US1708399A - Sifting antenna - Google Patents

Description

April 9, 192

J. PLr-:BNsYKl Filed Feb. 2e 1*.924

2 Sheets-Sheet l of 7%@ @fiery/37%? weve .Inventor z @Josef PZea/fJ/f April 9, 1929. J. PLEBANSKI SIFTING ANTENNA Filed Feb. 2, 1924 2 Sheets-Sheet 2 J t R. .receiver .Attorney Patented Apr. 9, it-i292.

JGSEF PLEBANSK, OF WAR-SAN, POLAND.

SIFTING ANTENNA.

Application led February 2, 1924, Serial No. 690,120, and in Germany IFebruary 8, 1923.

In the telegraphy and telephony with and without wire by means of high frequency carrier current it is desired to have iilters which let a predetermined range ot :trequency pass through without substantial attenuation but damp Astrongly the frequencies above and below the limits of this range of frequency.

lllutually distuned .oscillatory circuits have already been proposed tor this object. he well known sitting chains ot Campbell and 1Wagner are also very good means tor the sitting out ot predetermined frequencies. The object to be fulfilled by such chains and sitting arrangements is always to produce a resonance curve which comes as close possible to a rectangular term. lt to be mentioned that C ifting chain7 and sitting arrangement are synonymous to the well determined term wave filter.

The present invention deals with a novel arrangement ot several parallel circuits coupled together to provide a :trame or open antenna and closed oscillatory circuits which produce the same eifects by a simpler arrangement or means than with the arrange ments wherein filters and the like are at present used. rlhe term parallel circuits is used in this application with the meaning ythat all ot the circuits must be simultaneously excited by the same source of electrical energy. The diilerence between the wave arrangement according to this invention, and the actual lilters heretofore used, is dependent upon the following` physical phenomenon It n oscillatory circuits coupled with one another in any manner are simultaneously energized by one current source with constant wave length a deformed resonance curve is produced in the circuit I Fig. 1 to which for instance an amplifier or detector is connected, by the circuits 2, 3 etc., to a, il" the nth circuit is varied, the circuit l, 2 u-l however remaining` unvaried and being tuned to the wave or slightly distuned, said deformed resonance curve possessing, according to the designs ot the circuits 1, 2 n, a more or less pronounced maximum and minimum in the proximity ot the resonance point.

lt,'liowever, we tune all coupled. circuits for a given wave and then without changing the circuits we change the wave we can observe that the resonance curve will not be the same as tor one circuit only but will be a deformed one. It we choose the circuits suitably we can obtain a very great Iselectivity and the resonance curve can be very sharp. ln this case the simultaneously eX- cited circuits are acting as a good wave iilter, if .one otl them is an output circuit all waves lying inl a given band ot frequencies will become auipliiied by the other coupled circuits. the waves lying outside this band will be weakened by the adjacent circuits.

The connection is shown in Figs. l and Q of the accompanying drawings. i

Fig. l shows diagraininatically a preferred torni of the receiving arrangement. 2 is a similar view showing a modilied forni of receiving arrangement.

F 3 is a diagrammatic view showing a connection arrangement for a transmitting station.

4 to 7 show diagrams tor dillerent couplings ot the circuits.

Fig. S illustrates diagraininatically the connection for a counter station. i

F 9 illustrates diagrammatically the connection for precision wave meters.

Fig. l0 is a diagrammatic view showing a connection tor the determination oi the angle oit incidence of the wave.

ln Fig. l ot the drawings a. receiver arrangement is diagrammatically illustrated. `he circuits l, 2 u, can be coupled with one another inductively, galvanically or ca]jiacitatively, it being not necessary that the saine coupling be used between the several circuits. The receiving` apparatus (in tensitier, detector .or the like) is preferably connected with one circuit only which may be simultaneously the primaryand the endcircuit. rllhe sitting' effect and the effects which will be hereinafter described are produced merely by the vicinity ot the coupled circuits, as vdistinguished from the so-called differential connections, in which the differenceor sum-current is utilized by several parallel circuits.

The effect of the coupling arrangement according to the invention is based on the fact that when a circuit, with which the receiving apparatus is connected, is influenced by adjacent circuits, with which it is coupled in any manner, the iirst circuit receives, at a predetermined dimension of the adjacent circuit, for a predetermined wave range more of the energy from the source of current than if it were alone. For the wave trains, which lay outside this range, the relative resistance of this circuit becomes greater in proportion to the resistance which it would have if it were alone. t is however necessary, as already mentioned, that the adjacent circuits are also excited from the sources of current and that all the circuits react only insigniticantly upon the source of current.

vThe connection arrangement possesses, besides its simplicity, the advantage that it is well adapted to serve as wave iilter for wireless telegraphy and telephony and eilects further a goed interference elimination as it damps all waves (for instance disturbingwaves, atmospheric waves and the like) much more strongly than a single circuit, ior instance an antenna. circuit could do this. The circuits may be constructed as frame coil circuits or as antenna circuits 2).

For a transmitting station the connection arrangement according to the invention is preferably constructed as shown in Fig. 3. To the circuits 1, 2 and 3, which is shown as an open antenna circuit, energy is impressed from a high frequency source S in parallel, the coupling relations between the circuits being indicated by arrows. t is to be seen. that the circuit l is simultaneously the output circuit having the aerial and the earth terminals. In order to avoid reaction upon the high frequency current source S due to the parallel circuits especially when closely coupled, either a high frequency machine or separately controlled thermionic valve transmitters are used in this case, i. e. current supplying sources which by the tuning of the parallel circuits are not affected. Either several dummy antennae and one radiating antenna or several radiating antennae and several dummy antennae or only several parallel radiating antennae may be used. However, the radiation of the wave spectrum can take place only from one of the antennae circuits connected in parallel.

The phenomena.J which occur in such a connection arrangement are illustrated in the diagrams shown on the drawings:

Fig. l shows for instance the course of the energy reception or of the energy consumption of the circuit l (J12R1), tuned to the waves and coupled with the receiver, and of the circuit 2 (JQRZ), it being assumed that the circuit l is tuned to the waves (or slightly distuned), circuit 2 being altered. The current in the circuit 1 drops at first to a` determined minimum whereupon lit increases rapidly to a maximum. It drops again hereafter. `Whether at iirst the minimum and later on the maximum of the current comes into existence depends on the phase-displacement between the electromotive forces which are excited in the corresponding circuits.

It inV the arrangement shown in Fig. 8 in the receiver l a minimum ot current occurs at first and then a maximum, the inverse will take place in the receiver 2 as the phasedisplacement in the receiver 2 amounts to 1800 or as at the same phase of the E. M. F. the inverse coupling is produced. The resonance curve indicated in dotted lines in Fig. l shows the curve ot' the current or the energy consumption of the second current it it were alone. Itit is coupled with the circuit l its resonance curve is much flatter,

the proportion of the energy consumption in circuit l (useful circuit) to the energy consumption in circuit 2 in the maximum range is therefore very great and consequently also the efficiency of the whole arrangement is very favorable in comparison with the commonly used chain connections which consume very much energy and in which so high degrees of etliciency as in the connection according to the invention can never be obtained. It is evident thatthe parallel circuits must be ot' convenient dimensions, so that the coupling between the circuits is in a certain proportion to the damping and the other values. y

Fig. 5 shows a group of curves for diiferent couplings of the two circuits with the same damping.

Fig. 6 illustrates the sifting eiiect.

rlhree circuits are supposed to be excited under the above mentioned conditions. All curves relate only to the first circuit which is connected with the receiving apparatus. rllhe circuits 2 and 3 are coupled and of corresponding dimensions and they take up energy from space simultaneously with kthe first circuit. If the exciter wave is altered and if the resonance wave for the rst circuit is traced when the other two circuits are removed, the curve I is obtained. It' the three circuits are coupled with one another and if the resonance curve for the circuit l is traced again, the curve H is obtained from which the reduction of the resistance and the equally strong receiving for a determined wave range can be seen as well as the intensicd damping of the frequencies outsideA this range.

The curve Hl shown in dash and dot lines illustrates the same curve as curve but with the ditterence that the maximum value of the same has been supposed as equal to that of the curve H.

The connection arrangement of oscillation circuits according to the invention. may be used also for other purposes. It for instance a receiving antenna is built in such a manner that it consists of two frame antennae, oitI which the first one possesses a greater resistance than the second one, and if the receiving apparatus is connected with the first antenna a curve of energy consumption is obtained in dependency of the wave length as illustrated in Fig. 7. If the several values are selected accordingly the difference between maximum and minimum can be very great (for instance amount to a million times and more). A receiving apparatus of this type can therefore be put up at short distance from the transmitter` without being disturbed from the same if the transmitter works with a wave which corresponds te the minimum of the system; the receiver can well receive the wave of the counter station which corresponds to its maximum. The two frame antennae on the counter station must however be coupled inversely in order that the two stations can worl together. This connection is diagrammatically illustrated in Fig. 8.

The arrangement described can be carried out also with several parallel circuits. lf the receiving apparatus works with return coupling reception the return coupling coil may be re-coupled with one or several of the circuits working in parallel.

Such circuits may be used also for the building of precision wave meters (Fig. 9). f for instance two such circuits are excited from one source of current to be measured, oscillations are produced in .both circuits according to the above indicated curves. lf the first circuit is tuned to the wave and if the second circuit is made t0 act, this circuit being repeatedly closed and opened in one second by means of a suitable ticker, the interruptions are strongly heard at the moments of the minimum and maximum but weakly only at all other points, if however, the tuning of the second circuit is situated exactly at the point where the curve intersects the line M-fo, the interruption is not heard.

Then the single values are correctly determined the error of the measuring of the second circuit can amount only to several percent of the curve of measuring of the first circuit. If at the measuring of the circuit l an error of 8% has occurred the error at the re-measuring with the circuit II is for instance only 0.03%. This method is well adapted to be used for undamped oscillations.

rihe maximum and minimum as well as the zero peint (point of intersection with line lid-0) of the curve depends on the amplitude of the E. M. forces, that is on E1 and K2. lf two controlling antennae (frame antennae and the like) standing at a predetermined angle t'o one another the angle of incidence of the wave can be found by the connection shown in Fig. l0.

At a predetermined selection of the indi-- vidual values L, C, E phase displaced currents of such a kind can be produced in the circuits that a rotating field can be produced with the aid of specially located coils this being applied for energy transmission, for measuring purposes or the like.

1. An aerial arrangement consisting of a plurality of tunable circuits coupled with one another, one of said circuits being an output circuit, the totality of said circuits being designed to be energized from the same source of high frequency currents, means for coupling said circuits and determiningtheir values in such a manner that the aforesaid output circuit will receive, amplify and transmit without substantial attenuation a given range of frequencies and will damp all frequencies lying beyond thelimits of said band. 2. In a twoway signalling system for radio-communication in opposite directions, according to claim l, means for tuning the transmitting stations to the waves corresponding respectively to the maximum of the resonance characteristic curve determined by a wave filter apparatus, and mea-ns in the respective receiving stations for reversing the maximum and minimum relation of said curve in view of the maximum and minimum relation of the other receiving station.

Signed at lVarsaw, this 11th day of J anuary, 1924.

JOSEF PLEBANSKI.

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