Stop-band type NGD RLC-resonant circuit sensitivity analysis

Abstract

This paper investigates on the rarely studied negative group delay (NGD) RF circuit with innovative stop-band (SB) behavior. In difference with the classical filter, the SB-NGD function is identified in function of frequency bands where the group delay (GD) presents negative sign. The ideal diagram specifying the SB-NGD function is introduced by indicating all the appropriate parameters. The S-parameter analytical model of the circuit is established. The SB-NGD analysis is developed. The main specifications of the SB-NGD circuit are expressed in function of its constituting components. Then, the design synthesis equations enabling to determine the SB-NGD circuit in function of the desired specifications as the center frequency and GD are built up. To illustrate concretely the feasibility of the SB-NGD function, a circuit proof-of-concept composed of LC-series network is theoretically analyzed. A parametric analysis on the SB circuit elements is accomplished to appraise the influence of each element on the SB-NGD specifications. To validate the unfamiliar SB-NGD theory, a prototype is fabricated and tested. The GD measured response of the considered circuit is compared by simulations and analytical calculations. SB-NGD responses showing a good agreement between the calculation and simulation are obtained with a 15 MHz center frequency, 44 ns GD and 3 MHz bandwidth.