Time domain radio transmission system

• US RE39,759 E1
• Filed: 04/30/2004
• Issued: 08/07/2007
• Est. Priority Date: 12/03/1984
• Status: Expired due to Term

• Current Assignee: Time Domain Corporation (Humatics Corporation)
• Original Assignee: Time Domain Corporation (Humatics Corporation)
• Inventors: Fullerton, Larry W.
• Primary Examiner(s): Gregory; Bernarr E.
• Application Number:
  US10/836,859
• Time in Patent Office: 1,194 Days
• Field of Search: 375130-153, 375/256, 380/34, 342/21, 342/22, 342/27, 342/28, 342/118, 342/120, 342/127, 342/132, 342/134, 342/145, 342/201
• US Class Current: 342/27
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/18 wherein range gates are used
• CPC Class Codes: G01S 7/282 Transmitters
• CPC Class Codes: G01S 7/292 Extracting wanted echo-signals
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00
• CPC Class Codes: H04B 1/71632 Signal aspects H04B1/7172 and H04B1/7176 take precedence
• CPC Class Codes: H04B 1/71637 Receiver aspects H04B1/7183 takes precedence
• CPC Class Codes: H04B 1/7174 Pulse generation in general H04L25/03834
• CPC Class Codes: H04B 1/719 Interference-related aspects
• CPC Class Codes: H04B 14/026 using pulse time characteristics modulation, e.g. width, position, interval
• CPC Class Codes: H04L 27/103 Chirp modulation for spread spectrum techniques H04B1/69

Abstract

A time domain communications system wherein a broadband of time-spaced signals, essentially monocycle-like signals, are derived from applying stepped-in-amplitude signals to a broadband antenna, in this case, a reverse bicone antenna. When received, the thus transmitted signals are multiplied by a D.C. replica of each transmitted signal, and thereafter, they are, successively, short time and long time integrated to achieve detection.

Claims

1. A wideband transmission system comprising:

a transmitter comprising;

generating means for generating a plurality of time spaced signals, each signal of said plurality of signals having a stepped-in-amplitude portion;

transmitting means including a broad frequency band radiator responsive to said generating means for transmitting wideband, time spaced, burst signals into a selected medium; and

receiving means responsive to wideband burst signals present in said medium, as received signals, for processing said received signals, by, (1) coherently detecting said received signals, (2) integrating, separately, a plurality of coherently detected signals, and (3) integrating the resultant plurality of integrated signals and therefrom providing intelligence signals.

2. A system as set forth in claim 1 wherein said system includes reciprocal electrical-signal-to-sonic translation means and said last-named means includes said broad frequency band radiator, and said receiving means includes signal means responsive to said reciprocal electrical-signal-to-sonic translation means and to said times of initiation of said burst signals for coherently detecting said signals.

3. A system as set forth in claim 2 wherein said medium is a liquid.

4. A system as set forth in claim 1 wherein said medium is a liquid.

5. A system as set forth in claim 1 wherein said broad frequency band radiator comprises a broadband light radiator.

6. A system as set forth in claim 5 wherein said broadband-frequency band radiator comprises:

a laser;

a light modulator comprising;

an elongated optical channel having an entrance end for receiving light from said laser and a light exiting end and having a refractive index variable by an electrical field, and

conductive means extending along said optical channel for applying an electrical field to said optical channel;

signal means for generating a generally ramp-shaped voltage and applying said voltage to said conductive means generally in the region of said exiting end of said channel; and

a dispersive medium disposed to intercept the output of said channel and emit a responsive beam which is characterized by a broad spectrum of light.

7. A system as set forth in claim 1 wherein said receiving means includes template generating means for generating timed spaced signals as template signals and multiplier means responsive to a signal of said received signals and a template signal of said template signals for providing an output, being a product signal, and thereby coherently detecting the signal present during a said template signal.

8. A system as set forth in claim 7 wherein said template generating means generates said template signal at a time subsequent to the transmitting of a burst signal of said burst signals by said transmitting means.

9. A system as set forth in claim 7 wherein said template generating means includes means for providing a variably delayable template signal.

10. A system as set forth in claim 7 wherein:

said template generating means including for generating first and second said template signals, said second template signal being delayed with respect to said first template signal;

said system includes first and second said multiplier means, said first multiplier means being responsive to a said received signal and said first template signal for providing one said first product signal and second multiplier means responsive to said second template signal and a said received signal for providing another said product signal;

first integrating means responsive to said first product signal for integrating said first product signal during the presence of said first template signal and providing a first integrated signal;

second integrating means responsive to said second product signal for integrating said second product signal during the presence of said second template signal and providing a second integrated signal; and

final integrating and combining means responsive to said first and second one integrated signals for combining and integrating said first and second said integrated signals and providing intelligence signals therefrom.

11. A system as set forth in claim 10 wherein integrating of said first and second signals precedes combining.

12. A system as set forth in claim 7 wherein said template signal is of a discrete polarity.

13. A system as set forth in claim 7 wherein said receiving means includes:

timing means responsive to the time of transmitting of said burst signals for generating a set of said template signals, each said template signal of said set of said template signals being delayed by a like amount with respect to the transmitting of a burst signal of said burst signals; and

output means responsive to said timing means and a set of resulting intelligence signals for indicating the presence and distance of a target illuminated by said burst signals at a range determined by said delayed said amount.

14. A system as set forth in claim 13 wherein said receiving means includes short time integrating means for, during the presence of each said template signal of said set of template signals, individually integrating each product signal from a said set as (2) and including another integrating means for integrating the resulting set of integrated product signals as (3).

15. A system as set forth in claim 7 wherein a said template signal is generated responsive to a received signal of said received signals.

16. A system as set forth in claim 1 wherein said transmitter includes a source of potential, and switching means coupled to said source and said radiator, and responsive to said signals from said generating means, for abruptly changing the potential on said radiator.

17. A system as set forth in claim 16 wherein said source of potential is normally applied to said radiators and said switching means reduces the potential on said radiator.

18. A system as set forth in claim 16 wherein:

said switching means comprises;

a layer of normally high-resistance, but light-responsive, low-resistance material,

a pair of electrodes coupled to said material, and

said radiator has a pair of terminals;

said electrodes, said terminals,and said source of potential are connected in series; and

trigger means including a light source and fiber optic, and responsive to said generating means for applying a discrete increment of light from said light source through said fiber optic to said layer of said material wherein said material transitions from a high-resistance state to a low-resistance state.

19. A system as set forth in claim 18 wherein said material is diamond.

20. A system as set forth in claim 1 wherein said radiator comprises a broadband dipole antenna having a pair of triangular-shaped elements.

21. A system as set forth in claim 20 wherein said transmitter includes a source of potential coupled to said dipole, and switching means responsive to said generating means for abruptly changing the potential on said dipole.

22. A system as set forth in claim 21 wherein said transmitting means includes means for applying a switched source of potential to said elements of said dipole antenna at points generally intercepted by a line between the apices of said elements.

23. A system as set forth in claim 20 wherein said dipole antenna is planar, and said system includes a plurality of like length dipoles generally lying in a plane.

24. A system as set forth in claim 23 further comprising a reflector positioned in a parallel plane to that of said plurality of like length dipoles.

25. A system as set forth in claim 20 wherein said transmitter includes:

first and second electrical resistances; and

power switching means positioned adjacent to said dipole antenna and being connected to one pole of said dipole through said first said electrical resistance and connected to the other pole of said dipole through said second resistance and responsive to a signal from said generating means for abruptly changing the voltage across poles of said broadband dipole antenna through said resistances.

26. A system as set forth in claim 25 comprising:

third and fourth electrical resistances;

a source of D.C. potential having first and second terminals;

a first terminal of said source of D.C. potential being connected through said third resistance to one pole of said dipole, and said second terminal of said source of D.C. potential being connected through said fourth resistance to the other pole of said dipole; and

said power switching means includes means for switching the state of D.C. potential on said dipole to a reduced D.C. potential.

27. A system as set forth in claim 26 wherein said system includes a coaxial cable through which said signals from said generating means are supplied to said switching means.

28. A system as set forth in claim 27 wherein said source of potential is applied through said coaxial cable to said dipole.

29. A system as set forth in claim 28 including constant current means coupled through said coaxial cable and said dipole for regulating current, charging current, to said dipole through said third and fourth resistances.

30. A system as set forth in claim 1 wherein said time spaced signals are varied in a time pattern.

31. A system as set forth in claim 30 wherein said time spaced signals are a function of modulation.

32. A system as set forth in claim 1 further comprising:

second and third receiving means, the three said receiving means being spaced apart; and

combining means for combining intelligence signals from said three receiving means and providing an indication of a target illuminated by said transmitter and its direction.

33. A system as set forth in claim 1 wherein said receiving means includes filter means responsive to said intelligence signals for providing a signal responsive to a selected range of frequencies.

34. A system as set forth in claim 1 wherein said receiving means includes a dipole antenna comprising a pair of elements, each of which, when viewed normal to the dipole length in at least one plane, appears triangular, and wherein the bases of said elements are parallel and and from which elements said received signals appear.