2026-03-08 Latest Published
By Aixia Yuan
Zhiyang Feng
Junzheng Liu
Yuwei Meng
Niannan Chang
Hongjun Zhang
Progress In Electromagnetics Research C, Vol. 167, 32-38, 2026
Abstract
This study proposes a novel π-type circuit topology designed to achieve broadband and flat negative group delay (NGD) characteristics. Featuring a simple structure composed entirely of passive lumped elements, the proposed design offers significant advantages in terms of ease of fabrication, low cost, and seamless integration into larger microwave systems. First, a comprehensive theoretical analysis was conducted to establish the operational principles and derive the design equations. We then systematically investigated the sensitivity of the circuit's performance to variations in individual component values, which provides crucial guidelines for practical implementation. To validate our theoretical findings, a physical prototype with compact dimensions of 32 mm × 35 mm was designed and fabricated. Experimental results demonstrate that at the center frequency of 107.5 MHz, the circuit achieves an NGD of -2.27 ns with an insertion loss of 19.5 dB. Notably, the circuit maintains a wide flat NGD bandwidth of 151 MHz, exhibiting a group delay fluctuation of merely 4.1% across the band. These results confirm the effectiveness and robustness of the proposed circuit for broadband microwave applications.
