US2048751A

US2048751A - Ultra short wave carrier wave apparatus

Info

Publication number: US2048751A
Application number: US730625A
Authority: US
Inventors: Mathieu Gaston Adelin
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1933-06-27
Filing date: 1934-06-14
Publication date: 1936-07-28
Anticipated expiration: 1953-07-28

Description

July 28, 1936. G. A. MATHIEU I ULTRA SHORT WAVE CARRIER WAVE APPARATUS Filed June 14, 1934 w a ..R ..Y m m .NA. wwgm Nm i l A m M .4

m w M7 1 Patented July 28, 1936 TED STATES PATENT OFFiiCE "ULTRA SHORT WAVE CARRIER WAVE APPARATUS Application June 14, 1934,?SerialNo.1730.625 In Great Britain June 27, 1933' .Thisinvention relates toultrashort wave carrierwave apparatus and moreiparticularly to "apparatusfor use in wireless :signalingon so-called micro or ultra short waves, by which expression-is meant waves of a length .below tone meter, or thereabouts.

:In ordinary wireless apparatus as :at present inicommon'use, it is customary=to'use-tuned -circuits consisting of lumped capacity andlumped inductance .(i. e. ordinary condensers :and inductance coils) generally connected :in parallel but when wave lengths of below about onermeter are in question the use of tuned circuits constituted by such lumped .inductances --.and capacities becomes impracticable, in ipart because of the extremely small dimensions required for the said inductances and capacities, and-inrpart because at such very short wavelengths the selfcapacity of any ordinary form of coil and the self-inductance of any ordinary form of =condenser become important factors.

Accordingly, in the art of wireless signaling with micro-waves distributed self-inductances an'dcapacities have been made use of instead of 'lumped'inductances and capacities for purposes of tuning. The well known Lecher wire arrangementillustrated in Fig. 1 of-the drawing may be regarded as typical of the arrangements which have been used and proposed hitherto. In 'the said Fig. li'the'Lecher-wire arrangement consists of two parallel wires joined'together at their ends, the length of the circuit being one half the working wave length. This'is represented con- .ventionally in the said Fig. .1 by the dimension .pointsoizero potential.- and maximum current.

.Now,.although.a' Lecher wire arrangement as-is shown in Fig. 1 is quite a satisfactory device for .the purpose for .which. it was originally intended, namely that of approximately measuringmicrowaves, his not so satisfactory for the purpose ior'whichit'hasbeen more recently used, i. e.

as-a tuned circuit in a micro-wave transmitter, receiver oramplifier. The reason for this is that 'the'rapid variationo'f the current and voltage along the length-of the Lecher wires renders such a systemdifiicult to couple satisfactorily to another :circuit andunsatisfactory asa device for storing energy to betransferred'to-another-cir cuit. Moreover, where it is requiredto accomplishwariable, i.:e..- adjustable tuning, there is the 5 difficultyfthatthelength .of the Lecher wires must be altered ran'clathisrmay involve practicaldifficulties: and inconveniences.

According-"to this: invention, an ordinary Lecher wire =system-for:use:as;a;tuned circuit in a carrier 10 wave:apparatus operating on wave lengths of the order of one meter orzlessis modified by providing conductive .platesiin conductive connection with the Lecher wires, saidxplates being in electrostatic association xwithcone another and being 15 positionedat andxnearpoints of maximum voltagezor zero current. in this'way the effective self-capacity :of "the .whole arrangement is increased. at and near the said points of maximum voltage: andi-zero current.

Referringito-ithe drawing, Fig. .1 shows a well known form =of :Lecher 'wire system;

Fig. 2 illustrates a :simple formof Lecher wire arrangement inza'ccordance with the principles of thisinvention;

Figs. 3, 5, 6 and -7 show various modifications of'the invention;

Fig. 4 represents, schematically, the bending or hinging of the plates for tuning,as shownin Fig. 3; and- Fig.8 shows a circuit arrangement 'foramultra short wave transmitter embodyingthe-tuningarrangement of the invention.

One simple arrangement in accordance with this'invention is'shown in Fig.2, which figure-il- 35 lustrates a Lecher wire .arrangement as shown in Fig. l, modified'in accordancewith this invention. Upon reference to said .Fig. 2, it will be seen that there is upstandingfromeach of the Lecher wires a conductive plate A or 13, these 40 plates being mechanically'in the .form of'plates such as are used in ordinary ultra .short wave tuning condensers. The effect'ofuprovidingithe plates Aand B is to increase theelfective selfthe distances w+b+c is less than 'onehalf wave length. The longer the distance burelative to the overall length of the Whole system and the greater the dimension of the plates at right angles to=theLecher wires, theinearer must'the physical length a-|-"b-+c approachithe half wave length and the more closely .will'the current and voltage distribution-.approach:the'distributionoh- 555 taining in an ordinary tuned circuit (such as is used on longer wave lengths) consisting of lumped capacity and inductance in parallel.

At first sight it would appear that an arrangement as shown in Fig. 2 could be regarded as consisting of one condenser with two loop inductances in parallel; but the said arrangement is not in fact equivalent to this because the points I and 2 retain the zero potential, maximum current conditions characteristic of a simple Lecher wire sys:

tem. However, the sharpness of-the zero potential points increases as the ratio of the length increases.

The actual dimensions adopted for the'plates A and B, i. e., their length and height, fora given the arrangement of Fig. 2 modified by bending up the length a. The effect'of bending up one end in this manner is to give a still further approach towards a quasi-constant distribution of current in the portion left unbent.

The tuning of an arrangement as shown in the Figs. 2 and3 above described can be varied over a range of several centimetres: by varying merely the relative positions of the plates A and B, e. g. by arranging the plates tobe warped or hinged about axes such as are represented in the said Fig. 2 by broken lines. This bending or hinging of the plates for tuning'is represented schematicallyin Fig; 4, which is a diagrammatic and. sectional View of an arrangement as shown in I Fig. 2 of the plates A and B being shown in three possible positions marked, respectively, m, y and 2. As the plates are brought closer together the wavelength to which the device is tuned is, of course, increased.

Fig. 5 shows an arrangement similar to that shown in Fig. 2 associated with an aerial, via a tubular concentric high frequency cable. The aerial is indicated at AN, the inner conductor of the high frequency cable being shown at 10 and the outer conductor of this cable (which is earthed) being shown at C. Thehigh frequency cable, which is of form well known per se and may consist of two tubes arranged concentrically within one another and separated from one another mainly by air insulation,.is of a length equal to the working wave length. 1

Fig. 6 shows a further modification in accordance with the invention. The arrangement of Fig. 6 may be regarded as consisting-in efiect of two arrangements as shown in Fig.2 (above described) placed end to end and united in a single structure. The distribution of theicurrent in Fig. 6 isindicated in conventional form by the broken line I and the individual plates are marked conventionally to indicate. their instantaneous polarities at a particulantime. An arrangement such as shown in Fig. 6 will, of course, act to some extent as a dipole aerial with end capacities and to avoid this the polarities of the plates may be reversed by crossing the Lecher wires. between the pairs of plates as Shown in Fig. '7. Furthermore, if desired, losses by radiation can be reduced to a minimum by placing the whole arrangement in a screening box made, for example, of solid copper sheet and having its sides running parallel to the plates at distances therefrom of one'quarter the working wavelength.

Fig.8 shows diagrammatically the circuit arrangement of a powerful and efficient practical 'micro-wave transmitter. In this Fig. 8 AN is the 10 aerial, .which is connected through a tubular feeder IC-OC to a Lecher wire arrangement, in accordance with this invention, and consists in eiTect of two arrangements, as shown in Fig. 3 .(above described), placed end to end and united in a single system. i'he transmitting valves which operate-on the Barkhausen-Kurz principle as oscillators are shown at V1 V2 and V1 and V2 andthe plate circuits, grid circuits, and cathode circuits of these valves are all tuned as shown so that from this point of view thearrangem'ent of Fig. 8 is in accordancewith theinvention con-. tained in the specification of United States 'ap-. plication Serial No. 639,462, filed October 25,1932, by Gaston A. Mathieu. The points at which 'high tension potential is applied for the grids of the valves are indicated at HT+ while thepoints at which negative potential is applied for the plates of the valves are indicated at HT. With=regard to the connections from the points HT. to the plates of the valves, it will be noted thatthese connectionspass through the bent up ends of the Lecher wires, the zero points of potential of the Lecher wire arrangement being thus made use of for feeding the required plate potentials: to'the valves. The common negative connection for the cathodes is shown at CN, and R1 R2 R3, R4 are filament resistances. The connections to :the plates are in practice made as short as possible but this is diflicult to show in the drawing which is purely diagrammatic. 1 1 4 i. What is claimed is: r l. A tuned circuit arrangement for use'on very high frequencies corresponding to wave lengths of the order of one meter and comprising apair of Lecher wires each providedwith an'attached conductive plate in conductive connection therewith, said plates being in electrostatic association with one another and being positioned at points substantiallyof'maximurn voltage or zero cur-. rent, whereby the'efiective self-capacity of the whole arrangement is increased at or near the said points, portions of said plates'located on oppositely disposed Lecher wires 'being separated from one another along a line substantially at right angles to the wires by a distance at least equal to the separation of said Lecher wires. 2. A tuned circuit arrangement for use on very high frequencies corresponding to wave lengths of the order of one meter and comprising a pair of Leche r wires each in conductive connection with a conductive plate, said platesfwhich are slmilarbeing opposite one another and beinglar ranged atpoints. of substantially maximum voltage or zero current, each @Lecher wire passing substantially, along one edge of the plate asso- 'ciated therewith. V 3.1 An arrangement as defined in' claim wherein the Lecherwires-arejbent up'app mately through. a right angleand connected to} ,gether at one end, the arrangement being such that the connection betweentheLecher-wires. is substantially at right angles to the general direction of said wires; said bent up portionlyiug 7 on the same side of said wires as do the plates.

4. An arrangement as defined in claim '2 and wherein the conductive plates are movably mounted with relation to one another in a direction substantially perpendicular to the axes of their surfaces.

5. A tuned circuit arrangement for use on very high frequencies corresponding to wave lengths of the order of one meter and comprising a pair of Lecher wires each provided with a conductive plate in conductive connection therewith, said plates being in electrostatic association with one another and being positioned at points substantially of maximum voltage or zero current, whereby the effective self-capacity of the whole arrangement is increased at or near the said points, portions of said plates located on oppositely disposed Lecher wires being separated from one another along a line substantially at right angles to the wires by a distance at least equal to the separation of said Lecher wires, said conductive plates being movably mounted with relation to one another and in effect hinged upon axes lying in or parallel to the general directions of the Lecher wires.

6. A tuned circuit arrangement for use on very high frequencies corresponding to wave lengths of the order of one meter and comprising a pair of Lecher wires each in conductive connection with a conductive plate, said plates which are similar being opposite one another and being arranged at points of substantially maximum voltage or zero current, each Lecher wire passing substantially along one edge of the plate associated therewith, and another similar tuned circuit whose Lecher wires are united with the Lecher wires of said first tuned circuit to form one prolonged Lecher wires system, the wires of which are joined together at both ends, there being two conductive plates associated with each '7. A system as defined in claim 6, characterized in this that said Lecher wires are crossconnected at their points of juncture between the pairs of plates.

8. An ultra high frequency circuit comprising a pair of electron discharge devices each having cathode, anode and control electrodes, corresponding electrodes of said devices being coupled together, and another pair of electron discharge devices similarly arranged, and a tuned Lecher wire circuit for coupling the anodes of one pair of devices to the anodes of the other pair of devices, said Lecher wire circuit comprising a pair of wires each in conductive relation with at least one conductive plate, the plates on different wires of said pair having portions thereof separated from one another along a line substantially at right angles to the wires by a distance at least equal to the separation of said Lecher wires.

9. A transmitter circuit in accordance with claim 8 including means for maintaining the con trol electrodes of said devices at a high positive potential and their respective anodes at a much lower potential relative to their respective cathodes.

10. An ultra. high frequency circuit comprising a pair of electron discharge devices each having cathode, anode and control electrodes, corresponding electrodes of said devices being coupled together, and another pair of electron discharge devices similarly arranged, and a tuned circuit for coupling the anodes of one pair of devices to the anodes of the other pair of de-- vices, said tuned circuit comprising a pair of Lecher wires each in conductive connection with a conductive plate, said plates which are similar being opposite one another and being arranged at points of substantially maximum voltage or zero current, each Lecher wire passing substantially along one edge of the plate associated therewith.

11. A tuned circuit arrangement for use on very high frequencies corresponding to wave lengths of the order of one meter and comprising a pair of Lecher wires each in conductive connection with an attached conductive plate in the plane of the wire, said plates being similar and opposite one another and being arranged at points of substantially maximum voltage or zero current, each Lecher wire passing substantially along one edge of the plate associated therewith.

12. In combination, a tuned circuit arrangement for use on very high frequencies corresponding to wave lengths of the order of one meter and comprising a pair of Lecher wires each in conductive connection with a conductive plate, said plates which are similar being opposite one another and being arranged at points of substantially maximum voltage or zero current, each Lecher wire passing substantially along one edge of the plate associated therewith, said Lecher wires having an electrical length substantially equal to half the operating wave, an antenna, and a concentric line having inner and outer conductors coupling said antenna with said Lecher wires, said outer conductor of said line being grounded.

GASTON ADELIN MATHIEU.