Power Divider Research Articles

A Miniaturized Filtering Power Divider With High Selectivity and Wide Stopband Based on 3-D Heterogeneous Integration Technology

A Miniaturized Filtering Power Divider With High Selectivity and Wide Stopband Based on 3-D Heterogeneous Integration Technology

Comments on “A New Approach to Design Triple-Band Filtering Power Dividers Based on Coupled Lines”

Comments on “A New Approach to Design Triple-Band Filtering Power Dividers Based on Coupled Lines”

Reply to Comments on “A New Approach to Design Triple-Band Filtering Power Dividers Based on Coupled Lines”

Reply to Comments on “A New Approach to Design Triple-Band Filtering Power Dividers Based on Coupled Lines”

Quad port P-shaped MIMO antenna array for 60 GHz applications

This article describes the design and fabrication of a 4 × 4 MIMO antenna array intended for operation at 60 GHz. The antenna comprises of half-circular p-shaped radiator connected with a microstrip line printed on the Rogers 4003 substrate of area 22.5 × 22.5 mm2 with εr, thickness, and tan δ of 3.5, 0.203 mm, and 0.0027, respectively. This single radiator is doubled and connected to the power divider to obtain a 1 × 2 antenna array for gain enhancement purposes. The array model is duplicated on the same substrate to achieve 2 ports and 4 ports MIMO antenna. Thereafter, the model is experimentally fabricated and tested to validate the simulated results. The measured results demonstrate the antenna's 60 GHz operating bandwidth extended from 57 GHz to 63 GHz and with insertion losses ≤ −30 dB between ports (1,2) and (1,4) (the orthogonal ports), while it equals around ≤ −23 dB between ports (1,3) (the mirrored ports) within the achieved band with good consistency between both simulated and tested results. Also, it has achieved a gain of more than 9 dBi at 60 GHz with a broadside radiation pattern in both planes. Furthermore, the MIMO parameters are also carried out (ECC, DG, CCL, MEG, and TARC). The ECC is below 0.0025, the DG is approximately 10 dB, the CCL is below 0.2 bits/s/Hz, the MEG is −3 dB and the TARC is below −10 dB over the achieved frequency band. All the MIMO parameters are investigated to prove the diversity characteristics of the antenna array which supports the antenna to be suitable for the 60 GHz communication.

Hybrid Beamforming for mm-Wave Massive MIMO Systems with Partially Connected RF Architecture

To satisfy the capacity requirements of future mobile systems, under-utilized millimeter wave frequencies can be efficiently exploited by employing massive multiple input-multiple output (MIMO) technology with highly directive beamforming. Hybrid analog-digital beamforming has been recognised as a promising approach for large-scale MIMO implementations with a reduced number of costly and power-hungry radio frequency (RF) chains. In comparison to fully connected architecture, hybrid beamforming (HBF) with partially connected RF architecture is particularly appealing for the practical implementation due to less complex RF power division and combining networks. In this paper, we first formulate single- and multi-user rate maximization problems as weighted minimum mean square error (WMMSE) and derive solutions for hybrid beamformers using alternating optimization. The algorithms are designed for the full-array- and sub-array-based processing strategies of partially connected HBF architecture. In addition, we propose lower complexity sub-array-based zero-forcing algorithms. The performance of the proposed algorithms is evaluated in two different channel models, a simple geometric model and a realistic statistical model. The performance results of the WMMSE HBF algorithms are meant to reveal the potential of partially connected HBF and serve as upper bounds for lower complexity methods. Numerical results imply that properly designed partially connected HBF has the potential to provide an good compromise between hardware complexity and system performance in comparison to fully digital beamforming.

Political (de)modernization of Russia in the 1990s: turning events and models of conflict dynamics

A set of theoretical models are presented to explain the complex political dynamics in Russia in the 1990s.The parametric model is used to analyze the fluctuations of the political system in a conditional space defined by two axes: the scale of collegial division of power (CDP) and the level of state success. Major turning events as closely related structural changes shift the state of the political system along bothaxes. Political modernization occurs when success and CDP rise, while demodernization is defined as a decline on one or both scales. The contours model combines structure and agency processes and takes into account two contours of political dynamics. In the large - socio-political - contour, turning events affect grassroot structures and processes related to objective conditions of life, subjective moods, and behavioral attitudes of broad groups of the population. In the small contour (interactions of political actors with their rivalry and conflicts) the same turning events change the balance of power of the main players in national politics. The general principles of the dynamics of the CDP, state success in their interrelation, as a result of turning events as a consequence of the interaction of actors in the small loop under the influence of processes in the large loop are formulated. A step-by-step model explaining the natural shift to authoritarianism on the basis of these principles and under special conditions is proposed. Through these models, the mechanisms of conflict dynamics and socio-political processes of the 1990s in Russia are presented, when the processes of political modernization began to be combined with and then replaced by trends of demodernization.

Compact Ultra-Wideband Wilkinson Power Divider in Parallel Stripline with Modified Isolation Branches.

An efficient design method for a compact and ultra-wideband multi-stage Wilkinson power divider in a parallel stripline (PSL) is proposed. To enhance the frequency bandwidth of the proposed power divider while reducing its size, the isolation branch is modified; that is, two capacitors are connected to both sides of a resistor at each isolation branch. For an efficient design process, the PSL power divider is equivalently represented by two microstrip power dividers, and the design equations are derived. Based on the design equations, an in-house algorithm is utilized to optimally determine the design parameters, including the line impedance, resistance, and capacitance of each stage. For example, a three-stage PSL power divider is designed with three λ/4 transmission lines at a base frequency of 5 GHz. To verify the accuracy of the design procedure, 3D EM simulations and measurements are performed, and the results show good agreement. Compared with the conventional three-stage Wilkinson power divider, the proposed PSL power divider achieves a wider frequency bandwidth of 1.16 to 6.51 GHz (139.5%) and a 23% shorter transmission line length of 207°, while exhibiting an insertion loss of 0.7 to 1.4 dB.

Compact coaxial-waveguide four-way power divider with low insertion loss and high output isolation

ABSTRACT This paper presents a compact coaxial-waveguide four-way power divider with high efficiency, low insertion loss, and high isolation. To improve power capacity and facilitate fabrication, the power divider adopts a square coaxial-waveguide structure. Furthermore, to enhance isolation performance, a star-shape isolation microstrip circuit is utilized, connected with four resistors. The measurements demonstrate that the return loss of the sum port is greater than 20 dB from 7.8 GHz to 10 GHz, while the return loss of the output ports is greater than 20 dB from 7.25 to 9.18 GHz. The insertion loss is approximately 0.3 ± 0.1 dB and the isolation is greater than 23 dB from 7 GHz to 10 GHz. The combining efficiency is over 92%. Additionally, the power divider has a compact size of approximately 0.8 λ × 0.8 λ × 0.19 λ for the central frequency of 8.5 GHz.

Division of Powers of Public Authorities in Modern Conditions

In the context of the implementation of the provisions of the Constitution of the Russian Federation regarding the formation of a unified system of public power, the issue of improving the delimitation of powers of public authorities remains relevant. Significant amount of problems has been accumulated over the course of more than twenty-five years. This fact has an impact on the sustainability of regional budgets. The author of the article is considering the authority of regional government bodies in questions of joint jurisdiction of the Russian Federation and its constituent entities. The purpose of the work is to develop recommendations for improving the division of powers of public authorities and financial support this process from the position of increasing the sustainability budgets of the constituent entities of the Russian Federation. In the course of the work, based on scientific methods such as institutional, retrospective and comparative analyses, it was concluded that there are problems in the mechanism for delimiting regional powers that impede the increase in the sustainability of regional budgets. The main results of the study include suggestions for the harmonization of budget legislation and legislation in the field of delimitation of powers from the position of expanding the rights of regions to participate in the implementation of non-transferred powers, regulation of the process of introducing new powers, inventory count of regional powers established by subordinate legislation or bylaws, introduction of the practice of financial support for certain regional powers in cases and to the extent of receipt of certain non-tax revenues and the development of debt financing instruments for powers, as well as for improving the practice of financial support for delegated powers. The prepared recommendations may be useful when conducting the inventory count of regional powers from the standpoint of increasing the sustainability of regional budgets; introducing a reasonable assessment of the resource provision for new powers proposed for the implementation; shifting the emphasis from the subordinate or by-law regulation of regional powers towards strengthening their legislative regulation.

A Wide Bandwidth Vivaldi Antenna Suitable for 5G/6G Communication Utilizing a CMOS 0.18 μm Process

This text proposes a Vivaldi structure array antenna, using a power divider structure. The composition includes an antenna array with four antennas, suitable for a wideband array structure antenna in the 100 GHz frequency band. The goal is to address the challenges faced by monolithic systems in modern wireless communications, particularly the issue of the inapplicability of antennas on silicon substrates. The Vivaldi antenna was chosen for its wide bandwidth, high efficiency, and stable radiation pattern. It combines the characteristics of a wide scanning angle and ultra-wide bandwidth. Through integration with CMOS technology, the developed antenna achieved a bandwidth of 85.47–102.40 GHz. The peak gain reached −4 dBi, corresponding to a bandwidth of 17.7%. And the antenna volume was only 1.2 mm × 1.2 mm, demonstrating its immense potential in high-frequency wireless applications.

An ultra-wideband power amplifier designed through a bandwidth expansion strategy

Abstract A bandwidth expansion strategy for ultra-wideband power amplifiers (PAs) is presented in this letter by adopting a parallel impedance matching architecture. This design strategy can effectively reduce the impedance conversion ratio between the load and the target impedance of the PA, thereby providing a feasible solution for broadband impedance matching. Subsequently, a commercially available 10 W gallium nitride device and a two-stage Wilkinson power divider network are combined to achieve the verification of the proposed theory. The results of the measurement show that within the target frequency band of 0.9–3.9 GHz, 58.5–71.2% of the drain efficiency and 9.1–12 dB of gain can be achieved with a saturated output power of 39.1–42 dBm.

Two port high gain and low mutual coupling dielectric resonator based array antenna for 5G mm-wave applications

In this communication, a two-port ceramic based array radiator at mm-wave frequency range is structured and analysed. 3-dB power divider based microstrip feed line is utilised to excite the rectangular aperture. The same aperture is used to feed the ceramic, which creates fundamental hybrid mode (HEM11δ ) inside the dielectric resonator. Feeding structure is designed on RT Duroid substrate having thickness 0.254 mm and permittivity 2.2. The length and width of the substrate is 60.0 mm and 30.0 mm respectively. Alumina material is used to design the ceramic having permittivity 9.8. The exclusive feature of the proposed antenna design is to get highly directional pattern along with high gain (more than 13.5 dBi) in mm-wave frequency range with the assistance of 1*4 array structure. Orthogonal orientation of antenna ports adds the polarization diversity concept, which in turns improve the isolation level more than 50 dB. Measured results confirm that the designed antenna works effectively in between 31.5–32.8 GHz. Broadside radiation pattern and good value of Envelop correlation coefficient (less than 0.1)/Diversity gain (10.0 dB) make the designed antenna employable for n257 frequency band of 5G mm-wave applications.

Dual-band ends-fed dipole-like driver for dual-band antenna arrays

The article addresses the problem of dual-band structure designs based on the quasi-Yagi arrangements. The reported dual-band dipole antenna comprises the out-of-phase power divider, whose outputs excite the corresponding dipole arms to produce appropriate surface current distribution on them. The topology of the antenna itself is designed the way to provide high matching (the realized input reflection coefficient is not exceed minus 25 dB) at both central working frequencies. The low-band dipole is meandered to fit the substrate size. In addition, both the dipoles are excited on their remote terminals, which allows the more efficiently use of the circuit body space. The low profile implementation contributes to meeting the high demands of today and future wireless communications. The fundamental properties of linear dipole antennas, such as the Yagi, of being relatively simple in design, pure linearly polarized, having almost omnidirectional patterns made them of the great interest among researches. In addition, the Yagi arrangement itself allows building on its base even more complex antenna structures, comprised a number of linear dipoles, maintained along one of orthogonal axis. When centrally fed, the classical single-band Yagi antenna suffers from narrow band characteristics, becoming a kind of challenge, which has successfully been addressed by a number of researches in the past. At the same time, on the base of Yagi and quasi-Yagi designs it is possible to combine a number of radiating elements, producing, therefore, multi-band or wideband characteristics. This approach is highly efficient when designing multipurpose devices with different transmitting rates. In this project the novel approach for dual-band dipole antennas design is presented. The driven elements are excited from their remote terminals, forming the quasi-Yagi arrangement with untraditional excitation. The balancing scheme is formed by an out-of-phase power divider, whose outputs are connected to the dipoles arms. The topology of the antenna itself is designed to provide high matching (input reflection coefficient does not exceed minus 25 dB) at both center operating frequencies. When integrating a dual band balancing unit with the radiating elements it is crucial to provide low interference for better radiation characteristics. Besides, the surface currents on the ground plane, should not affect those on the radiating elements for better matching.

Design and development of efficient and compact 20 kW 325MHz solid-state amplifier for superconducting accelerator applications.

An efficient and compact, 20 kW solid-state power amplifier (SSA) at 325MHz has been designed and developed in-house, using single stage combining. It comprises of 24 nos. of 1 kW power amplifier (PA) modules, a 24-way Wilkinson power combiner and divider, and other peripheral systems. The typical gain and conversion efficiency of the PA modules at 1.0 kW output is 21.7 dB and 66.6%, respectively. It is demonstrated that overall power gain and AC to RF efficiency of this SSA at 20 kW is 88.5 dB and 54.8%, respectively, which matches closely with the design estimates. The harmonic content in the RF output is < -40 dBc for all the harmonics. The results of the Monte Carlo simulation are also presented, showing lower bound on combining efficiency with a degree of confidence if magnitude and phase data for 24 inputs are randomly chosen from a normal distribution's pre-defined interval. The salient features of this SSA include power density of 12.7 kW/m3, AC to RF efficiency of 54.8% at 20 kW, and guaranteed output of 20 kW with one failed PA module and 18.1 kW under two failed PA modules condition.

Self-Packaged mm-Wave Broadband Air-Filled SIW Filtering Power Divider With Sharp Roll-Off Skirt and High In-Band Isolation

Self-Packaged mm-Wave Broadband Air-Filled SIW Filtering Power Divider With Sharp Roll-Off Skirt and High In-Band Isolation

Highly selective single-mode graphene bandpass filter based on Wilkinson power divider structure

In this paper, we introduce a novel graphene nanoribbon bandpass filter designed using the Wilkinson power divider structure for single-mode operation. Through the three-dimensional finite-difference time-domain (3D-FDTD) technique, we analyze transmission spectra and electromagnetic field distributions. Our primary goals are to achieve high transmission efficiency, improved adjustability, and an excellent quality factor (Q-factor). The proposed single-mode graphene nanoribbon bandpass filter exhibits outstanding performance characteristics, including a 45 THz free spectral range (FSR), 95 % transmission efficiency, and a full width at half maximum (FWHM) of 0.14 THz at the resonant frequency of 15 THz. By changing the chemical potential (or bias voltage) to manipulate the conductivity and dielectric constant of the graphene surface, we successfully tune the center frequency of the filter within the 10–20 THz range. This flexibility, combined with exceptional transmission efficiency and Q-factor, positions our filter as a prime candidate for seamless integration into compact optical devices. Additionally, by adjusting the refractive index of the substrate, we achieve a sensitivity exceeding 7 THz/RIU or 7500 nm/RIU, making our filter a promising sensor for applications requiring precise detection and measurement capabilities.

Miniaturized filtering equal/unequal Wilkinson power dividers

In this paper, two miniaturized Wilkinson power dividers with equal and unequal power division ratios capable of suppressing spurious harmonics over a wide frequency range are presented. First, an asymmetric high-low impedance resonator with coupled open-stubs and folded structure is employed to design the equal power divider. Then, how connecting an inductor in series with the introduced resonator can lead to affecting the transmission coefficient of the power divider branch and achieving an unbalanced power division ratio at output ports, is analytically clarified. In the third step, a combination of the resonator with folded structure and the inductor is utilized to design an unequal 2:1 divider. To validate the performed analysis, two equal and unequal Wilkinson power dividers at 900 MHz are fabricated and measured. Regarding S31, both dividers can suppress the 4th to 13th spurious frequencies and with respect to S21 of the unequal case, the 2nd-harmonic to 14th-harmonic are omitted. The occupied areas of the equal and unequal structures are 7.35 mm × 18.9 mm and 7.5 mm × 17.9 mm, respectively, which indicate almost 84 % size reduction in each case.

Design of Wilkinson Power Dividers with SITL Compensated Microstrip Bandpass Filters

Design of Wilkinson Power Dividers with SITL Compensated Microstrip Bandpass Filters

Multi-functional balanced-to-single-ended filtering power divider with all-band output reflectionless and common-mode suppression

In this paper, a multi-functional balanced-to-single-ended (BTSE) filtering power divider (FPD) with reflectionless response is proposed. The attractive multi-functional features, including filtering, power dividing, common-mode (CM) suppression, isolation, as well as output reflectionless can be realized without introducing additional circuits. It consists of a half-wavelength coupling line (CL) loaded with two unequal-width three-coupled lines (TCLs), an auxiliary resistor (AR), and an isolation-absorption composite network (IACN). Meanwhile, the theoretical analysis and parametric study of this design are provided. To validate this design, a sample of the proposed balanced-to-single-ended reflectionless filtering power divide (BTSE-RFPD) is fabricated and measured for verification. The 10-dB reflectionless bandwidth, 17.1-dB isolation, and 17.4-dB CM suppression can cover 0–5 GHz, achieving a wide bandwidth of 250 %. The experimental results show good agreement with the simulated.

Design of Microstrip Antenna Arrays with Rotated Elements Using Wilkinson Power Dividers for 5 G Customer Premise Equipment Applications

Microstrip antenna arrays are proposed in this paper for the customer premise equipment (CPE) applications in the frequency range 1 (FR1) of the 5th generation (5 G) mobile networks. The proposed antenna arrays consist of three FR4 substrates. Antenna elements and feeding networks are optimized separately through parameter studies and then combined to form the proposed antenna arrays. Bandwidth-enhancing parasitic elements on the top substrate are broadside coupled to the microstrip antennas in the middle substrate, which are probe-fed by the microstrip feeding network using Wilkinson power dividers realized in the bottom substrate through the ground plane and the stud supporting air layer between the lower two substrates. Two antenna arrays, with four and eight antenna elements, are proposed for different gain specifications, 10 dBi and 12 dBi, respectively. Bandwidths of 10-dB return loss for both arrays fully covered the 5 G n78 frequency band (3.3–3.8 GHz). 20 dB isolation between antenna elements can also be achieved using the proposed layouts with rotated elements. The dimensions, radiation gain, and efficiency of the proposed antenna units, four-element array, and eight-element array are 65 × 65 × 11.4, 115 × 115 × 11.4, and 115 × 215 × 11.4 mm3, 6.2, 10.5, and 13 dBi, 74%, 56%, and 50%, respectively. The proposed antenna arrays exhibit the advantages of simple, low-cost, low-profile, and high-gain characteristics, which is potentially applicable to 5 G CPE outdoor unit (ODU)-related devices.