A Low-Cost Compact Low-Pass Filtering Power Divider Based on Elliptic Function with Wide Attenuation Band

Abstract

A filtering power divider (FPD) with low-pass property and wideband harmonic suppression is presented in this paper. The microstrip structure of the FPD is designed based on elliptic function. The open stubs are embedded in the transmission line to obtain low-pass effect. An isolation resistor of 100Ω is connected between the two output ports to achieve good isolation. The operating frequency of the power divider is 2.9 GHz and the low-pass filter (LPF) has the cut-off frequency of 3 GHz with a sharpness factor of 55 dB/GHz. The attenuation band is extended up to 20 GHz (simulated) with a suppression of −19 dB. The maximum insertion loss in the passband for the FPD is −3.6 dB and the structure occupy an area of 0.7${\lambda }_g$ × 0.21 ${\lambda }_g$. A lumped equivalent circuit of the LPF structure is also proposed. The LPF and the FPD both are fabricated using low-cost substrate FR4 of height (h) of 0.8 mm, a dielectric constant (ε_r) of 4.4, conductor thickness (t) of 0.04 mm and loss tangent (δ) of 0.02. For experimental verification, the measured data are compared with the simulated ones.

KEYWORDS:

• Filtering power divider
• Isolation resistor
• Low-pass filter
• Odd and even modes

Acknowledgement

This work was supported by Shri Dipesh Debnath of National Institute of Technology, Agartala, Tripura, India.

Additional information

Notes on contributors

Sarbani Sen

Sarbani Sen (born in 1990) received the bachelor's degree (BTech in electronics and communication engineering) from SRM University, Chennai, India, in 2012 and completed the post graduation (M.Tech.) in the field of Communication Engineering from National Institute of Technology, Agartala, India, in 2016. Currently, she is pursuing PhD from National Institute of Technology, Agartala, India, in the field of RF and microwave circuits from Electronics and Communication Engineering Department. Corresponding Author. E-mail: [email protected]

Tamasi Moyra

Tamasi Moyra (born in 1978) received the AMIE (India) degree in electronics and communication engineering from Institution of Engineers, India, in the year of 2003. She did ME in the year of 2007 from Bengal Engineering and Science University, Shibpur, India, in the Department of Electronics and Telecommunication Engineering. She received her PhD degree in the year of 2014 from the Department of Electronics and Telecommunication Engineering at Indian Institute of Engineering Science and Technology (IIEST), Shibpur, India. Presently, she is working as an assistant professor in the Department of Electronics and Communication Engineering at National Institute of Technology, Agartala. She has published more than 25 research articles in different peer reviewed journals, international conferences, and book chapters. Her current research interests include the planar circuits, microstrip filters, antenna elements, LHM, meta-materials, etc. She is a member of Institution of Engineers and IEEE. E-mail: [email protected]