Conventional Wilkinson Power Divider Research Articles

A Wilkinson power divider with harmonic suppression through low-pass filter for GSM and LTE applications

Conventional Wilkinson power dividers (WPDs) perform satisfactorily near the intended operation frequency. Nonetheless, these WPDs demonstrate subpar performance in the stopband and necessitate a significant physical space. To enhance the existing level of advancement and in order to improve on the current state-of-the-art, a modified WPD is designed and fabricated, demonstrating a significant improvement in stopband and superior isolation between output ports. To improve the stopband and suppress unwanted harmonics, a low-pass filter (LPF) structure is placed in the both branches of the conventional WPD. The proposed modified WPD depicts a wide stopband bandwidth (fSB > 17.25 GHz) from 2.75 to over 20 GHz with an attenuation level of 20 dB, suppressing 2nd to 11th harmonics. According to measured results, the input return loss (|S11|), insertion loss (|S21|) and output isolation (|S32|) at f = 1.8 GHz are better than 33 dB, 3.2 dB and 21 dB, respectively. Indeed, the proposed modified WPD exhibits a magnitude imbalance of 0.00018, a phase imbalance of 1.25 degrees and a group delay of 0.5 ns. The proposed WPD depicts a compact size of 35 mm × 25 mm (0.38 λg × 0.27 λg), where λg is the guided wavelength at f = 1.8 GHz. There is a good agreement between the simulated and measured results. According to the obtained results, the proposed modified WPD shows a desirable performance for modern LTE and GSM communication applications.

Design of N-Way Wilkinson Power Dividers with New Input/Output Arrangements for Power-Halving Operations

In this paper, new single/double-layer N-way Wilkinson power dividers (WPDs) were designed by using slow-wave structures such as narrow-slit-loaded and meandered transmission lines. For size reduction, the slit-loaded and meandered lines were used instead of the quarter-wavelength transmission lines of a conventional WPD. Based on the proposed approaches, two-, four-, and eight-way power dividers were designed, simulated, and fabricated. The fabricated 2-, 4-, and 8-way circuits were measured at the center frequencies of 2.03, 1.77, and 1.73 GHz, which are in excellent agreement with the predicted ones. The meandered transmission lines were also used to design WPD types with novel input/output port arrangements. For this purpose, two three-way WPDs were located on both sides of the same board to have different power-splitting ratios at different inputs and outputs in order to provide alternative solutions for antenna arrays. Furthermore, a five-way dual-layer WPD was introduced by locating the meandered transmission lines into two layers. The most important advantage of the proposed 3- and 5-way WPDs is that they allowed the input power at the next output port to be halved, in the order of P/2, P/4, P/8, P/16, and P/16. All the designed power-halving WPDs were simulated, fabricated, and successfully tested.

Design and fabrication of a Wilkinson power divider with harmonic suppression for LTE and GSM applications

Conventional Wilkinson power dividers (WPDs) can provide acceptable performance close to the nominal center frequency. However, these WPDs can also exhibit poor out-of-band performance while requiring a large footprint. In order to improve on the current state of the art, a modified microstrip WPD is proposed that exhibits a substantially improved stopband and high isolation. A lowpass filter (LPF) structure is utilized in both branches of the power divider to provide harmonic suppression. According to the obtained results, the input return loss (|S11|), output return loss (|S22|), output insertion loss (|S21|) and isolation (|S32|) are better than 34.2 dB, 26.2 dB, 3.52 dB and 31.2 dB, respectively. The proposed modified WPD has a wide 20 dB stopband (from 2.54 GHz to 13.48 GHz) and filters the second to seventh harmonics with attenuation levels of greater than 20 dB. The proposed WPD has a small size of 33.8 mm × 27 mm (0.42 λg × 0.33 λg), where λg is the guided wavelength at the operating frequency of 1.8 GHz. The WPD has been fabricated and tested and shows good agreement between simulated and measured results and the proposed design has desirable characteristics for LTE and GSM applications.

Designing ultra-small Wilkinson power divider with multi-harmonics suppression

ABSTRACT This paper presents a miniaturized Wilkinson Power Divider (WPD) with the capability of attenuating unwanted harmonics up to the 19th harmonic. In this study, a low pass filter was embedded as the quarter-wavelength transmission lines of the conventional WPD. To reduce the size of the proposed structure, the high impedance line is meandered. A simple T-shape resonator is added to suppress the high frequency. The even and odd mode analysis were reported as the analytical descriptions. The operational frequency of the presented WPD is 1.95GHz, and S21, S11, S22, and S23 in this frequency are -3.79dB, -15.56dB, -14.15dB, and -10.89dB, respectively. The overall size of implemented WPD is only 8.8 mm × 8.02 mm, and its normalized circuit size equals 0.078 × 0.071. The designed structure has been fabricated and measured on the RT-5880 substrate with a thickness of 20mil. The desired matching between the simulation results and the measurement ones has been evident.

A Novel Filtering Power Divider Based on Ring Resonator

In this paper, a compact dual-band filtering power divider (FPD) combined by conventional Wilkinson power divider and dual-mode resonators is proposed. The resonators submitting the quarter wavelength transmission line can act as a filter. The proposed resonator is composed of two cascading symmetrical ring branches connected to the ground in the middle. The inter-digital coupling structure constitutes the feed lines of the band-pass filter (BPF) operating at 2.45/5.8 G. The resonator with symmetrical structure is analyzed by the odd-even mode method in detail. The two resonant frequencies can be adjusted by the length of the stub separately. In addition, two isolation resistors are placed at proper position for ensuring the isolation effect. The proposed FPD is fabricated for verifying simulation results, and good agreements between the simulated and measured results are achieved here.

2 n -Way Wideband Filtering Power Dividers With Good Isolation Enhanced by a Modified Isolation Network

In this article, a class of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2^{n}$ </tex-math></inline-formula> -way wideband filtering power dividers (FPDs) is presented and designed with a wide isolation band. It consists of ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2^{n}-1$ </tex-math></inline-formula> ) two-way power-dividing units and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> three-line coupled lines. The basic two-way power divider is achieved by replacing a simple isolation resistor of the conventional Wilkinson power divider with a modified isolation network, so as to improve the bandwidth of better-than-20-dB isolation band from 40% to 120%. The modified isolation network is composed of one quarter-wavelength coupled line, two quarter-wavelength transmission lines, and one resistor. The three-line coupled line is introduced at each output of the proposed FPD to improve its frequency selectivity and passband bandwidth. Furthermore, after placing one additional isolation resistor on each three-line coupled line, the number of output ports in the proposed power divider could be doubled without introducing more two-way power-dividing units. Finally, a prototype two-way and two prototype four-way wideband FPDs with different occupied sizes are designed and fabricated. The feasibility of the proposed design method is verified by the good agreement between the simulated and measured results.

A 65‐nm 28‐GHz CMOS Wilkinson power divider with improved isolation

AbstractIn this study, we implemented a Wilkinson power divider/combiner composed of lumped elements suitable for 28‐GHz of fifth‐generation mobile communication technology. To improve the isolation of the system, signal perfect cancellation analysis is used with optimized values of the lumped elements of the Wilkinson power divider, which is fabricated using bulk complementary metal–oxide–semiconductor (CMOS) 1P9M 65‐nm process and the fabricated circuit area was 0.046 mm2. The measured insertion loss of this system is less than 0.62 dB, input/output matching exceeds 16.9 dB, and isolation between the output ports exceeds 19.6 dB in the operating frequency range of 25.5–29.5 GHz. The circuit thus has low insertion loss and good isolation compared to conventional Wilkinson power dividers manufactured for use in the similar frequency bands.

Compact Wilkinson power divider with extensive suppression of harmonics, using a combination of trapezoidal, circular and rectangular resonators

A low pass filtering power divider (LPFPD) with good isolation and extensive suppression of harmonics has been presented. In the design of the Wilkinson power divider, a new structure has been proposed by replacing two quarter wavelength stubs of the conventional Wilkinson power divider (CWPD) with a combination of trapezoidal, circular, and rectangular resonators. In this power divider, the undesired harmonics have been suppressed. The WPD has a miniaturized structure, which the normalized circuit size (NCS) is 0.1 λg × 0.08 λg and the operating frequency is located at 1.67 GHz. Ultimately, the power divider has been fabricated and tested. The return loss is about 28 dB and the isolation between the output ports is higher than 23 dB. The experimental results mimic the early design results. Thus, the proposed WPD has a good performance and can be used in many communication systems.

A Dual-Mode Power Divider With Embedded Meta-Materials and Additional Grounded Resistors

This article presents a dual-mode power divider (PD) that offers new working mechanism, compact size, significant design freedom, wide working bandwidth, arbitrary power division, and ultrawide isolation between the two output ports. The structure is simple in comparison with conventional Wilkinson PDs in that only two composite right-and left-handed (CRLH) transmission lines (TLs) grounded through two resistors are used. Different from previous CRLH-TL-embedded studies in that almost all CRLH-TLs operate at quarter-wavelength phase responses, in the present work, the zero-degree property is noted and used to modify the impedance variation curves. Additionally, because of the use of grounded resistors, the proposed PD can operate in two modes, such that when high-value resistors are used, the PD operates in a lossless mode, while when low-value resistors are used, the PD operates in an attenuated mode. Because working power has been significantly improved due to progress in modern RF system development, more attenuation elements are required. This means that attenuated PDs will become very useful in the future. For verification, two PDs operating in different working modes and power divisions are designed and fabricated. Based on the experimental results, both PDs demonstrate good performance over more than 60% of the bandwidth with reference to the 15-dB S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> , ultrawide isolation, full port matching, and compact size.

A W-Band 1-dB Insertion Loss Wilkinson Power Divider Using Silicon-Based Integrated Passive Device

This work presents an on-chip Wilkinson power divider using silicon-based integrated passive device (IPD) technology that operates from 70 to 110 GHz, thereby covering the entire W-band (75-110 GHz). Based on a simple impedance transformation different from the conventional Wilkinson power divider topology, the proposed silicon IPD power divider with a core size of 0.417 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> can demonstrate power loss of less than 1.1 dB along with input-output return loss better than 14 dB throughout the entire band.

Novel Wilkinson Power Divider with an Isolation Resistor on a Defected Ground Structure with Improved Isolation

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.

Size reduction and performance improvement of a microstrip Wilkinson power divider using a hybrid design technique

In 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.

Design and Analysis of Integrated Wilkinson Power Divider-Fed Conformal High-Gain UWB Array Antenna with Band Rejection Characteristics for WLAN Applications

Flexible ultra-wideband (UWB) antenna arrays with band notching characteristics are proposed in this work. A new wideband and high-isolation Wilkinson power divider (WPD) is designed to construct the feed systems of the UWB antenna arrays. The proposed WPD is achieved by introducing a significant modification to the conventional WPD and the new one is composed of four isolation stages. Multiple stages helped to achieve wideband from 2[Formula: see text]GHz to more than 12[Formula: see text]GHz with high isolation characteristics of more than 20[Formula: see text]dB and insertion losses around 3.3[Formula: see text]dB. The designed WPD is then applied to feed two UWB monopole antenna arrays which offer a notched band centered at 5.5[Formula: see text]GHz to reject interference from wireless local area network (WLAN) system and can be integrated with curved surfaces. To verify the performance of the proposed structure, two array configurations are practically fabricated and measured. The results show that both the arrays have UWB operational bandwidth (3.5–11.8[Formula: see text]GHz for [Formula: see text] array and 3.6–12[Formula: see text]GHz for [Formula: see text] array) that includes the UWB spectrum. Attractive agreement between simulation and measurement results is obtained. Furthermore, the bending test is carried out on the [Formula: see text] array showing the good performance of the proposed system when installed on curved surfaces for different bent angles.

A miniaturized Wilkinson power divider with 12th harmonics suppression

ABSTRACT In this study, a miniaturized Wilkinson Power Divider (WPD) has been designed. Central frequency of the passband for designed power divider (PD) is 1.55 GHz. Using the oval and rectangular- shaped resonators instead of each quarter-wavelength transmission lines of conventional Wilkinson power divider (CWPD) will result in reducing the size of proposed PD by 55%. Presented PD has many advantages, such as low insertion loss (3.015 dB), high return loss (24 dB), high isolation rate between output ports (27 dB), and suppressing the high-frequency harmonics (eliminating the 2nd to 12th unwanted harmonics). Finally presented PD was fabricated and measured on The RT-5880 with ϵr = 2.2 and TanD = 0.0009 with a thickness of 0.787 mm as the substrate. The measured results have good agreement with the simulation one. Due to the appropriate specifications and the small size of the designed divider, this divider can be nominated to use in many communication applications.

Ultra-compact wideband dual-mode Wilkinson power divider based on thin film integrated passive device fabrication technology

ABSTRACT This paper presents an ultra-wideband and highly miniaturized dual-mode Wilkinson power divider fabricated using thin film integrated passive device (TFIPD) technology for GSM band (0.9 GHz). The four quarter-wavelength lines of conventional two-section Wilkinson power divider are replaced with π-type transformer. In addition, a RC filter is introduced at the input port to minimize the return loss. The presented power divider prototype is micro-fabricated on a gallium arsenide (GaAs) substrate through TFIPD technology to reduce overall structure size and minimize overall parasitic losses. The fabricated power divider exhibits compact size at central frequency of 0.9 GHz with an ultra-wideband working bandwidth. To the best of authors’ knowledge, the designed power divider is approximately 8 times smaller than the previously reported power dividers.

Compact Wilkinson power divider with multi-harmonics suppression

Conventional Wilkinson Power Divider (CWPD) occupies a large area using the quarter-wavelength transmission lines and has a low Fractional BandWidth (FBW). Also, unwanted harmonics have not been eliminated. In this research, using semicircular- shape resonators instead of each quarter-wavelength transmission lines, a novel Wilkinson power divider has been introduced. This innovation has been improved the performance of the proposed Power Divider (PD). The use of semicircular resonators reduces the size of the CWPD by about 69%. The central frequency of this power divider is 0.935 GHz, with FBW of about 36%. The return loss of port 1 and port2, the isolation and insertion loss in operational frequency are 20.9 dB, 22 dB, 18.7 dB, and 3.05 dB, respectively. Presented PD provides a high rejection band (2.5–27 GHz) that capable of suppressing third to twenty-seventh harmonics. Finally, the proposed PD has been fabricated and the measured results are well matched to the simulated results.

A theoretical design of ultra‐wideband multisection Wilkinson power divider using Euler polynomials

AbstractWhen the broadband impedance matching techniques are applied to the Wilkinson power divider, it operates in a larger frequency range and covers many communication bands. In this study, an ultra‐wideband (UWB) multisection Wilkinson power divider (WPD) circuit has been designed. Euler method has applied to the circuit that had equal power dividing feature on its two output ways. In the three‐section of the WPD, the Euler function has been modeled as a reflection coefficient on the output branches. The Euler polynomials have been used to calculate the characteristic impedance of each section. The isolation resistors have been calculated by odd‐even mode analysis according to the line impedances. In the Euler WPD, center frequency was 2.45 GHz and the limits for the return loss and isolation was selected as 15 dB and 20 dB, respectively. The bandwidth was measured as 0.75 to 3.80 GHz. The percent bandwidth of the WPD was calculated as 124.5%. Along the operation band interval, the minimum insertion loss measured lower than 0.75 dB. The design has been compared with a quarter wave (QW) WPD. It has been shown that the Euler method can achieve higher bandwidth, lower return loss and better Isolation than the conventional WPD.

Design and realization of multi-section sum and diff 8 ways Wilkinson Power Divider at S-Band frequency for 3 dimensional radar application

The Wilkinson Power Divider (WPD) is one of the most common components used in array antenna feeding networks. It is lossless if the output ports are matched, reciprocal, and largely isolated. Many designs and modifications such as multi-section, open circuited stubs, or tapered transmission were proposed to increase the bandwidth of the conventional WPD. In this paper, we will discuss the design of multi-section sum and diff Wilkinson Power Divider for 3-dimensional radar application using CST Studio Suite 2018. The WPD operates at S-Band Frequency, realized in microstrip using substrate Rogers R0-4003C (lossy) with thickness 1.524 mm and relative permittivity 3.55. The simulation and measurement results are met the desired specification, which are less than -20 dB return loss, more than -10 dB insertion loss, less than - 20 dB port isolation, and 180º phase difference.

Design method of new power divider employing zero-degree transmission line with arbitrary power dividing ratio

In this paper, a new structure of power divider (PD) employing zero-degree transmission line (TL) with arbitrary power dividing ratio is firstly proposed. Detailed analysis is performed according to the modified even- and odd-mode analytical method. This procedure shows that the resistor between the two output ports corresponds to the wide isolation band, while the other two grounded resistors can not only realize the two output ports matching, but also provide better power handling capability in comparison with the conventional Wilkinson PD. Specifically, a zero-degree composite right- and left-handed (CRLH) transmission line (TL) is used in the PD structure, which results in a smaller size, higher design flexibility, and wider operating band than the conventional Gysel PD with the reference of 10-dB return loss and 1-dB insertion loss. Closed-form design equations are derived, and the proposed design theory is verified by two PDs with the same centre frequency but different power dividing ratio (P2/P1) as 1:1 and 2:1, respectively. According to the experiment results, both PDs have a better out-of-band rejection than the conventional Wilkinson PD, more than 100% fractional operating bandwidth under full port matching, and more than 85% isolation bandwidth with the reference of 15-dB S32.

Analysis of asymmetric coupling lines and design of a Wilkinson power divider based on harmonic suppression network

In this paper, symmetric (equal impedance lines) and asymmetric coupling lines (unequal impedance lines) are analyzed and investigated. From the research, it has been ascertained that the coupling effect in the equal impedance lines creates a new transmission zero. Also, the coupling effect in unequal impedance can control two created transmission zeros. The purpose of this work is to design a network for suppressing large numbers of harmonics with a large number of controlled transmission zeros. Therefore, a harmonic suppression network (HSN) is designed based on asymmetric coupling lines. Designed HSN generates a large number of transmission zeros with an acceptable stopband bandwidth. The proposed HSN has been replaced with two quarter-wavelength transformers in the conventional Wilkinson power divider. The number of suppressed harmonics by the HSN is greater than the number of suppressed harmonics by the quarter-wavelength, while the size of the HSN is much more compact. Also, a power divider is designed based on the proposed HSN. The designed power divider has a compact size and low insertion loss for S21 and S31 at 1.2 GHz. The number of suppressed harmonics is up to the 16 harmonic. The measured results show a frequency operation range from 0.7 to 1.26 GHz (109.6%) with a more than 10-dB return loss. The isolation in the entire operation range, agreeing well with the simulation results.