Design of multi-band circuit with negative group delay and lower insertion loss characteristics

A novel multi-band pass negative group delay (NGD) circuit with lower insertion loss is proposed in this paper. Firstly, a single-band NGD circuit cell is designed as the fundamental component of the multi-band circuit. Secondly, this paper utilizes a tri-band circuit as an illustrative example to demonstrate the implementation of multi-band circuit. The scattering parameters are utilized to analyze the proposed two-port circuits. The circuit was subjected to theoretical analysis based on the relevant principles of microwave circuits. Finally, by simulating the circuit on ADS software, the impact of each component on the performance of the circuit is obtained. The proposed circuits are fabricated and measured, from the measured results, the single-band cell can generate a group delay of −3.73 ns at 138.1 MHz, with an associated insertion loss of only 2.5 dB. The group delay value of the multi-band circuit in the three bands are −3.99 ns, −3.47 ns and −3.12 ns, and the maximum insertion loss is only 3.31 dB. The bandpass NGD measured results agree well with the theoretical prediction. The proposed NGD bandpass circuit can be applied for signal delay correction.