A simple model is developed to characterize the behavior of radio-frequency absorbers at low frequency. The absorber is represented by a flat, homogeneous, isotropic slab of lossy material, with effective constitutive parameters. These parameters are determined by a fit to measured data. Excellent fits are obtained in the two applications considered. The model is intended for use in the charact...

A computer program has been written to investigate the design tradeoffs of high frequency diode frequency multipliers. Velocity saturation and breakdown have been included in a device model that is part of a nonlinear multiple reflection simulation. The device doping, epitaxial layer length and velocity vs. electric field curve are input parameters. The program has a search routine to match the...

A discrete-time, discrete-frequency Wigner distribution is derived using a group-theoretic approach. It is based upon a study of the Heisenberg group generated by the integers mod N , which represents the group of discrete-time and discrete-frequency shifts. The resulting Wigner distribution satis es several desired properties. An example demonstrates that it is a full-band time-frequency repre...

Radio resources planning for frequency hopping military systems is very complex task due to the size of considered deployments, the radio resource limitations and the complexity of the radio phenomena to take into account. In this paper, we present some aspects of the local search algorithm proposed to deal with this problem. We focus more specially on the developed degradation control mechanis...

This Letter presents a measurement of the spectral content of frequency shifted pulses generated by a lightwave synthesized frequency sweeper. We found that each pulse is shifted in frequency with very high accuracy. We also discovered that noise originating from light leaking through the acousto- optical modulators and forward propagating Brillouin scattering appear in the spectrum.