| United States Patent Office.
Lee de Forest, of New York, N. Y., Assignor by Mesne Assignments, to de Forest Radio Telephone Co., a corporation of New York. Wireless Telegraphy. | ||
| No. 1,101,533. | Patented June 30, 1914. | |
| Specification of Letters Patent.
Application filed June 20, 1906. Serial No. 322,534. | ||
To all whom it may concern:
Be it known that I, Lee de Forest, a citizen of the United States, and a resident of New York, in the county of New York 5and State of New York, have invented a new and useful Improvement in Wireless Telegraphy, of which the following is a specification.
My invention relates to wireless telegraphy10 and the objects of my invention are to provide transmitting and receiving systems whereby the radiation of electromagnetic signal waves may be concentrated in a definite general15 direction and whereby the general direction from which the electromagnetic signal waves which operate a receiving device emanate may be determined; to increase the efficiency of transmission of electromagnetic waves over land; and to 20increase the efficiency of duplex working.
The principles upon which my invention is based are illustrated in the drawings, which accompany and form a part of this specification and which show in diagram 25several embodiments of my invention which have proven efficient in practice; but it is to be understood that I do not limit myself to the particular circuits and systems herein shown inasmuch as many modification may 30be made therein without departing from the principle of my invention.
In the drawings, Figures 1, 2, 3 and 7 represent wireless telegraph systems each comprising a transmitting system at one station 35and a receiving system at another station. Figs. 4, 5 and 6 represent receiving systems. Figs. 8, 9 and 10 represent duplex wireless telegraph systems, each comprising a transmitting and a receiving system at each 40station.
In the figures, A represents a horizontal or an approximately horizontal transmitting antenna; A′ A′1 represent horizontal or approximately horizontal receiving antenna; 45V′ V′1, represent vertical transmitting antenna; L L′ are inductances; C C′ are condensers; S is a spark gap; M is a high potential transformer; G is an alternator; K is a key; D is an oscillation detector; F is a 50telephone or signal indicating device; B is a batter; and P is a potentiometer.
T, T′, represent transmitting systems and R, R′, represent the corresponding receiving systems.
In Fig. 1 the preferably symmetrically-55placed, horizontally-extending, transmitting antennæ A A at station T are shown as connected by the inductance L, which constitutes an auto-transformer, with the oscillating circuit S C L; and similar receiving60 antennæ A&prime, A′ at station R are connected by the inductance L′ to the receiving circuit L′ C&prim; D which is attuned to the frequency of the waves radiated by the antennæ A, A. Any suitable means however may be 65employed to create electrical oscillation in A, A and any suitable system of circuits may be employed for conveying the oscillations created in A′, A′, to the oscillation detector D.70
In Fig. 1 the antennæ are not connected to earth, while Figs. 2 and 3 show systems which are substantially the same as that of Fig. 1, except in Figs. 2 and 3 each antenna is grounded.75
In Figs. 1, 2 and 3 the transmitting antenna A and the receiving antenna A′ extend in substantially the same direction so that each antenna A of station T is substantially a continuation of its corresponding80 antenna A′ at station R and the antennæ, consequently lie in substantially the same vertical plane.
In Fig. 2 the transmitting antenna A points directly away from the receiving station85 R and the receiving antenna A′ points directly toward the transmitting station T.
In Fig. 3, the transmitting antenna A is directed away from the receiving station R and the receiving antenna A′ points directly90 away from the tranmitting station T.
Fig. 2 represents the preferred arrangement of antennæ and Fig. 3 represents the next best arrangement.
By arranging the antenna A in the manner95 shown in Figs. 2 and 3 the radiation from the transmitting systems is a maximum in the general direction of the receiving systems, and by directing the horizontally-extending receiving antennæ toward or away100 from the source of the radiation, which source may be a vertical antenna, the response of the oscillation detector is a maximum. In this manner the general direction from
