US1487308A

US1487308A - Radio receiving system

Info

Publication number: US1487308A
Application number: US438552A
Authority: US
Inventors: Harold H Beverage
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1921-01-20
Filing date: 1921-01-20
Publication date: 1924-03-18
Anticipated expiration: 1941-03-18
Also published as: FR25949E

Description

March 18 1924. 1,487,308

H. H. BEVERAGE RADIO RECEIVING SYSTEM Filed Jan. 20. 1921 InVenCOY'I Harold H. Deva-age,

by /r 4. M H'ls Attorney.

Patented Mar. 18, 1924.

UNITED STATES PATENT OFFICE.

HAROLD H. BEVERAGE, OF RIVERHEAD, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

RADIO RECEIVING SYSTEM.

Application filed January 20, 1921. Serial No. 438,552.

To all whom it may concern:

Be it known that I, HARoLn H. BEVERAGE,

. a citizen of the United States, residing at Riverhead, county of Suffolk, State of New York, have invented certain new and useful Improvements in Radio Receiving Systems,

of which the following is a specification.

My present. invention relates to radio receiving systems, and more particularly to receiving systems by means of which signal waves from a desired direction may be received without interference from disturbing waves coming from other directions.

One of the objects of my invention is to provide in conjunction with a unidirectional receiving antenna, a simple and efficient means whereby the receiving station may be located at any desired point which may be some distance from the point in the antenna at which the desired signaling currents are strongest.

In my prior application, Serial No. 372,933, filed April 10, 1920, issued June 7, 1921 as Patent 1,381,089 of which this application is a continuation in part, there is described and claimed a receiving antenna which will have marked unidirectional prop erties. In this case, a long horizontal antenna is employed which extends preferably in the general direction of transmission of the signals to be received, and which preferably has a length of the order of magnitude of a half wave length of the signal to be received. In case such an antenna is properly constructed signals coming from a desired station will be found to be strongest at the end of the antenna which is farthest from the transmitting station, while signals coming from the opposite direction will be very weak at that end.

In my prior application above referred to, I have indicated one method whereby the desired signaling currents may be transmitted from a point in the antenna where they are strongest to a receiving station located at some distance from that point. In the present application I will describe other ways in which this desired result may be accomplished.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended clanns, the invention itself, however, both as to its organization and method ofoperation, to

As indicated in Fig. 1, I provide a long horizontal antenna 1, the opposite ends of which are grounded at 2 and 3. This antenna is preferably so constructed or its constants so adjusted that the current wave therein will travel along its length at] the same velocity as that of the signaling wave in space so that the current wave will gradually grow inamplitude as it travels along the conductor. If it is desired to receive a signal which approaches the-antenna from the end 2 the amplitude of the current set up in the antenna at 2 by the desired wave will be extremely small while at the end 3 the amplitude of the current will be maximum. It may, however, in some cases be more convenient to locate the receiving station at some point distant from the end 3 of the antenna. In such case I have found that a transmission line may be employed between the antenna and the receiving station.

I have indicated in Fig. 1 such a transmission line 4, which is coupled to the antenna at the end 3 by means of the coupling U transformer o. The two conductors of this transmission line are preferably located in the same horizontal plane so as to be symmetrically located with respect to ground. Since any simple transmission line will also act as an antenna the use of an ordinary transmission line in such case will tend to modify the directivity of the receiving system. To overcome this difficulty I have indicated transpositions along the length of the transmission line to neutralize the effect of currents received thereon. \Vhen this expedient is employed the receiver which is connected to the transmission line by means of the coupling transformer 6 will be substantially unaffected by currents received on the two conductors of the transmission line in parallel.

The end 2 of the antenna is preferably antenna so that no reflection can occur from this end of the antenna, and therefore no currents will be transferred to the transmission line from waves traveling from the end 3 toward the end 2 of the antenna. The

end 3 of the antenna may also, if desired, be

grounded through a resistance 8.

In Fig. 2 I have shown a modification in which the transmission line is made up of a pair of

conductors

9 and 10 which extend parallel to the antenna conductors 11 and 12. In this casemid points of the secondary of transformer 5 and the primary of transformer 6 are grounded through damping resistances 13 and 1 1 so that any currents which may be received upon the transmission line will flow in opposite directions through the two portions of these transformer windings and hence will produce equal and opposite effects upon transformer 6 and as a result the receiver will be unaffected by such currents. In this case also the transmission line may be loaded by means of inductances 15, or by other suit-- able apparatus in order to eliminate any inductive effects between the transmission line and the antenna.

While the long horizontal antenna such as that I employ has decided unidirectional properties, mathematical analysis indicates and experience shows that at theend farthest from the transmitting station small currents will under some conditions be produced by waves coming from the opposite direction even though the end nearest the transmitting station is grounded through a resistance approximately equal to the surge impedance of the antenna so that no reflection occurs. In some cases also it may happen that while the antenna is adjusted so that the receiving apparatus is not affected by disturbing waves coming from a direction exactly opposite to that of the signal it is afiected by disturbances coming from some other direction, for instance, 160 from the transmitting station, and that it is more important to limit the effect of the disturbing waves coming from this direction than of those coming from a direction 180 from the transmitting station. In order to eliminate the effect upon the receiving apparatus of the undesired waves mentioned, I insert in the ground connection of the antenna at end 2 a phase rotator by means of which currents of the desired phase to neutralize the undesired currents may be selected and impressed upon the receiving apparatus by means of the coupling transformer 16.- This coupling transformer may be varied to adjust the intensity of the currents thus impressed upon the receiving apparatusto the desired value.

While in this case I have indicated the receiving station as being located at the end 2 of the antenna where all of the apparatus which requires any adjustment in the operation of the system may be conveniently controlled by the receiving operator, the receiving apparatus may, if desired, be located at any other point and the neutralizing currents conveyed to the receiving apparatus by means of a suitable transmission line.

While I have illustrated and described the preferred embodiment of my invention, it will be apparent that my invention is not limited to the particular embodiments indicated, but that many modifications in the particular means whereby my invention may be carried into effect, may be made without departing from the scope of my invention as set forth in the appended claims.

As an example of one particular construction which may be employed in carrying my invention into effect I have found that satisfactory results can be obtained with an antenna about 14,000 meters longconsisting of a pair of wires supported on poles about thirty feet high. By means of a transmission line consisting of a pair of conductors supported'on the same poles below the antenna the signaling currents have been successfully transmitted from one end of the antenna to the other. Signals have been successfully received by this arrangement varying from 10,000 to 23,000 meters in wave length.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. A receiving s stem for radio signals comprising a long orizontal unidirectional receiving antenna, a transmission line for conveying signaling currents from a selected point in said antenna to a distant receiving station, and means for eliminating in the receiving apparatus the effect of currents received upon the transmission line due to the exposure of said line to the effect of ether waves.

2. A receiving system for radio signals comprising a long horizontalunidirectional receiving antenna, a transmission line for conveying signaling currents from a selected point in said antenna where signaling currents from a desired station are strongest, to a distant receiving station, and means for eliminating in the receiving apparatus the effect of currents produced in the antenna at the selected point by waves coming from a different direction from that of the desired signaling waves.

3. A receiving system for radio signals comprising a long horizontal unidirectional receiving antenna, a transmission line for conveying signaling currents from a selected point in said antenna to a distant receiving station, a receiving apparatus, means for impressing upon said receiving apparatus currents transmitted over said transmission l ne, and means for impressing upon said receiving apparatus currents of equal magnitude and opposite phase to those produced in the antenna at the selected point by waves coming from a different direction from that of the desired signaling waves.

4. A receiving system for radio signals comprising a long horizontal unidirectional receiving antenna, a transmission line for conveying signaling currents from a selected point in said antenna to a distant receiving station, a receiving apparatus, means for impressing upon said receiving apparatus currents transmitted over said transmission line, and means for selecting from said antenna at a point distant from the selected point, and impressing upon said receiving apparatus currents of equal magnitude and opposite phase to those produced in the antenna at the selected point by waves coming from a difi'ereiit direction from that of the desired signaling waves.

5. A receiving system for radio signals comprising a long horizontal unidirectional receiving antenna, a transmission line for conveying signaling currents from a selected point in said antenna to a distant receiving station, means for eliminating in the receiv-ing' apparatus the effect of currents received upon the transmission line due to the exposure of said line to the eflect of the ether waves, and means for eliminating in the receiving apparatus the effect of currents produced in the antenna at the selected point by waves coming from a different direction from that of the desired signaling waves.

6. A. receiving system for radio signals comprising a long horizontal unidirectional receiving antenna, a transmission line for conveying signaling currents from a selected point in said antenna to a distant receivti l ing station, a receiving apparatus, means for impressing upon said receiving apparatus currents transmitted over said transmission line, means for impressing upon said receiving apparatus currents of equal magnitude, and opposite phase to those produced in the antenna at the selected point by waves coming from a different direction from that of the desired signaling waves, and means for eliminating in the receiving apparatus the eifect of'currents received upon the trans mission line due to the exposure of said line to the effect of ether waves.

A receiving system for radio signals comprising a long horizontal unidirectional receiving antenna, a transmission line for conveying signaling currents from a selected point in said antenna to a distant receiving station, a receiving apparatus, means for impressing upon said receiving apparatus currents transmitted over said transmission line, means for selecting from said antenna at a point distant from the selected point, and impressing upon said receiving apparatus currents of equal magnitude and opposite phase to those produced in the antenna at the selected point by waves coming from a different direction from that of the desired signaling waves, and means for eliminating in the receiving apparatus the efiect of currents received upon the transmission line due to the exposure of said line to the effect of ether waves.

8. A receiving system for radio signals comprising a long horizontal receiving antenna, a transmission line comprising a pair of conductors for conveying signaling currents from the point in said antenna where signaling currents from a desired station are strongest to a distant receiving station said transmission line being so arranged that the desired signaling currents will flow through the two conductors of the pair in series, a receiving apparatus at the receiving station and means for impressing currents flowing through the two conductors of the transmission line in series upon the receiving apparatus, and at the same time eliminating the effect upon the receiving apparatus of currents flowing through the two conductors of the transmission line in parallel.

9. A receiving system for radio signals comprising a long horizontal receiving antenna, a transmission line comprising a pair of conductors for conveying signaling currents from a selected point in said antenna to a distant receiving station, a transformer hav ing its primary winding connected to said antenna and having the two terminals of its secondary winding connected to the two conductors of the transmission line so that the desired signaling currents will flow through the two conductors of the pair in series, a receiving apparatus at the receiving station, a transformer having the terminals of its primary winding connected to the two conductors of the transmission line and its secondary winding connected to the receiving apparatus for impressing currents flowing through the two conductors of the transmission line in series upon the receiving apparatus, the midpoint of the secondary of the first transformer and of the primary of the second transformer being grounded so as to eliminate the effect upon the. receiving apparatus of currents flowing through the two conductors of the transmission line in parallel.

10. A receiving system for radio signals comprising a long horizontal receiving antenna which is grounded at both ends, a transmission line for conveying signaling currents from a selected point in said antenna to a receiving station located at a distant point along the length of said antenna, receiving apparatus at the receiving station, means for impressing upon the receiving apparatus the signaling currents conveyed on said transmission line, and

means for eliminating in the receiving apparatus the efiect of currents produced in the antenna at the selected point by waves coming from a different direction from that of the desired signaling waves.

11. A receiving system for radio signals comprising a long horizontal receiving antenna which is grounded at both ends, a transmission line for conveying signaling currents from a selected point in said antenna to a receiving station located at a distant point along the length of said antenna, receiving apparatus at the receiving station, means for impressing upon the receiving apparatus the signaling currents conveyed over said transmission line and means for selecting from the ground connections at one end of said antenna and impressing upon the receiving apparatus currents of equal magnitude and opposite phase to those produced in the antenna at the selected point by waves coming from a different direction from that of the desired signaling Waves.

12. A receiving system for radio signals comprising a long horizontal receiving antenna which is grounded at both ends, a transmission line for conveying signaling currents from a selected point in said antenna to av receiving station located at a distant point along the length of said antenna, receiving apparatus at the receiving station, means for impressing upon the re ceiving apparatus the signaling currents conveyed on said transmission line, means for eliminating in the receiving apparatus the effect of currents produced in the antenna at the selected point by waves coming from a different direction from that of the desired signaling waves, and means for eliminating in the receiving apparatus the effect of currents received upon the transmission line due to the exposure of said line to the effect of ether Waves.

13. A receiving system for radio signals comprising a.horizontal receiving antenna which is grounded at both ends, a receiving set, means for impressing upon said receiving set desired signaling currents produced in said antenna at a selected point, and means for impressing upon the receiving set to neutralize the effect of undesired currents therein currents of equal intensity and opposite phase derived from said antenna at a second selected point.

14. A receiving system for radio signals comprising a horizontal receiving antenna which is grounded at both ends, a receiving set, means for impressing upon said receiving set desired signaling currents produced in one of the ground connections of said antenna, and means for impressing upon the receiving set to neutralize the effect of undesired currents therein currents of equal intensity 'and opposite phase derived from the second ground connection of said antenna.

15. A receiving system for radio signals comprising a horizontal receiving antenna which is grounded at both ends, a receiving set, a transmission line for transmitting to said receiving set desired signaling currents produced in said antenna at aselected point, and means for impressing upon the receiving set to neutralize the effect of undesired currents therein currents of equal intensity and opposite phase derived from said antenna at a second selected point.

16. A receiving system for radio signals comprising a horizontal receiving antenna which is grounded at both ends, a receiving set, a transmission line for transmitting to said receiving set desired signaling currents produced in one of the ground connections of said antenna, and means for impressing upon the receiving set to neutralize the effect of undesired currents therein currents of equal intensity and opposite phase derived from the second ground connection of said antenna.

17. A receiving system for radio signals comprising a horizontal receiving antenna which is grounded at both ends, a receiving set, means for impressing upon said receiving set desired signaling currents produced insaid antenna at a selected point, and means for impressing upon the receiving set to neutralize the efiect of undesired currents therein currents of equal intensity and opposite phase derived from said antenna at a second selected point, said receiving set being located adjacent one of said selected points and one of said means including a transmission line connecting the receiving set with the other selected point.

18. A receiving system for radio signals comprising a horizontal receiving antenna which is grounded at both ends, a receiving set, means for impressing upon said receiving set desired signaling currents produced in one of the ground connections of said antenna, and means for impressing upon the receiving set to neutralize the effect of undesired ucurrents therein currents of equal intensity and opposite phase derived from the second ground connection of said antenna, said receiving set being located adjacent one of said ground connections and one of said means including a transmission line connecting the receiving set with the other ground connection.

19. The method of operating a radio receiving system comprising a horizontal receiving antenna which is grounded at both ends and a receiving set which consists in impressing upon said receiving set currents produced in said antenna at a selected point by desired signaling waves and neutralizing the effect in the receiving set of undesired currents therein by impressing thereon ourrents of equal intensity and opposite phase produced in said antenna at a second selected point.

20 The method of operating a radio receiving system comprising a horizontal receiving antenna which is grounded at both ends and a receiving set which consists in impressin upon said receiving set currents produced y desired signaling waves in one of said ground connections and neutralizing 10 the effect in the receiving set of undesired currents therein by impressing thereon cur rents of equal intensity and opposite phase produced in the second ground connection. In Witness whereof, I have hereunto set my hand this 15th day of January, 1921.

HAROLD H. BEVERAGE.