Abstract: Pulse propagation analysis to ascertain whether and anomaly such as surface corrosion exists on a section of conductive member such as pipe. Anomalies such as surface corrosion result in localized velocity changes of pulses propagating along a conductive member. These localized velocity changes exhibit themselves in changes in waveform, rise and fall time, amplitude, and time delay of a pulse with respect to a fixed time reference. To allow such anomalies to be located, two pulses are generated such that they intersect at intersecting locations along the conductive member. The resulting modified pulses are analyzed for perturbations indicative of localized velocity changes.

Abstract: A hand held diagnostic test device enables determination of the integrity of low observable (L.O.) properties in structures or surfaces of a structure, and includes a housing containing a first component for coupling energy signals into the structure or a surface of the structure, a second component for detecting the response energy signals, a third component for determining whether the response energy signals indicate flaws in the surface of the structure, and a fourth component for signaling an operator of the diagnostic test device of the results. The energy signal is an RF signal, and a microprocessor in the test device enables determination of the integrity of the structure of surface by comparing the returned signals against a stored acceptable signal. Acceptability or non-acceptability is signaled to the operator of the diagnostic test device by indicator lamps located on the sensor housing and/or a digital display.

Abstract: A probe (6) is brought into contact with a plasma produced by ionizing Ar gas, a saturation current (Ies2) at which current flowing through the probe is saturated when the potential of the probe is changed in a potential region where the potential of the probe is higher than a ground potential, and a saturation current (Iis2) at which current flowing through the probe is saturated when the potential of the probe is changed in a potential region where the potential of the probe is lower than the ground potential. Similarly, saturation currents (Ies2, Iis2) are measured by bringing the probe (6) into contact with a plasma produced by ionizing a mixed gas containing Ar gas and a process gas, such as C4F8 gas, and changing the potential of the probe (6). The negative ion density of the plasma produced by ionizing C4F8 gas is determined by using saturation current ratios (Iis1/Iis2, Ies1/Ies2).

Abstract: The invention relates to a combination of a feedthrough element for an electric high-frequency signal in a TDR level metering device, and a probe for guiding said high-frequency signal from the feedthrough element to the filling product surface of a filling product to be measured and back. The feedthrough element comprises at least one guiding element (6), into which the electric high-frequency signal is to be fed at an inlet point (10), and which transmits at an outlet point (17) the electric high-frequency signal to a probe (7) meant for guiding said high-frequency signal, a one-part or multipart mechanical carrier element (1), and a one-part or multipart insulation (11, 12) present between the carrier element (1) and the guiding element (6). The mentioned combination is characterized in that the impedance of the feedthrough element and the impedance of the probe (7) following the outlet point (17) are substantially matched to each other at the outlet point (17).

Abstract: A frequency domain measurement device multi-phase modulates an RF frequency signal with a broadband signal, such as a pseudo random number, to produce an RF spread spectrum signal that encompasses a frequency range of interest. The RF spread spectrum signal is transmitted to a device under test, and a corresponding reflected signal from the device under test is correlated with the RF spread spectrum signal to produce information from which location of and distance to a fault in the device under test may be determined. A FIR filter is used as part of the correlation process to determine magnitude and phase versus frequency over the frequency range of interest for the device under test as well as location of and distance to the fault.

Abstract: A time domain reflectometry measuring instrument uses a microprocessor that provides added functionality and capabilities. The circuit electronics and probe are tested and calibrated at the factory. Installation and commissioning by the user is simple. The user installs the probe. The transmitter is attached to the probe. The user connects a standard shielded twisted pair to the electronics. Power is applied and the device immediately displays levels. A few simple parameters may need to be entered such as output characteristics and the process material dielectric constant.

Abstract: This invention provides a method and apparatus for the sensing of moisture using microwave technology. The apparatus provides a wave guide having a linear array of slots in its broadwall. A detector detects reflected energy of microwave signals over a frequency range once the material is positioned over the slots. A value indicative of the power spectral density of the reflected signals is computed and a value for the moisture content of the material determined from the value of power spectral density. The slots are at an angle with respect to the longitudinal axis of the wave guide and the angle can be varied according to the material being tested.

Abstract: A computer-based method and computer-readable medium containing computer-executable instructions for assimilating data collected by a time domain reflectometer and displaying more than two waves representing reflections of a pulse on conductors is provided. The method includes a means for wave reversal, wave shifting, multi-wave display, segmented velocity of propagation adjustment, multi-cursor option multi-flagging options and calculating of the total length of wet cable. The combination of these functions provides a highly accurate means for identifying the location of splices, faults, corrosion, cable damage and other anomalies that are typically found on any length of conductor cable. The ability of this method to display a greater number of waves simultaneously adds additional benefit to a technician attempting to locate particular anomalies with multi-conductor cables.

Abstract: A sensor apparatus (1) designed for industrial applications is provided for transmitting electrical pulses from a signal line (2) into and out of a vessel to measure a process variable, which has a low outer diameter, preferably of 1½″ or lower, while providing high mechanical stability and maintaining a high degree of transmission efficiency.

Abstract: A system for measuring power of a circuit on a printed circuit board (PCB) including first and second circuits, a power strip, a power plane, and a calibration strip. The power strip is connected to the power plane to the first circuit, is embedded in the PCB during the manufacturing process, and also has at least two vias for measuring a voltage drop. The calibration strip is also embedded in the PCB during the manufacturing process and has at least two vias for measuring a voltage drop. The second circuit is configured to measure a voltage drop across the power strip as a first voltage and a voltage drop across the calibration strip as a second voltage, and to calculate the power being fed to the first circuit based on the first voltage and the second voltage.

Abstract: A sensor system for use with time domain reflectometry systems to allow measurement of relative proportions of intermixed constituents having differing electrical permittivities contained in a fluid mixture. The sensor has at least one primary electrode and one secondary electrode which are spaced apart across a flow channel. One electrode is connected to a first conductor carrying the active time domain reflectometry signal pulse. The other electrode is connected to the passive or ground conductor which carries any reactive signal resulting from the active signal. A fluid mixture of variable proportions will demonstrate a variable dielectric constant which affects the reflected signals sensed by the time domain reflectometer.

Abstract: A method and a communications device are described, comprising a radio telephone (5) with connected antenna path (1) which can be used to locate precisely a defective area (F) in the antenna path (1) in order to be able to repair the antenna path (1) in a selective fashion. For this purpose, initially a wave with a starting frequency (f0) is coupled into the antenna path (1), and the amplitude of the standing wave at an angular position is measured. Then, the frequency of the wave is increased until a corresponding amplitude is detected at the same angular position. From the frequencies present then and from a reading (n) which indicates how often the corresponding amplitude has been obtained, the fault interval (Ed) between the detector (18) and defective area (F) is then calculated.

Abstract: A method and apparatus of detecting termites in which microwaves are transmitted into a region and reflected microwaves are detected. The received signals are processed to identify the presence or otherwise of termites or other insects. Various hardware configurations and signal processing algorithms are described including planar antenna arrays and neural net signal processing. The system comprises a microwave assembly, modulator and a processor. Microwaves are transmitted into a structure and the reflected microwaves are received in the microwave assembly. The output of the processor is displayed on a display.

Abstract: An apparatus for measuring a voltage standing wave ratio of a base station. The apparatus comprises: a unit for measuring the voltage standing wave ratio of a transmitting terminal by coupling an input signal from the base station, and by comparing the difference of the coupled signal and a signal reflected from a transmitting antenna; and another unit for measuring the voltage standing wave ratio of a receiving terminal by comparing an input signal from a base-station test unit with the signal reflected from a receiving terminal.

Abstract: The present invention discloses a harmonic rejection load pull tuner. The tuner of the invention has a large-band tuner having an input and an output, and a transmission line having a longitudinal axis. The transmission line has an input connected to the output of a DUT and an output connected to the input of the large-band tuner. In parallel with the transmission line is at least one stub, the at least one stub having a length adapted to reflect out an nth order harmonic of a base frequency, where n is an integer greater than 1. The tuner of the present invention can be used to perform input or output characterisation (or both) of a DUT, by selectively reflecting out at least one harmonic frequency of the base frequency. Consequently, the characterisation of the DUT is improved, since the effects of the harmonics are considerably reduced. The present invention also concerns a method for performing input or output characterisation.

Abstract: This invention provides apparatus for and a method of locally or remotely monitoring a number of geophysical and other variables related to the refractive index of materials, e.g., soil and pavement moisture content; the moisture content of bulk food products such as grains and beans; liquid levels in storage tanks; interface levels between water and floating layers of oil; the thickness of ice layers; the water/ice interface in partially frozen ground; the location of liquid and gas leaks on roofs, in landfill liners, geosynthetic membranes, and pipelines; and the cables. The detection technique is based on the reflection of frequency-modulated continuous waves during their propagation along transmission line probes embedded in the material being tested.

Abstract: A method and tool using a continuous electromagnetic wave from a transverse magnetic-dipole source with a coaxial electric-dipole receiver is described for the detection of external sidewall cracks and other anomalies in boiler tubes and other enclosures. The invention utilizes the concept of radar backscatter rather than eddy-currents or ultrasound, which are sometimes used in prior art crack-detection methods. A numerical study of the distribution of the fields shows that the direct transmission from the source to the receiver is reduced from that in free space. Further, if the diameter of the receiver dipole is made sufficiently small, it should be possible to detect cracks with a scattering loss of up to −40 dB in thin-walled boiler tubes.

Abstract: The stopping of a load suspended from a crane requires a swing control or, respectively, a swing damping. Upon employment of microwave measuring units, spacings between a carrying cable suspension and a load suspension point are determined on the basis of transit time measurements. The position of the load suspension point can be determined from the transit time measurements quickly and with high precision. Swinging motions are avoided by controlled opposing control of the carrying cable suspension.

Abstract: This level measuring instrument which operates with microwaves, has a radiation characteristic with a pronounced forward lobe and can be used to transmit and/or receive microwaves with a large frequency bandwidth. A housing section is designed as a waveguide short-circuited at one side and one end by a rear wall, and is virtually completely filled with an insert made of a dielectric. An exciter element, projects into the housing section and is connected to a microwave source. An antenna adjoins the housing section, for transmitting and/or receiving microwaves. A gap is arranged in the insert between the exciter element and the antenna. The gap forms a filter which is essentially non-transparent to higher modes of the waveguide.

Abstract: The bulls-eye mid-frequency impedance probe has probe electrodes of a larger surface area that conform to the test surface to provide a very low impedance coupling between the probe and surface, unlike other open end coaxial probes. This probe provides accurate measurement of the dielectric properties of dielectric materials in the mid-frequency range of 10 MHz to 1 GHz on flat and curved solid surfaces, while conforming simple or complex curved surfaces by providing a resilient means between the probe contact surface and the probe box.

Abstract: The method for measuring the thickness of a material which transmits a detectable amount of microwave radiation includes irradiating the material with coherent microwave radiation tuned over a frequency range. Reflected microwave radiation is detected, the reflected radiation having maxima and minima over the frequency range as a result of coherent interference of microwaves reflected from reflecting surfaces of the material. The thickness of the material is determined from the period of the maxima and minima along with knowledge of the index of refraction of the material.

Abstract: Disclosed is a low power time domain reflectometry radar (LPTDRR) level transmitter for calculating levels of first and second products in a tank. A termination extends into the first and second products in the tank. A pulse generator transmits a pulse along the termination into the first and second products. A pulse receiver receives first and second reflected wave pulses corresponding to reflection of a first portion of the transmit pulse at a first product interface and reflection of a second portion of the transmit pulse at a second product interface, respectively. A threshold controller generates a first threshold for detection of the first reflected wave pulse and a second threshold for detection of the second reflected wave pulse. A dielectric constant calculator determines a dielectric constant of the first product as a function of the first reflected wave pulse. A level computer calculates levels of the first and second products.

Abstract: A composite tool and instrument is configured as a hammer having a metal striking head electrically coupled to capacitive sensing electronics disposed in a handle of the hammer. The head can thus serve as a sensing plate portion of a capacitive sensor responsive to a change in the effective dielectric constant of a building surface caused by the proximity of a structural member hidden behind that surface. The head can also serve as a sensing electrode portion of a sensor used to sense the proximity of AC power lines hidden behind the surface. In a preferred composite tool, the hammer has a handle made of an electrically insulating polymeric material and has an electrical conductor axially threaded through the handle so as to electrically couple the striking head to sensing electronics located in a cavity at the end of the handle distal from the head.

Abstract: An arrangement for measuring the liquid level in a tank. The arrangement has a microwave transmitting/receiving device and a waveguide that extends into the tank for guiding a coupled-in microwave. The waveguide has clear and constant wave propagation characteristics for a wave with the operating frequency.

Abstract: A system for point-level detection of material within a vessel includes a transmission line probe adapted to be mounted to a wall of the vessel so as to extend within the vessel for contact with material when the material reaches a preselected level within the vessel. Electronics are operatively coupled to one end of the probe for launching microwave energy along the probe. The electronics are responsive to a change in microwave energy reflected from the free end of the probe within the vessel when the material is in contact with the probe, employing time-domain reflectometry techniques, for indicating that the material is in contact with the probe. This change in reflected microwave energy may comprise a change in phase or, more preferably, a change in apparent length of the probe resulting from contact with material having a higher dielectric constant than that of air when air surrounds the probe.

Abstract: Targeted portions of material layered structure is probed by microwave radiation focussed onto the targeted portion by adjustment of antenna position and orientation establishing a single oblique incidence path for reflection of antenna emitted probing radiation. Signal measurements of the radiation along the oblique incidence path is obtained to provide for evaluation and detection of defects in the targeted portion of the structure being probed.

Abstract: A self calibrating method and apparatus for measuring butterfat and protein content based on measuring the microwave absorption of a sample of milk at several microwave frequencies. A microwave energy source injects microwave energy into the resonant cavity for absorption and reflection by the sample undergoing evaluation. A sample tube is centrally located in the resonant cavity passing therethrough and exposing the sample to the microwave energy. A portion of the energy is absorbed by the sample while another portion of the microwave energy is reflected back to an evaluation device such as a network analyzer. The frequency at which the reflected radiation is at a minimum within the cavity is combined with the scatter coefficient S.sub.11 as well as a phase change to calculate the butterfat content in the sample. The protein located within the sample may also be calculated in a likewise manner using the frequency, S.sub.11 and phase variables.

Abstract: A sensor system for use with time domain reflectometry systems to allow measurement of relative proportions of intermixed constituents having differing electrical permittivities contained in a fluid mixture. The sensor comprises at least one primary electrode and one secondary electrode which are spaced apart across a flow channel. One electrode is connected to a first conductor carrying the active time domain reflectometry signal pulse. The other electrode is connected to the passive or ground conductor which carries any reactive signal resulting from the active signal. A fluid mixture of variable proportions will demonstrate a variable dielectric constant which affects the reflected signals sensed by the time domain reflectometer.

Abstract: An improved time domain reflectometer (TDR) includes a capacitor coupled in series between a transmission medium under test and the TDR receiver input. A switch, operating under microprocessor control, selectively couples and uncouples the capacitor to a voltage reference, such as ground. During the generation of interrogating pulses from the TDR and the acquisition of data from the transmission medium under test, the capacitor is uncoupled from the voltage reference and acts as a DC blocking capacitor. During periods of non-TDR activity, the capacitor is coupled to voltage reference and acts as a load for low frequency interference appearing on the transmission medium. The capacitor-switch operation blocks low frequency interference signals from the receiver input of the TDR.

Abstract: An apparatus for detecting and monitoring scouring of a bed of sediment bath a body of water uses time-domain reflectometry (TDR) to measure the level of sediment adjacent to underwater sensors. The apparatus includes an electrical pulse generator which produces and intermittently transmits a series of electrical pulses along a permanent transmission line arranged adjacent to the area of concern, a timer to measure the travel time of the pulses within the transmission lines, a transmitter for transmitting a radio signal corresponding to the travel times of the pulses, a receiver for receiving the signal, and a signal analyzer which interprets the signal to determine a measurement of scouring. Knowledge of the position of the interfaces before and after a scouring event and the dielectric constants of the surrounding media allows the user to detect and monitor the level of erosion caused by scouring.

Abstract: A method and apparatus for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable for a material in a vessel. The method includes the steps of determining an initial reference signal along a probe, storing the initial reference signal as an active reference signal, periodically detecting a TDR signal along the probe in the vessel, and computing the output result using the TDR signal and the active reference signal. The method also includes the steps of determining an appropriate time for updating the active reference signal, automatically computing an updated reference signal at the appropriate time, and overwriting the active reference signal with the updated reference signal for use in subsequent computations of the output result.

Abstract: Pulse propagation analysis to ascertain whether and anomaly such as surface corrosion exists on a section of conductive member such as pipe. Anomalies such as surface corrosion result in localized velocity changes of pulses propagating along a conductive member. These localized velocity changes exhibit themselves in changes in waveform, rise and fall time, amplitude, and time delay of a pulse with respect to a fixed time reference. To allow such anomalies to be located, two pulses are generated such that they intersect at intersecting locations along the conductive member. The resulting modified pulses are analyzed for perturbations indicative of localized velocity changes.

Abstract: A method of measuring a width of an undoped or lightly doped polysilicon line is disclosed. The width measuring method includes generating carriers in the polysilicon line with an energy source; measuring a capacitance between the polysilicon line and a substrate separated from the polysilicon line by a dielectric layer; and determining a line width of the polysilicon line from the measured capacitance. The capacitance measurement includes connecting first and second probes to the polysilicon line; connecting a third probe to the substrate; connecting a first terminal of a capacitance meter to the first and second probes; connecting a second terminal of the capacitance meter to the third probe; and applying a direct current bias across the first and second probes. A capacitor may be connected between the first and second probes. Further steps include, connecting a fourth probe to a conductor that supports the substrate; and connecting the fourth probe to the third probe.

Abstract: A system for and method of electromagnetically detecting an embedded dielectric region within a target object are provided. The method includes the steps of: (i) selecting a target object including a plurality of discrete scattering mediums, wherein the plurality of discrete scattering mediums include the embedded dielectric region and an adjacent dielectric region, and wherein the plurality of discrete scattering mediums define at least one dielectric interface between the embedded dielectric region and the adjacent dielectric region; (ii) directing electromagnetic radiation at the target object, wherein the electromagnetic radiation is characterized by a diagnostic frequency that is varied incrementally over a diagnostic frequency band; (iii) detecting electromagnetic radiation reflected by the target object over the predetermined frequency band such that there are M measurements of a reflected electromagnetic signal at frequencies f.sub.1, f.sub.2, . . . , f.sub.

Abstract: The stopping of a load suspended from a crane requires a swing control or, respectively, a swing damping. Upon employment of microwave measuring units, spacings between a carrying cable suspension and a load suspension point are determined on the basis of transit time measurements. The position of the load suspension point can be determined from the transit time measurements quickly and with high precision. Swinging motions are avoided by controlled opposing control of the carrying cable suspension.

Abstract: Electromagnetic waves are driven in the pipe to be inspected in the piping system by a transmitting antenna of a transmitter, to be propagated in the pipe; while a receiving antenna of a receiver is moved outside the pipe along the pipe, to receive leaking electromagnetic waves for inspecting elements of the piping system, and the location concerned of each element of the piping system to be inspected is detected in reference to the location of the receiving antenna where the level of electromagnetic waves received by the receiver becomes a peak. The locations to be inspected are the damaged portions such as holes formed by corrosion, cracks, etc. in the pipes, and the locations of joints, etc. It is also possible to move the transmitting antenna outside along the pipe, while arranging the receiving antenna at proper place in the pipe. Furthermore, it is also possible to move both the transmitting antenna and the receiving antenna in synchronization to effect the above inspection.

Abstract: A system for determining the position of a piston moveable within a cylinder, or of an implement or joint, is disclosed herein. Electromagnetic (EM) bursts such as ultra-wideband or frequency pulses are generated and applied to a transmitter/receiver unit. The EM bursts are launched by the transmitter via a focusing antenna assembly from an end of the cylinder housing towards the piston. The fluid in the cylinder housing is in electrical communication with the piston such that a surface of the piston represents an electrical impedance discontinuity which causes the EM bursts to be reflected back to the receiver. The time for the EM bursts to travel from the transmitter to the piston and for the reflections to travel back to the receiver via the antenna assembly is determined and converted into a position signal representing the piston's position. A compensation signal can be used to compensate the position signal for variations in a parameter of the fluid within the cylinder.

Abstract: Frequency domain reflectometer and method of locating faults in a transmission line utilized by the reflectometer are disclosed. The reflectometer suppresses harmonics that may be interpreted as faults that in actuality do not exist. In general, the reflectometer applies a sweep signal to the transmission line in order to obtain a reflected sweep response signal. Then, the reflectometer obtains a sweep response spectrum from the reflected sweep response signal. The reflected sweep response signal includes a plurality of spectral peaks which represent the frequency components of the reflected sweep response signal. Then, the reflectometer mathematically determines which spectral peaks of the reflected sweep response spectrum were generated due to harmonics in the reflected sweep response signal.

Abstract: A system for determining the position of a piston moveable within a cylinder, or of an implement or joint, is disclosed herein. Electromagnetic (EM) bursts such as ultra-wideband or frequency pulses are generated and applied to a transmitter/receiver unit. The EM bursts are launched by the transmitter along a transmission guide from an end of the cylinder housing towards the piston. The transmission guide can be a dipstick mounted within the cylinder housing or the cylinder housing itself. The dipstick or cylinder housing is in electrical communication with the piston such that a surface of the piston represents an electrical impedance discontinuity which causes the EM bursts to be reflected back to the receiver. The time for the EM bursts to travel from the transmitter to the piston and for the reflections to travel back to the receiver is determined and converted into a position signal representing the piston's position.

Abstract: Method and device for indicating movements of gas bubbles in a liquid, droplets of liquid in a gas or a level of liquid, the liquid or the gas forming a medium in a conduit (15) or a container. Microwave signals of a predetermined frequency are transmitted through a section (G) of the conduit (15) or the container (16) that is pervious to microwaves toward said medium, and microwave signals reflected from the medium are received. Received microwave signals are then utilized to indicate presence of gas bubbles, droplets, or a level of a liquid moving in said conduit (15) or said container (16).Said conduit (15) is designed with a section (G) that is pervious to microwaves, and a microwave transmitter (S) is provided to transmit microwave signals towards said section (G). A microwave receiver (M) is provided to receive microwave signals that are reflected from the medium, and said microwave receiver (M) is operatively connected to a detector (6).

Abstract: A vector network analyzer (VNA) has a first harmonic generator multiplying an RF signal by an odd number M1 to produce incident and reflected test signals received at inputs of mixers providing IF signals. A second harmonic generator multiplies an LO signal by an odd number M2 offset by 2 from M1 to provide signals to additional inputs of the mixers providing IF signals. With the harmonic generators providing odd harmonics separated by 2, a single filter removes remaining harmonics from IF signals provided from each mixer. Each harmonic generator includes two step recovery diodes (SRDs) with opposing ends connecting the signal path to ground, the SRDs functioning to cancel even harmonics. A first coupler provides the output of the first harmonic generator to the mixers, the first coupler having a minimal size enabling its output power to increase with frequency.

Abstract: A process for detecting totally or partially hidden faults, such as cracks, and bubbles and the like in an opaque medium, by using microwave radiation. Microwaves from a transmitting antenna are directed against the surface of the medium which is to be inspected, and microwave radiation reflected or back scattered from the medium is detected and analyzed. In order to maximize the signal to noise ratio, minimizing the detection of radiation reflected by the surfaces of the medium itself, at least one of the transmitting antenna and the receiving antenna is oriented at an oblique angle relative to the surface of the medium.

Abstract: A non-destructive and non-invasive method for monitoring a selected characteristic of a fabricated semiconductor sample while inside a fabrication chamber and during the fabrication process, where selected materials are deposited on a planar surface of a wafer substrate in a fabrication chamber, employs one or more viewports in the walls of the fabrication chamber. A focused electromagnetic wave is generated external to the fabrication chamber, and directed through a viewport to impinge upon a selected portion of the planar surface of the wafer substrate at an oblique incident angle relative to the planar surface of the wafer substrate. In turn, a reflected electromagnetic wave emanating from the planar surface of the wafer substrate is detected. A signal processor then determines a reflection coefficient as a function of a selected characteristic of the focused electromagnetic wave and the reflected electromagnetic wave.

Abstract: A waveguide for microwave radar level gages that includes a process sealed barrier in the waveguide that is impedance matched with bore transition sections of the waveguide at opposite ends thereof. The impedance matching results in positioning of the tapered end of the barrier offset from the ends of the bore transition sections.

Abstract: A device for measuring electromagnetic radiation absorption of a test surface includes an electromagnetic transceiver, an x-y axis positioning mechanism, and a z axis positioning mechanism. The x-y axis positioning mechanism facilitates mapping of electromagnetic radiation absorption at different locations upon the test surface and the z axis positioning mechanism enhances the accuracy of electromagnetic radiation measurements by facilitating phase matching of electromagnetic radiation transmitted by the electromagnetic transceiver with electromagnetic radiation received thereby.

Abstract: An electromagnetic, reflective type, active proximity sensor includes a transmitter, the transmitter including a voltage controlled oscillator circuit, a transmitter circular waveguide and a transmitter polarization circuit. The voltage controlled oscillator circuit generates an output signal which is modulated such that the frequency of the output signal varies over time between a range of frequencies. The frequency varying, output signal is provided to the transmitter circular waveguide and propagated to the transmitter polarization circuit where it is circularly polarized in a first circular direction. The circularly polarized, frequency varying, output signal is radiated by the transmitter to the target, where it strikes the target and reflects back toward the sensor to form return signals. The return signals, upon being reflected, rotate in a second circular direction opposite to the first circular direction.

Abstract: A device utilizes micropower, impulse radar and time domain reflectometry to determine the dielectric constant of a fluid. An electrically conductive probe preferably in the form of a transmission line, is inserted at least partially into the fluid. The device includes a signal generator that generates an impulse signal that is propagated along the probe. The time that it takes for the signal to reach the end of the probe is determined. The time of travel of the signal along the probe is then used to determine the dielectric constant of the fluid.

Abstract: A millimeter wave sensor is provided for non-destructive inspection of thin sheet dielectric materials. The millimeter wave sensor includes a Gunn diode oscillator (GDO) source generating a mill meter wave electromagnetic energy signal having a single frequency. A heater is coupled to the GDO source for stabilizing the single frequency. A small size antenna is coupled to the GDO source for transmitting the millimeter wave electromagnetic energy signal to a sample material and for receiving a reflected millimeter wave electromagnetic energy signal from the sample material. Ferrite circulator isolators coupled between the GDO source and the antenna separate the millimeter wave electromagnetic energy signal into transmitted and received electromagnetic energy signal components and a detector detects change in both amplitude and phase of the transmitted and received electromagnetic energy signal components.

Abstract: An apparatus and a method for determining the cure state of thermosetting polymers using time domain reflectometry. A miniature capacitor is constructed at the end of a coaxial transmission line which is immersed in the curing polymer so that the polymer is the dielectric of the capacitor, and step function voltage pulses are fed to the transmission line, while the reflected signal from the line is monitored. The amplitude and decay characteristics of the reflected signals, which are related to the degree of cure and the viscosity, respectively, are fed to a computer for interpretation and display.

Abstract: Microwave radiation emitted from a single antenna is focused on a targeted material from which reflected radiation is received by the same antenna to provide signal measurement data from which detected material defects are evaluated by determination of void location and size. Antenna position and orientation is adjusted to obtain the signal measurement data from of the microwave radiation reflection along at least two target incidence paths from the same target location, one of which is normal to said targeted surface of the material and the other oblique thereto at a scattering angle at which the signal radiation intensity is minimized.