Open source cable models for EMI simulations

This paper describes the progress of work towards an Open Source software toolset suitable for developing Spice based multi-conductor cable models. The issues related to creating a transmission line model for implementation in Spice which include the frequency dependent properties of real cables are presented and the viability of spice cable models is demonstrated through application to a three conductor crosstalk model. Development of the techniques to include models of shielded cables and incident field excitation has been demonstrated

Advances in the Spectral Index method for the analysis of photonic integrated circuits

The prolific rate at which advances in photonics have been made in recent years has increased the need for accurate and efficient computer aided design tools. New device technologies and material systems mean the designer is faced with many more degrees of freedom with which to optimise a design. Because of this versatile techniques that yield results accurately and quickly are foremost in the designers mind. Throughout this work a well proven technique, the Spectral Index (SI) method is extended and generalised to a wide variety design situations of practical importance. The design of a novel Silicon Germanium based device was used to prove the suitability of an iterative design methodology in developing and optimising practical waveguiding components. The novel development of the SI method for the accurate analysis of waveguide losses is then presented further extending its suitability to the analysis and design of rectangular rib waveguides. Following this the generalisation of the SI method to structures of non-rectangular cross-section is presented allowing for the analysis of a wider range of optical rib waveguides. A novel implementation of the SI method is then developed for the analysis of the whispering gallery class of resonant modes supported by cylindrical dielectric disc and ring structures, allowing for the characterisation of the optical properties of this important class of devices. A 3D circuit analysis technique based upon a robust implementation of the SI method in its complex form is developed that allows for the characterisation of any waveguide system that may be represented by a number of discrete waveguide components. Finally the SI method is generalised to the full 3D exact analysis of optical waveguiding structure

Open source cable models for EMI simulations

This paper describes the progress of work towards an Open Source software toolset suitable for developing Spice based multi-conductor cable models. The issues related to creating a transmission line model for implementation in Spice which include the frequency dependent properties of real cables are presented and the viability of spice cable models is demonstrated through application to a three conductor crosstalk model. Development of the techniques to include models of shielded cables and incident field excitation has been demonstrated

Statistical Characterization of Wireless MIMO Channels in Mode-Stirred Enclosures

We present the statistical characterization of a 2x2 Multiple-Input Multiple-Output wireless link operated in a mode-stirred enclosure, with channel state information available only at the receiver (agnostic transmitter). Our wireless channel measurements are conducted in absence of line of sight and varying the inter-element spacing between the two antenna elements in both the transmit and receive array. The mode-stirred cavity is operated: i) at a low number of stirrer positions to create statistical inhomogeneity; ii) at two different loading conditions, empty and with absorbers, in order to mimic a wide range of realistic equipment level enclosures. Our results show that two parallel channels are obtained within the confined space at both the operating conditions. The statistical characterization of the wireless channel is presented in terms of coherence bandwidth, path loss, delay spread and Rician factor, and wideband channel capacity. It is found that the severe multipath fading supported by a highly reflecting environment creates unbalance between the two Multiple-Input Multiple-Output channels, even in presence of substantial losses. Furthermore, the channel capacity has a multi-modal distribution whose average and variance scale monotonically with the number of absorbers. Results are of interest in IoT devices, including wireless chip-to-chip and device-to-device communications, operating in highly reflective environments

Advances in the Spectral Index method for the analysis of photonic integrated circuits

The prolific rate at which advances in photonics have been made in recent years has increased the need for accurate and efficient computer aided design tools. New device technologies and material systems mean the designer is faced with many more degrees of freedom with which to optimise a design. Because of this versatile techniques that yield results accurately and quickly are foremost in the designers mind. Throughout this work a well proven technique, the Spectral Index (SI) method is extended and generalised to a wide variety design situations of practical importance. The design of a novel Silicon Germanium based device was used to prove the suitability of an iterative design methodology in developing and optimising practical waveguiding components. The novel development of the SI method for the accurate analysis of waveguide losses is then presented further extending its suitability to the analysis and design of rectangular rib waveguides. Following this the generalisation of the SI method to structures of non-rectangular cross-section is presented allowing for the analysis of a wider range of optical rib waveguides. A novel implementation of the SI method is then developed for the analysis of the whispering gallery class of resonant modes supported by cylindrical dielectric disc and ring structures, allowing for the characterisation of the optical properties of this important class of devices. A 3D circuit analysis technique based upon a robust implementation of the SI method in its complex form is developed that allows for the characterisation of any waveguide system that may be represented by a number of discrete waveguide components. Finally the SI method is generalised to the full 3D exact analysis of optical waveguiding structure

Electromagnetic shielding effectiveness of carbon fibre reinforced composites

This paper reports results on the shielding effectiveness parameter of laminated epoxy composites with carbon fibre reinforcements. Measurements of shielding effectiveness were carried out with a coaxial transmission line testing chamber according to ASTM 4935 standard and epoxy-matrix composites with continuous carbon-fibres were proven to be an excellent electromagnetic interference shielding material, where a composite slab made of 4 layers of prepregs provided more than 99.9% of electromagnetic attenuation. It was found that the reflection mechanism of the shielding material was mainly influenced by the fibre volume ratio, and that an increase in the number of layers of the composite resulted in higher shielding effectiveness due to a greater absorption mechanism. Calculations of the shielding effectiveness parameter of the material used were made by means of commercial electromagnetic simulation tools, having determined experimentally the overall resistivity of the composite. The findings presented in this work suggest that in presence of a greater number of interfaces at different impedance the separate modelling of matrix and fibres at mesoscopic scale must be taken into account

2x2 MIMO Prototype for BER and EVM Measurements in Metal Enclosure

In this work, we present a 2x2 near-field multi-input multiple-output (MIMO) prototype for bit-error-rate (BER) and error vector magnitude (EVM) measurements in a metal enclosure. The near-field MIMO prototype is developed using software-defined-radios (SDRs) for over-the-air transmission of QPSK modulated baseband waveforms. We check the near-field MIMO BER and EVM measurements in three different scenarios in a highly reflecting metal enclosure environment. In the first scenario, the line-of-sight (LOS) communication link is investigated when the mode-stirrer is stationary. In stationary channel conditions near-field MIMO BER and EVM measurements are performed. In the second scenario, BER and EVM measurements are performed in dynamic channel conditions when the mode-stirrer is set to move continuously. In the third scenario, LOS communication near-field MIMO BER and EVM measurements are performed in stationary channel conditions but now in the presence of MIMO interference. In three different scenarios, near-field MIMO BER and EVM measurements are investigated at different Tx USRP gain values and in the presence of varying levels of MIMO interference.Comment: 10 page

“Evaluación y mejoramiento del sistema de agua potable del centro poblado Guayaquil, distrito de frías - Ayabaca – Piura”. 2021

En el presente proyecto el objetivo principal fue “LA EVALUACIÓN Y MEJORAMIENTO DEL SISTEMA DE AGUA POTABLE”, ubicada en el centro poblado Guayaquil en el distrito de Frías, provincia de Ayabaca, departamento de Piura, fueron evaluadas para mejorar el estilo de vida de toda la población, teniendo agua potable de forma no continúa. Los objetivos específicos, Evaluar el sistema de agua potable, Elaborar el mejoramiento del sistema agua potable para la condición del Centro Poblado Guayaquil, para abastecer el centro poblado Guayaquil que cuenta actualmente con 272 habitantes actual que sirve para determinar a una población futura y dar un mejor resultado con el paso del tiempo. El tipo de investigación propuesta corresponde al estudio exploratorio, cuantitativo y correccional teniendo un nivel y descriptivo no experimental donde se tomó como muestra la forma de recolección de datos se selecciona el centro poblado de Guayaquil donde se desarrollará la investigación, tomando como parte representativa de la población 83 personas. Se logró evaluar el sistema de agua potable a través de encuestas a los pobladores donde se encontró como resultado las deficiencias de la línea de conducción, línea de distribución, captación, reservorio y red de distribución. Como resultado a los objetivos se proyecta mejorar un reservorio circular apoyado 5m3, se empleará una línea de impulsión 22335 ml con PVC Ø 1” –CLASE 15-10, y distribución 1,010.03ml con PVC ø 1” -11/4”-11/2 de la línea de impulsión la misma que tendrá 749.00 ml.Tesi

Multi-path fading and interference mitigation with Reconfigurable Intelligent Surfaces

We exploit multi-path fading propagation to improve both the signal-to-interference-plus-noise-ratio and the stability of wireless communications within electromagnetic environments that support rich multipath propagation. Quasi-passive propagation control with multiple binary reconfigurable intelligent surfaces is adopted to control the stationary waves supported by a metallic cavity hosting a software-defined radio link. Results are demonstrated in terms of the error vector magnitude minimization of a quadrature phase-shift modulation scheme under no-line-of-sight conditions. It is found that the magnitude of fluctuation of received symbols is reduced to a stable constellation by increasing the number of individual surfaces, or elements, thus demonstrating channel hardening. By using a second software-defined radio device as a jammer, we demonstrate the ability of the RIS to mitigate the co-channel interference by channel hardening. Results are of particular interest in smart radio environments for mobile network architectures beyond 5G