US1892151A

US1892151A - Direction finding system

Info

Publication number: US1892151A
Application number: US356135A
Authority: US
Inventors: Lawrence A Hyland
Original assignee: Wired Radio Inc
Current assignee: Wired Radio Inc
Priority date: 1929-04-18
Filing date: 1929-04-18
Publication date: 1932-12-27
Anticipated expiration: 1949-12-27

Description

8C. 27, D' I DIRECTION FINDING SYSTEM Filed April 18, 1929 INVENTOR.

A TTORNEY marries starts Patented Dec. 27, 1932 LdtZdSt seranreeetee na'wzannon A. HYLAND, or wesnrne'ron, nrs'rnrcr or 'ocnnnnra, Assrenon r0 WIRED nAnIo, ING., or new YORK, n. 1., n conrona'rronor DELAWARE DIRECTED? FINDING- SYSTEIi/I Application filed April 18,

My invention relates broadly to direction finding systems, and more specifically to antenna arrangements for direction finding systems.

One of the objects of my invention is to provide an antenna system in which a plurality of antennae are interconnected and cooperate to impress signaling energy, induced into the antennae by wave trains transmitted from one direction, upon the inpu circuitof a translating device.

Another object of my invention is to provide an antenna system in which a plurality of interconnected antennae cooperate together to impress signaling energy received from one or more determinable directions upon the circuits associated with an observing device. Still another object of my invention is to provide an antenna system which may be employed either unidirectional or multidirectional reception.

A further object of my invention is to provide an antenna system which may be readily converted from a unidirectional to a bidirecti'onal system. I

A still further object of my invention is to provide an antenna system for use on moving craft for reception of signals and for determining the direction from which the signals approach the moving craft.

' Other objects of this invention will be apparent to'those skilled in the art to which the invention pertains from the following specification and by reference to the accompanying drawing.

A According to this invention an antenna of a substantially nondirectional type is connected to acircuit arrangement comprising an inherently directional antenna system, a plurality of series connected condensers, a couplin g transformer for transferring signaling energy from the circuit arrangement to sig nal translating and interpreting devices and a tuning condenser for tuning the inherently directional antenna system. The nondirectional antenna is connected to the terminals of the directional antenna system and terminals of theprimary winding of the coupling transformer through the series connected condensers to permit theadj ustment of the phase ieae. Serial no. 356,185.

relation between the currents flowing to oppoi'ite terminals of the directional antenna system and the primary winding of the coupling transformer and thus eliminate or partially eliminate the efi ectsof the substantially nondirectional antenna and render the whole antenna system, which comprises, the nondirectional, as well as the directional-antennae, directive in a certain. direction or in certain directions. 7 A resistance unit is connected into circuit instead of one of the series connected condensers by means of a simple switching arrangement, when it is desired to obtain an antennasystem having the conventional. cardioidal signal diagram.

Referring to the drawing, the sole figure illustrates a circuit diagram embodying a form of this invention.

In the drawing reference numeral 1 designates a vertical or horizontal antenna having substantially nondirectional characteristics. A variable condenser 2 and a switch 5 are connected tothe antenna 1. A variable resistance unit 4 'anda variable condenser 3 are connected to contact pointsof the switch 5.. A directional antenna, comprising the sections 6 and 7 which may be separate loop antennae positioned adjacent to each other or portions of a split loop antenna,,is connected across the primary winding 9 of the coupling transformer. 10. A ground connection 12 comprising a connection to the metal framework of an aircraft, ship or land vehicle upon which this system is employed, is provided at the electrical center or approximate electrical center of primary winding 9. Where the sys tem of my invention is employed in permanent land installations, such as aircraft landing fields, any conventional ground connection may be employed. A condenser 8 is connected between sections 6 and 7 of the directional antenna and is employed for tuning the circuit of the directional antenna. The input circuit of an electron discharge device 13 is connected to the secondary winding 11 of the transformer 10. A coupling transformer 1 is connected between the output circuit of the device 13 and the input circuit of the device 16.

A tuning element 15 is connected into the input circuit of device 16 and an observing device 17 which may consist of-a telephone receiving device, a vibrating reed indicating instrument or any other device adapted for observing signaling energy. Any type of receiving set may be employed in conjunction with the antenna system herein described in place of the receiving set 18.

WVhen it is desired to employ an antenna system having a bilateralsignal response characteristic for the reception of signals from opposite directions, the directional antenna is oriented so that signals which it is desired to receive are received with, a minimum intensity. The condensers 2 and 3 are then adjusted until the nondirectional antenna currents are balanced outas is indicated, usually by a further reduction in the signal as observed through the operation of device 17 The directional antenna comprising sections 6 and 7 is then oriented so that the observed signal is substantially zero and in this position the plane of the directional antenna will be perpendicular to the direction of the line of approach of the signal. It the directional antenna is rotated to the position of maximum signal strength the plane of the directional antenna will be in line with the direction of approach of the signals. When it is desired to obtain the heart shaped orcardioidalsignal response characteristic in the antenna system and thus determine the sense of direction, the resistance 4 is connected into circuit by means of the switch 5.

The capacity 2 is preferably left constant at the value employed when the antenna system was used as a bilateral system and the variable resistance unit 4 is varied to obtain the desiredphase shift between the currents flowing'to the terminals of the winding 9.

In employing the antenna system as a unilatera-lor unidirectional system it is not desirable to eliminate the total efiect of the antenna 1, and the resistance unit 4: is adjusted accordingly until the maximum response is obtainedfrom signals approaching from one direction. capacities 2, 3 and 8 and the resistanceunit 4e are adjusted for any wave length the system may be employed either in unilateral or bilateral reception by manipulating the switch 5 and connecting either the resistance unit 4:, which is preferably noninductive, or the capacity 3 into circuit.

While I have described my invention in one of its preferred embodiments, I desire it to be understood that other modifications thereof may be made and that no limitations upon this invention are intended other than are imposed by the scope of the appended claims.

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

1. In a direction finding system, the cornbination'of an antenna having a substan- Once the values a of tially nondirectional characteristic, a direc-- tlonal antenna, said directional antenna com-. J j prising a plurality of sections, a condenser connected to said sections for tuning, said directional antenna a' condenser connected be:

tween said nondirectional antenna and one of one of the sections of said directional antenna and said nondirectional antenna, and a 0011- pling device associated with the circuitsj of said antennae for transferring energy there- I from. i

2. In a direction finding system, 3;.dll80 tional antenna 'comprising 'a pair of sections a tuned circuit interconnecting saidpair, of

sections, a non-directional antenna, a balance; mg condenser connected between said nondirectional antennafand one of the;

of said directional antenna, a second balanqing condenser, a resistor, a switchfa circuitconnecting said non directional antenna to the other of said sections of said directional antenna through said switch whereby either said resistor or said second balancing con:

denser may be selectively connectedin Said. last mentioned c1rcu1t,a signal receivingcit cuit'and means connecting said signal receiving circuit across the sections; of said'dired tional antenna.

3;In a direction finding systemfa directional antenna comprising a pairiof sections-,ja

tuned circuit connecting'said sections in series,

a non directional antenna, a balancing condenser connected between said non-d1rect1on-- al' antenna and one of the sections of said directional antenna, a second balancingcon-fi denser, a variable resistor, aswitch, a. circuit connecting said non-directional antenna to theother of said sections ofsaiddirectional antenna through said switch whereby either said'resistor or said second balancing con.- f denser may be selectivelyfconnected: in said' lastmentioned circuit, a signal receiving ci rcuit and coupling means interconnecting said I i circuit and the terminals ofsaiddirectional antenna. r

4. In a direction finding system, a directional antenna comprising a-pair ofsections, a tuned circuit connecting said sections-in series, a non-directional antenna, a balancing condenser connected between said nondirec tional antenna and one of the sections of said directional antenna, a second balancing con denser, a resistor, a switch, a circuit-connecting said non-directional antenna-to the other of said sections of said d1rectional antenna through said switch whereby either said tosistor or said second balancing condenser may be selectively connected in said last 'mentioned circuit, an output circuit connected across said directional antenna, a ground connection approximately at the electrical midpoint of said output circuit and a receiving circuit connected with said output circuit, said 5 antenna system being selectively connected to impart a unilateral or a bilateral characteristic to said receiving circuit.

5. In a direction finding system, a directional antenna comprising a pair of sections, a tuned circuit connecting said sections in series, a non-directional antenna,a balancing condenser connected between said non-directional antenna and one of the sections of said directional antenna, a second balancing condenser, a resistor, a switch, a circuit connecting said non-directional antenna to the other of said sections of said directional antenna through said switch whereby either said resistor or said second balancing condenser may be selectively connected in said last mentioned circuit, an output circuit connected to said directional antenna, and a signal responsive system connected in electrical relation with said output circuit, whereby when said switch is connected to said second balancing condenser a true null setting may be obtained and when said switch is connected to said resistor a true pointing minimum setting may be obtained. LAWRENCE A. HYLAND.