Showing papers on "Return loss published in 1972"

Cating system for waveguide transmission line utilizing spaced reflectors

Abstract: Faults having negligible reflectivity but causing substantial signal loss in an overmoded waveguide transmission line can be located by utilizing reflectors spaced at substantially equal intervals along the line. Return loss from these reflectors is measured and faults localized between any two of such reflectors by detecting any departure of the return loss from a linear increase with distance.

Time-Domain Reflectometer Measurement of Random Discontinuity Effects on Cable Magnitude Response

Abstract: Time-domain reflectometry (TDR) is used to specify the structural return loss and structural transmission loss that are caused by the randomly spaced electrically short structural defects that are present in commercially available coaxial cables. The theory for the statistical prediction of these effects is presented and TDR methods for making measurements are described. The results should be of particular interest in telephony and CATV applications.

A Precision System for Radio-Frequency Network Analysis

Abstract: A system is described that characterizes two-port RF networks from 0.4-500 MHz. Parameters measured are characteristic insertion loss, characteristic phase, and return loss, as well as group delay. Emphasis is placed on dynamic range specifications and the choices made in arriving at them. The factors controlling dynamic range are considered in detail with particular regard to those decisions that were made before hardware design began. An example is given demonstrating 115-dB range from maximum drive level to all noise and crosstalk.

Automated Attenuation Test in Multimodal Waveguides by Resonance Return-Loss or Insertion-Loss Measurements

Abstract: Two methods for testing short lengths of multimodal circular waveguides, working in the TE/sub 01/ mode accompanied by many spurious modes are described. One method is based on the measurement of the return loss of a resonant one-port cavity; the second one measures the insertion loss of a cavity coupled to the rectangular main waveguide. Automatic data selection and manipulation are emphasized.

Panoramic and automatic return loss measuring system

Abstract: A system for determining the return loss of an impedance device employs a bridge network coupled to the impedance. The frequency of an input signal to the bridge network is swept continually from a first frequency to a second frequency and then back to the first frequency. A conversion circuit converts the varying frequency input and output signals of the bridge network to a pair of fixed frequency signals which are alternately coupled via a switch to the input connection of a logarithmic channel the output of which is connected to the vertical deflection terminal of an oscilloscope. A signal proportional to the logarithm of the bridge network input signal is displayed in the oscilloscope when the frequency is being swept in a first direction and a signal proportional to the logarithm of the bridge network output signal is displayed when the frequency of the input signal is being swept in the second direction, thus enabling the return loss to be read directly from the oscilloscope.

Propagation loss measuring device

Abstract: This disclosure is directed to a system for determining the propagation loss of a signal passing through water. A signal generator directs a signal through a hydrophone into the water simultaneous with directing a signal into a computer. The return signal is directed into the computer and the pulse energy of the returned signal is compared with the original signal. The difference is a measure of the signal loss.