Abstract: A heater controller for controlling a heater precisely in the equi-power mode is disclosed. The controller includes a current source, a voltage monitor to detect a voltage drop caused in the heater, and a controller. The voltage drop may be converted to the digital form as refereeing to the first reference, while, the heater current is converted from the digital form as referring to the second reference. The second reference shows substantial temperature dependence, while, the first reference has lesser temperature dependence. The control corrects the temperature dependence of the second reference as referring to the first reference.

Abstract: A method is provided for tuning the fiber optic retarder of a fiber optic current sensor towards a desired temperature dependence, the sensing fiber is exposed to a magnetic field or corresponding electric current and the sensor signal as well as the signal's dependence on the retarder temperature are measured. From this initial sensor signal and its temperature dependence, a target sensor signal can be determined, at which the dependence on the retarder temperature equals a desired value. Then, the retarder is thermally treated until the sensor signal reaches the target value. The method obviates the need for repetitively measuring the temperature dependence during the tuning process.

Abstract: Systems, methods and sensors detect changes in incident optical radiation. Voltage is applied across one or more active areas of a detector while the incident optical radiation illuminates the active areas. Current is sensed across one or more of the active areas, a change in the current being indicative of the changes in incident optical radiation.

Abstract: An electric measuring apparatus is constructed in such a way as to include a signal processing circuit equipped with at least a polarized light separating unit, Faraday rotators, a light source, a photoelectric conversion element, and optical fibers for a sensor. The optical fibers for the sensor are placed around the periphery of an electrical conductor through which electric current to be measured flows. Furthermore, the rotation angle of each Faraday rotator at the time when the magnetism of each Faraday rotator is saturated is set to 22.5°+?° at a temperature of 23° C., thereby changing the rotation angle of each Faraday rotator by ?° from 22.5°.

Abstract: A power measurement circuit and method are described. The circuit comprises: a transconductance rectifier arrangement including an input and configured to receive a periodically varying input voltage signal having an approximate 50% duty cycle; and an averaging filter for producing a time averaged DC output signal proportional to the mean square of the voltage at the input of the transconductance rectifier arrangement and representative of the average power of the input voltage signal within a range of voltages at the input.

Abstract: The present invention relates to a radio frequency (RF) power measurement circuit that measures delivered power to a load. The RF power measurement circuit includes a measurement RF transmission line coupled to the load, and measurement and power calculation circuitry coupled to either end of the measurement RF transmission line to measure an RF input signal feeding the measurement RF transmission line and to measure an RF output signal fed from the measurement RF transmission line to the load. The measurement and power calculation circuitry uses the measured RF input and output signals to calculate and provide a delivered power signal that is indicative of the delivered power to the load.

Abstract: A self-testing transceiver having an on-chip power detection capability is provided. The self-testing transceiver can include a semiconductor substrate and a transmitter having a high-power amplifier disposed on the substrate. The self-testing transceiver also can include a receiver disposed on the substrate for selectively coupling to an antenna. The self-testing transceiver can further include at least one power detector disposed on the semiconductor substrate for determining a power such as an RMS and/or peak-power of a signal at an internal node of the self-testing transceiver. Additionally, the self-testing transceiver can include a loopback circuit disposed on the substrate.

Abstract: It is proposed to use the gun barrel or launcher tube or the muzzle brake as a waveguide, which, however, is operated at a frequency that is below the cutoff frequency of the relevant waveguide mode. The transmit coupler excites the relevant waveguide mode. An oscillator generates the signal, which is then sent to the transmit coupler. The waveguide and the projectile form a system in which the electromagnetic field at the receive coupler is influenced by the position of the projectile. The characteristic change over time of the strength of the electromagnetic field at the location of the receive coupler that results from the change in the distance between the projectile and the receive coupler is measured and used to determine the muzzle velocity.

Abstract: A clamp assembly for bringing an RF sensor into electrical contact with an RF current carrier is provided herein. The clamp assembly (101) comprises a first wedge-shaped element (103), and a second wedge-shaped element (105) which is slidingly engaged with said first wedge-shaped element. Preferably, the clamp assembly also comprises a collar (113) within which the first and second wedge-shaped elements are disposed. The clamp assembly preferably further comprises a fastener (111), such as a screw, which adjoins the first and second elements, in which case the clamp assembly is adapted such that, as the screw is rotated in a first direction, at least one of the first and second elements expands against the collar and/or the RF current carrier.

Abstract: An optical device includes an optical element, a detector and a controller. The optical element has an optical waveguide. Refractive index of the optical waveguide is controlled by a heater. A temperature of the optical element is controlled by a temperature control device. The detector detects a current flowing in the heater and/or a voltage applied to the heater. The controller controls an electrical power provided to the heater so as to be kept constant according to the detection result of the detector.

Abstract: Low cost millimeter wave imagers using two-dimensional focal plane arrays based on backward tunneling diode (BTD) detectors. Two-dimensional focal arrays of BTD detectors are used as focal plane arrays in imagers. High responsivity of BTD detectors near zero bias results in low noise detectors that alleviate the need for expensive and heat generating low noise amplifiers or Dicke switches in the imager. BTD detectors are installed on a printed circuit board using flip chip packaging technology and horn antennas direct the waves toward the flip chip including the BTD detectors. The assembly of the horn antennas, flip chips, printed circuit board substrate, and interconnects together work as an imaging sensor. Corrugated surfaces of the components prevent re-radiation of the incident waves.

Abstract: A sensor for sensing a measurand is described, the sensor comprising a coplanar waveguide with a first surface and a second surface opposite to the first surface; a first structure with a first periodically varying dielectric characteristic, the first structure being arranged on the first surface of the coplanar waveguide; and a second structure with a second periodically varying dielectric characteristic, the second structure being arranged on the second surface of the coplanar waveguide, wherein a unit-cell of the structures with periodically varying dielectric characteristics is dimensioned such that the sensor has a frequency dependent transfer behavior with at least one transfer minimum, and wherein the sensor is implemented such that the measurand influences the first periodically varying dielectric characteristic of the first structure or the second periodically varying dielectric characteristic of the second structure or a relation between such first structure and second structure.

Abstract: A field detection device such as a micro-strip portion of a transmission line may detect an electric field and a magnetic field induced by current steps injected into the chassis coupled to a ground plane. The shield portions of the transmission line may be coupled to a first and a second port of an I/O connector. A measurement system coupled to the connector may determine the electric field and the magnetic field detected by the micro-strip. The measurement system may determine the electric field and magnetic field based on computing the sum and difference of the signals provided by the first port and the second port.

Abstract: A radio frequency (RF) testing system (100) includes a RF signal source (10) generating RF signals, an antenna (50), a RF testing circuit (40) disposed on a printed circuit board (PCB) (41), a testing probe (20) for receiving the RF signal from the RF testing circuit, and a testing apparatus (30) for testing the RF signals from the testing probe. The RF testing circuit includes a first pad (42), a second pad (44), a transmission line (48), and at least one ground portion (49) parallel to the transmission line. A distance between a first region defined by the first pad and a second region defined by the second pad positioned between the first region and the antenna is equal to one-fourth of the wavelength. During testing, the testing probe is electrically connected to the first pad, and the second pad is electrically connected to ground of the PCB.

Abstract: For testing an RF device, such as an RF receiver/decoder chip that receives an RF signal via an antenna terminal and outputs a digital code at an output terminal, an inexpensive non-RF programmable tester is used. The programmable tester is a commercially available tester that need only generate and receive non-RF digital and analog signals. The RF signals needed for the testing of the RF device are totally supplied by RF generators on a single printed circuit board, external to the commercial tester housing. The board contains controllable RF generating circuitry whose possible output amplitudes and frequencies need be only those necessary for testing the particular DUT. The frequencies may be changed by switching in different crystal resonators mounted on the board.

Abstract: A power sensor includes a substrate, an aperture within the substrate, a membrane formed over at least a portion of the substrate and extending over the aperture, and an electro-thermal transducer partially supported by the insulating membrane. The electro-thermal transducer includes an impedance matched, bifurcated load supported over the aperture by the insulating membrane, and a thermopile extending over the aperture and supported by the insulating membrane, the thermopile being adapted to generate a voltage in response to heat generated in the impedance matched, bifurcated load. A signal conductor is electrically connected with one end of the impedance matched, bifurcated load to guide electromagnetic signals to the load, and a conductive under-layer stratified from the signal conductor by an intermediary dielectric is connected with an opposite end of the impedance matched, bifurcated load to act as a ground plane.

Abstract: An RF power detector having a wide dynamic range may comprise a chopping amplifier and is configured to detect pulsed high frequency RF signals. The chopping amplifier controlled by a bias current regulator amplifies and chops an RF signal by periodically enabling and disabling the amplifier according to a system clock. The chopped high frequency RF signal feeds a Schottky diode biased to operate in the square law region for weak signals. The Schottky diode voltage is tapped and high pass filtered. The voltage drives a logarithmic and linear converter. The converter outputs are summed to produce an output voltage that is a repeatable and stable monotonically increasing function of the RF power.

Abstract: According to one embodiment, a surface-plasmon (SP) beam generated by an SP source and directed via an SP waveguide is applied to a gate node of a field-effect transistor (FET). The FET also has a source node and a drain node. In a representative configuration, the gate, source, and drain nodes are electrically biased to pass an electrical current between the source and drain nodes in a manner that makes the electrical current responsive to the intensity of the SP beam.

Abstract: Low cost millimeter wave imagers using two-dimensional focal plane arrays based on backward tunneling diode (BTD) detectors. Two-dimensional focal arrays of BTD detectors are used as focal plane arrays in imagers. High responsivity of BTD detectors near zero bias results in low noise detectors that alleviate the need for expensive and heat generating low noise amplifiers or Dicke switches in the imager. BTD detectors are installed on a printed circuit board using flip chip packaging technology and horn antennas direct the waves toward the flip chip including the BTD detectors. The assembly of the horn antennas, flip chips, printed circuit board substrate, and interconnects together work as an imaging sensor. Corrugated surfaces of the components prevent re-radiation of the incident waves.

Abstract: A micromechanical sensor for measuring millimetric wave or microwave power, which sensor includes a wave line for conducting the millimetric or microwave power and a moving part and a fixed electrode, in such a way that the capacitance (C) between the moving part and the fixed electrode couples to the wave power advancing in the wave line. According to the invention, the capacitance (C) between the moving part and the fixed electrode is divided into at least two portions (C/n), which are located at a distance from each other, in such a way that the wave power advancing in the wave line couples to the portions (C/n) of the capacitance (C) consecutively and experiences the inductive load between the portions (C/n) of the capacitance (C). Thus the frequency band of the sensor can be substantially broadened and the reflective coefficient can be kept reasonably small.

Abstract: Systems, methods and sensors detect changes in incident optical radiation. Current is driven through one or more active areas of a detector while the incident optical radiation illuminates the active areas. Voltage is sensed across one or more of the active areas, a change in the voltage being indicative of the changes in incident optical radiation.

Abstract: An optical device includes an optical element, a detector and a controller. The optical element has an optical waveguide. Refractive index of the optical waveguide is controlled by a heater. A temperature of the optical element is controlled by a temperature control device. The detector detects a current flowing in the heater and/or a voltage applied to the heater. The controller controls an electrical power provided to the heater so as to be kept constant according to the detection result of the detector.

Abstract: Power measurement and control in transmission systems are affected by changes in load conditions. A method and system are provided for detecting and controlling power levels independent of such load conditions.

Abstract: A power-sensor module comprises a housing enclosing the power-sensor module. An input port of the housing brings an input signal into the housing. A power distributor, is within the housing. The power distributor has a first arm transmitting a first portion of the input signal and a second arm transmitting a second portion of the input signal. A first resistor is in the first arm and a second resistor in the second arm of the power distributor. An output port of the housing outputs from the housing the first portion of the input signal. A first thermal-based power detector detects heat generated by the second resistor caused by the second portion of the input signal and outputs a first power measurement signal based on the heat detected.

Abstract: An RF power sensor is enclosed within a housing. An input port of the housing brings an RF signal into the housing. An RF switch within the housing switches the RF signal between an amplified and filtered path, a through-path and an attenuated path. An RF power detector within the housing detects the electric field of the RF signal and rectifies it into a current to measure the RF energy of the RF signal passing through the amplified path, through-path or attenuated path.

Abstract: A thermocouple power sensor includes the ability to monitor the value of a RF load resistor. A meter connects to the input of a thermocouple-based RF signal power detector. The apparatus can sense its own load resistor DC impedance, so it can detect both aging in and damage sustained through overload to the RF dissipation element.

Abstract: An improved directional coupler that significantly reduces the signal degradation problems associated with distortion caused by circuit elements used to measure the transmitted power. In a selected embodiment, the directional coupler of the present invention comprises a plurality of active elements, such as capacitors, that have values selected to ensure that the distortion created by circuit elements used to measure forward transmitted power. In an embodiment of the invention, capacitors have values selected to minimize in-band distortion signals at the fundamental carrier frequency of the transmitted signal and also at the second and third harmonics of the fundamental carrier frequency.

Abstract: A power detection system implemented using a pair of directional couplers and a transmission line (or equivalent) disposed between the directional couplers, wherein the transmission line (or equivalent) provides a 90° phase shift between the directional couplers. Accurate power detection is provided by combining the powers detected at each of the directional couplers, whereby the combined power is independent of load phase. The total power in the forward case is given by Pc1=2*Pf*C, where Pf is the forward power and C is the coupling coefficient the directional couplers. The total power in the reflected case is given by Pc1=2*Pf*C*(?2+D2), where Pf is the forward power, C is the coupling coefficient of said directional couplers, ? is the reflection coefficient, and D is the directivity of the directional couplers.

Abstract: A power detection system implemented using a pair of directional couplers and a transmission line (or equivalent) disposed between the directional couplers, wherein the transmission line (or equivalent) provides a 90° phase shift between the directional couplers. Accurate power detection is provided by combining the powers detected at each of the directional couplers, whereby the combined power is independent of load phase. The total power in the forward case is given by Pc1=2*Pf*C, where Pf is the forward power and C is the coupling coefficient the directional couplers. The total power in the reflected case is given by Pc1=2*Pf*C*(?2+D2), where Pf is the forward power, C is the coupling coefficient of said directional couplers, ? is the reflection coefficient, and D is the directivity of the directional couplers.

Abstract: A detection circuit for detecting the output power of a power amplifier comprises a first current minor transistor (Ti 1) having a base, which is connectable to a power transistor (T10), and a collector, a RF detection means (RF-det) for detecting the RF current flowing through the current mirror transistor (T11). Said RF detection means (RFdet) is connected to the collector of said first current mirror transistor (T11). Said detection circuit further comprises a biasing means (bias-RF-det) for biasing said RF detection means (RF-det), wherein said biasing means is connected to said collector of said first current mirror (T11) and said RF detection means (RF-det).

Abstract: In an apparatus for measuring a specific absorption rate (SAR), a first near magnetic field distribution of a radio wave radiated from an array antenna of a reference antenna including a plurality of minute antennas is measured, and an SAR distribution with respect to the radio wave radiated from the array antenna is measured with a predetermined phantom. Then a distribution of a transformation coefficient ? is calculated by dividing the measured SAR distribution by a square of the measured first near magnetic field distribution, a second near magnetic field distribution of a radio wave radiated from a measured radio communication apparatus is measured, and an SAR distribution with respect to the radio wave radiated from the radio communication apparatus is calculated by multiplying a square of the measured second near magnetic field distribution by the calculated distribution of the transformation coefficient ?.

Abstract: A distributed active transformer on a semiconducting substrate is provided. The distributed active transformer includes an outer primary, a secondary disposed adjacent to the outer primary, and an inner primary disposed adjacent to the outer primary and the secondary. A plurality of first three terminal devices is coupled to the outer primary at a plurality of locations. A plurality of second three terminal devices coupled to the inner primary at a plurality of locations, and each second three terminal device is disposed opposite from and coupled to one of the plurality of first three terminal devices. A plurality of power control actuation circuits is also provided, where each power control actuation circuit is coupled to one of the first three terminal devices and the second three terminal devices.

Abstract: A system for measuring radiant signals includes a detector circuit for detecting a time multiplexed, measured radiant signal and reference signal. A switch is connected to the detector circuit for receiving signals from the detector circuit. A measured signal sampling circuit, a reference signal sampling circuit, a measured alias circuit and a reference alias circuit are connected to the switch, which is operative for switching among the sampling and alias circuits to remove sampling noise and improve switching latency.

Abstract: Power measurement and control in transmission systems are affected by changes in load conditions. A method and system are provided for detecting and controlling power levels independent of such load conditions.

Abstract: The present invention provides an efficient way to detect the transmit power provided by an amplifier. A power sense signal indicative of the transmit power of the amplifier is generated and fed back to a control system, which will react accordingly to control input signal levels, bias, gain, or a combination thereof for the amplifier in traditional fashion to control transmit power. Detection circuitry representing a scaled version of the amplifier receives the radio frequency (RF) drive in parallel with the amplifier to provide a scaled output signal. The scaled output signal is rectified and filtered to generate the power sense signal.

Abstract: The invention provides a method of apparatus for testing circuit boards which does not require any inner wide power plane so as to detect an open circuit defect and/or a short circuit defect in a conductor path network formed in the circuit board quickly and accurately. An apparatus for testing a circuit board according to the present invention includes a transmission unit (2) for transmitting electromagnetic (radio) wave signal by way of an antenna (1) to a circuit board (3) to be tested, a detecting unit (3) for detecting signal received by a conductor path (4) of the circuit board (3) by using the conductor path (4) as a receiving antenna, and compare unit (8) for determining whether or not there is an open circuit defect or a short circuit defect in the conductor path (4) by comparing the detected signal with reference data of corresponding to a conductor path not including any defect.

Abstract: In a high frequency circuit property measurement method, prior to property measurements of a high frequency circuit with RF measurement probe heads, RF measurement probe heads are calibrated using a calibration pattern comprising a signal line having a characteristic impedance and extending on a dielectric substrate, a first GND pad having one end disposed close to and at an interval from a first end of the signal line, a second GND pad having one end disposed close to and at an interval from a second end of the signal line, and a conductor electrically coupling the first GND pad to the second GND pad.

Abstract: Power measurement and control in transmission systems are affected by changes in load conditions. A method and system are provided for detecting and controlling power levels independent of such load conditions.

Abstract: A portable voltage and current (VI) probe including voltage and current probes, a clamshell assembly, and insulation sections for attachment to at least one transmission line. A stripper tool removes sections of a cover and a shield from the transmission line. Probes are then installed onto the transmission line. A clamshell assembly is placed onto the exposed transmission line surrounding the probes. The probes are insulated and connected to at least one detecting circuit.

Abstract: A radio frequency power generation and power measurement system includes power sensors to measure both the radio frequency (RF) power transmitted by radio equipment under test, and the RF power received by the radio equipment under test. Power sensors are mounted in a separate assembly remote from the main power measurement and generation. The RF power sensors and other components in the remote assembly are interconnected to allow measurement of both received and transmitted RF power at the RF connector or connectors of the radio equipment under test. The main assembly and the remote assembly are connected by a flexible link.

Abstract: A power detector for measuring the average power, without constant voltage, of modulated or unmodulated high frequency or microwave signals is described. The power detector includes a signal line connected to a high frequency input. A detection line is capacitively and/or inductively coupled to the signal line and, seen in the longitudinal direction, is connected to the signal line. The signal is tapped from the detection line at two or more detection positions which are staggered in the longitudinal direction.

Abstract: An unknown RF power is converted to a voltage by a detector (11). The voltage is converted to a number by a digitiser (12). A separate and fixed RF power reference (14) drives a second detector (15), whose voltage output is also converted to a number by the digitiser (12). The RF detectors are thermally coupled. Temperature variations in the RF power to voltage characteristic of the detector (11) are corrected by measuring the RF power reference (14) via the detector (15).

Abstract: The invention relates to a method for measuring a radio frequency signal in a wireless station (1). In this method, radio frequency power is measured by means of testing equipment (6, 7, 12), which includes at least a testing apparatus (7), a measuring head (6) and means (12) for transmitting electrical signals between the testing apparatus (7) and measuring head (6). The wireless station (1) includes at least one radio part (8), a wiring board (2), an antenna (5) and switching means (3, 22). This test switch has at least an first position, in which the radio frequency signal is directed between the radio part (8) of the wireless station (1) and the antenna (5), and a second position, in which the radio frequency signal is directed between the radio part (8) of the wireless station (1) and the testing apparatus (7) via the switching means (3, 22) and the measuring head (6).

Abstract: This invention relates to the reduction of insertion losses and by consequence maximization of reflection factors for on-wafer load pull testing of high power or low noise transistor chips, using as much a direct integration as possible between the slotted airline of the tuners and low loss probes, said probes being either modified commercial probes or probes made as an extension of the tuner slotted airline itself.

Abstract: An electromagnetic probe having at least one assembly including in combination: a coaxial type connectio, a ground plane connected to the outer sheath of the coaxial connection, a reflector cone placed facing the ground plane and shaped to define impedance that is at least substantially constant along its profile, the reflector being electrically isolated, and a dielectric medium interposed at least in part between the reflector cone and the ground plane.

Abstract: An antenna apparatus for detecting a leaked electromagnetic signal is provided. The apparatus includes a telescoping antenna and a casing, which has a portion of the antenna mounted in it. The antenna can move telescopically relative to the casing between an extended configuration, in which the antenna extends away from the casing, and a retracted configuration, in which the antenna is housed in the casing. A signal analyzer is located in the casing and is connected to the telescoping antenna. The antenna detects the electromagnetic signal, which is analyzed by the signal analyzer.

Abstract: A testing device is operative to sense or monitor a radiated field emitted by an igniter for heating equipment such as an oil burner and to indicate the detection corresponding to a normal operating state of the igniter.

Abstract: A coupler circuit for sampling an output power of a signal from an output power source has at least one first sampling element for sampling a first portion of the signal and at least one second sampling element for sampling a second portion of the signal. The first sampling element and the second sampling element are separated by an output matching network defined by a set of S-parameters. A processor coupled to the at least one first and second sampling elements determines the output power based on at least the first portion of the signal and the second portion of the signal. A detector may be coupled to the processor to measure whether the first and second portion of the signal or the output power determined by the processor.

Abstract: The occurrence of spurs when analyzing signals is reduced. A first signal is mixed with a local oscillator signal to produce an intermediate signal. When a spur is predicted to occur when high side mixing is performed, low side mixing is performed. When a spur is predicted to occur when low side mixing is performed, high side mixing is performed.

Abstract: A detecting device for detecting electromagnetic waves generated by electric facilities includes a support having a peripheral surface for attaching a number of wave detectors which detect the electromagnetic waves generated by the electric facilities. The support may include a housing having a chamber for receiving the electric facilities, or having a curved outer peripheral surface for supporting the wave detectors. The wave detectors each has a number of light devices for indicating the strength of the received electromagnetic waves.