Radio wave systems for indicating the presence, range or location of an object

Abstract

Abstract 581,168. Radiolocation. BUSH RADIO, Ltd., and HARRISON, W. H. July 28, 1941, No. 9573. [Class 40 (v)] A radio-wave system for indicating the presence, range, or location of an object by the reflection of waves therefrom comprises means for transmitting radio-wave signal impulses, a super-regenerator adapted for receiving a reflection of such impulse, and means operative to register little or no response to the reception of such reflected impulse during the time of low sensitivity of the super-regenerator, but substantial response if such reflected impulse is received at the time of greater sensitivity. A single-valve self-quenching super-regenerator 4, Fig. 1, is provided with a dipole autenna 5 and a reflector 6. The quench frequency is variable by means of a condenser 7. The super-regenerator serves as an impulse transmitter and also as a receiver, its cycle of operation comprising a negative resistance period, during which a train of radio-frequency oscillations is generated and transmitted and a positive resistance period, during which oscillations are quenched. This latter period is divided into two parts during which the arrangement functions as a receiver of low and high sensitivity respectively, the latter part being established just prior to the initiation of another and similar cycle. The quench frequency is adjusted by the condenser 7 until the period of greater sensitivity coincides with the reception of a reflector signal corresponding to the transmitter pulse, as indicated by phones 8. The condenser 7 is provided with a scale 9 calibrated in terms of distance. Instead of a combined transmitter and receiver a separate radio-wave transmitter may be provided for co-operation with a superregenerative receiver, the timing of the initiation of the periodic cycles of operation of the latter being controlled by impulses from the transmitter. In a modification, Fig. 2, a combined transmitter and receiver as shown in Fig. 1 has a neon lamp 9 in place of the phones. The'condenser 10 is continuously rotated at 10 to 20 times a second, together with a spirally slotted stroboscopic disc 11 by a motor 12. A scale 13 is calibrated in terms of distance.

Inventors

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