Tektronix, Inc.

Desmond L Murphy

Gary W Reed

Scott R Jansen

Warren K Wimmer

John C Hastings

Kenneth C Holland

Bret Ericsen

A resistor formed by a film of resistive material deposited on a dielectric substrate is trimmed by removing resistive material along a line such that the film is divided into at least two discrete areas, one, and only one, of which areas includes two terminal portions of the film.

Film resistors

An improved signal input circuit suitable for use in wideband oscilloscopes includes a high impedance controllable attenuator stage.

Oscilloscope signal input circuit including an attenuator

A termination for high impedance attenuator to be connected to the input of such high impedance attenuator. The termination circuit includes a series combination of a termination resistor, a delay line and an inductor, thereby cancelling the negative reflection due to the capacitive element at the output of the attenuator while maintaining the overall input impedance constant over a wide frequency range.

Termination for high impedance attenuator

A high-impedance cascade attenuator device includes a plurality of attenuator stages mounted on a single substrate by means of metallization and thick film processes. The attenuator stages are conventional frequency-compensated voltage dividers designed for high-frequency operation; however, the capacitive compensation is included in the thick film process, and the attenuator components may be trimmed to provide precise impedance ratios so that calibration or circuit adjustments are never required.

Hybrid cascade attenuator

A high-impedance programmable attenuator utilizing field-effect transistor (FET) switching in both the high-impedance and low-impedance sections. In the high-impedance section, hybrid passive attenuator elements are employed to provide attenuation of electrical signals, and both series and shunt forms of active switching are employed to align the appropriate signal paths. The low-impedance amplifier section includes a FET-switched resistive network.

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Portland, OR, United States of America

Desmond L Murphy