Electronic assembly for range finding using radio wave signal strength
First Claim
1. A radio range finding system comprising:
- (a) a radio frequency transmitter for generating a radio signal of a selected frequency and adapted to be disposed in or adjacent an area in which distance is to be monitored;
(b) a transmitting antenna operatively connected to said transmitter for radiating said radio frequency signal generated by said transmitter; and
(c) a receiver unit adapted to be disposed within said area and comprising;
(i) a multiplicity of radio signal receivers each having a receiving antenna with said receiving antennae of said multiplicity of receivers having their axes of maximum sensitivity oriented in different direction and each operative to receive signals of said selected frequency;
(ii) means for deriving a composite field strength based upon the field strengths of said radio signal generated by said transmitter and received by all of said receiving antennae; and
(iii) means for providing an output indication of composite field strength based upon said composite field strength derived from said signal detected by said receiving antennae.
2 Assignments
0 Petitions
Accused Products
Abstract
A radio range finding system includes a radio frequency transmitter adapted to be located adjacent an area in which distance is to be monitored, a transmitting antenna, and a receiver unit. The receiver unit has a multiplicity of radio signal receivers each having a highly directional receiving antenna with the receiving antennae of the multiplicity of receivers having their axes of maximum sensitivity oriented in different directions, and an analyzer for determining a composite of the field strengths of the radio signals received by the receiving antennae, and providing an output indicative of the composite field strength. The receiver may detect when the composite field strength at the receiving antennae fails below predetermined values, and generate a signal at that time. The vector sum of the field strengths of the radio signals are derived from the square root of the sum of the squares of the field strengths of the several signals. The field strength signals are multiplexed and converted to a DC voltage by an RMS to DC converter. The transmit antenna is a loop comprising one or more turns shielded by two partial spaced apart shields, each connected only to the shield of the antenna cable at its junction to the loop.
60 Citations
26 Claims
-
1. A radio range finding system comprising:
-
(a) a radio frequency transmitter for generating a radio signal of a selected frequency and adapted to be disposed in or adjacent an area in which distance is to be monitored; (b) a transmitting antenna operatively connected to said transmitter for radiating said radio frequency signal generated by said transmitter; and (c) a receiver unit adapted to be disposed within said area and comprising; (i) a multiplicity of radio signal receivers each having a receiving antenna with said receiving antennae of said multiplicity of receivers having their axes of maximum sensitivity oriented in different direction and each operative to receive signals of said selected frequency; (ii) means for deriving a composite field strength based upon the field strengths of said radio signal generated by said transmitter and received by all of said receiving antennae; and (iii) means for providing an output indication of composite field strength based upon said composite field strength derived from said signal detected by said receiving antennae. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. A radio range finding system comprising:
-
(a) a radio frequency transmitter for generating a radio signal of a selected frequency and adapted to be disposed in or adjacent an area in which distance is to be monitored; (b) a transmitting antenna operatively connected to said transmitter for radiating said radio frequency signal generated by said transmitter; (c) a receiver unit adapted to be disposed within said area and comprising; (i) three radio signal receivers each having a highly directional receiving antenna with said receiving antennae of said multiplicity of receivers having their axes of maximum sensitivity orthogonally oriented and each operative to receive signals of said selected frequency; (ii) digital processing circuitry; (iii) means for determining a vector sum of the field strengths of said radio generated by said transmitter and received by all of said receiving antennae, said vector sum of the detected field strength of said signals received by said antennae being derived from the square root of the sum of the squares of the field strengths of said signal as received by the three receivers; (iv) means for detecting when the vector sum of field strengths detected by said receivers falls below a predetermined value; and (v) signal generating means in said unit for generating a signal, said signal generating means being actuated when the detected vector sum of said field strengths falls below said predetermined value. - View Dependent Claims (18, 19, 20, 21)
-
-
22. A radio signal field strength analyzer operable to analyze the field strength of a signal of a single frequency emanating from a common transmitter as received by a multiplicity of receivers comprising:
-
(a) at least three radio signal receivers each having a receiving antenna with said receiving antennae of said receivers having their axes of maximum sensitivity oriented in different directions, said receivers all operating at the same frequency; and (b) means for deriving a composite field strength based upon the field strengths of the radio signals of the same frequency received by all of said receiving antennae, said composite field strength being the vector sum of the detected field strengths as derived by taking the square root of the sum of the squares of the field strengths of the signals received by three highly directional equally sensitive antenna oriented with mutually perpendicular axes of maximum sensitivity. - View Dependent Claims (23, 24, 25)
-
-
26. In a radio signal field strength analyzer comprising:
-
(a) means for detecting at least three component radio signals of independent field strength; and (b) means for deriving a composite field strength based upon the field strengths of said radio signals received, said composite field strength being the vector sum of the detected field strengths as derived by taking the square root of the sum of the squares of the field strengths of the signals received by three highly directional equally sensitive antennae oriented with mutually perpendicular axes of maximum sensitivity, said deriving means including means functioning to time division multiplex and convert to a DC voltage the field strength vector of the signals received by said antennae, said conversion being effected by an RMS to DC converter.
-
Specification