Journal of Microwaves, Optoelectronics and Electromagnetic Applications
On-line version ISSN 2179-1074
RAVELO, Blaise and DE BLASI, Serge. An FET-based microwave active circuit with dual-band negative group delay. J. Microw. Optoelectron. Electromagn. Appl. [online]. 2011, vol.10, n.2, pp. 355-366. ISSN 2179-1074. http://dx.doi.org/10.1590/S2179-10742011000200006.
Recent studies proved that certain electronic active circuits are capable to exhibit simultaneously a negative group delay (NGD) and amplification in microwave frequency bands. One of the simplest topologies generating this counterintuitive NGD function effect is formed by a series RLC-network in cascade with a transistor. By using this cell, similar to the classical electronic functions, dual-band NGD microwave devices with loss compensation possibility can be designed. Theoretic demonstrations concerning the theory of the NGD circuit considered are presented. The dual-band NGD concept feasibility is concretely illustrated by an example of EM/circuit co-simulations. So, in frequency domain, dual-band NGD with minimal values of about -1 ns was observed simultaneously within two frequency bands centered at about 1.05 GHz and 2.05 GHz. To highlight the functioning of the hybrid device considered, time-domain analysis showing the RF/microwave signal advancement is performed. As application, the concept investigated can be envisaged for data synchronization in multi-channel wireless communication systems eventually degraded by undesired EMI effects.
Keywords : Dual-band device; microwave active circuit; negative group delay (NGD); signal synchronization.