Article
A Novel Analytical Design Technique for a Wideband
Wilkinson Power Divider Using Dual-Band Topology
Asif I. Omi
1
, Rakibul Islam
2
, Mohammad A. Maktoomi
3
, Christine Zakzewski
3
and Praveen Sekhar
1,
*
Citation: Omi, A.I.; Islam, R.;
Maktoomi, M.A.; Zakzewski, C.;
Sekhar, P. A Novel Analytical Design
Technique for a Wideband Wilkinson
Power Divider Using Dual-Band
Topology. Sensors 2021, 21, 6330.
https://doi.org/10.3390/s21196330
Academic Editor: Ángela María
Coves Soler
Received: 10 September 2021
Accepted: 19 September 2021
Published: 22 September 2021
Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affil-
iations.
Copyright: © 2021 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
1
Department of Engineering & Computer Science, Washington State University Vancouver,
Vancouver, WA 98686, USA; asif.omi@wsu.edu
2
Department of Electrical & Computer Engineering, University of Illinois at Urbana-Champaign,
Urbana, IL 61801, USA; rakibul2@illinois.edu
3
Department of Physics & Engineering, The University of Scranton, Scranton, PA 18510, USA;
mohammad.maktoomi@scranton.edu (M.A.M.); christine.zakzewski@scranton.edu (C.Z.)
* Correspondence: praveen.sekhar@wsu.edu
Abstract:
In this paper, a novel analytical design technique is presented to implement a coupled-
line wideband Wilkinson power divider (WPD). The configuration of the WPD is comprised of
three distinct coupled-line and three isolation resistors. A comprehensive theoretical analysis is
conducted to arrive at a set of completely new and rigorous design equations utilizing the dual-band
behavior of commensurate transmission lines. Further, the corresponding S-parameters equations
are also derived, which determine the wideband capability of the proposed WPD. To validate the
proposed design concept, a prototype working at the resonance frequencies of 0.9 GHz and 1.8 GHz
is designed and fabricated using 60 mils thick Rogers’ RO4003C substrate. The measured result of
the fabricated prototype exhibits an excellent input return loss > 16.4 dB, output return loss > 15 dB,
insertion loss < 3.30 dB and a remarkable isolation > 22 dB within the band and with a 15 dB and 10
dB references provide a fractional bandwidth of 110% and 141%, respectively.
Keywords: coupled-line; coupler; dual-band; S-parameter; Wilkinson power divider
1. Introduction
Power divider/splitter circuits are one of the essential building blocks in all modern
microwave and wireless communication systems [
1
]. The three-port Wilkinson power
divider (WPD) is considered a paragon among such passive components. WPD was first
published in 1960 by Ernest J Wilkinson and used to provide electrically isolated output
branches with the same phase and equal power division, with all terminated ports matched,
in a very simple layout [
2
]. However, the presence of the intrinsically narrow bandwidth
of the conventional WPD has turned out to be one of the major design challenges. A
variety of modified WPD configurations have emerged over the years to cater to the needs
of wideband, harmonic-suppressed, and multi-standard topologies [
3
–
27
]. Recently, the
wideband WPDs have gained paramount importance in various applications such as power
amplifiers [
28
–
31
], Hilbert transformer-based dual-band single sideband modulator [
32
,
33
],
antenna arrays [
34
], phase shifters [
35
], and other RF front-end systems [
36
]. This is
mainly due to the recent progress in high data-rate 5G/6G wireless systems that has
refueled significant research interest in developing the next generation of wideband power
dividers [37–48].
To broaden the operational bandwidth, the fundamental idea has been to incorporate
a multi-section topology as proposed by Cohn [
3
]. Many different varieties of broadband
power dividers ensued [
4
–
12
] following Cohn’s idea. The conventional multi-section
WPD design [
2
] is a fully analytical technique but only for a two-section WPD. For three
and more sections, the reported technique is a table-based design and is, therefore, less
computer friendly. Furthermore, among the multiple other demonstrated techniques to
Sensors 2021, 21, 6330. https://doi.org/10.3390/s21196330 https://www.mdpi.com/journal/sensors
