US2810906A

US2810906A - Electronic antenna

Info

Publication number: US2810906A
Application number: US244149A
Authority: US
Inventors: Leonard J Lynch
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-08-29
Filing date: 1951-08-29
Publication date: 1957-10-22
Anticipated expiration: 1974-10-22

Description

United States Patent ()fifice 2,810,906 Patented Oct. 22, 1957 ELECTRONIC ANTENNA Leonard J. Lynch, De Kalb, Iii.

Application August 29, 1951, Serial No. 244,149

10 Claims. (Cl. 343-100) art from that antenna-reflector combination, because, in

accordance with the present invention, electronic circuit means interconnects the front and back sections to build up the regenerative action therebetween below the point of oscillation, there beinga radio frequency amplifier provided between the front dipole and the two-element reflector disposed a quarter wave-length behind the front dipole. The tuned amplifier amplifiesthe radio wave and sends it out along the reflector elements and the wave is thus radiated back toward the front dipole, adding to' the waves entering the antenna. There again the amplified wave may be amplified again and further regeneration obtained through the amplifier. The amount of regeneration could be continued up to the point of oscillation but a gain control on the amplifier prevents reaching that condition and the antenna accordingly operates just below the point of oscillation for maximum sensitivity.

The invention is illustrated in the accompanying drawing, in which Fig. 1 is a conventional diagram illustrating. a radio wave;

Fig. 2 is=a diagrammatic plan view of an antenna-reflector combination indicating diagrammatically the reflection of wavesthrough the quarter wave-length air spaceback to the front dipole to increase the signal strength to the set or receiver;

Fig. 3 is a similar diagrammatic plan view of the electronic antenna of my present invention, and

Fig. 4 is a less diagrammatic illustration than that of Fig. 3, the electronic antenna.

Similar reference characters are applied to corresponding parts in these views.

To enable a clearer understanding of the electronic antenna of my invention it will be necessary, first of all, to state briefly how the conventional antenna operates. In this statement I shall follow more or less the general conception of the operation of all antenna, regardless of shape or form. To start with, Fig. 1 shows the generally accepted conventional representation of a radio wave, a full wave length being measured from 5 to 6 or A to C, A to B representing a half-wave length. Now, a simple dipole 7, whose length is cut to resonance of some desired frequency, is placed in front of a conductor 8, whose length is somewhat longer than the dipole, the conductor being parallel to and behind the dipole and being referred to as a reflector. Reflector 8 is spaced a quarter wave-length 2, from the front dipole 7. The incoming wave from the radio station transmitter strikes the front dipole 7, as indicated by the arrows 9. It may be assumed that this wave compares with the wave from 5-6 or AC of Fig. l and that all portions of the curves above the line XY are positive and those below negative. The front dipole.7 therefore cuts lines of force in much the same way as a winding in a generator cuts lines of force to generate an electric current. As the positive radio wave passes the frontdipole7 it'proceeds toward the reflector 8 giving it a positive electric charge also. Then,-since 7 and 8 are a quarter wave-length apart, the front dipole 7 goes negative simultaneously as the reflector 8 goes positive, and vice versa; The reflector 8 h'as the property of reradiating the energy received from the radio wave passing it and someof the'energy is thus radiated back toward the front dipole and, since it must be remembered that the spacing from 7 to 8' is a quarter wave-length the radiated wave from the refiector'reaching the front dipole adds to another wave, the commencement of which is indicated at C in Fig. 1, accordingly increasingthe signal strength to. the set or receiver which is connected with the front dipole by conductors 10. It is this general principle of reflection that I have utilized in the antenna-reflector combination disclosed'in my -copending application. However, in that case 'the reflector'is especially designed with a view to cancelingout undesired signals from one of two television stations operating on the same channel, in order that the user of'a setmay enjoy the program broadcast from the other station-without interference,ythe reflector being always disposed as a shield on that side of the dipole facing the station whose interfering signals are to be rejected.

In accordance with the present invention, as shown in Figs; 3 and 4, an antenna-reflector combination similar to that ofFig. 2 is provided, there being a front dipole 7 and a'two-element reflector 811-812 in parallel relation to-and spaced behind the front dipole a quarter wave length away, with a radio frequency amplifier 11 tuned to theincoming radio wave 9'. This'amplifier 11 has its input sideconnected by conductors 12 with the front dipole and has its output side connected by conductors 13 with the reflector elements 8a8b, thereby amplifying the waves radiated from the reflector elements back to the front dipole and accordingly adding greatly to the signal strength going to the set or receiver through conductors 10' 'connectedto the dipole. The wave may be amplified and re-amplified through the amplifier 11 and the amount of regeneration could continue to the point of oscillation wereit not for the fact that a gain control is provided in the amplifier 11 to prevent reaching that condition, so that the antenna operates just below the point of oscillation for maximum sensitivity. I have purposely represented the amplifier 11 diagrammatically inasmuch as I do not limit my invention to any specific amplifier, amplication being obtainable by ratio tubes in the well-known way or by the more recent development known as the transistor. Furthermore, this means of adding sensitivity to an antenna, it must be understood, may be applied to any conventional antenna. By using a broad-banded amplifier at 11, waves of different frequencies can be amplified in the manner described. Hence, in the present television sets, sound waves and television waves, which are of different frequencies, can be amplified at the same time with the one electronic antenna. Without thereby appearing or meaning to impose any limitation upon the scope of the invention I might add that the physical length of each of the dipole elements 7' is preferably exactly frequency length or one-fourth thereof, and the physical length of each of the associated reflector elements 8a and 8b is longer, the length being such as to produce the proper phase change so that the reradiated amplified signal adds to the strength of the incoming signal on the front dipole elements 7'.

In operation, my electronic antenna serves to build up the regenerative action between the antenna proper and the associated reflector below the point of oscillation, so that weaker radio signals may bedetected, thus enabling good television reception at much greater distances from the selected stations than has heretofore been considered possible. This electronic antenna extends radio communication generally to greater distances with no increase in the transmitter power. Sensitivity could be increased to infinity, that is, to the oscillation point, and as the sensitivity is increased the frequency band width is reduced, thereby reducing side band interference. In closing, I should add that while I have stated the spacing of the main and secondary sections is a quarter wave-length, the position can more broadly be stated to be that which, with the amplifier connection described, gives the desired additive effect on the main section. The reflector or other radiating section or sections, in other words, can be placed in any position near the antenna so long as an additive effect is obtained.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn to cover all legitimate modifications and adaptations.

I claim:

1. In a signal receiving antenna, the combination of a regenerative amplifier, a principal antenna section connected to the input side of the regenerative amplifier, and a secondary antenna section in parallel spaced relation to and behind the principal antenna section in relation to the direction of a signal transmitting source and acting as a reflector and coupled to the output side of the amplifier to provide regeneration by means of energy reflected back to the input antenna.

2. In a signal receiving antenna, the combination of a tuned radio frequency amplifier, a principal antenna section connected to the input side of the amplifier, a secondary antenna section in parallel spaced relation to and behind the principal antenna section in relation to the direction of a'signal transmitting source and acting as a reflector and coupled to the output side of the amplifier to provide regeneration by means of energy reflected back to the input antenna to build up the regenerative action therebetween below the point of oscillation.

3. An antenna as set forth in claim 1 wherein the secondary antenna section is spaced a quarter wavelength from the principal antenna section.

4. An antenna as set forth in claim 1 wherein the principal antenna section is of a length which is approxi- 4 mately one-half wave length of the frequency to be received, and the secondary antenna section is longer.

5. An antenna as set forth in claim 1 wherein the secondary antenna section is spaced a quarter wavelength from the principal antenna section and wherein the principal antenna section is of a length which is approximately one-half wavelength of the frequency to be received, and the secondary antenna section is longer.

6. In a signal receiving antenna, the combination of a regenerative amplifier, dipole elements connected to the input side of the regenerative amplifier, and re flector elements in parallel spaced relation to and behind the dipole elements in relation to the direction of a signal transmitting source, said reflector elements being coupled to the output side of the amplifier to provide regeneration by means of energy reflected back to the dipole elements.

7. In a signal receiving antenna, the combination of a tuned radio frequency amplifier, dipole elements connected to the input side of said amplifier, and reflector elements in parallel spaced relation to and behind the dipole elements in relation to the direction of a signal transmitting source, said reflector elements being coupled to the output side of said amplifier to provide regeneration by means of energy reflected back to the dipole elements to build up the regenerative action therebetween below the point of oscillation.

8. An antenna-reflector combination as set forth in claim 6 wherein the reflector elements are spaced a quarter wave-length from the dipole elements.

9. An antenna-reflector combination as set forth in claim 6 wherein the reflector elements are spaced a quarter wave-length from the dipole elements and wherein the dipole elements are of an exact length which is approximately one-half Wave length of the frequency to be received, and the reflector elements are longer.

10. An antenna-reflector combination as set forth in claim 6 wherein the dipole elements are of an exact length which is approximately one-half wave length of the frequency to be received, and the reflector elements are longer.

References Cited in the file of this patent UNITED STATES PATENTS 1,964,570 Gothe June 26, 1934 1,996,804 Gothe Apr. 9, 1935 2,183,562 Hansell Dec. 19, 1939 2,192,187 Gordon Mar. 5, 1940 2,349,976 Matsudaira May 30, 1944 2,396,884 Robinson Mar. 19, 1946 2,480,164 Royden Aug. 30, 1949 ere