System for evaluating the inner medium characteristics of non-metallic materials

• US 5,420,589 A
• Filed: 06/07/1993
• Issued: 05/30/1995
• Est. Priority Date: 06/07/1993
• Status: Expired due to Fees

• Current Assignee: C. T. Wells, Rob Peterson
• Original Assignee: C. T. Wells, Rob Peterson
• Inventors: Peterson, Rob, Wells, C. T.
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US08/073,451
• Time in Patent Office: 722 Days
• Field of Search: 342/22
• US Class Current: 342/22
• 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 13/885 for ground probing prospecting or detecting using electromagnetic waves G01V3/12
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005
• CPC Class Codes: H01Q 13/085 Slot-line radiating ends

Abstract

A pulse radar system for determining the subsurface structure of a medium comprising an electronics unit for providing electronic signals and control comprising a utility controller, a sampler controller, and a timing controller such that the timing controller provides a pulser trigger and the sampler controller provides a sampler trigger; a microwave unit comprising all the microwave components within the system including a pulser for generating pulses as directed by the timing controller in the electronics unit, a transmitting antenna for receiving the pulses directly from and being in close proximity to the pulser, a receiving antenna for accepting the pulses emitted from the transmitting antenna, and a receiver in close proximity to and for accepting the pulses from the receiving antenna, and a data unit for receiving signals from the electronics unit and for displaying the data for review and analysis. In accordance with another embodiment of the present invention, a method is provided for determining the characteristics of a medium. Also provided in the present invention is a pulser which utilizes all microwave components and a novel antenna assembly.

Claims

1. A pulse radar system for determining the subsurface structure of a non-metallic medium using a reflected signal representative of the subsurface structure comprising:

(a) a controller for generating and receiving electronic signals including a pulser trigger signal and a sampler trigger signal; and

(b) an integrated, monocoque microwave unit for incorporating all the microwave components associated with the pulse radar system such that all the components are in close microwave communication one with the other and all communication of microwaves between components is maintained in and restricted to the integrated microwave unit, the integrated microwave unit comprising

(1) at least one antenna unit comprising

(A) at least one former of low dielectric material having a generally triangular shape with an apex at one end, a bottom at the other end and legs extending there between and having two substantially parallel sides.such that as the legs extend from the apex to the base splayed surfaces are formed between the sides, and further as the splayed surfaces approach the bottom, the splayed surfaces are flared for expanding in shape at a rate greater than the splayed portion of the surfaces near the apex,

(B) a first and second support member of low dielectric material each support member having a planar configuration for engaging the splayed and flared surfaces of the former such that the support members are shaped to conform to the splayed-flared surface configuration, and

(C) a first and second antenna leaf operationally engaged with the first and second support members, respectively, for operating in the transverse electromagnetic (TEM) mode,

(2) a plurality of spacers of low dielectric material for engagement with the sides of the formers for secureally fixing the antenna units in positional relationship and extending from the antenna unit,

(3) a base of low dielectric material for engagement with the bottoms of the formers and the spacers for rigidly securing the antenna units in positional relationship for forming a monocoque structure comprising the antenna unit, the spacers and the base,

(4) a plurality of covers of low dielectric material for engagement with the base and the spacers for protecting the antenna leafs and support members,

(5) an intermediate member securedly fixed to the spacers and the covers which extends from the antenna unit,

(6) a top of low dielectric material for engagement with the formers and the covers for forming an enclosure bounded by the top, the formers, the covers and the intermediate member,

(7) a pulser integral with the microwave unit and located in the enclosure for receiving the pulser trigger signal from the controller and for generating microwave pulses, the pulser for providing microwave pulses to the antenna unit, and

(8) a sampler integral with the microwave unit and located in the enclosure for receiving the reflected signal from the antenna unit.

2. A pulse radar system for determining the subsurface structure of a non-metallic medium as defined in claim 1 further comprising a data unit for receiving signals from the controller and for analyzing, generating and displaying data.

3. A pulse radar system for determining the subsurface structure of a non-metallic medium as defined in claim 1 wherein the antenna unit comprises an air-coupled, horn, antenna in close proximity to the pulser for operating in the transverse electromagnetic (TEM) mode sufficient for transmitting a non-dispersed, broadband of frequencies ranging from approximately 100 MHz to above 2.0 GHz.

4. A pulse radar system for determining the subsurface structure of a non-metallic medium as defined in claim 1 further comprising a high absorption, low reflectivity material surrounding the antenna unit.

5. A pulse radar system for determining the subsurface structure of a non-metallic medium as defined in claim 1 wherein the low dielectric material is Polystyrene®

.

6. A pulse radar system for determining the subsurface structure of a non-metallic medium as defined in claim 1 wherein the low dielectric material is Styrofoam®

.

7. A pulse radar system for determining the subsurface structure of a non-metallic medium as defined in claim 1 wherein the pulser comprises a first microwave transmission line for replicating a positive-going microwave pulse, and a second microwave transmission line for replicating a negative-going pulse such that the positive-going microwave pulse and the negative-going microwave pulse are precisely fitted together to form a monocycle microwave pulse whereby at least one microwave transmission line comprises a planar waveguide structure.

8. A pulse radar system for determining the subsurface structure of a non-metallic medium as defined in claim 7 wherein the planar waveguide structure comprises a coplanar waveguide structure.

9. A pulse radar system for determining the subsurface structure of a non-metallic medium as defined in claim 7 wherein the planar waveguide structure comprises a microstrip waveguide structure.

10. A pulse radar system for determining the subsurface structure of a non-metallic medium as defined in claim 1 wherein the controller is housed in the enclosure of the integrated, monocoque microwave unit.