Miniaturized negative group delay circuit using defected microstrip structure and lumped elements

Abstract

In this paper, a design of miniaturized negative group delay circuit (NGDC) using U-shaped defected microstrip structure (DMS) and lumped elements is presented. The resonant center frequency and group delay (GD) time are controlled by an external capacitor and resistor connected across the DMS slot. To verify the design concept, a single stage NGDC is designed, fabricated and compared with the circuit simulation. To get wideband bandwidth of GD, two stages NGDC is also demonstrated and the GD of -7 ns with the maximum insertion loss of 34 dB was obtained over 60 MHz bandwidth.