Multi-port matching efficiency in antenna systems with cascaded networks

A general compact formula for multi-port matching efficiency in the presence of an arbitrary number of cascaded networks is introduced. A comparison between the decoupling efficiency and multi-port matching efficiency is presented. Similarly, a compact formula for decoupling efficiency in a cascaded chain is provided. The presented compact formulas are quite advantageous for optimization of radiation efficiencies by designing a proper matching network

Multi-mode Propagation in 2D filters and Metamaterials

Meta-materials are characterised using a modal technique for the analysis of 2N- port two dimensional filter networks. It will be shown that in general, all such networks support N modes of propagation each with different propagation constants unless as with the TEM multi-wire transmission line, the inductance matrix is the inverse of the capacitance matrix. Furthermore a simple equivalent circuit for these 2N port networks is derived, enabling complete network analysis for any combination of modal excitations. An explicit formula is derived for the propagation constants of a quasi lowpass filter. This demonstrates that there are always N modes even when the transverse network is infinite in extent

A performance model of multicast communication in wormhole-routed networks on-chip

Collective communication operations form a part of overall traffic in most applications running on platforms employing direct interconnection networks. This paper presents a novel analytical model to compute communication latency of multicast as a widely used collective communication operation. The novelty of the model lies in its ability to predict the latency of the multicast communication in wormhole-routed architectures employing asynchronous multi-port routers scheme. The model is applied to the Quarc NoC and its validity is verified by comparing the model predictions against the results obtained from a discrete-event simulator developed using OMNET++

Container transport network for sustainable development in South Korea

The ever-increasing tendency toward economic globalization highlights the importance of sustainable container transport networks to a country’s international trade, especially for an economy that is highly dependent on exports. This paper aims to develop a transport network connectivity index (TNCI) to measure the container transport connectivity from a multi-modal perspective. The proposed index is based on both graph theory and economics, considering transport infrastructure and capacity, cargo flow, and capacity utilization. Using the case of South Korea as an example, we apply the TNCI to assess the connectivity of the Busan, Gwangyang, and Incheon ports, representing approximately 96% of the container throughput in South Korea. The calculated TNCI not only provides insight into the assessment of sustainable port competitiveness, it also helps policymakers identify bottlenecks in multi-modal transport networks. To eliminate these bottlenecks, this paper offers some appropriate measures and specific strategies for port development, which in turn improves the connectivity of container transport networks for sustainable development

Circuit Based Optimization of Radiation Characteristics of Single and Multi-Port Antennas

A method for analyzing and optimizing multiport antennas is presented and exemplified. The method was first presented in [1]-[3] and uses data from full wave electromagnetic field (EM) solvers in combination with circuit simulations for efficient calculations of radiation properties of multi-port antennas. The main advantage of the proposed method is that only a few full-wave simulations, which usually are time consuming, are needed when e.g. optimizing the matching circuits for a multi-port antenna. Since embedded element patterns are used, all relevant antenna parameters such as radiation efficiency, diversity gain, available MIMO capacity etc. can efficiently be computed for any port excitation and loading configuration. The methodology has been implemented in software called MPA (Multi-Port Antenna evaluator) which imports port response matrices and embedded element patterns from commercial full-wave codes and post processes the data making it possible to e.g. optimize capacity for a MIMO system. The optimization is done by changing the feeding and matching networks in a circuit simulator that is invoked by the MPA. Finally the software is used on two examples which are analyzed and optimized to illustrate the potential of the method

Noise Characterization of Differential Multi-Element Multiport Networks - the Wave Approach

In this paper there is presented and discussed a general analysis method for noise characterization of noisy multi-element multiport differential networks. It is based on mixed mode, differential and common mode, noise waves representation of noise, generalized mixed-mode scattering parameters and generalized mixed-mode noise wave correlation parameters for the network. There are derived analytical relation between the noise figure for a given output port and the noise matrix and the scattering parameters of the network, as well as the correlations between the input port noise waves. The signal to noise ratio degradation factor is derived and discussed, too. Presented results can be implemented directly in a CAD software for noise analysis of differential microwave multi-element multiport networks with differential as well as with conventional single ended ports

Asynchronously coupled resonant junctions for diplexers and multiport filtering networks

This paper proposes the use of asynchronously coupled resonator junctions in the design of diplexers. This is to ease the control and implementation of the external couplings at the common port of an all-resonator-based diplexer. A comparison study has been performed between a conventional diplexer and the proposed diplexer. To further explore the possibilities of the proposed junction technique, a four-port multi-port filtering networks was proposed and designed to function as a double diplexer. Good agreements have been achieved between the measurements of the prototype devices and the simulations

Magnetic-field-free nonreciprocal transport in graphene multi-terminal Josephson junctions

Nonreciprocal superconducting devices have attracted growing interest in recent years as they potentially enable directional charge transport for applications in superconducting quantum circuits. Specifically, the superconducting diode effect has been explored in two-terminal devices that exhibit superconducting transport in one current direction while showing dissipative transport in the opposite direction. Here, we exploit multi-terminal Josephson junctions (MTJJs) to engineer magnetic-field-free nonreciprocity in multi-port networks. We show that when treated as a two-port electrical network, a three-terminal Josephson junction (JJ) with an asymmetric graphene region exhibits reconfigurable two-port nonreciprocity. We observe nonreciprocal (reciprocal) transport between superconducting terminals with broken (preserved) spatial mirror symmetry. We explain our observations by considering a circuit-network of JJs with different critical currents