Abstract: Systems, methods, assemblies, and components for aftertreatment of an engine can comprise an aftertreatment module including an exhaust enclosure with at least one inlet port to receive exhaust gas, an outlet port to output exhaust gas, a first compartment, and a second compartment; a plurality of particulate filters extending in parallel with each other within the exhaust enclosure such that, for each of the particulate filters, an inlet of the particulate filter is in the first compartment and an outlet of the particulate filter is in the second compartment; and at least one radio frequency (RF) sensor set including an RF transmitter assembly and an RF receiver assembly. The RF transmitter assembly can be provided in the first compartment at the inlet of one of the particulate filters, and the RF receiver assembly can be provided at the outlet of said one particulate filter.

Abstract: Embodiments of the invention include dielectric waveguides and connectors for dielectric waveguides. In an embodiment a dielectric waveguide connector may include an outer ring and one or more posts extending from the outer ring towards the center of the outer ring. In some embodiments, a first dielectric waveguide secured within the dielectric ring by the one or more posts. In another embodiment, an enclosure surrounding electronic components may include an enclosure wall having an interior surface and an exterior surface and a dielectric waveguide embedded within the enclosure wall. In an embodiment, a first end of the dielectric waveguide is substantially coplanar with the interior surface of the enclosure wall and a second end of the dielectric waveguide is substantially coplanar with the exterior surface of the enclosure wall.

Abstract: Particulate filters are used to remove particulate matter such as soot and ash in the emissions control systems of vehicles, including gasoline direct injection (GDI) engines. Methods are provided to predict the long-term performance and durability of emissions control systems having particulate filters. The methods account for factors such as thermal aging, soot accumulation and regeneration, and ash loading.

Abstract: A system for particulate filter regeneration includes a pre-converter universal heated exhaust gas oxygen (UHEGO) sensor disposed upstream from a three-way catalytic (TWC) converter and a particulate filter (PF), and a post-converter UHEGO sensor disposed downstream from the TWC converter and upstream from the PF. An engine controller for an internal combustion engine (ICE) and in communication with the pre-converter UHEGO sensor and the post-converter UHEGO sensor is included. The engine controller is configured to determine an amount of particulate mass accumulated in the PF during operation of the ICE and deactivate at least one of a plurality of cylinders of the ICE such that a deactivated cylinder intake air (DCIA) pass-through volume flows through the at least one deactivated cylinder and into the TWC converter and the PF. The DCIA pass-through volume is a function of the determined amount of particulate mass accumulated in the PF.

Abstract: Operating an exhaust particulate filter system for an internal combustion engine includes transmitting electromagnetic energy, for example having a frequency above about 2 GHz, through an exhaust particulate filter containing trapped soot. The transmitted electromagnetic energy may be attenuated in response to the trapped soot, and a filter soot loading value calculated based at least in part upon a correlation among an attenuation of the electromagnetic energy, a temperature of the filter, and a mass of the trapped soot. An algorithm based upon a partial derivative of an equation representing the correlation may be used in calculating the filter soot loading value, and a resulting soot mass. The calculated soot mass is used to determine a relative soot loading state of the filter in conjunction with information as to ash loading. Responsive to determining the relative soot loading state satisfies regeneration suitability conditions, a regeneration initiation command may be outputted.

Abstract: A variable impedance device includes a passive tuner that includes at least one variable component, which is controllable to apply a variable impedance value to an input signal of the passive tuner. A low noise amplifier is configured to supply the input signal to the passive tuner by amplifying an input RF (radio frequency) signal.

Abstract: An ultra wideband frequency compensated resistor and related methodologies for frequency compensation are disclosed. In exemplary configuration, a resistive layer is provided over a substrate, and a frequency compensating structure is provided over at least a portion of the resistive layer and separated therefrom by an insulative layer. In certain embodiments, the insulating layer may be an adhesive that may also be effective to secure a protective cover over the resistive material and supporting substrate. In selected embodiments, the frequency compensating structure corresponds to a plurality of conductive layers, one or more of which may be directly electrically connected to terminations for the resistive material while one or more of the conductive layers are not so connected.

Abstract: A system and method for determining loading of a filter having a first dielectric constant with a material having a different dielectric constant, is disclosed. The filter is contained within a metallic container forming a microwave cavity, and microwave or RF energy is created within the cavity and changes in the cavity microwave response are monitored. The changes in cavity microwave response are related to filter loading. In a preferred embodiment, the microwave energy includes multiple cavity modes thereby allowing determination of spatial distribution of the contaminant material loading. In one embodiment, the microwave cavity response includes a shift in frequency of a resonant mode. Alternatively, the microwave cavity response includes a shift in quality factor Q of a resonant mode. The microwave cavity response may include a shift in amplitude or peak width of the microwave's signal at resonance.

Abstract: A method for characterizing dielectric loss tangent of a dielectric material. The method includes: introducing an incident wave in a mismatched transmission line; measuring a first insertion loss from a first resulting standing wave, at a given frequency; augmenting the mismatched transmission line with the dielectric material; introducing the incident wave in the transmission line augmented with the dielectric material; measuring a second insertion loss from a second resulting standing wave, at the given frequency; and calculating the dielectric loss tangent based on the differences between the first and second measured insertion losses.

Abstract: A self-checking analyzer system is provided according to an embodiment of this disclosure. The analyzer system includes a pipeline for receiving a multi-phase fluid flow and a first measuring device configured to provide a first frequency response corresponding to the multi-phase fluid flow. The analyzer system also includes a second measuring device differing in frequency response from the first measuring device and configured to provide a second frequency response corresponding to the multi-phase fluid flow. The analyzer system is configured to validate the first frequency response using the second frequency response.

Abstract: A cylindrical waveguide (1) used for analyzing a flowing stream of corn masa (18) using a guided microwave spectroscopy (GMS) process. The waveguide (1) includes opposed spaced apart plates (2, 5) that each define a plane within the waveguide housing (3) that is parallel to the direction (47) of corn masa flow through the waveguide. The housing (1) includes two opposed frames (7, 19) that each surround an aperture (6) that permits access to the region between the waveguide plates (2, 5). A microwave probe assembly (81) is mounted at each frame (7, 19) to permit the radiation and reception of electromagnetic waves within the housing (1) as required to perform the GMS process. A temperature probe (51) is inserted into the interior of the housing (1) at a fitting (13). In an actual installation a y-shaped assembly (89) can be used to divide the corn masa flow into two separate paths with one path containing the waveguide (1).

Abstract: A method and apparatus for determining the attenuation of an RF signal caused by a DPF at an unknown or different ambient temperature than the temperature used for DPF sensor calibration is disclosed. The method and apparatus determine the sensor attenuation just prior to determining the DPF attenuation by disconnecting the antennas and determining the attenuation of a loopback path. This sensor attenuation can then be deducted from the attenuation determined for the normal path that includes the attenuation caused by the loopback path, the cables, and the DPF. This method compensates for variation in the attenuation of the sensor caused by changes in ambient temperature of the sensor. Further temperature compensation is be achieved by determining additional factors to account for variations caused by changes in ambient temperature.

Abstract: A particulate trap regeneration system is provided, which may include a particulate trap having a filter medium configured to remove one or more types of particulate matter from an exhaust flow of an engine and a regeneration device configured to reduce an amount of particulate matter in the particulate trap, as well as a radio frequency-based particulate loading monitoring system configured to determine an amount of particulate matter trapped by the filter medium. The particulate loading monitoring system may include at least one radio frequency probe configured to transmit radio frequency signals of predetermined magnitude and predetermined frequency toward the filter medium and at least one radio frequency probe configured to receive and measure the magnitude of received radio frequency signals that pass through the filter medium. Further, the system may be configured to transmit radio frequency signals along a length of the exhaust conduit.

Abstract: Method for determining loading of a filter. The filter has a first dielectric constant. The filter becomes loaded with contaminant material that has a second dielectric constant. The filter, such as a diesel particulate filter, is contained within a metallic enclosure forming a microwave cavity. The method includes establishing microwave energy in the cavity and monitoring changes in the cavity microwave response, the changes being related to filter loading.

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: Dynamic insertion insertion loss for an ethernet power on differential cable pairs is shown in a power feed circuit that supplies power to a network attached device (PD). An insertion loss control circuit limits power loss in a coupled power feed circuit. determines an insertion loss limit, and senses an average power of the power signals to produce a common mode feedback signal to the power feed circuit.

Abstract: An impedance tuning measurement setup and method for characterizing high frequency devices-under-test whereby one inserts an extremely low loss directive coupling structure between the terminal of the device-under-test and that part of the impedance tuner that generates the variable impedance. One or both coupled arm outputs of the directive coupling structure are connected to the inputs of a broadband RF receiver. By using the extremely low loss directive coupling structure one avoids the loss of energy caused by the distributed directional couplers or the resistive bridges used in prior art. The low loss directive coupling structure is formed by a small piece of conductive wire, which is inserted into the electro-magnetic waveguiding structure that guides the RF signals towards and from the DUT terminals. The ends of the small piece of conductive wire are connected to the center conductors of two electromagnetic waveguiding structures, which act as the coupling arms.

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: 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: A coaxial radio frequency adapter and method are disclosed. An adapter has a tapered signal pin and a tapered ground sleeve to maintain a consistent impedance and minimize reflections while connecting two elements having different dimensions. A method employs an adapter to characterize losses in a system for evaluating a device under test.

Abstract: A compensating resistor includes a substrate with a first termination at one end and a second termination at the other end. A frontside resistor is on the frontside of the substrate and extends between the first termination and the second termination. A backside resistor is on the backside of the substrate. One end of the backside resistor is attached to the first termination, but the other end of the backside resistor is free from the second termination. The frontside resistor and the backside resistor are capacitively coupled through the substrate. An alternative embodiment has includes a metal termination pad on the substrate backside to which the free end of the backside resistor connects. The compensating resistor preferably has an attenuation that decreases proportionally to the square root of frequency over the range of frequencies.

Abstract: A method and apparatus for determining the insertion loss of a conductor. The method includes introducing a test signal into a first signal transmission path and a second signal transmission path. The conductor is included in the first path but at least partially excluded from the second path. The method includes measuring the strength of the test signal from the two paths and obtaining the insertion loss of the conductor from the two measured values.

Abstract: According to some embodiments, time domain reflectometry based transmitter equalization is provided.

Abstract: A frequency selective improved directivity of a return loss bridge is achieved by generating a counteractive reflected energy vector to cancel a reflected energy vector caused by imperfections, such as parasitic effects and an unbalanced balun, in the return loss bridge. The counteractive reflected energy vector of equal magnitude, but opposite in phase, to the undesired reflected energy vector may be induced into a transmission path between a test port and a coupled port. An open circuit stub in the transmission path between the test port and the coupled port may be used to provide the counteractive reflected energy vector. Alternatively a path across a coupling resistor in a return loss path coupled from the test port to the coupled port may be used to provide the counteractive reflected energy vector, with PIN diodes in the coupled path being used for tunability if desired.

Abstract: Arrangement to test HF tightness of a junction between two adjacent parts including HF generator (4), HF line that guides the signal over junction (1), measuring device (10) as well as a signal analyzer. HF line includes two waveguides (5a, 5b) that have inner conductors (6a, 6b) connected all the way through by a connection conductor (9) and outer conductors (7a, 7b) interrupted and each connected with electrodes (8a, 8b). A capacitive coupling of the HF signal occurs on one side of the junction and a capacitive decoupling of the HF signal takes place on the other side. By comparing the measured transmission and/or reflection of the HF signal with a transmission or reflection characteristic for the junction, it can be determined if the junction is HF tight. This makes it possible to test HF shielded cases for HF tightness in a non-destructive manner and without interfering with the contents.

Abstract: A monitor for monitoring the moisture content of grain comprises at least one programmable PIN diode attenuator connected between a microwave measurement signal source and a transmit antenna. A controller stores an addressable attenuation table, each location in the table storing an attenuation value and an associated attenuator address. A counter accesses the table locations sequentially and the attenuator addresses are applied to the attenuator to cause a step-wise decreasing attenuation of the measurement signal which is then transmitted through the grain. After the signal passes through the grain, it is detected and applied to a threshold comparator. When the magnitude of the detected signal reaches the threshold, the counter is stopped and the attenuation value at the location pointed to by the counter is taken as the attenuation of the measurement due to moisture in the grain. Once the attenuation has been determined, the moisture content and mass grain flow may be calculated.

Abstract: An electromagnetic compatibility (EMC) test cell has an electromagnetically screening enclosure which is rectangular in cross-section with a length and first and second pairs of opposed side walls. A first antenna array comprises a first array of conductors extending lengthwise in the enclosure distributed at positions between the first pair of side walls to produce, when energized in TEM-mode, an electric field in a first test region of the enclosure which is predominantly polarized in a direction parallel to the first pair of side walls. Second and third antenna arrays comprising respective second and third arrays of conductors extend lengthwise in the enclosure on opposite sides of the first test region.

Abstract: An apparatus for detecting the accumulation of particulate material on a filter medium formed of dielectric material and disposed in a chamber is provided. The apparatus is operable for generating and transmitting an RF signal through the filter medium and for monitoring the transmission loss of the signal through at least a portion of the filter medium so as to provide an indication of the content of particulate material accumulated on the filter medium. The apparatus includes an input antenna for transmitting the signal and having at least one antenna element extending longitudinally of the chamber and disposed within the filter medium; and an output antenna for receiving the signal transmitted by the input antenna and having at least one antenna element extending longitudinally of the chamber and disposed within the medium in parallel, spaced apart, axially overlapping relation with respect to the input antenna element.

Abstract: A method of detecting the accumulation of particulate material collected on a filter medium formed of dielectric material in a chamber having the property of a microwave waveguide or transmission line comprises the steps of exciting the chamber with a microwave signal and monitoring the transmission loss of the signal through the line to sense the effective dielectric loss factor and thereby to provide an indication of the concentration or level of particulate material accumulated on the filter medium.

Abstract: A system and method for monitoring conditions in a fluid medium. A stream of the fluid medium is flowed through a fluid container which is electrically configured as a transmission line segment and which is electrically connected to load to UHF or microwave oscillator. The oscillator is not isolated from the load, and is operated free-running, at a starting frequency which is chosen to provide a particularly strong shift in permittivity of the fluid medium, as the chemical reaction progresses. Preferably the frequency and insertion loss of the oscillator are monitored, to gauge the progress of the reaction.

Abstract: A coaxial microwave absorption diagnostic device comprises a hollow cylindrical outer layer conductor with a coaxially aligned conductor rod extending therethrough and a dielectric material which interconnects the outer layer to the conductor rod. The device is formed with a passageway which is directed perpendicular to the longitudinal axis of the device and which passed through the outer layer, the conductor rod and the dielectric material. As so formed, the passageway is positioned for receiving a sample holder, such as a small capillary tube holding a sample solution. A variable or fixed frequency oscillator is electrically connected to an input end of the conductor rod for sending microwave power through the device and a diode senses the output portion of this microwave power which has passed through the device. The absorbed power, i.e. the input microwave power less the output microwave power, is determined by a comparator and used to analyze the sample.

Abstract: The petroleum stream watercut monitor includes a test cell having a petroleum stream flowing through it. A microwave transmitter provides microwave energy through an antenna through an isolator. The antenna irradiates the test cell with the microwave energy so that the microwave energy enters the test cell and is reflected from the petroleum stream back to the antenna. A circulator connected to the isolator connects the transmitter to the isolator means and provides microwave energy to the antenna through the isolator and receives from the antenna again through the isolator the reflected microwave energy. An indicator provides an indication of the watercut of the petroleum stream in accordance with the phase difference between the transmitted microwave energy and the test microwave energy.

Abstract: An instrument for measuring the high frequency characteristics of a sheet-like material comprising: a pair of opposed slits formed in a pair of opposed tube walls of a cavity resonator having an optional cross-sectional shape, said slits extending parallel to the tube axis and enabling a sheet-like material to be inserted such that it extends across said cavity resonator; a driving section disposed at one end of said cavity resonator and having a driving conductor for producing microwaves for driving said cavity resonator in the direction to form an electric field which is perpendicular to the tube wall surfaces formed with said pair of slits; a detecting section disposed at the other end of said cavity resonator and having a probe conductor for receiving said microwaves; and a controlling and calculating device for detecting the resonant frequency or attenuation of received microwaves and calculating the high frequency characteristics of the sample from the detection result.

Abstract: In an arrangement for measuring transfer impedances of coaxial systems (3), a generator (1) is connected via a coaxial, supplying system (2) to a conductor shield (6) of the coaxial system (3) at a first end of the coaxial system (3). A voltage measuring instrument is connected to the first end between the conductor shield (6) and the inner conductor (5) of the coaxial system (3). The electrical contact between the supplying system (2) and the conductor shield (6) is created by a gripping collet (12). The conductor shield (6) and the inner conductor (5) are short-circuited at a second end of the coaxial system (3).