Single-Sideband Filter Theory with Television Applications

Given the phase and amplitude characteristics of a filter, a graphical method is presented for deriving the phase and amplitude characteristics of the modulation envelope or video-frequency response when a modulated carrier is impressed. Sources of distortion are briefly discussed. Several filter structures are considered as to their suitability for use in attenuating one side band of a television signal. Radio-frequency phase and amplitude characteristics are given, with notes as to the physical realizability of the structures. Resulting video-frequency phase and amplitude characteristics are derived after demodulation, and in some cases the video-frequency transient response resulting from a suddenly impressed carrier is given. Design formulas are given for a filter using transmission lines as circuit elements. Some problems in the application of a filter to the transmitter are considered. The gain of amplifier stages is treated for many types of video- and radio-frequency amplifiers, for single- and double-sideband use, and for one- and ten-stage amplifiers, when meeting certain tolerances to a fixed maximum modulation frequency.