scholarly journals A Generalized 90° Out-of-Phase Wilkinson Power Divider for Dual Port UHF CP RFID Antennae with variable Port Distance

Author(s):  
W Akash Sovis ◽  
Manilka Jayasooriya

In this paper a microstrip Wilkinson power divider with a 90° phase delay at one output port is proposed to obtain circular polarization to feed a dual port RFID antenna. The 90° phase delay was obtained by embedding an extra quarter wavelength at one port of the Wilkinson power divider. The feeding circuit is then mounted on the ground plane of the microstrip antenna feeding the radiating patch directly through the ground plane and dielectric layer thus reducing any fringing effect and resulting a mechanically compact unit. The proposed feeding method offers better expectation of antenna performance with minimal attenuation and coupling losses. The design process generalizes geometric pa- rameters of the Wilkinson power divider for variable port distances. The paper considers both UK and US RFID center frequencies, 870 MHz and 915 MHz respectively. Numeri- cally computed values for geometric design parameters for both frequencies are tabled as future design tools for port distances varying from 18 mm up to 34 mm at 870 MHz and 17 mm up to 32 mm at 915 MHz. Simulation results indicate a return loss (S11) of -20 dB and -26 dB at 870 MHz and 915 MHz operational frequencies respectively at 270° angled quarter wavelength.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Behdad Jamshidi ◽  
Saeed Roshani ◽  
Jakub Talla ◽  
Sobhan Roshani ◽  
Zdenek Peroutka

AbstractIn the design of a microstrip power divider, there are some important factors, including harmonic suppression, insertion loss, and size reduction, which affect the quality of the final product. Thus improving each of these factors contributes to a more efficient design. In this respect, a hybrid technique to reduce the size and improve the performance of a Wilkinson power divider (WPD) is introduced in this paper. The proposed method includes a typical series LC circuit, a miniaturizing inductor, and two transmission lines, which make an LC branch. Accordingly, two quarter-wavelength branches of the conventional WPD are replaced by two proposed LC branches. Not only does this modification lead to a 100% size reduction, an infinite number of harmonics suppression, and high-frequency selectivity theoretically, but it also results in a noticeable performance improvement practically compared to using quarter-wavelength branches in the conventional microstrip power dividers. The main important contributions of this technique are extreme size reduction and harmonic suppression for the implementation of a filtering power divider (FPD). Furthermore, by tuning the LC circuit, the arbitrary numbers of unwanted harmonics are blocked while the operating frequency, the stopband bandwidth, and the operating bandwidth are chosen optionally. The experimental result verifies the theoretical and simulated results of the proposed technique and demonstrates its potential for improving the performance and reducing the size of other similar microstrip components.


Electronics ◽  
2021 ◽  
Vol 10 (17) ◽  
pp. 2168
Author(s):  
Antra Saxena ◽  
Mohammad Hashmi ◽  
Deepayan Banerjee ◽  
Muhammad Akmal Chaudhary

This article presents the design scheme of a wideband Wilkinson Power Divider (WPD) with two-stage architecture utilizing quarter-wave transmission lines and short-circuit stubs. The bandwidth of the proposed WPD is flexible and can be controlled using the design parameters. The proposed design achieves excellent isolation between output ports in addition good in-band performance. The analysis of the proposed circuit results in a simplified transfer function which is then equated with a standard band-pass transfer function to determine the parameters of transmission lines, stub’s impedances, and the value of the isolation resistors. Furthermore, it is also demonstrated that a simple alteration in the proposed circuit enables the design of a wideband DC isolated WPD that maintains a good in-band and isolation performance. A number of case studies have been included to highlight the flexibility of the proposed design. Two distinct prototypes are developed on different boards to demonstrate the wideband performance of the proposed design. An excellent agreement between the experimental and measured results for both the designs over a wide band including very good isolation between ports validate the proposed design.


2014 ◽  
Vol 23 (10) ◽  
pp. 1450135
Author(s):  
YONGLE WU ◽  
QIANG LIU ◽  
JUNYU SHEN ◽  
YUANAN LIU

A Wilkinson power divider with improved bandpass filtering and high isolation performance is proposed. These characteristics are achieved by replacing the quarter-wavelength transmission line in the conventional coupled line Wilkinson power divider with quarter-wavelength side-coupled ring (QSCR). Additional features such as DC blocking between arbitrary two ports, single-layer via-less structure for low-cost fabrication and convenient integration (as only one isolation resistor required) are highlighted. A 2-GHz Wilkinson microstrip power divider with a fractional bandwidth of 4% has been fabricated and experimentally characterized. The consistency between simulated and measured results validates the effectiveness of our proposed design.


2015 ◽  
Vol 8 (8) ◽  
pp. 1253-1263 ◽  
Author(s):  
R. Hafezifard ◽  
Jalil Rashed-Mohassel ◽  
Mohammad Naser-Moghadasi ◽  
R. A. Sadeghzadeh

A circularly polarized (CP) and high gain Microstrip antenna is designed in this paper using metamaterial concepts. The antenna, built on a metamaterial substrate, showed significant size reduction and less mutual coupling in an array compared with similar arrays on conventional substrates. Demonstrated to have left-handed magnetic characteristics, the methodology uses complementary split-ring resonators (SRRs) placed horizontally between the patch and the ground plane. In order to reduce mutual coupling in the array structure, hexagonal-SRRs are embedded between antenna elements. The procedure is shown to have great impact on the antenna performance specifically its bandwidth which is broadened from 400 MHz to 1.2 GHz for X-band and as well as its efficiency. The structure has also low loss and improved standing wave ratio and less mutual coupling. The results show that a reduction of 26.6 dB in mutual coupling is obtained between elements at the operation frequency of the array. Experimental data show a reasonably good agreement between simulation and measured results.


2015 ◽  
Vol 713-715 ◽  
pp. 1048-1051
Author(s):  
Xin Cao ◽  
Zong Xi Tang

In this paper, an ultra-wideband Wilkinson power divider based on the quarter wavelength transformation is proposed. The proposed power divider utilizes the resonance property of the four stage quarter wavelength microstrip stubs to increase the isolation between the to output ports. As the measured results show that, the power divider has the insertion loss less than 1.3dB with the minimum isolation 15.4dB in the working frequency range from 1GHz to 5GHz. The simulated results and measured results are in good agreement and the proposed power divider can be applied in the communication systems in modern electronic engineering.


Frequenz ◽  
2017 ◽  
Vol 71 (11-12) ◽  
Author(s):  
Saeed Roshani

AbstractIn this paper, a novel compact Wilkinson power divider with harmonics suppression using meandered compact microstrip resonating cells (MCMRC) at 2 GHz is proposed. In the design structure an open stub is used to suppress 2nd harmonic and two proposed MCMRC units are inserted into quarter wavelength lines of the conventional power divider to suppress 3rd–7th harmonics. The proposed power divider reduces the size over 65 % compare to the conventional one and impressively suppresses the harmonics (2nd–7th) with high level of attenuation. The proposed resonator and power divider are fabricated and measured. The measured and simulated results are in good agreements. The overall dimensions of the resonators and proposed power divider are only about 1.56 mm×9.2 mm (0.013 λg×0.08 λg) and 9.1 mm×13.1 mm (0.08 λg×0.11 λg) respectively.‎


Author(s):  
Kalyan Mondal

In this work, a broadband high gain frequency selective surface (FSS)-based microstrip patch antenna is proposed. The dimensions of the microstrip antenna and proposed FSS are [Formula: see text] and [Formula: see text]. A broadband high gain reference antenna has been selected to improve antenna performance. The reference antenna offers 1.2[Formula: see text]GHz bandwidth with 6.03[Formula: see text]dBi peak gain. Some modifications have been done on the patch and ground plane to enhance the bandwidth and gain. The impedance bandwidth of 7.70[Formula: see text]GHz (3.42–11.12[Formula: see text]GHz) with 4.9 dBi peak gain is achieved by the microstrip antenna without FSS. The antenna performance is improved by using FSS beneath the antenna structure. The maximum impedance bandwidth of 7.70[Formula: see text]GHz (3.32–11.02[Formula: see text]GHz) and peak gain of 8.6[Formula: see text]dBi are achieved by the proposed antenna with FSS. Maximum co- and cross-polarization differences are 21[Formula: see text]dB. The simulation and measurement have been done using Ansoft Designer software and vector network analyzer. The measured results are in good parity with the simulated one.


Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 677
Author(s):  
Elham A. Serria ◽  
Mousa I. Hussein

This study is addressing the slotted ring resonator effect on the performance of the ultra-wide band (UWB) microstrip antenna. Two types of metamaterial with double slotted ring resonators (SRR), circular (C-SRR) and square (S-SRR), are studied and implemented on back of the antenna. The design examines the effect of the number of the SRR and its position with respect to the antenna’s ground plane and the rotation of the inner and outer C-SRR rings on different antenna characteristics. The dimensions of the antenna are 45 mm × 31 mm × 1.27 mm. The implementation of the SRR increased the antenna bandwidth to cover the range from 2.2 GHz to 9.8 GHz with rejected bands and frequencies. Antenna simulated characteristics like return loss, maximum gain and radiation pattern are obtained utilizing HFSS. The return loss measurement and the VSWR of the antenna with all SRR configuration studied are in good agreement with simulated results.


2021 ◽  
Vol 11 (9) ◽  
pp. 4148
Author(s):  
Maaz Salman ◽  
Youna Jang ◽  
Jongsik Lim ◽  
Dal Ahn ◽  
Sang-Min Han

A modified Wilkinson Power Divider is proposed in this paper that utilizes defected ground structure (DGS) in parallel with an isolation resistor. The proposed DGS section is incorporated between the output ports, and the isolation resistor is soldered in parallel with the DGS in the ground plane, instead of on the top plane as in a conventional Wilkinson power divider, to achieve improved or preferable isolation. The proposed design is comprised of two pairs of microstrip transmission lines with equal impedances and varied electrical lengths. The parameters of the main circuit and the DGS section are acquired separately. The parameters of the proposed main circuit are derived by applying conjugate matching theory. Dumbbell-shaped DGS is introduced in the ground plane between the output ports, which acts as a parallel resonator, yielding an attenuation pole at the resonant frequency that contributes to improved isolation. By applying the previous well-known circuit theory, the lumped elements of the equivalent circuit of the DGS were achieved. The physical dimensions of the equivalent circuit for the DGS section were obtained by three-dimensional EM simulation. The measured results show improved isolation, return loss and better bandwidth as compared with other similar works. Furthermore, the proposed circuits designed at resonating frequencies of 3 and 2 GHz presented comparatively good return losses, S11 of about −25.54 and −31.24 dB, respectively, and achieved improved isolations, S32 between the output ports, in an order of about −40.83 and −36.05 dB, respectively, which is rather exceptional and desirable.


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