摘要:
An apparatus (10) for contactless measurement of sheet charge density and mobility includes a microwave source (16), a circular waveguide (50) for transmitting microwave power to a sample (59), such as a semiconductor wafer or panel for flat panel displays, at a measurement location, a first detector (18) for detecting the forward microwave power, a second detector (23) for detecting the microwave power reflected from the sample, and a third detector (95) for detecting the Hall effect power. An automatic positioning subsystem (700) is also provided for allowing automatic positioning of a wafer (59) within the test apparatus (10). The positioning system (700) includes a first end effector (706) and a rotator-lifter (704). The first end effector (706) can grasp a sheet element (59) and move it to a desired position within the test apparatus (10), while the rotator lifter (704) provides incremental adjustment of a theta angle of the sheet element (59) to allow automated mapping of an entire sheet element without the need for manual adjustment of the position of the sheet element. A second end effector (716) can be mounted opposite the first end effector (706) and can be used to automatically position the sheet element (59) within a sheet resistance testing module (718) located at an opposite end of the apparatus (10).
摘要:
An improved microwave spectrometer for measuring the concentration of ethylene oxide gas and the concentration of water vapor in one or more gas samples taken from an ethylene oxide sterilization chamber.
摘要:
A technique is disclosed for determining inductive and resistive components of power line impedance. A measurement circuit switches a burden or drain resistor between power line conductors to cause a droop or sag in a voltage waveform. The voltage waveform is sampled prior to inclusion of the resistor in the circuit, as well as after to identify the droop. The short circuit between the power lines is then removed by opening the circuit and a capacitor in the test circuitry causes a resonant ring due to the inductive component of the power line impedance. Based upon the period or frequency of the resonant ring, and upon the voltage measurements with and without the resistor in the circuit, the inductive and resistive components of power line impedance can be computed.
摘要:
Method and device for determining an electromagnetic reflection coefficient of an antenna, a method and device for automatically changing the matching of a power amplifier to an antenna, and a method and a device for automatically reducing the output power of a power amplifier.
摘要:
There are provided a laminate with an inside layer circuit for use as a multilayer printed circuit board, a method for measuring a circuit impedance of the laminate, and a measuring device that enables a nondestructive impedance measurement accurately. The laminate with the inside layer circuit has a dielectric substrate, a first conductive layer disposed on an upper surface of the dielectric substrate to form a high frequency circuit, a second conductive layer disposed on a lower surface of the dielectric substrate, and a third conductive layer disposed over a first dielectric layer on the upper surface of the dielectric substrate. A test conductor is formed independently of the inside layer circuit within the first conductive layer. The test conductor has its one end exposed to an end face of the laminate such that a probe can be kept into contact with the end face to direct a high frequency signal to the test conductor with at least one of the second conductor and the third conductor both exposed to the end face being held at the ground potential.
摘要:
A data communications terminal (102) includes an antenna circuit (106) for delivering a power signal to a portable data device. The terminal further encompasses a method for automatically adjusting the power seen by the portable data device without any communications feedback from the portable data device by monitoring an impedance characteristic for the antenna circuit. When a change in the monitored impedance characteristics is detected, the data communications terminal adjusts a power level for the power signal delivered to the portable data device.
un transformateur courant/tension (1) couplé par son enroulement primaire entre un dispositif d'accord (2) d'une antenne (3) et la sortie d'un amplificateur (4) d'alimentation de l'antenne (3) un premier (5a) et un deuxième (5b) dispositif de transposition de fréquence numérique en bande de base couplé respectivement à la sortie de l'amplificateur (4) et à l'enroulement secondaire du transformateur (1), et un dispositif de calcul (7) pour calculer l'impédance de l'antenne (3) à partir des signaux fournis par le premier (5a) et le deuxième (5b) dispositif de transposition de fréquence.
摘要:
Tuning of an RF probe (10) by comparison with a 50 ohm terminator. A Fourier transform NMR spectrometer is used in the comparison operation. The spectrometer comprises an oscillator (30) modulated by a modulator (32) and a signal is directed through duplexer (34) to a probe (10). The signal output of the probe presented to duplexer (34) is directed to an RF amplifier (38). Phase sensitive detector (40) operates on a reference phase derived from the RF oscillator (30) and the RF amplifier output signal to resolve the RF amplifier signal into phase quadrature components by incorporating two phase detectors fed with reference signals at the same frequency but differing in phase by 90o. For a signal frequency exactly equal to the reference frequency, the quadrature detection method provides independent determination of two quadrature components of the signal. Analog to digital conversion (42) operates on the phase sensitive detector outputs and the digital signals are available for further processing by processor apparatus (44). The present timing procedure measures two parameters, phase and amplitude, rather than the single parameter techniques of prior art such as signal peaking, reflected wave nulling and the like. The two channels of the quadrature resolving receiver are ideally suited for processing of the relevant information and storage in the spectrometer memory. During operation according to the present invention on the modulator (32) may be considered bypassed in the operational sense. The RF carrier is applied through the duplexer to the probe (10) or a probe substitute in the preferred form of a standard 50 ohm termination.