Showing papers on "Return loss published in 1968"
TL;DR: These amplifiers were required to meet stringent specifications beyond the general scope of previous art, related to the simultaneous availability of relatively large output power, tight linearity, minimal delay distortion across a 40 per cent band, high input and output return loss, large dynamic range, and time stability.
Abstract: Two amplifiers, each covering a different band in the VHF range, were constructed for test set applications. These amplifiers were required to meet stringent specifications beyond the general scope of previous art. These specifications related to the simultaneous availability of relatively large output power, tight linearity, minimal delay distortion across a 40 per cent band, high input and output return loss, large dynamic range, and time stability. The performance problems were solved by using: (i) Quadrature couplers in a corporate structure array to provide a high multiplicity of “paralleled” transistors, yielding both the power and return loss capabilities. (ii) The emitter follower configuration as the basic amplifier element, providing broad band, high level performance owing to the large self degeneration of that configuration. (iii) A “feed-forward,” instead of a feedback, system for error control and noise cancellation.
39 citations
TL;DR: In this paper, the authors show how a properly tuned coupling network may be selected, how the appropriate component values may be determined, and how the network can be accurately tuned, showing that the resulting tuned network has the following characteristics: 1) performance unaffected by substation bus conditions at the point of coupling; 2) predictable bandwidth and band location; 3) low coupling loss (less than?dB) from entrance cable to phase wire; 4) smooth frequency response (high return loss) over the derived band; 5) high blocking loss (greater than 25 dB) from
Abstract: The major objectives of this paper are to show how a properly tuned coupling network may be selected, how the appropriate component values may be determined, and how the network may be accurately tuned. Two new concepts relative to power line carrier coupling are introduced. The first deals with the establishment of workable limits for the range over which the coupling network may be detuned by 60-Hz bus conditions (while still meeting transmission objectives), and the second shows means for evaluating the effect of the coupling unit (return loss) upon the standing wave ratios in the wire line as well as in the entrance cables. The resulting tuned coupling network has the following characteristics: 1) performance unaffected by substation bus conditions at the point of coupling; 2) predictable bandwidth and band location; 3) low coupling loss (less than ?dB) from entrance cable to phase wire; 4) smooth frequency response (high return loss) over the derived band; 5) high blocking loss (greater than 25 dB) from phase wire to substation bus.