On the investigation of contactless bandpass NGD control with microstrip patch-based circuit

This paper presents an investigation on innovative bandpass negative group delay (NGD) control. The bandpass NGD theory is elaborated with patch antenna-based circuit input impedance. The S-matrix and group delay (GD) models are expressed in function of the circuit geometrical parameters. To validate the no-contact electromagnetic coupling bandpass NGD control, proof of concept is designed, fabricated and tested. The bandpass NGD behavior is in good agreement between theoretical model, EM full wave simulation and measurement, which shows NGD center frequency, 2.2 GHz, value, -0.67 ns and insertion loss, -2.93 dB, and reflection loss, -11.39 dB. It is also demonstrated that the NGD parameters vary in function of the metallic sheet-patch distance increased progressively from 0 to 26 cm.