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A compact upper wideband unequal power divider with planar configuration is proposed. This power divider includes two-section asymmetric coupled transmission lines and non-uniform microstrip. The measured results of the prototype divider show that the 12.1 dB return loss and ports-isolation band is in the range from 3.1 to 10.6 GHz, the unequal power division coefficient is almost in the range 4.03–5 dB (the simulated result: 4.3–4.75 dB).

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.

In this paper, we propose a 1.8 GHz microwave coupler with arbitrary power division. It consists of a wideband unequal power division hybrid coupler with higher-order harmonic filtering that covers all GSM (0.8 GHz – 1.9 GHz) and WiFi (2.4 GHz) bands. The architecture consists of a 4 port unequal power division, which is usually of the 0° and 180° coupler types.

In this paper, a method for designing a feeding network to obtain a low peak sidelobe pattern of an 8*1 linear antenna array is proposed. The optimized element weights were first obtained using genetic algorithm. Then two different networks based on equal and unequal power dividers are designed for the linear antenna arrays. In an equal power divider structure, the power is divided equally into all branches of the network to reach the final ports, while in the unequal structure; the division is only made equal in some branches and unequal in other branches to build an unequal power divider. In the two methods, the design process is based on two stages, the first stage uses a T-junction power divider, and the second stage a Wilkinson power divider is used. In an equal power divider, T-junction and Wilkinson divide the power equally, while in the case of an unequal power divider the T-junction divider is only unequal. In the two designs, the feeding network is designed according to the following specifications: the substrate (FR-4 with ϵ r =4.3) and ground dimensions are 440.4mm × 103.8mm ×1.6 mm and 440.4mm × 103.8mm × 0.035mm respectively, and at a resonant frequency of 2.36 GHz. The simulation results showed the effectiveness of the designed power dividers that to be used as a feeding network in the linear antenna arrays.

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.

Purpose The purpose of this paper is to build a neural network (NN) inverse model for the multi-band unequal-power Wilkinson power divider (WPD). Because closed-form expressions of the inverse input–output relationship do not exist, the NN becomes an appropriate choice, because it can be trained to learn from the data in inverse modeling. The design parameters of WPD are the characteristic impedances, lengths of the transmission line sections and the isolation resistors. The design equations used to train the NN inverse model are based on the even–odd mode analysis. Design/methodology/approach An inverse model of a multi-band unequal WPD using NNs is presented. In inverse modeling of a microwave component, the inputs to the model are the required electrical parameters such as reflection coefficients, and the outputs of the model are the geometrical or the physical parameters. Findings For verification purposes, a quad-band WPD and a penta-band WPD are designed. The results of the full-wave simulations verify the validity of the design procedure. The resulting NN model outperforms traditional time-consuming optimization procedures in terms of computation time with acceptable accuracy. The designed WPDs using NN are implemented by microstrip lines and verified by using full-wave analysis based on high-frequency structure simulator (HFSS). The results of the microstrip WPDs have good agreements with the corresponding results obtained by using ideal transmission line sections. Originality/value The associated time-consuming procedure and computational burden in realizing WPD through optimization are major disadvantages; needless to mention the substantial increase in optimization time because of the multi-band design. NNs are one of the best candidates in addressing the abovementioned challenges, owing to their ability to process the interrelation between electrical and geometrical/physical characteristics of the WPD in a superfast manner.

The papers in this volume discuss the strategies adopted by people to accumulate assets through migration, housing investments, natural resources management, and informal businesses and consider how an asset-based social policy could enable those strategies or help them overcome the constraints of an unfavorable institutional environment.

A compact unbalanced two-way filtering power splitter with an integrated Chebyshev filtering function is presented. The design is purely based on formulations, thereby eliminating the constant need for developing complex optimization algorithms and tuning, to deliver the desired amount of power at each of the two output ports. To achieve miniaturization, a common square open-loop resonator (SOLR) is used to distribute energy between the two integrated channel filters. In addition to distributing energy, the common resonator also contributes one pole to each integrated channel filter, hence, reducing the number of individual resonating elements used in achieving the integrated filtering power splitter (FPS). To demonstrate the proposed design technique, a prototype FPS centered at 2.6 GHz with a 3 dB fractional bandwidth of 3% is designed and simulated. The circuit model and layout results show good performances of high selectivity, less than 1.7 dB insertion loss, and better than 16 dB in-band return loss. The common microstrip SOLR and the microstrip hair-pin resonators used in implementing the proposed integrated FPS ensures that an overall compact size of 0.34 λg × 0.11 λg was achieved, where λg is the guided-wavelength of the 50 Ω microstrip line at the fundamental resonant frequency of the FPS passband.

The outdated and discredited notion of a binary urban–rural divide remains stubbornly widely used. However, it both sets up and reflects oppositional politics and processes between the two supposedly mutually exclusive categories of space and place, which hamper urban–rural partnerships. Empirical reality on the ground is far more complex. Just as more appropriate conceptualisations and approaches have evolved, so new research methods and tools have been developed to overcome the different institutional barriers and stakeholder priorities in the face of contemporary real-world complexities and the urgency of tackling the ‘wicked’ challenges of sustainability, which also underpin the New Leipzig Charter. The focus here is on co-production and related methods, which can be considered as representing the top-most rungs of Arnstein’s (1969) Ladder of Participation. The relevance and application of these methods are exemplified from the work of Mistra Urban Futures in relation to transcending conventional European urban–rural divisions and forming partnerships, with due attention to problems and limitations. Such methods have considerable potential, including for addressing unequal power relations, but are time-consuming and require careful adaptation to each situation.

The problem of source number detection based on a distributed polarization-sensitive array (DPSA) is considered in this paper. We propose a DPSA to improve the matching coefficient that can be used to measure the eigenvalues. We theoretically prove that DPSA has a lower matching coefficient than the traditional uniform circular array (UCA) when the incident sources are uncorrelated, and we then obtain the eigenvalues by using the matching coefficient. Moreover, we discuss the change in eigenvalues under the assumption that the power of the signals is unequal. Numerical simulations show that the source detection probability of the DPSA is enhanced compared with the traditional UCA. Meanwhile, increasing the power of the stronger received signal improves the detection probability when the source power is unequal.