S-matrix-based bandpass negative group delay innovative model of inverted parallel arm distributed topology
Samuel Ngoho, Mariam Dème Camara, Yuandan Dong, Alexandre Douyère, Nour Mohammad Murad, Preeti Thakur, Atul Thakur, Rivo Randriatsiferana, Blaise Ravelo
Abstract
This paper develops an innovative model of bandpass (BP) negative group delay (NGD) inverted arm topology of parallel lines. The S-matrix model is established from impedance and admittance matrix operations of elementary transmission lines constituting the topology. Parametric analysis is performed to assess the influence of inverted arm structure sizes on the BP NGD specifications. To validate the theoretical concept, a proof of concept is designed in microstrip technology. The calculated and simulated results are in very good agreement. NGD value, center frequency and bandwidth of about −8 ns, 3.6 GHz and 4 MHz, respectively, are observed with insertion loss better than 1 dB and reflection loss better than 18 dB. The innovative NGD physical structure could be an important asset to reduce propagation delay in the upcoming telecommunications systems as the 5G system.