The Boeing Company

John Fluke Mfg. Co., Inc.

Thomas H Turnbull

James Benjamin Turner

Ramesh C Goyal

A broadband, inductively coupled, duplex, radio frequency (RF) transmission system for communcating between a central unit (10) and a plurality of remote units (31) is disclosed. The central unit (10) includes an RF signal source (11) and an RF receiver (21) connected to one end of a balanced transmission line (25) via a signal splitter (15) and a transmission line impedance matching network (27). Each remote unit (31) includes a receiving section (33) and a transmitting section (35) separate from one another. Each receiving section (33) and each transmitting section (35) includes U-shaped couplers (37,43) positioned so as to overlie the balanced transmission line (25). The U-shaped couplers (37,43) are oriented such that the cross-members of the U-shaped couplers (37,43) lie orthogonal to the balanced transmission line (25) and the legs of the U-shaped couplers (37,43) lie parallel to the balanced transmission line (25). The legs of the U-shaped couplers (37,43) are connected to electronic transmit and receive system RF receivers and Rf signal sources (41,47), via impedance matching networks (39,45).

Broadband, inductively coupled, duplex, RF transmission system

A method of, and an apparatus for, high speed resistance (R), inductance (L) and capacitance (C) measurement is disclosed. A voltage or current based excitation signal having a very low voltage level and a predetermined waveform is applied to the item whose R, L or C parameter(s) is (are) to be measured; and, voltage measurements are made at predetermined points in the time domain of the output voltage waveform. Whether the excitation signal is voltage based or current based, the particular shape of the waveform (preferably trapezoidal or dual polarity rectangular wave) and the voltage measurement points in the time domain of the output voltage waveform are determined by: (i) the nature of the parameter (R, L or C) to be measured; (ii) the magnitude of the parameter (small or large) in the case of R and C parameters; and, (iii) the series/parallel nature of the parameters in situations where significant amounts of two parameters coexist in the item being measured. The measured voltage values are used to determine the value(s) of the R, L or C parameter(s). The voltage level of the excitation signal can be maintained below the activation level of contemporary printed circuit board active circuit elements (e.g., transistors), without loss of accuracy. As a result, the invention can be used to measure the R, L and C parameters of in-circuit components.

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Everett, WA, United States of America

Thomas H Turnbull