Electricity: measuring and testing – Measuring – testing – or sensing electricity – per se – With rotor
Patent
1989-01-06
1990-12-11
Karlsen, Ernest F.
Electricity: measuring and testing
Measuring, testing, or sensing electricity, per se
With rotor
324 731, G01R 3126, G01R 3128
Patent
active
049773712
ABSTRACT:
A variable-frequency I-V measurement system for testing the IC device, such as a GaAs MESFET, has probes for measuring the bias voltage, drain voltage, drain current, and gate signal voltage, a gate signal source, and a computer controller for controlling the gate signal source to provide, in sequence, gate signals varied in waveform, voltage, and frequency, in order to measure the I-V characteristics of the device in response to variable frequency gate signals. Values for maximum drain current (Imax) and percentage drop in Imax at different frquencies are derived and used to predict the RF performance characteristics of the device and to select good wafers early in the fabrication process, as well as for non-destructive testing of frequency dispersion effects on the device. For GaAs MESFET C-band devices fabricated with epitaxial layers, a single gate, and a surface passivation layer, a percentage drop in Imax of about 12-15% or less, measured at 10 Hz and 1 MHZ gate signal frequencies, are correlated to good levels of RF power output and efficiency.
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Biles Kenneth A.
Kasemset Dumrong
Oliver, Jr. James D.
Indyk Eugene S.
Karlsen Ernest F.
Moran John F.
Morris Jeffrey P.
Siemens Aktiengesellschaft
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