INVESTIGATION OF A VOLTAGE TUNABLE FILTER FOR P-BAND COMMUNICATION RECEIVERS,
Abstract
An experimental study is described of a backwardwave tube for use with communication receivers over that part of P-band from 225 to 400 Mc. Such receivers, particularly those which must operate in an environment of strong adjacent signals, need an increased degree of discrimination against these spurious signals. Since the backward-wave amplifier is inherently a very narrow bandwidth filter, its use in this application is apparent. A backward-wave oscillator was operated just below the threshold of oscillation as a high-gain amplifier over the frequency range 270 to 432 Mc. This gave a maximum ''electronic'' gain of 30 db; however, the overall gain of the device was unity, with the major portion of the loss occurring in the input and output couplers. The off-frequency signal attenuation capabilities were found to be 20 db over a bandwidth of 4 Mc at 330 Mc and 6 Mc at 400 Mc. These measurements were made with a power output of the device in the neighborhood of 50 db below 1 mw. Other characteristics of the tube such as oscillation starting current, large signal behavior, and cross modulation were studied briefly, with major emphasis being put on frequency rejection characteristics. While rapid electronic tuning would not be feasible with this tube. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 16, 1963
- Accession Number
- AD0427256
Entities
People
- H. D. Arnett
- H. E. Brown
- S. T. Smith
Organizations
- United States Naval Research Laboratory