Abstract: A tissue-sensing adaptive radar method of detecting tumours in breast tissue uses microwave backscattering to detect tumours which have different electrical properties than healthy breast tissue. The method includes steps for reducing skin reflections and for constructing a three-dimensional image using synthetic focusing which shows the presence or absence of microwave reflecting tissues.

Abstract: The present invention relates to a device for analyzing the composition of the contents of a receiver comprising: means (40) for emitting/receiving an electromagnetic field at a variable frequency over a determined frequency range, means (22) for supporting a container (R), the contents of which should be analyzed, adapted in order to provide relative accurate positioning between the emitting/receiving means (40) and the container (R), means (50) capable of measuring the complex impedance of the emitting/receiving means influenced by the load formed by the container (R) and its contents, representative of the complex dielectric characteristics of the container and of its contents, and means (50) capable or providing a piece of information related to the measured complex impedance and consequently to the nature of the contents of said container.

Abstract: A signal conductor whose first end is an open end, and a ground conductor are connected to associated measurement ports of a network analyzer. A short standard is connected between the signal conductor and the ground conductor at least three points in the longitudinal direction of the signal conductor, and electrical characteristics are measured, thereby calculating error factors of a measurement system including a transmission line. An electronic device to be measured is connected between the signal conductor and the ground conductor, and an electrical characteristic is measured. The error factors of the measurement system are removed from the measured value of the electronic device to be measured, thereby obtaining a true value of the electrical characteristic of the electronic device. Accordingly, a highly accurate high-frequency electrical characteristic measuring method, using a reflection method, that is not affected by connection variations can be implemented.

Abstract: The invention relates to a device for analyzing the composition of the contents of a container, comprising: electromagnetic field emitting/receiving means (40) at least several frequencies comprised in a determined range of frequencies, means (22) supporting a container (R), the contents of which have to be analyzed, suitable for ensuring accurate relative positioning between the emitting/receiving means (40) and the container (R), means (50) capable of measuring the complex impedance of the emitting/receiving means influenced by the load formed by the container (R) and its contents, representative of the complex dielectric characteristics of the container and of its contents, means (53, 55) for obtaining at least one additional physical datum relating to a characteristic of the container (R), and means (50) capable of providing information relating to the nature of the contents of said container (R) depending on the measured complex impedance and on the additional physical datum

Abstract: The present invention provides for an improved scanning process having microwave arrays comprised of microwave transmitters in radiographic alignment with microwave receivers. The microwave array emits controllably directed microwave radiation toward an object under inspection. The object under inspection absorbs radiation in a manner dependent upon its metal content. The microwave radiation absorption can be used to generate a measurement of metal content. The measurement, in turn, can be used to calculate at least a portion of the volume and shape of the object under inspection. The measurement can be compared to a plurality of predefined threats. The microwave screening system can be used in combination with other screening technologies, such as NQR-based screening, X-ray transmission based screening, X-ray scattered based screening, or Computed Tomography based screening.

Abstract: Non-invasive THz spectroscopic apparatus and methods are provided for detecting and/or identifying constituents such as variations in a structural entity where chemical or biological entities can reside. Position dependent scattering of THz radiation is employed to image voids and defects in the internal structure of samples, enabling the determination of contamination, spoilage or readiness of products such as wine in sealed containers.

Abstract: The present invention relates to a device for analyzing the composition of the contents of a receiver comprising: means (40) for emitting/receiving an electromagnetic field at a variable frequency over a determined frequency range, means (22) for supporting a container (R), the contents of which should be analyzed, adapted in order to provide relative accurate positioning between the emitting/receiving means (40) and the container (R), means (50) capable of measuring the complex impedance of the emitting/receiving means influenced by the load formed by the container (R) and its contents, representative of the complex dielectric characteristics of the container and of its contents, and means (50) capable or providing a piece of information related to the measured complex impedance and consequently to the nature of the contents of said container.

Abstract: Bi-directional (longitudinal and angular) three-dimensional volumetric microwave scanning of a whole roll or pallet of paper (FIGS. 3, 4), including three-dimensional volumetric mapping of internal properties and characteristics (moisture content, density, material uniformity, defects and types thereof, and variabilities thereof) of the roll or pallet of paper. Transmitted microwaves propagate through longitudinally and angularly defined portions of individual cross-sectional volumetric segments of the roll or pallet of paper. Microwave parameters (amplitude, phase) are perturbed by, and are a function of the internal properties and characteristics of, the contents of volumetric segment portions of the roll or pallet of paper. Microwave differential parameters (amplitude attenuation, phase shift) are calculated and used for calculating and determining values, relationships, two-dimensional graphs and maps, and, three-dimensional volumetric graphs and maps (FIGS.

Abstract: An interface detection apparatus detects a position of a hidden interface between first and second materials, the first material having a different physical property from the second material. The apparatus encompasses (a) an irradiation mechanism configured to irradiate an electromagnetic wave onto a sample implemented by the first and second materials, (b) a detection mechanism configured to detect the electromagnetic wave that has passed through the sample, and (c) a traveling mechanism configured to change the relative position of the hidden interface with respect to the position of the detection mechanism.

Abstract: An inspection apparatus for acquiring information on a measurement object using electromagnetic waves, comprising a substrate; a transmission line that is formed on the substrate; an electromagnetic wave generating unit for supplying an electromagnetic wave to the transmission line; an electromagnetic wave detecting unit for detecting the electromagnetic wave that has propagated through the transmission line; and a walled structure. The walled structure includes a side wall portion that extends along the transmission line within a region in which the electromagnetic wave that propagates through the transmission line and the measurement object interact with each other.

Abstract: The present invention relates to measurement of conductivity. A microwave oscillated by an oscillator using a Gunn diode is applied through an isolator, a circulator, and a horn antenna to a silicon wafer. The isolator is used for reducing the standing wave influencing the operation of the instrument. The reflected wave is received by the same horn antenna, detected by a detector connected to the circulator, and outpufted in the form of a voltage. The detector produces an output voltage proportional to the square of the amplitude of an electric field. Since the amplitude of the reflected wave from a silicon wafer is proportional to the absolute value of the reflectance, the output voltage is also proportional to the square of the absolute value of the reflectance. The reflectance is in a certain relationship with the conductivity, the conductivity of the silicon wafer can be determined.

Abstract: A system and method for inspecting a composite structure, such as to assess thermal degradation or resin curing, are provided in which the dielectric constant of the composite structure is determined using a microwave inverse scattering technique. The dielectric constant of the composite structure may be compared to the dielectric constant of one or more sample structures to determine the presence of thermal degradation or improper curing in the structure. In this regard, a system for inspecting a composite structure comprises a transmitter, a receiver, and a controller. The transmitter may be capable transmitting microwave energy directed toward the structure. The receiver may be capable of receiving microwave energy scattered from the structure. The controller may be capable of determining a dielectric constant of the structure using an inverse scattering algorithm and comparing the dielectric constant of the structure to a dielectric constant of at least one sample structure.

Abstract: A damage detection system includes a processor and a transmitter communicatively connected to the processor. The transmitter sends a signal to the processor and the processor is programmed to assign a spatial coordinate to the transmitter. The processor is further programmed to identify a transmitter location as damaged when the transmitter fails to send the signal. The damage detection system may analyze the damaged area and report potentially affected sub-systems to users of a machine or vehicle equipped with the damage detection system.

Abstract: An inspection apparatus including a transmission line for propagating an electromagnetic wave; an electromagnetic wave supply unit for supplying a terahertz wave to the transmission line; an electromagnetic wave detection unit for detecting the terahertz wave from the transmission line; a conductive region; an inspection object supply unit; and a deposition unit. The conductive region is arranged at a site including at least a part of the range to which an electric field distribution of the electromagnetic wave propagating through the transmission line extends. The inspection object supply unit holds and supplies the inspection object to the outside, and the deposition unit deposits the inspection object selectively on the conductive region by electrostatic force. The electromagnetic wave supplied from the electromagnetic wave supply unit and propagated through the transmission line is detected by the electromagnetic wave detection unit to obtain information on the inspection object.

Abstract: A dielectric constant waveguide measuring apparatus preferably comprises a rectangular waveguide aperture on each end with a width a and height b. The waveguide frame is preferably split to permit the waveguide to be opened for insertion of the unknown material into a middle reduced cross-sectional area portion of the waveguide frame. In one embodiment, a metal septum is inserted between two samples of the unknown material to thereby reduce the cross-sectional area of the waveguide aperture by splitting width a of the rectangular waveguide in half. The waveguide frame is closed and a frequency response of the waveguide is then measured. The dynamic dielectric constant of the unknown material is determined from the frequency of the lowest order minimum value of the frequency response of the waveguide apparatus wherein the unknown material has been inserted.

Abstract: Provided are an analysis method and an analysis apparatus that can perform analysis of a substance and information obtainment with relatively high accuracy and reproducibility without previously allowing a carrier to carry a reagent for a color reaction. In the analysis method and the analysis apparatus, the information on an analyte is obtained by using an electromagnetic wave of a frequency including a frequency band which is at least a part of a frequency range of 30 GHz or more and 30 THz or less. A non-fibrous, isotropic porous material is allowed to hold the analyte, the analyte held by the porous material is irradiated with the electromagnetic wave, a change in the propagation state of the electromagnetic wave due to transmission through or reflection by the porous material is detected and information on the analyte is obtained based on the result of the detection.

Abstract: The disclosed technology can be used in the development and operation of multistatic probes that can characterize substances and relationships between substances. A multistatic probe can include transmitting and receiving conductive elements that are electrically distinct and which are capable of conveying electromagnetic energy to/from a substance of interest. The transmitting and receiving conductive elements can be arranged to be in contact with at least one dielectric mismatch boundary between substances of interest, whereby an electromagnetic signal transmitted on the transmitting conductive element causes a corresponding electromagnetic signal to be coupled to the receiving conductive element in response to the transmitted signal being in proximity to the dielectric mismatch boundary.

Abstract: The field of the invention is that of devices for detecting non-metallic objects concealed on human subjects. These devices are more particularly dedicated to the surveillance and protection of reserved access areas, such as airport areas. The device according to the invention comprises a portable detector comprising a transmitter and a receiver of microwave frequency signals disposed in an enclosure of chaotic geometry including a plurality of measurement holes. The microwave frequency signal measured by this detector depends on the nature of the objects disposed under the holes. A processing device linked to this detector is used to correlate the measured signals with prerecorded signals. When the correlation exceeds a certain threshold corresponding to the presence of suspect objects, an alarm is generated.

Abstract: A particulate sensing system for a particulate trap including a radio frequency transmit circuit and a radio frequency receive circuit is disclosed. The transmit circuit may include a wideband signal generator configured to produce a wideband radio frequency signal and a wideband radio frequency amplifier, coupled to the wideband signal generator. The transmit circuit may include a transmit antenna coupled to the wideband radio frequency amplifier and configured to propagate the wideband radio frequency signal through a filter medium. The receive circuit may include a receive antenna configured to receive the wideband radio frequency signal that has been propagated through the filter medium, and a bandpass filter coupled to the receive antenna and configured to limit a frequency range of the received wideband radio frequency signal.

Abstract: Systems and methods for evaluating electromagnetic interference that may be employed, for among other things, to evaluate electronic system immunity to radiated electromagnetic fields and/or to identify particular electronic system areas that are susceptible to electromagnetic radiation.

Abstract: A two-port S-parameter calibration between a first port and a second port of a test system having a multi-port vector network analyzer is performed to provide a first S-parameter calibration of the test system. A transfer device is connected between the first and second ports of the test system. A port of the test system is changed to provide a second state of the test system, and a plurality of ratioed un-corrected parameters of the transfer device are measured with the test system in the second state. A second S-parameter calibration of the test system in the second state is determined using the ratioed un-corrected parameters and S-parameter data.

Abstract: Embodiments cause interaction of an ultra-wide band signal with a substance over a broad range of frequencies simultaneously to obtain a response signal whose distortion is indicative of a composition of the substance.

Abstract: An apparatus and method for analysing an amount of at least one component in a sample (21) by measuring a microwave signal (13) that has passed at least partially through the sample (21), the apparatus comprising: a microwave generator that generates a continuous linear sweeping microwave signal varying in frequency, a microwave transmitter (11), a microwave receiver (12), at least one microwave analyser that analyses phase shift and/or change in amplitude of a transmitted and received signal (13), a (40) for determining a depth of the sample (21) and a processor that determines the amount of the component(s) in the sample (21) from the microwave analyser.

Abstract: A system and method for detecting soot and or ash loading within a filter is provided. The method comprises the steps of transmitting a source RF signal through a filter, measuring a reflected RF signal, measuring a transmitted RF signal, calculating reflected power by comparing the source RF signal with the reflected RF signal, calculating attenuated power by comparing the source RF signal with the transmitted RF signal, and determining soot loading based on reflected power and transmitted power. The system and method may also determine ash loading.

Abstract: The invention relates to methods and a circuit for increasing the interference resistance of a time frame reflectometer, in particular with respect to high frequency irradiation. A transmitted pulse (XS) is generated at a pulse repeater frequency (fprf) and coupled to a wave guide (4). A return signal (Xprobe) is returned to the wavwguide (4) by a reflector (14) which is connected to said waveguide (4) and is scanned for time-expanded representation as a reflection profile with scan pulses (XA) which are repeated at a scan frequency (fA) and measurement values are continuously calculated from said reflection profiles, expressing the distance from the reflector (14) to the process connection.

Abstract: A method and apparatus are disclosed for determining the concentration of individual components within a fluid mixture by determining the permittivity of the individual components. The method and apparatus use a reference sensor and at least one measurement sensor positioned inside the same sensor device that is immersed in the fluid mixture to be measured. Signals, such as radio frequency or microwave, are sequentially transmitted at multiple, known, constant frequencies to and reflected from both the reference and measurement sensor(s). Permittivities of the individual components are determined from these transmitted and reflected signals and information about the concentration of the individual fluids and other compounds within the fluid mixture and the density of the fluid mixture are produced. Repetitive sampling and processing of these signals allow determination and real-time monitoring of the concentration of individual components within a mixture of fluids.

Abstract: A method and system for non-contact measurements of microwave capacitance of miniature structures patterned on wafers used for production of modern integrated circuits. A near-field balanced two-conductor probe is brought into close proximity to a test key built on a wafer of interest and replicating the miniature structure of interest. The resonant frequency of the probe for the test key is measured. The probe is then positioned at the same distance from an “open” calibration key and “short” calibration key, and the resonance frequencies of the probe for the calibration keys are measured. A shear force distance control mechanism maintains the distance between the tip of the probe and the measured test key and calibration keys. The microwave capacitance of the test key is then calculated in accordance with a predefined formula.

Abstract: A method and apparatus for monitoring a condition having a known relation to, or influence on, the transit time of a cyclically-repeating energy wave moving through a transmission channel, by: (a) transmitting a cyclically-repeating energy wave through the transmission channel from a transmitter at one end to a receiver at the opposite end; (b) continuously changing the frequency of the transmitter according to changes in the monitored condition while maintaining the number of waves in the transmission channel as a whole integer; and (c) utilizing the changes in frequency of the transmitter to provide a continuous indication of the monitored condition. Operation (b) is preferably performed by detecting a predetermined fiducial point in each cyclically-repeating energy wave received by the receiver, but may also be performed by the use of a phase-locked loop circuit, to maintain the number of energy waves in the loop of the transmission channel as a whole integer.

Abstract: An electromagnetic wave is input to a resonator 14 filled with a dielectric and a gas, and a resonance frequency, an insertion loss and a half-power width in the resonance mode of the electromagnetic wave output from the resonator 14 are measured by a network analyzer 16 in response to the input of the electromagnetic wave and the complex dielectric constant of the dielectric is calculated from the resonance frequency, the insertion loss and the half-power width which are thus measured.

Abstract: Narrow pulses transmitted wirelessly from a transmitting antenna to a receiving antenna are used to measure the electrical permittivity of the medium of interest between the two antennas. Timing signals are transmitted along a shielded transmission line coincident with the wireless transmission through the medium. The received waveform is digitized in the time domain and analyzed to determine the propagation time. The effects of dispersion caused by the conductive and dielectric properties of the medium on the transmitted waveform are overcome through analysis of the digitized waveform, resulting in an accurate measurement of the propagation time and thus the permittivity of the medium, from which volumetric moisture content may be derived.

Abstract: The present invention discloses a device for measuring and monitoring electron density of plasma. The device includes a chamber filled with plasma having varying electron density; a frequency probe having transmission/receiving antennas and a pair of waveguides, one end of which is mounted in the chamber, for radiating and receiving electromagnetic waves; an electromagnetic wave generator electrically connected to one of the waveguides of the frequency probe for generating electromagnetic waves; and a frequency analyzer for scanning the frequency of received electromagnetic waves and analyzing the scanned frequency with respect to the amplitude of the received electromagnetic waves. Coupled to the rear end of the frequency probe is preferably a transfer unit having a hydraulic cylinder structure such that the frequency probe is moved in the chamber to detect the spatial distribution of electron density.

Abstract: An improved microwave spectrometer for measuring the concentration of ethylene oxide gas and the concentration of water vapor in one or more gas samples taken from an ethylene oxide sterilization chamber.

Abstract: A radar level gauge for measuring the level of a surface of a product stored in a tank by use of radar. The radar transmits microwaves towards the surface and receives microwaves reflected by the surface and is adapted to transmit and receive microwaves within two widely separated frequency bands. Widely separated frequency bands are chosen to utilize the differences in attenuation due to foam on the surface and the differences in beam-width or other disturbances. The ratio between the center frequencies of the two widely separated frequency bands can be quantified as at least greater than 1.5:1 or preferably greater than 2:1.

Abstract: In a method for monitoring the properties of pharmaceutical articles (2), in particular capsules (2), in a machine (1) that makes the articles (2), the pharmaceutical articles (2) are fed in single file from a station (3) where the articles (2) are made to an article (2) outfeed portion (6) of the machine (1) along a defined feed path (P) passing through an inspection station (8). In the inspection station (8) each pharmaceutical article (2) passes through an electromagnetic field (E) created by microwave radiation.

Abstract: A non-destructive method of detecting and measuring machining induced surface defects on gas turbine engine components is provided. In an exemplary embodiment, the method includes positioning an evanescent microwave microscope probe adjacent a turbine component surface, and scanning the turbine component surface by moving at least one of the evanescent microwave microscope probe and the component surface in an x-y plane while maintaining a predetermined distance between the probe and the component surface constant.

Abstract: Embodiments of the present invention quantify lengthwise shrinkage to a higher degree of accuracy over currently known methods by employing reactive force values, such as stiffness measurements, in conjunction with motive force values, such as chemical composition, of the wood product.

Abstract: Method and apparatus are provided for determining a superstrate on or near a sensor, e.g., for detecting the presence of an ice superstrate on an airplane wing or a road. In one preferred embodiment, multiple measurement cells are disposed along a transmission line. While the present invention is operable with different types of transmission lines, construction details for a presently preferred coplanar waveguide and a microstrip waveguide are disclosed. A computer simulation is provided as part of the invention for predicting results of a simulated superstrate detector system. The measurement cells may be physically partitioned, non-physically partitioned with software or firmware, or include a combination of different types of partitions. In one embodiment, a plurality of transmission lines are utilized wherein each transmission line includes a plurality of measurement cells.

Abstract: A device for electromagnetic characterization of a tested structure elevates, on a predetermined frequency band, distribution parameters of the structure and parameters characteristic of the spurious rays of the structure. The device includes an electric signal generator and an analyzer for analyzing the signal transmitted by the generator and signals reflected by the structure and signals transmitted by the structure. In addition, the electric signal generator is a pulsed signal generator whereof the spectrum is at least as broad as the predetermined frequency band, and the analyzer includes a filter for temporal filtering of the signals it receives, to eliminate spurious signals.

Abstract: A method and apparatus for measuring a predetermined parameter, by providing a displaceable sensor on a mounting member such that the displaceable sensor changes in location, form or length with respect to the mounting member in accordance with the predetermined parameter. A cyclically-repeating energy wave is transmitted to or through the displaceable sensor, and a predetermined fiducial point in the received cyclically-repeating energy wave is detected and used for continuously changing the frequency of the transmitted cyclically-repeating energy wave such that the number of waves received is a whole integer. The change in frequency is used to produce a measurement of the predetermined parameter. Several embodiments are described wherein the displaceable sensor is a deformable membrane, an end wall of a bellows, a spring-mounted member, a displaceable plunger, and a bar changing its length in accordance with the parameter to be measured.

Abstract: A testing device tests a mat that is moved in one direction and that is made of biomass particles for manufacturing boards. On one side of the mat, radiation sources are positioned with a transversely spaced-apart relationship transverse to the direction of motion. On the other side of the mat, a line of detector elements is arranged beneath each of the radiation sources. A fan-shaped beam impinges on said detector elements. The beam passes either through one standard body, through the mat, or through neither the standard body nor the mat and is received by the detector elements and converted into electric output signals. The output signals are transferred via lines to an evaluating circuit that controls a device for removing mat portions that contain unwanted matter or the weight per unit area of which is too low.

Abstract: Disclosed herein is a method of measuring a dielectric constant of a Printed Circuit Board (PCB) for a Rambus Inline Memory Module (RIMM), which includes the steps of measuring a length of a Rambus product of a PCB, applying an input waveform to the Rambus product at a certain probing position and obtaining a cross point of rising times of the input waveform and an output waveform generated by reflection of the input waveform, obtaining time corresponding to the cross point, and calculating a dielectric constant by substituting the measured length of the Rambus product and the obtained time for corresponding variables of a dielectric constant calculating equation.

Abstract: A microwave resonator apparatus (35) includes a microwave resonant cavity (36) in fluid communication chamber (38) are dimensioned to ensure high attenuation of resonant electromagnetic fields without impeding fluid flow. The resonant properties of the cavity (36) are therefore completely insensitive to variations in the volume of the pressure chamber (38). The resonator has a specialised reentrant geometry. Consequently, two of the cavity's resonant modes depend sensitively upon the formation and volume of any liquid phase present in the cavity. The apparatus and the method are suitable for measuring dielectric properties and phase envelope of fluid mixtures (such as a gas condensate fluid). The apparatus can be used for making several phase envelope measurements without risk of contamination.

Abstract: An anechoic test chamber for testing an electromagnetic loss characteristic of a material specimen has first and second opposed and tapered conical sections. The chamber has an anechoic material covering its inside surface. Feed and receive antennas are disposed on the ends of the conical sections. An aperture plate is disposed between the first and second sections. The aperture plate electromagnetically isolates the first and second conical sections except for the aperture itself. A method of determining an electromagnetic loss characteristic of a material specimen utilizes a dual tapered conical chamber for processing S-parameter measurements to determine impedance, complex permittivity, or complex permeability of the specimen.

Abstract: A method and apparatus of measuring a predetermined parameter having a known relation to the transit time of movement of an energy wave through a medium, by transmitting from a first location in the medium a cyclically-repeating energy wave; receiving the cyclically-repeating energy wave at a second location in the medium; detecting a predetermined fiducial point in the cyclically-repeating energy wave received at the second location; continuously changing the frequency of transmission of the cyclically-repeating energy wave from the first location to the second location in accordance with the detected fiducial point of each received cyclically-repeating energy wave received at the second location such that the number of waves received at the second location from the first location is a whole integer; and utilizing the change in frequency to produce a measurement of the predetermined parameter.

Abstract: A system for emitting and detecting terahertz frequency electromagnetic pulses. The system comprises a single transceiver device, which may be an electro-optic crystal or photoconductive antenna, for both emitting and detecting the pulses. A related method comprises using a single transceiver device to both emit and detect electromagnetic terahertz frequency pulses. The transceiver device is excited by a pump pulse to emit a terahertz output pulse, which is modulated with a chopper. An object reflects the terahertz pulse and the reflected pulse is detected in the transceiver using a probe pulse. A lock-in amplifier set to the same frequency of the chopper is used to reduce noise in the signal detected by the transceiver. An image of the object may be created using the intensity or the timing of the peak amplitude of the terahertz pulses reflected from the object.

Abstract: A method of determining at least one characteristic of one or more security documents such as banknotes, each security document including a sheet-like substrate of plastics material and opacifying layers applied to opposing faces of the substrate, the method comprising the steps of:(a) projecting radiation from a radiation source into the substrate of each security document for propagation therein, the opacifying layers acting to guide the projecting radiation within the substrate; (b) detecting a radiation emission of the substrate of each security document, the radiation emission resulting from the propagated radiation; and (c) analysing one or more characteristics of the radiation emission.

Abstract: A load-pulled oscillator circuit in which RF blocking on the power supply connections is achieved by an active stage rather than an inductor. This avoids the problems of temperature dependence, low-frequency oscillation, and backward tuning which can occur when using an inductor in a load-pulled oscillator.

Abstract: Briefly, a system that may be used to provide characteristics of a signal propagation medium.

Abstract: A device and method for detecting the presence of insects in a structure utilize a plurality of transceivers, each of which generates separate and distinct microwave signals and receives separate and distinct signals reflected from a structure being tested. The reflected signals received by each of the transceivers are processed, for instance by a microprocessor, so as to provide output signals that indicate the presence or absence of insects in the structure. If most or all of the transceivers receive positive signals indicative of the possible presence of insects in the structure, which is a false indication of the presence of insects, the microprocessor distinguishes this false indication from an actual indication of the presence of insects, thereby enabling the detection of insects despite the existence of motion signals caused by non-insect motion.

Abstract: The invention is a device for inspecting an assembly including a surface coating containing magnetic radar-absorbing materials on a conductive surface. In detail, the device includes a first system for transmitting an electromagnetic signal to the assembly, which includes a first waveguide made of a conductive material coupled in series to a second waveguide made of a dielectric material. A second system is provided for receiving the portion of the electromagnetic signal reflected from the assembly, which includes a third waveguide made of a conductive material coupled in series to a fourth waveguide made of a dielectric material. Thus the electromagnetic signal is transmitted from the first waveguide to the second waveguide on to the assembly and the portion of the electromagnetic signal reflected off the assembly is received by the fourth-waveguide and transmitted to the third, waveguide.