Institute for Telecommunication Sciences
the research laboratory of the National Telecommunications and Information Administration

Frank Sanders

Abstract: When radiofrequency pulse envelopes are observed away from their fundamental frequency their shapes differ from those at their fundamental frequency. Off-fundamental pulse envelopes tend to exhibit spikes at their rising and falling edges with lower-amplitude energy between the spikes. This phenomenon, called the rabbit ears effect, is described in this NTIA Report. Examples of rabbit ears pulse envelopes are provided in a mathematical simulation and from measurements of off-fundamental pulse envelopes of two models of 5 GHz weather radars. Morphologies of rabbit ears pulses are examined. A method is provided for using this effect to determine the durations and bandwidths of chirped pulses in bandwidth-limited measurement systems. Implications for off-fundamental detection of pulsed signals for dynamic frequency selection (DFS) algorithms are considered.

Keywords: radar spectrum; chirped pulses; dynamic frequency selection (DFS); off-fundamental signal detection; pulsed radiofrequency (RF) signals; rabbit ears

To request a reprint of this report, contact:

Lilli Segre, Publications Officer
Institute for Telecommunication Sciences
(303) 497-3572

For technical information concerning this report, contact:

Frank H. Sanders
Institute for Telecommunication Sciences
(303) 497-7600

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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