduces- a glow~ 35 an electric field of a predetermined intensity, and in the presence ofV an electric ñeld 0f a predeter a scale extending along said bore. mined intensity, and- a calibrated scale extending 117'. A device for measuring the intensity of an along said bore. ‘ lïlï. A device for measuring the intensity of an ultra high-frequency electric field comprising an elongated envelopeof translucent, insulating ma ultra high-frequency electric field comprising an elongated envelope oftranslucent, insulating ma terial having therein anl exciting chamber andy a bore of a diameterr of the order of .5 to 320 milli terial having a capillary bore therein filled with gas of the type which produces a glow inthe meters opening into» said chamber, said bore and chamberV being ñlled with gas- of the type which presence of lan electric» ?leld` of a predetermined intensity, and- conducting electrode means ex» produces- a glow in' the» presence of' an electric' field of a predetermined intensity. 19;; A> device for measuring-the intensity' of-r an tending into said bore at a selected»k point. 12. A device for measuring »thein-tensity of yan ultra high-frequency electric field comprising an elongatedv envelope of' translucent, insulating‘ma terial having a capillary bore therein of a diam- I eter of the order ofl .5to 3> millimeters filled with gas of the type which produ-ces a gloW in the presencevof an electric- ñeld oi a predetermined intensity, and conducting> electrode means ex ten-ding into said bore at a` selected point. 1‘3. A device' for measuring the intensityof an ultra high-frequency elec-tric ñeld comprising an elongated envelope of "translucent, insulating ma ul'tra high-frequency electric-lleid-1 comprising an elongated> envelope of 'translucentà insulating m-a terial having' a capillary bore'- therein filled with gas oi the type which produces`V a glow inthe presence ofì an electric ñ‘eld above- a predeter-Í mined intensity; conducting electrode- rnea-ns' ex-- tending' into» saidY bo-refor introducing the elec--` tric fieldï to be measured» intovsaid bore ata' se v lected' point-whereby said field travels along said bore from said-pointì and a scale extending along said bore. ` J@HNi W2 COLT-MAN.