Dual-Band Negative Group Delay Microwave Circuit With Low Signal Attenuation and Arbitrary Frequency Ratio

Yuwei Meng,Shaojun Fang,Te Shao,Hongmei Liu,Zhongbao Wang,Zhining Chen

doi:10.1109/access.2020.2978545

Yuwei Meng, Shaojun Fang + Show 4 more

Open Access

https://doi.org/10.1109/access.2020.2978545

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Abstract

A dual-band negative group delay (NGD) microwave circuit with low signal-attenuation and arbitrary frequency ratio is proposed. Closed-form analytical equations are derived for the design of the proposed dual-band negative group delay circuit (NGDC) with the variable frequency ratio. The characteristic parameters of the microstrip lines that influence the frequency ratio are investigated. Under the condition that the microstrip circuit can be implemented with the common printed circuit board (PCB) fabrication technology, the frequency ratio can vary between 1.1 and 6.3. For verification, three dual-band NGDCs with the frequency ratio of 1.105, 3, and 5.667 are designed, fabricated, and measured. Good agreements are observed between simulated and measured results, indicating the validity of the proposed methods.

Highlights

Modern wireless communication systems are required to operate at several frequency bands and work across different communication standards
The negative group delay (NGD) characteristics could be generated by RLC resonant circuits [10] or left-handed materials [11]
Based on the mode of transmission, the negative group delay circuit (NGDC) can be divided into two categories: the reflection type and

Summary

INTRODUCTION

Modern wireless communication systems are required to operate at several frequency bands and work across different communication standards. The couplers are usually needed to transform the circuit into transmission type [12]–[15]. Some passive circuits or structures based on the amplifier are presented to reduce the insertion loss (IL) [18]–[23]. These circuits only operate at one frequency and are incompetent for multiband application. Y. Meng et al.: Dual-Band NGD Microwave Circuit With Low Signal Attenuation and Arbitrary Frequency Ratio to achieve gain compensation [29]. A dual-band NGDC with arbitrary frequency ratio is proposed to reduce the signal attenuation. A wider range of frequency ratios can be obtained by using different stubs

THEORY AND DESIGN EQUATION

FREQUENCY RATIO OF DUAL-BAND NGDC WITH OPEN-CIRCUITED STUB

EXPERIMENTAL VERIFICATION

DISCUSSION

CONCLUSION