Unequal Power Divider Research Articles

Theoretical design and implementation of equal and unequal split ultra-wide band Wilkinson power divider with Chebyshev impedance transform

Abstract In this study, we designed multi-section UWB Wilkinson power dividers for both equal and unequal power divider. The key innovation is successfully matching these power dividers using the Chebyshev method. The proposed method achieves very low insertion losses and high transmission coefficients across the ports. For the three-section equal power divider, Chebyshev polynomials were used to model the reflection coefficient, and the characteristic impedance for each section was calculated symmetrically. The design achieved a fractional bandwidth of 106% for a 20 dB return loss, with an insertion loss of 0.3 dB. For unequal multi-section dividers, power division ratios of 1.5:1 and 2:1 were chosen. Theoretical microwave calculations were used to determine the input and output transmission line impedances. Chebyshev approximation was then applied to design the three-section unequal power dividers. The return losses for these unequal dividers were measured at 17 dB and 15 dB, with fractional bandwidths of 120% and 126%. Both circuits had insertion losses of 0.25 dB. The consistent results from analytical calculations, simulations, and measurements confirm the effectiveness of the Chebyshev method for both equal and unequal power division.

Exact synthesis of couple‐line based wideband four‐way filtering power divider with unequal power division

AbstractIn this paper, a coupled‐line‐based wideband four‐way filtering power divider (FPD) with unequal power division is presented. It is composed of three groups of coupled lines (CLs), four types of open‐ended stubs, and three kinds of resistors. By setting the CLs in each group with different parameters, unequal power distribution is obtained. Besides, open‐ended stubs with different characteristic impedances are inserted to each output port to generate two extra transmission zeros, at the same time maintaining good impedance matchings. Resistors are inserted to each group of the CLs to improve the isolations. By applying twice parity mode analysis, the exact synthesis of the proposed FPD is first derived. For demonstration, a prototype with power division ratio of 1:1.2:1.5:1.8 is designed and manufactured. Measurement results verified that more than 60% fractional bandwidth (FBW) is obtained under the criterion of 10 dB return loss and 10 dB isolation. Besides, the 3 dB passband FBWs for the four outputs reach 70% with high frequency selectivity and low insertion loss. And more than 15 dB out‐of‐band rejections are achieved for both the lower and upper stopbands.

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.

Miniaturized equal/unequal Wilkinson power dividers capable of harmonic suppression utilizing microstrip π-shaped resonators modified by lumped elements

In this paper, modified π-shaped resonator composed of both microstrip transmission lines and lumped elements are employed to design a Wilkinson power divider. Utilizing these resonators leads to designing a compact divider featuring a selectable operating frequency with optional power division ratio and very wide-range harmonic suppression. To vary the operating frequency and the power division ratio, the values of just the utilized lumped elements are changed without manipulating the dimensions of microstrip lines. As a design sample, a miniaturized divider capable of operating at four frequencies i.e., 0.5, 1.0, 1.5 and 2 GHz with optional equal or unequal power division and harmonic suppression ability at each of these frequencies is designed and simulated. Finally, as a feasible sample, another Wilkinson power divider which can optionally operate at 700 MHz with equal power division or 1.2 GHz with unequal power division is designed and implemented. Based on the measurement results, the spurious harmonics from 2nd to 25th in the 700 MHz-divider and 2nd to 15th in the 1.2 GHz-divider are suppressed. Moreover, almost 96% and 93% size reduction at 700 MHz and 1.2 GHz, respectively, are achieved. The S21 and S31of the unequal divider are − 8.8 and − 3.73 dB, which indicate an unequal 3.2:1 power division.

Wideband Filtering Power Divider With Unequal Power Division Ratio and All-Frequency Input Absorptive Feature

Wideband Filtering Power Divider With Unequal Power Division Ratio and All-Frequency Input Absorptive Feature

Unequal Power Division Ratio Nonreciprocal Filtering Power Divider With Arbitrary Termination Impedance and Center Frequency Tunability

Unequal Power Division Ratio Nonreciprocal Filtering Power Divider With Arbitrary Termination Impedance and Center Frequency Tunability

Comments on “A Simple and Universal Phase Control Method for Designing Directional Couplers With Adjustable Phase Difference Slope and High Linearity”

In the above article (Pan et al., 2023), it is shown that the solution given for the –90 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^\circ$</tex-math> </inline-formula> directional coupler with adjustable phase difference slope is inadequate for equal power division purposes. The proposed solution results in a significant error between the two outputs of the coupler. Exact, correct solutions are derived for the coupler, which proves that the proposed solution in Pan et al. (2023) corresponds to the coupler for an unequal power division case rather than the equal power division.

Defect‐Adjusted Valley Edge States and Rainbow Trapping of Elastic Waves in 2D Topological Phononic Crystals

Topological phononic crystals (PnCs) with topologically protected boundary states have important applications in the fields of acoustic wave transmission and control. However, previous studies based on solid‐state PnC systems are mostly limited by fixed structures, resulting in the difficulty to deform the edge states, which partly limits its practical applications. Herein, a 2D solid topological PnC coupled with the defect is designed to achieve the adjustable valley edge state and rainbow trapping. First, by breaking the spatial inversion symmetry, the valley Hall phase transition of elastic wave is realized and valley edge states are obtained. Next, by introducing defects of different widths between the two different valleys’ topological PnCs, both the defect‐adjusted valley edge state and defect state are achieved. Then, by designing different topological PnCs waveguides, the robust transport characteristics of the two above states are compared. Subsequently, a new power divider based on the defect‐adjusted valley edge state is designed, which is found to possess various manners of operation such as equal and unequal power divisions. Finally, based on defect adjustment of the edge states, a rainbow trapping is implemented. This research provides an important guidance for ultrasonic devices, such as waveguides, energy harvesters, and power dividers.

Design of Vivaldi array antenna with low sidelobe for Monopulse tracking application

The article will present the array antenna system for Monopulse tracking application. The Antenna includes 3 parts: monopulse comparator, unequal power divider, and antenna array. The monopulse comparator and unequal power divider are designed by microstrip line on PCB. Antenna array consists of 244 Vivaldi elements. Conducted simulation of the antenna system and obtained the following results: The bandwidth of the antenna system is greater than 10% with Voltage Standing Wave Ratio smaller than 1.6 (VSWR ≤1.6); Realized gain of the sum beam (radiation pattern) at the central frequency reaches 26.2 dBi; Sidelobe level of sum beam is less than -20dB in the whole frequency range; The peak and null of two difference beams are smaller than 20dB. With the results obtained, the Antenna Monopulse system is mentioned as completely suitable for use for tracking applications and arrangement in narrow space locations with compact size.

Dual-Polarized Wideband Low-Sidelobe Slot Array Antenna for V-Band Wireless Communications

A dual-polarized wideband low sidelobe slot array antenna for wireless communication systems in the V-band is proposed in this work. Taylor distribution is applied with each radiating slot as a tapering unit in both polarizations. A compact 2 × 2 elements subarray is designed to achieve stable amplitude and phase distribution among elements with two sets of integrated compact wideband unequal power dividers for the E- and H-planes inside the subarray. Then, two layers of orthogonally polarized feeding networks with unequal E-plane T-junction power dividers are used to connect the subarrays to two standard waveguides WR-15 as input ports. The prototype of 8 × 8 elements is fabricated and measured in an anechoic chamber. The maximum measured gain is 25.3 dBi and 25.4 dBi for V- and H-polarization, respectively. The overlapped impedance bandwidth is from 57 to 66.4 GHz with reflection coefficiencies below -10 dB, and the isolation between two input ports is around 35 dB. Sidelobe levels of both polarizations are below -22 dB with good agreement with the simulations.

Analysis and Design of High-Efficient High-Power Spatial Power Divider

This paper presents the design of a high-efficiency spatial power divider that utilizes hologram technology to split an incident beam into multiple beams with varying power ratios and channel numbers. In order to avoid the crosstalk coupling among different beam channels, the distinguishable distance limit of beams is deduced. On the basis of the analysis, a synthesis procedure which considers the power capacity further is proposed to profile the mirror. Following the design method, a 1-to-2 unequal power divider and a 1-to-4 equal one are designed based on an identical hologram structure. The simulation results show that both power dividers achieved high efficiency, with over 95% and maintained efficiency over 90% over a wide fractional frequency range of more than 29% in Ka band, making them suitable for broadband high-power systems. For validation purposes, the 1-to-4 spatial power divider are fabricated and tested by the radiation field measurements, and the test results are highly consistent to the simulation. The proposed method provides a generic way to realize high efficient power division in high power systems, and can be easily extended to other applications where low attenuation and high power capacity are required.

Frequency-Controlled Fixed-RF Beam-Steering Array Based on Two-Wave Mixing With Cascaded Unequal Power Divider

Large-scale phased array now becomes one of the most critical components in wireless communication system. However, the high cost and complexity of the phase controlling in conventional phased array make it difficult to be widely deployed in commercial use. Alternatively, a frequency-controlled beam-steering method with fixed radiation frequency based on sequential mixing of the propagating IF and local oscillator (LO) waves has been proposed as a low-cost solution. The beam pointing direction can be changed by a single-frequency controller rather than varying any phase shifters or tunable components on the antennas. However, this technique relies on accurately splitting the input IF and LO waves to a mixer’s array through all passive power distribution networks. This communication discusses the practical design consideration of a robust two-wave mixing array and two sets of cascaded unequal power dividers are employed to efficiently distribute the IF and LO signals. To ensure constant radiation frequency, an external reciprocal mixer is used to keep the frequency difference between LO and IF being same as the desired RF. The measured result shows that the proposed signal distribution network successfully achieves the desired phase and amplitude of the converted RF signal.

A Novel Unequal Power Divider With General Isolation Topology: Design and Verification

In this letter, a novel unequal power divider (PD) with three standard 50- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> ports is presented. It consists of two transmission line (TL) sections, two resistors, and a general isolation topology (GIT). Through analyzing voltages and currents of each branch, the constraint conditions of such a GIT are newly established. Considering realization of GIT, two types of topologies, i.e., asymmetrical coupled line and cascaded TL, are selected for verification. From the design charts and several design examples, the proposed PD could not only provide high power ratio <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$k^{2}$ </tex-math></inline-formula> with compact size but also independently adjust their fractional bandwidths ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{11}$ </tex-math></inline-formula> or <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{32}$ </tex-math></inline-formula> ) with the same power ratio <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$k^{2}$ </tex-math></inline-formula> . Finally, an unequal PD with the power ratio <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$k^{2} =8$ </tex-math></inline-formula> is fabricated, and the measured results meet the simulated results very well.

A Novel Design Method for Unequal Coupled Line Dual-band Wilkinson Power Divider

A Novel Design Method for Unequal Coupled Line Dual-band Wilkinson Power Divider

DESIGN AND ANALYSIS OF 1:8 RADIO FREQUENCY FEEDING NETWORK USING STEP-DOWN IMPEDANCE TRANSFORMER FOR C-BAND AIRBORNE SYNTHETIC APERTURE RADAR APPLICATIONS

In this research, we developed a unique power divider circuit construction that suppresses harmonic components while providing unequal power division ratios. In antenna arrays, a power divider is used to divide the power among the array's elements. Depending on the design, different power dividers have distinct properties. The purpose of this project was to create a design and examine a 1:8 unequal power divider for C-band applications that operates at 5.3 GHz. The prototype was built on a single board using a duroid RT5880 substrate with relative permittivity of 2.2 and thickness of 1.6 mm. A quarter-wave transformer was utilized to evenly distribute the entire incident power. This design involves adding an extra transmission line to the input side, which is known as a step-down transformer. The input impedance values were reduced and outstanding performance was achieved by using the step-down transformer. Advanced design system software was used in the simulations. The isolation network, which consisted of resisters between the transmission lines, was critical in implementing the radial layout styles and also improved the output port matching and port-to-port isolation. In the operating frequency range, the return loss parameters (S&lt;sub&gt;11&lt;/sub&gt;–S&lt;sub&gt;99&lt;/sub&gt;) and the isolation were greater than −17 and −37 dB, respectively. The intended structure is compact. The simulated results were in good agreement and demonstrated that all of the ports had matching impedance and the isolation matched the application's requirements.

Equal and unequal dual-band six-way power divider with band-distinct power division ratios

In this paper, a dual-band six-way power divider is designed with equal and unequal power division capabilities. The unequal design of the divider is capable of providing up to four different output levels at each band. Furthermore, it is capable of achieving band-distinct power division ratios. These capabilities are realized in the proposed divider by using dual-band pi-shaped impedance transformers. The S-parameters of the proposed divider are derived analytically, and its design procedure is explained in detail. Four prototypes operating at 0.9/1.4 GHz are designed and fabricated to demonstrate the divider’s capabilities. Simulation and measurements results of the four prototypes are presented. The measured output power levels of the four prototypes at each band are within 1 dB from their theoretical values. Also, good input matching (<-15 dB) is observed for the four prototypes at both bands.

Synthesizing Shaped-Beam Cylindrical Conformal Array Considering Mutual Coupling Using Refined Rotation/Phase Optimization

A novel method of synthesizing shaped-beam cylindrical conformal array by rotating the antenna elements and optimizing their excitation phases is presented. Rotation of antennas on curved surface is mathematically described by rotating its vectorial active element pattern (VAEP) in its local coordinate system (LCS). Then the scalar patterns and polarization unit vectors of all the rotated VAEPs are properly transformed and then interpolated at a unified angle sampling grid in a common coordinate system, where they are summed to obtain an approximated array expression. With this expression, element rotations and phases can be optimized using the constriction factor particle swarm optimization (CF-PSO) to synthesize desired shaped-beam pattern with controlled sidelobe level (SLL) and cross-polarization level (XPL). However, since rotations on curved surface introduce considerable variations to the element curvature and mutual coupling (MC), the synthesized array pattern would have considerable errors. A refined strategy is adopted then to improve the synthesis accuracy. The proposed method uses uniform amplitude weighting, thus saving many unequal power dividers. Three typical shaped pattern synthesis examples are provided to show the effectiveness of the proposed method. A cylindrical array prototype with 24 rotated U-slot loaded patch antennas is fabricated and measured for practical validation.

Design of a Low-Cost, Low-Sidelobe-Level, Differential-Fed SIW Slot Array Antenna with Zero Beam Squint

This paper presents a low-cost, low-sidelobe-level, differential-fed, substrate-integrated waveguide (SIW)-based slot array antenna with zero beam squint. The antenna consists of two identical six-way unequal power dividers (PDs) and a 6 × 16 slot array and is realized on a single-layer substrate. The six-way unequal PD provides tapered amplitude and in-phase excitation for six SIWs, and each of them has 16 radiating slots. The 1 × 16 linear slot array on each SIW is excited using a differential feed to avoid undesired beam squinting across its operating band. A two-way hybrid waveguide (WG)-to-SIW E-plane PD is developed to provide equal amplitude and out-of-phase excitation for two six-way unequal power dividers. Moreover, metallic decoupling walls are implemented between two adjacent linear slot arrays to reduce E-plane external mutual coupling. An antenna prototype is fabricated and experimentally verified. The fabricated antenna shows that the measured −10 dB reflection bandwidth is 7.15% (9.57–10.28 GHz), with the achieved gain ranging from 20.30 to 21.92 dBi. A stable boresight beam is observed over the entire operating band. Furthermore, at the designed frequency of 10 GHz, peak SLLs of −29.1 dB and −29.4 dB are achieved in the E- and H-plane, respectively.

Compact Ultra-Wideband Wilkinson Power Dividers Using Linearly Tapered Transmission Lines

In this work, compact extended ultra-wideband (UWB) Wilkinson power dividers (WPDs) using tapered transmission lines are analyzed, designed, and measured. Utilizing carefully designed tapered transmission sections results in widening the operational bandwidth and reducing the element dimensions. Analytical models and design procedures of simple and compact and equal and unequal UWB WPDs based on linearly tapered transmission lines are developed and outlined in this paper. Four different configurations of equal and unequal power dividers are designed and presented. The number and locations of the isolation resistors have a noticeable effect on extending the operational bandwidth of the dividers. The presented designs of the WPDs have superior performance over extended bandwidths. The simulation and experimental results are in very good agreement with good insertion and return loss, good matching, and isolation, over the extended UWB operational bandwidth from 3 GHz to 27 GHz.

Planar High-Gain Millimeter-Wave Slotted SIW Cavity Antenna Array with Low Sidelobe and Grating Lobe Levels

In this paper, a planar high-gain millimeter-wave (mmW) slotted substrate integrated waveguide (SIW) cavity antenna array with low sidelobe and grating lobe levels is proposed. The antenna consists of a slotted SIW resonator and an SIW transmission line (TL). To achieve a high gain and simplify the structure of the antenna element, the slotted SIW cavity is resonated in high-order mode. Then, a high-gain antenna array is implemented with only four such elements. By analyzing the pattern multiplication principle of the antenna array and accurately adjusting the element spacing, the high grating lobe level caused by the large spacing of the high-order mode resonator is considerably reduced. In addition, a one-four unequal amplitude power divider is introduced to further reduce the antenna array’s sidelobe levels (SLLs). Finally, the proposed antenna array is fabricated for verification. The measured peak gain is 21.4 dBi at 27.3 GHz. The measured grating lobe level in the E-plane is reduced to −17.9 dB, and the measured SLLs are lower than −19.1 dB.