The characterization of communication devices in a certain frequency band can be accelerated if a fast frequency sweep technique is used instead of a discrete frequency sweep. Existing fast frequency sweep techniques are either complex or specific for a certain electromagnetic solver. In this work, a new fast frequency sweep method is proposed that consists in segmenting the device under analysis into simple building blocks. Each building block is characterized with a generalized (multimode) circuital matrix whose elements present a simple and flat frequency response that is interpolated using natural cubic splines with very few points. In this way, the response of each block along the whole frequency band is obtained efficiently and accurately with as many frequency points as desired. Then, the circuital matrices of all the blocks are cascaded and the circuital matrix of the whole device in obtained. The new fast frequency sweep was successfully applied to the analysis of different types of devices (all metallic rectangular waveguide filter, dielectric loaded rectangular waveguide filter, and substrate integrated waveguide filter). The computational times were reduced to 15% or 19%, depending on the device, when compared with a discrete frequency sweep using the same electromagnetic solver.
Characterization of Hand Clenching in Human Sensorimotor Cortex Using High-, and Ultra-High Frequency Band Modulations of Electrocorticogram