Evaluation of high definition digital video signal over coaxial transmission lines

In this paper, the propagation of two different digital video transmission standards have been evaluated over fifteen different coaxial cables. The frequency dependence of the attenuation for each cable and the maximum cable length for each standard have been obtained. The results show that the propagation properties improve with the inner conductor thickness and it is better to use coaxial cable with an inner conductor based on several filaments.Peer ReviewedPostprint (author's final draft

Electromagnetic interference reduction in printed circuit boards by using metamaterials: a conduction and radiation impact analysis

This work aims to compare the implementation of two metamaterials for reducing electromagnetic interference (EMI) in printed circuit boards. Specifically, complementary split-ring resonators (CSRRs) and electromagnetic bandgaps (EBGs) were etched on the ground plane of a microstrip transmission line. Both techniques were compared as EMI filters, taking into account frequency response, signal integrity, and near- and far-field radiation with regard to a reference (solid ground) board. The results of electromagnetic simulations and experimental tests show similar EMI rejection levels in both cases, but CSRRs have a significantly better signal integrity response whereas EBGs behave as lower electromagnetic radiation elements in the operation frequency band.Peer ReviewedPreprin

Study of metamaterial resonators for decoupling of a MIMO-PIFA system

The impact of several subwavelength metamaterial particles based on split-ring inspired resonators to enhance the decoupling level in a two planar inverted-F antenna multi-input multi-output printed circuit board system is investigated. The Sparameters, antenna performance, electric and magnetic field distribution are simulated and analyzed by means of the full 3D electromagnetic simulator CST Microwave Studio at 2.45 GHz. The obtained results show a notable coupling reduction level in the three analyzed cases and a trade-off between isolation/antenna performance/area.Postprint (author's final draft

Wearable GPS patch ANTENNA on jeans fabric

In this work a wearable GPS adhesive copper sheet patch antenna on jeans fabric is designed, simulated and tested including the human body impact and specific absorption rate (SAR). The proposed textile antenna operates at the GPS L1 band (1575.42 MHz) and it has been designed by means of the commercial full 3D electromagnetic CST Microwave Studio simulator. The original textile antenna presents a -13.6 dB return loss at the GPS L1 frequency band with a fractional bandwidth of BW=3% (at S11=-10 dB), with a gain G= 1.7 dBi and efficiency ¿ =23.1%. A homogeneous phantom has been considered in order to simulate the SAR in the leg of an average human body. The impact of the human body on the antenna performance implies a detuning frequency of 1.6% and G= 1.2 dBi; ¿ =19% at the GPS operation frequency. In addition, several bending scenarios have been simulated to determine the degradation of the return loss, realized gain and efficiency. The proposed antenna is compliant with specific absorption rate (SAR) requirements from the IEEE C95.3 standard.Postprint (author's final draft

Evaluation of operational amplifier immunity by means of Weibull distribution

The immunity of operational amplifiers is a trend topic for electromagnetic compatibility EMC community. Radiofrequency interference is usually applied to the operation amplifier and the voltage offset is monitored as a parameter to evaluate the EMC degradation. However, this method does not provide enough information to know the probability of failure to electromagnetic interference of the devices. In this paper, an alternative statistical analysis based on the Weibull distribution is used to analyze the electromagnetic immunity performance of operational amplifiers under different frequency interferences and modulation index. The results confirm the feasibility of the Weibull distribution to evaluate the radiofrequency interference RFI behavior.Peer ReviewedPostprint (author’s final draft

An alternative characterization method of PFET sub-threshold slope under NBTI stress

The effects of negative bias temperature instability (NBTI) on the sub-threshold performance of a pFET have been investigated by means of experimental methods. Specifically, the sub-threshold slope under static and dynamic NBTI stress has been characterized for different NBTI stress conditions. In order to perform the characterization, a proposal based on an alternative measurement technique to obtain the sub-threshold slope is presented. Our first results indicate that similar sub-threshold slope is obtained in all stress conditions.Postprint (published version

Differential and common-mode filters based on metamaterial resonators

Two different techniques based on metamaterials for mitigating both the differential and common-mode propagation in differential signaling are addressed. The proposed filters are implemented by means of complementary split ring and spiral resonators applied to coupled parallel microstrip lines. Frequency response, signal integrity and radiation emission are analyzed.Peer ReviewedPostprint (author’s final draft

Characterization and modelling of EMI susceptibility in integrated circuits at high frequency

In this paper an alternative method for characterizing and modelling the EMI susceptibility in integrated circuits at frequencies above 1 GHz is presented. The PCB layout design is focused on the optimization of the impedance mismatch losses on the radio frequency interference injection path. The PCB has been tested with several commercial operational amplifiers and the methodology is validated through both electrical transmission line simulations and electromagnetic cosimulations.Peer ReviewedPostprint (author’s final draft

Potenciación del aprendizaje autónomo en electrónica analógica mediante el simulador Multisim

In this work, an experience based in the use of electronic circuit’s simulation tools is proposed, in order to promote the independent student learning on the field of the analog electronics teaching. The proposal considers the use of the Multisim simulator which allows increasing the learning degree related with the design and testing in the laboratory due to the useful virtual instruments. By means of this proposal, the interest of the students has been increased and, therefore, the academic achievement has been improved.Postprint (published version

Impact of temperature on the electromagnetic susceptibility of operational amplifiers

In this paper, the impact of temperature on the electromagnetic susceptibility of operational ampli¯ers at di®erent frequencies is presented. The IEC 62132-4 direct power injection standard has been used with several commercials operational ampli¯ers in a printed circuit board speci¯cally fabricated. The results show that the susceptibility of the operationals ampli¯er is reduced with the temperature.Peer ReviewedPostprint (published version