The Art of Power Dividing:A Review for State-of-the-Art Planar Power Dividers

In this paper,massive state-of-theart planar power dividers are presented and discussed. The innovations of these superiorly-performanced power dividers lie in the performance breakthrough,physical configurations and function integrations. Eventually,based on the trend presented,the future of the power dividers is predicted. This paper might have inspiration significance to illuminate the way for the development of power dividers.

A Miniaturized Broadband Wilkinson Power Divider Using Micro-Strip Branch Lines

A miniaturized broadband Wilkinson power divider is proposed. Micro-strip branch lines are introduced to replace multiple resistors used in multi-stage Wilkinson power dividers to increase the bandwidth of single-stage Wilkinson power dividers. To demonstrate its performance, an improved single-stage Wilkinson power divider with four micro-strip branch lines was designed. Simulated results show that the insert loss is better than 3.2 dB, the input return loss, output return loss, and isolation are better than 15 dB respectively, across a 76% bandwidth from 18 to 40 GHz. .

A power divider based on a new kind of composite right/left-handed transmission line (CRLH TL) unit

A new power divider, composed of a novel composite right/left-handed (CRLH) transmission line (TL) unit, is proposed. The properties of the power divider based on four CRLH TL unit cells are investigated theoretically. By adjusting the parameters of the capacitors and the inductors, the power divider shows perfectly symmetric power division at 5.13 GHz, return loss up to ?24 dB, with the transmitted power being close to ?3.1 dB. The phenomena are demonstrated by simulation results. Being compact in size and low-cost, the proposed power divider is very suitable for microwave and millimeter wave integrated circuits.

A new type of Wilkinson dual-frequency power divider with symmetrical transmission line stubs

To realize equal power splitting at two arbitrary gigahertz-frequencies, this paper presents a new type of Wilkinson dual frequency power divider, consisting of three-section transmission lines and a series RLC(resistor, inductor and capacitor)circuit. By equating the [ABCD] matrix of the proposed circuit to that of the quarter-wave impedance transformer, coupled with even/odd mode analyses, the design equations of the proposed network are derived. For verification, two dual-frequency power dividers with dual-band operating frequencies at 0.6 GHz and 3.0 GHz, and 3.8 GHz and 10 GHz respectively are designed and simulated. Simulation results show that the dual-band ratio of the proposed power divider can be as large as 5. Comparisons of the simulation results at X-band and S-band with different power dividers indicate that the proposed dual-band power divider performs better under the scenario of the upper operating frequency extending to X-band.

Superderivations for a Family of Lie Superalgebras of Special Type

By means of generators, superderivations are completely determined for a family of Lie superalgebras of special type, the tensor products of the exterior algebras and the finite-dimensional special Lie algebras over a field of characteristic p〉3. In particular, the structure of the outer superderivation algebra is concretely formulated and the dimension of the first cohomology group is given.

A COMPACT PLANAR ULTRA-BROADBAND SUM-AND-DIFFERENCE NETWORK

In this paper, the design of a planar ultra-broadband sum-and-difference network is presented. This network employs a novel power divider and anti-phase balun as a building block. An equivalent 180° coupler with a bandwidth of 6.2 - 14GHz is achieved by back-connecting the power divider and balun together. Four such couplers are connected to form an ultra-broadband sum-and-difference network which has a bandwidth of 91%. This network, with insertion loss less than 1.8dB in sum port and nulls less than -20dB in all delta ports, is verified to be excellent, resulting in the advantages of being compact, easy manufacturing and low cost.

Four-way radial waveguide power divider with high power-handling capacity

In this paper, a novel four-way radial waveguide power divider with low insertion loss and high power-handling capacity is proposed. This power divider consists of an input coaxial waveguide, a eentral probe, a radial waveguide, four equispaced identical coupling probes, four equispaced identical adjusting posts and four output coaxial waveguides. The novel coupling probes and the adjusting posts are used to realize favorable uniform power division. A power divider with the center frequency of 4.1 GHz is designed, fabricated and measured. Good agreement between simulation and experiment is noted. The measured 15 dB return-loss bandwidth of the power divider is about 600 MHz. The measured 0.5 dB insertion loss bandwidth is wider than 700 MHz. The differences and isolations between the output ports are also discussed. The power-handling capacity of the power divider is analyzed through simulation, and the result proves its usability in high power applications.

Design of a 3D Wilkinson power divider using through glass via technology

Due to its low electrical loss and low process cost, a glass interposer has been developed to provide a compelling alternative to the silicon-based interposer for packaging of future 2-D and 3-D ICs. In this study,through glass vias(TGVs) are used to implement 3-D inductors for minimal footprint and large quality factor. Using the inductors and parallel plate capacitors, a compact 3-D Wilkinson power divider is designed and analyzed.Compared with some reported power dividers, the proposed TGV-based circuit has an ultra-compact size and excellent electrical performance.

A high power active circulator using GaN MMIC power amplifiers

This paper presents a 2.4 GHz hybrid integrated active circulator consisting of three power amplifiers and three PCB-based Wilkinson power dividers. The power amplifiers were designed and fabricated in a standard 0.35-μm AlGaN/GaN HEMT technology, and combined with three traditional power dividers on FR4 using bonding wires. Due to the isolation of power dividers, the isolation between three ports is achieved; meanwhile, due to the unidirectional characteristics of the power amplifiers, the nonreciprocal transfer characteristic of the circulator is realized. The measured insertion gain of the proposed active circulator is about 2-2.7 dB at the center frequency of 2.4 GHz, the isolation between three ports is better than 20 dB over 1.2-3.4 GHz, and the output power of the designed active circulator achieves up to 20.1-21.2 dBm at the center frequency.

An integrated power divider implemented in GaAs technology

A compact lumped integrated power divider with low insertion loss using 0.5 μm GaAs pHEMT technology is presented. The proposed power divider uses the π-type LC network for transmission line equivalence and a thin film resistor for isolation tuning simultaneously. The quality factor of the inductor is analyzed and synthesized for insertion-loss influence. The measured insertion loss is less than 0.5 dB when the operating frequency is within the range of 5.15-6.15 GHz. The return loss and isolation are better than 15 dB and 20 dB, respectively. The compact dimension of the power divider is as small as 0.9 × 0.85 mm^2. The measured results agree well with the simulated ones.

Pulse swallowing frequency divider with low power and compact structure

A pulse swallowing frequency divider with low power and compact structure is presented.One of the DFFs in the divided by 2/3 prescaier is controlled by the modulus control signal,and automatically powered off when it has no contribution to the operation of the prescaier.The DFFs in the program counter and the swallow counter are shared to compose a compact structure,which reduces the power consumption further.The proposed multi-modulus frequency divider was implemented in a standard 65 nm CMOS process with an area of 28×22μm;.The power consumption of the divider is 0.6 mW under 1.2 V supply voltage when operating at 988 MHz.

Modular Lie Superalgebras of H-type

In this article the ■-graded transitive modular Lie superalgebra ⊕_(i≥-1)L_i,whose repre- sentation of L_o in L_(-1)is isomorphic to the natural representation of osp(L_(-1)),is determined.

Microwave frequency detector at X-band using GaAs MMIC technology

The design, fabrication, and experimental results of an MEMS microwave frequency detector are presented for the first time. The structure consists of a microwave power divider, two CPW transmission lines, a microwave power combiner, an MEMS capacitive power sensor and a thermopile. The detector has been designed and fabricated on GaAs substrate using the MMIC process at the X-band successfully. The MEMS capacitive power sensor is used for detecting the high power signal, while the thermopile is used for detecting the low power signal. Signals of 17 and 10 dBm are measured over the X-band. The sensitivity is 0.56 MHz/fF under 17 dBm by the capacitive power sensor, and 6.67 MHz / μV under 10 dBm by the thermopile, respectively. The validity of the presented design has been confirmed by the experiment.

On the Homology of the Dual de Rham Complex

We study the homology of the dual de Rham complex as functors on the category of abelian groups.We give a description of homology of the dual de Rham complex up to degree 7 for free abelian groups and present a corrected version of the proof of Jean’s computations of the zeroth homology group.

Matching Realization of U_q(sl_(n+1)) of Higher Rank in the Quantum Weyl Algebra W_q(2n)

In the paper, we further realize the higher rank quantized universal enveloping algebra Uq（sln＋1） as certain quantum differential operators in the quantum Weyl algebra Wq （2n） defined over the quantum divided power algebra Sq（n） of rank n. We give the quantum differential operators realization for both the simple root vectors and the non-simple root vectors of Uq（sln＋1）. The nice behavior of the quantum root vectors formulas under the action of the Lusztig symmetries once again indicates that our realization model is naturally matched.

Time-Modulated Arrays:A Four-Dimensional Antenna Array Controlled by Switches

With the rapid development of modern electronic technologies,antenna arrays typically operate in very complex electromagnetic environments.However,owing to the various errors such as systematic errors and random errors,conventional antenna arrays have relatively high sidelobes.Time modulated arrays(TMAs),also known as four-dimensional(4-D)antenna arrays,introduce time as an additional dimension for generating ultra-low sidelobes at fundamental component and realizing real-time beam scanning by harmonic components.Recently,the harmonic components can also be developed for various new applications including wireless communications and radar systems.In this review,we introduce comprehensively the fundamental methodologies and recent applications of TMAs.This aims to stimulate continuing efforts for the understanding of TMAs and explore their applications in various aspects.The methods mentioned in this review include three aspects:sideband radiation suppression,power efficiency of TMAs,and applications of harmonic components.These methods either improve the existing TMAs or promote the practical applications of TMAs.First,to suppress the sideband radiation,a method using non-uniform periodical modulation is introduced.The proposed method has an advantage of low computation and can be easily used for synthesizing a real-time radiation pattern according to the environmental need.Next,a TMA structure using reconfigurable power dividers/combiner is introduced to improve the power efficiency of feeding network.Finally,three applications of harmonic component including direction finding,calibration method,and space division multiple access are separately introduced to illustrate the development potential of TMAs.