Abstract: Mismatch detection using periodic structures is provided. Embodiments described herein can measure and detect mismatch between two loads in a radio frequency (RF) system without the need for external calibration by referencing their measurements into a small set of parameters that are intrinsic to the RF system design. This approach can be used to compare impedances of two loads and measure their impedances relative to each other without requiring any external calibration (e.g., the approach does not assume any prior known physical quantities in the system, such as a reference impedance). This approach can be used to compare the two loads to each other, as well as to quantify the amount of mismatch between these loads by calculating reflection coefficient between the loads. Loads can be passive devices, such as antennas, or they can be active devices, such as amplifiers.

Abstract: A multi-field zone proximity sensor (10) for measuring a distance (1) of an object (22) from the multi-field zone proximity sensor (10) The multi-field zone proximity sensor (10) has a housing (12) that includes an antenna structure (14) that is arranged in or close to a side (19) of the housing (12). The antenna structure (14) is set up for emitting an electromagnetic transmission free space wave (20) and for receiving an electromagnetic reflection wave (24) reflected on the object (22). The multi-field zone proximity sensor (10) has sensor electronics (16) which are set up to determine the distance (l) of the object (22) from the multi-field zone proximity sensor (10) based on the received reflection wave (24).

Abstract: The present invention relates to a measuring device for determining the thickness of a dielectric layer on a conductive substrate. The device comprises a resonance cavity for electromagnetic fields which has a rotationally symmetrical wall, an end plate and an open end and is adapted to be positioned with the open end on the dielectric layer. The device further comprises an antenna which is adapted to excite an electro-magnetic field in the resonance cavity, a reflection measuring unit for determining at least one property of the electromagnetic field and an evaluation circuit for determining the thickness of the dielectric layer from the at least one property of the electromagnetic field. A diameter of the rotationally symmetrical wall varies in a longitudinal direction of the resonance cavity.

Abstract: In order to accurately probe a structure of concrete, a series of probe signals with defined carrier frequencies are generated by a probe signal generator and coupled into the structure by an antenna. The returning echo signals are processed by an echo signal receiver. Processing includes phase and amplitude detection in a multiplier, frequency-specific scaling in a scaling unit, replacement of the measured phases and amplitudes in an interpolation unit, and the generation of time-domain data in a Fourier transformation module. The device is robust against RF noise, accurate and low-power.

Abstract: A signal source is described. The signal source comprises a signal generator, a first frequency divider and a second frequency divider. The first and the second frequency divider are each connected to the signal generator. The signal generator is configured to generate a source signal having a source frequency and to selectively forward the source signal to at least one of the first frequency divider and the second frequency divider. The first frequency divider is established as an integer frequency divider and is configured to generate a first output signal from the source signal. The second frequency divider is different from the first frequency divider and is configured to generate a second output signal from the source signal, wherein a phase noise of the second output signal is considerably lower than a phase noise of the first output signal. Moreover, a test system and a method for testing a device under test are described.

Abstract: Signals are transmitted from and to a plurality of terminals. The apparatus has a plurality of signal connections and at least two antenna connections. One signal connection is a main connection or a secondary connection. At least one main connection for each terminal can be connected. The number of signal connections is greater than the number of antenna connections. At least one linking element allows each main connection to be electrically linked to each antenna connection. A device for detecting transmitting activity detects a transmitting main connection based on a signal property of a signal, wherein the signal is present on a signal link section which is linked to the main connection. Signaling links between the signal connections and the antenna connections can be established on the basis of the detected transmitting main connections and the number of signal connections assigned to a terminal.

Abstract: A measuring system and method is configured to analyze numerous different types of interconnects having varying degrees of complexity. The measuring system and method characterizes an interconnect to be tested by a predefined reflection coefficient signature. Each specific interconnect is predefined by a reflection coefficient signature that is unique to that specific interconnect. Once the reflection coefficient signature is defined, a corresponding reflection envelope is defined which defines boundary limits about the reflection coefficient signature. Subsequent testing of the specific interconnect results in a measured reflection coefficient curve, which is compared to the corresponding reflection envelope. The specific interconnect under test is considered acceptable if the values of the measured reflection coefficient curve do not fall outside the reflection envelope.

Abstract: A method for determining a waveform expected to be received by a device under test, the method including outputting a waveform generated by a waveform generation section of an arbitrary waveform and function generator at an output of the arbitrary waveform and function generator; sending the waveform generated by the waveform generation section to the device under test through a cable; monitoring a waveform at the output by a waveform monitoring section of the arbitrary waveform and function generator; and determining by the waveform monitoring section a transformed waveform expected to be received at the device under test based on the generated waveform being modified by the cable.

Abstract: A system that incorporates teachings of the subject disclosure may include, for example, determining a first voltage standing wave ratio (VSWR), selecting a VSWR circle from among a group of VSWR circles based on the first VSWR, identifying a group of sets of tuning settings for variable reactance elements of a matching network of the communication device where the identifying of the group of sets of tuning settings is based on each set of tuning settings of the group of sets of tuning settings being associated with the VSWR circle, and selecting a set of tuning settings from among the group of sets of tuning settings responsive to a second VSWR determined for the set of tuning settings satisfying a VSWR threshold. Other embodiments are disclosed.

Abstract: A wireless transmission device (100) of the invention includes a VSWR measuring means (101) which measures VSWR; and a VSWR determining means (102) which determines reliability of a measurement value of the VSWR measured by the VSWR measuring means (101). The VSWR determining means (102) includes a baseband signal analyzing means (90) which analyzes a baseband signal by detecting a difference between the baseband signal, and a delay signal of the baseband signal; a baseband signal density determining means (19) which determines a density of the baseband signal, based on the difference between the baseband signal and the delay signal analyzed by the baseband signal analyzing means (90), and a VSWR output switching means (13) which restrains output of the VSWR measuring means, when the baseband signal density determining means (19) determines that the density of the baseband signal is low.

Abstract: An electronic device may be provided with wireless circuitry. The wireless circuitry may include wireless transceiver circuitry that transmits signals towards an antenna. A signal path may carry the transmitted signals to the antenna. Reflected signals from the antenna may be carried along the signal path towards the transceiver circuitry. Coupler circuitry may include a forward coupler that taps the transmitted signals, a first reverse coupler that taps the reflected signals from the antenna, and a second reverse coupler that taps the reflected signals that have passed through the first reverse coupler. Analog processing circuitry and digital processing circuitry may be used to produce an impedance measurement from the tapped signals from the coupler circuitry. The analog processing circuitry may include analog signal mixers, low pass filters, and analog-to-digital converter circuitry.

Abstract: TeraHertz signal generation system based on traveling-wave oscillators providing extraction of orders of magnitude higher oscillation frequencies resulting in frequency multipliers and THz transceivers that can generate, transmit and sense THz frequency signals for sensing/imaging.

Abstract: A system that incorporates teachings of the subject disclosure may include, for example, determining a first voltage standing wave ratio (VSWR), selecting a VSWR circle from among a group of VSWR circles based on the first VSWR, identifying a group of sets of tuning settings for variable reactance elements of a matching network of the communication device where the identifying of the group of sets of tuning settings is based on each set of tuning settings of the group of sets of tuning settings being associated with the VSWR circle, and selecting a set of tuning settings from among the group of sets of tuning settings responsive to a second VSWR determined for the set of tuning settings satisfying a VSWR threshold. Other embodiments are disclosed.

Abstract: A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

Abstract: Measurement arrangement and method for active load pull measurements of a device under test (1). A wideband analog-to-digital conversion block (3) is provided for obtaining measurement data. First and second injection signal generators (7, 8) are connected to a source side and a load side of the device under test (1). This set up allows to create predetermined reflection coefficients at reference planes of the device under test (1). Injection signal parameters as determined are converted into the injection signals at the source and load side by digital-to-analog conversion. The wideband analog-to-digital conversion block (3) is further arranged for analog-to-digital conversion of the intermediate frequency signals to obtain the actual measured reflection coefficient versus frequency functions with a first frequency resolution. The first frequency resolution applied in the analog-to-digital conversion is equal to or better than a second frequency resolution applied in the digital-to-analog conversion.

Abstract: An oscilloscope probe calibrating system for a single terminal probe and a differential probe includes an oscilloscope, a main branch module, a sub-branch module, and a resistor. The oscilloscope includes multiple inputs for receiving signals from the single terminal probe and the differential probe, an output for outputting an original calibration signal, and a display module displaying the waveforms of the original calibration signal and the signals from the single terminal probe and the differential probe. The main branch module converts the original calibration signals to a number of first calibration signals. The sub-branch module converts the first calibration signals to a number of second calibration signals. The sub-branch module includes a single terminal sub-branch module and a differential sub-branch module coupled to the main branch module. One end of the resistor is connected between the main branch module and the differential sub-branch module, and the other end is grounded.

Abstract: An explosive and narcotics detection system detects the presence of trace particles of those materials that are adhering to surfaces. The particles are removed from the surface, transported and collected in a particle collection medium, and then provided to detection instrument. Narcotics and explosive particles are often bound tenaciously to the surface, and simple techniques, such as blowing air, will either remove only the largest particles or none at all. Techniques for the removal of narcotics and explosives particles are described which utilize an aerosol mixture of aerosol particles in a gas stream to impact and more efficiently remove the target narcotics and explosives particles from the surface.

Abstract: The invention refers to a method for the non-invasive monitoring of the chemical reaction linked to the curing process of a thermoset plastic material using microwaves, from the real-time measurements of the reflection coefficient of a resonator sensor using a detector that simultaneously provides modulus and phase values. The invention also refers to, as an example of the application of the method, a device for the non-invasive determination of the degree of cure of a thermoset plastic material at microwave frequencies. In another aspect, the invention proposes a method for the determination of the unloaded resonance frequency and the unloaded quality factor of a very strongly coupled microwave resonator and a method for determining the complex permittivity of a material undergoing changes in density, such as those produced during the curing process of polyurethane.

Abstract: The invention refers to a circuit and a method for detecting the impedance of a load, whereby the circuit and the method can be used by an impedance matching circuit. Impedance matching circuits need a complex algorithm to adjust the impedance accordingly. This algorithm renders the response time to be long. It has been found out that the complexity partially stems from the fact that the phase of the reflection coefficient is not known over the full range of 0° to 360°. A quadrature phase detector is used to provide the full phase information.

Abstract: A method for determining the composition and water salinity of a multi-component mixture of a gas and at least one liquid, including water, in a pipe (1), the method comprising the following steps: a. electromagnetic phase measurements are performed between two receiving antennas (4) located at different distances from a sending antenna (3), b. based on an empirically determined constant(s) and the above measurements, the effective and imaginary dielectric constants are determined, c. the mixture density is determined, d. the temperature and pressure are determined e. based on the knowledge of densities, effective dielectric constants and imaginary dielectric constants of the components of the fluid mixture and the results of the above steps a-d, the volume fractions of the gas and liquid or liquids of the fluid mixture and salinity of the water are calculated. An apparatus for performing the method is also disclosed.

Abstract: A measuring apparatus that measures a characteristic of a device under measurement is provided. The measuring apparatus includes: a signal generating section that outputs a forward signal to the device under measurement through a device side terminal; a directional coupler that outputs a backward split signal obtained by splitting a part of a backward signal inputted from the device under measurement through the device side terminal; a backward mixer that outputs a backward detection signal obtained by multiplying a local signal having a predetermined frequency by the backward split signal; and an analysis section that analyzes a characteristic of the device under measurement based on the backward detection signal. The directional coupler is included in a multilayer substrate, and the backward mixer is included in a chip provided on a surface of the multilayer substrate.

Abstract: The present invention provides a micro sensor for monitoring the cleaning and drying processes of surfaces of dielectric films, micro features in porous dielectric films and biologic or other cells common in microelectronics fabrication, MEMS fabrication or microbiology test system fabrication. By embedding electrodes in the surface of a supporting dielectric, the sensor can probe the surface and pores of a covering dielectric or a cell on the covering dielectric. The addition of a guard reduces the effects of any parasitic capacitance, which extends the measurement bandwidth of the sensor and allows it to be manufactured at the scale of a single cell, a feature that is particularly important for applications in microbiology.

Abstract: A microwave measurement system is utilized for the determination of displacement of a piston in a fluid filled cylindrical structure. The piston plus cylindrical encasement of the hydraulic system is modeled as a uniform cylindrical waveguide terminated in a metal plate. A novel shaped probe antenna to measure the slope of the relative phase of the reflected equivalent voltage wave with respect to frequency. The idea to measure the slope of the relative phase is novel and requires a new antenna structure. Instead of using the phase slope with respect to frequency, the total phase shift in a given frequency range is used to determine the location of the piston in the cylindrical chamber. Simulation and measurement will be used to determine the impedance of the antenna as well as the electromagnetic field at different locations inside the cylinder. In addition, the antenna will be analyzed to optimize its design, which ought to result in minimizing the reflections.

Abstract: A method is provided and includes exciting a sensor with an incident signal and generating a reflected signal by reflecting the incident signal from the sensor. The incident signal and the reflected signal interfere to form a standing wave. The method also includes processing the signals to determine a sensed parameter based upon a frequency at which the standing wave exhibits a null.

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 invention refers to a circuit and a method for detecting the impedance of a load, whereby the circuit and the method can be used by an impedance matching circuit. Impedance matching circuits need a complex algorithm to adjust the impedance accordingly. This algorithm renders the response time to be long. It has been found out that the complexity partially stems from the fact that the phase of the reflection coefficient is not known over the full range of 0° to 360°. A quadrature phase detector is used to provide the full phase information.

Abstract: In a device for measuring the properties of a device under test connected by a signal transmission path having reciprocity, a terminal on the device under test side of the signal transmission path is opened; pulse signals are transmitted to a terminal on the measuring apparatus side of the signal transmission path; the transmitted pulse signals are monitored and spectrum analyzed on the measuring apparatus; the pulse signals reflected from a terminal on the device under test side of the signal transmission path are monitored and spectrum analyzed on the measuring apparatus; and the frequency properties of propagation delay of the signal transmission path are found by referring to the coefficient obtained based on the impedance of the resistance load, the spectrum of the transmitted pulse signals, and the spectrum of the reflected pulse signals. The effect of an error is eliminated from the measuring results using the resulting frequency properties or propagation delay in actual measurement.

Abstract: A system, apparatus and method for performing differential return loss measurements and other measurements as a function of frequency uses a digital storage oscilloscope (DSO) having spectral analysis functions. A waveform generator generates a differential test signal in the form of a series of pulses where each pulse includes spectral components associated with each of a plurality of frequencies of interest. A test fixture presents the differential test waveform to a load including at least one of a device under test (DUT), a short circuit, an open circuit and a balanced load. A signal acquisition device differentially measures the test waveform during each of the load conditions. The signal acquisition device computes an error correction parameter using measurements made during the short circuit, open circuit and balanced load conditions. The correction parameter tends to offset signal acquisition errors within measurements made during the DUT load condition.

Abstract: Provided is an apparatus for detecting a defect of a circuit pattern which includes a resonator, a first power supply unit connected to one end of the resonator to apply power to the resonator, a probe connected to the other end of the resonator to contact one end of the circuit pattern, a second power supply unit connected to the other end of the circuit pattern to apply a voltage thereto, and a detection portion connected between the resonator and the probe to measure a voltage generated from the circuit pattern and generate a measurement voltage, and determine presence of a defect in the circuit pattern from the measurement voltage.

Abstract: A radio-thermometer system, and a method for measuring electromagnetic energy radiated from an interior of a human body, includes an antenna for receiving thermal energy radiated from a target object having a temperature to be measured, first and second noise sources, which are maintained at different temperatures in order to obtain a reflection coefficient of an interface between the antenna and the target object, a first switch for periodically switching between outputting the first or second noise source, a circulator for adding a signal received by the antenna to a reflective wave output from the first switch, and for transmitting an addition result, third and fourth noise sources, which are maintained at different temperatures, a second switch for periodically switching between outputting an output of the third noise source, the circulator, and the fourth noise source, and an amplifier for amplifying an output of the second switch.

Abstract: The presence of trace molecules in air is often determined using high sensitivity gas sensing instruments, such as an ion mobility spectrometer. Such devices are commonly utilized in the fields of explosives detection, identification of narcotics, and in applications characterized by the presence of very low airborne concentrations of organic molecules of special interest. The sensitivity of such instruments is dependent on the concentration of target gas in the sample. The sampling efficiency can be greatly improved when the target object is warmed, even by only a few degrees. A directed emission of photons in the range between infrared and ultraviolet light can be used to significantly enhance vapor emission.

Abstract: An apparatus and method for testing a voltage standing wave ratio (VSWR) in a wideband code division multiple access (W-CDMA) mobile communication system. Upon detecting a VSWR test request, a controller determines an oscillation frequency information and a power level information of a test signal for a VSWR test, and generates a test signal generation request including the determined oscillation frequency information and power level information. Upon detecting the test signal generation request, a test signal generator generates a test signal corresponding to the oscillation frequency information and power level information, and provides the generated test signal to an antenna. A VSWR detector receives the test signal and a reflected signal of the test signal from the antenna, and calculates a VSWR using the received test signal and reflected signal.

Abstract: A four-port junction is substituted for a six-port junction in a frequency domain reflectometer, which reduces the parts count and therefore cost and size of the reflectometer while improving reliability. The frequency domain reflectometer can alternatively be used as an insertion loss tester. An algorithm including the Hilbert Transform is used to directly calculate the estimated reflection coefficient from the output power measured at only two output ports.

Abstract: A method and base station apparatus are presented for calculating the Voltage Standing Wave Ratio of a radio frequency transmission line which is coupled with a first and a second directional coupler, the first directional coupler developing a first voltage indicative of the forward power propagating along the radio frequency transmission line in a first direction, the second directional coupler developing a second voltage indicative of a reflected power propagating along the radio frequency transmission line in a reverse direction. The method includes, in a second stage of installation, collecting values of the first and the second voltage, connecting at least one correction value with the second voltage to form a corrected second voltage, and forming the Voltage Standing Wave Ratio on the basis of the first voltage and the corrected second voltage. The correction value is obtained in a calibration process in a first stage of installation.

Abstract: A propagation delay time of a cable assembly is measured by calculating a half of a time difference between a branch point of time-dependent variations of amplitude of reflection coefficient obtained by connecting a first connector with both terminals open-circuited and a second connector with one terminal short-circuited to a conversion adaptor in turn and a branch point of the time-dependent variations of the amplitude of reflection coefficient obtained by connecting one terminal of the cable assembly with other terminal connected to the first connector and one terminal of the cable assembly with other terminal connected to the second connector to the conversion adaptor in turn.

Abstract: A generator (6) directs microwave signals to a waveguide (1) having a linear array of slots (2), and the signals are received by measuring device (5). The local permittivity or moisture content of material adjacent the waveguide (1), such as a stack of timber, may be determined at each slot (2) via regression analysis. The total permittivity or moisture may be determined by averaging measurements obtained for both transmission directions of the waveguide (1). The apparatus may be used for controlling drying parameters, such as drying time, for the material.

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: The invention relates to an electronic circuit and method for testing a line (10). According to the invention the signal generator (20, 30) comprises a random bit series generating means for generating a spread spectrum test signal and the evaluating unit comprises means (60-90, 200-230) for calculating and evaluating the correlation function of the test signal and the reflected signal.

Abstract: An apparatus for determining the properties of a material, that is to be examined, by applying a swept-frequency high frequency signal and measuring a reflection factor of the resonance signal. The apparatus has a microwave supply conductor for feeding the high frequency signal, a sensor waveguide that is coupled to the microwave supply conductor, a helical conductor that is arranged inside the sensor waveguide, and an intermediate layer between a first end of the sensor waveguide and the helical conductor. Typically, the sensor waveguide is cylindrical and the helical conductor is supported centrally therein along the longitudinal axis of the sensor waveguide by a support that is part of the intermediate layer. A coupling layer is provided between the helical conductor and the material to be examined in the region of a second end face of the sensor waveguide.

Abstract: The invention is directed to a sensor unit for measuring the concentration of lesser components of a molten bath wherein the sensor unit includes a casing with an interior, an opening for measuring and a connecting area whereby a sensor with a reference electrode is arranged in the interior of the casing and is electrically insulated from the casing and there exist a means of measuring an electric potential between the casing and the sensor. The sensor unit can be used in a measuring unit and used in a method to make refined metals.

Abstract: A system, apparatus and method for performing differential return loss measurements and other measurements as a function of frequency using a digital storage oscilloscope (DSO) including spectral analysis functions.

Abstract: Determinations are made related to the presence of a predetermined material in concrete under test using previously obtained model information. In one embodiment, the predetermined material includes a chloride material and the model information is obtained using a number of cured cement specimens. The model information is stored in memory, such as in the form of a look-up table. When the concrete is being inspected, one or more magnitudes of reflections coefficients are measured and such is utilized with the model information to make determinations related to the presence of the predetermined material. In developing the model information, each of the plurality of cured cement specimens is located in a bath containing the predetermined material. The bath may be pressurized. The cured cement specimens are maintained in the bath for different, known time intervals. After the known time interval for a particular specimen, it is dried and one or more magnitudes of reflection coefficients are measured.

Abstract: A resonant microwave sensor (1) for determining properties of a material (3), that is to be examined, by means of the high-frequency measurement of a reflection factor (r) of a high-frequency resonance signal as measured variable for determining properties of a material to be examined, having

Abstract: An apparatus for localized measurements of complex permittivity of a material is provided. A probe (10) analyzes the complex permittivity of a sample (11), the probe (10) having a balanced two conductor transmission line (12) formed of conductive segments (13 and 14). A probing end (15) of the transmission line (12) is brought within close proximity of sample (11) and an opposite end (16) of the transmission line is connected to a terminating plate (17) to form a resonator structure (18) for measurement of the complex permittivity of sample (11).

Abstract: Methods and systems for measuring the reflection coefficient of a network are disclosed. The methods and systems measure the reflection coefficient by exciting a device under test with a driving signal. The driving signal incident on the device under test is measured and the source providing the driving signal is removed thereafter. A signal reflected from the device under test is sampled at a sample rate that may differ from the frequency of the driving signal. The reflection coefficient of the device under test is calculated by dividing the measured level of the reflected signal by the measured level of the driving signal.

Abstract: A method and apparatus for measuring complex permittivity of dielectric materials in solid, liquid, or gas form. The apparatus is includes a TEM or quasi-TEM transmission line test fixture, which contains the dielectric material under test, a set of unique reflective load assemblies for inducing reflections in the fixture, an analyzer that measures magnitude and phase, a custom calibration kit, and a computer with computational software. The method begins by sequentially placing the set of load assemblies at the input of the analyzer. One port s-parameters are then obtained. Next, the set of load assemblies is sequentially placed at one end of the test fixture while the other end of the fixture is placed at the input of the analyzer and one port s-parameters are then obtained. Connectors are coupled to both ends of the fixture. A computer then executes a program to solve a set of equations constructed from the s-parameter data for computing input reflection coefficients.

Abstract: The present invention provides a system and device for a network hub that includes a single valued resistor placed in series with each transmission line such that reflected and other unwanted waves in the transmission line are rapidly dampened to prevent interference and errors in transmission. The present invention also provides a method and system for determining an appropriate single valued resistor serially placeable within a transmission line in a network such that reflected and other unwanted waves in the transmission line are rapidly dampened to prevent interference and errors in transmission. The present invention locates the single valued resistors on a network hub board. The present invention further provides resistors having resistance of approximately 22 ohms for use with a wide range of impedance transmission lines and signal baud rates.

Abstract: Determinations are made related to the presence of a predetermined material in concrete under test using previously obtained model information. In one embodiment, the predetermined material includes a chloride material and the model information is obtained using a number of cured cement specimens. The model information is stored in memory, such as in the form of a look-up table. When the concrete is being inspected, one or more magnitudes of reflections coefficients are measured and such is utilized with the model information to make determinations related to the presence of the predetermined material. In developing the model information, each of the plurality of cured cement specimens is located in a bath containing the predetermined material. The bath may be pressurized. The cured cement specimens are maintained in the bath for different, known time intervals. After the known time interval for a particular specimen, it is dried and one or more magnitudes of reflection coefficients are measured.

Abstract: An apparatus and method for diagnosing antennas using switches, wherein a system is configured in such a manner that a plurality of switches determine a data flow of a signal for test. Therefore, the antenna diagnosing apparatus can be so simplified in circuitry construction that it can be easy to manufacture at low cost. Further, the antenna diagnosing apparatus can accurately measure standing wave ratios of the antennas without being subject to any error, so as to accurately diagnose the performance of the antennas.

Abstract: Methods and systems for measuring the reflection coefficient of a network are disclosed. The methods and systems measure the reflection coefficient by exciting a device under test with a driving signal. The driving signal incident on the device under test is measured and the source providing the driving signal is removed thereafter. A signal reflected from the device under test is sampled at a sample rate that may differ from the frequency of the driving signal. The reflection coefficient of the device under test is calculated by dividing the measured level of the reflected signal by the measured level of the driving signal.