Search

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.

The electromagnetic coupling of a conventional planar inverted-F antenna (PIFA) antenna in the nearby layout traces is investigated in the 2.45 GHz industrial, scientific and medical radio band. The impact of a complementary split-ring resonator (CSRR) to reduce the coupling as well as the overall antenna performance after perturbing the ground plane is reported. 2.5D and 3D full electromagnetic simulations are used to design and analyze the proposed layouts. Experimental results validate the CSRR usefulness to significantly decrease the antenna coupling.

This paper presents a novel approach to design a parametric RF stop band pass filter based on Low Temperature Cofired Ceramic (LTCC) Technology. The LTCC technology enables to miniaturize and development compact structures using not only the standard xy-planar circuit dimensions but also the z-height dimension. The proposed filters topologies are based on a stripline loaded with one or several complementary rings resonator CSRRs). Specifically, a parametric study z-location of the stripline respect to the CSRRs is carried out in order to determine the optimum configurations operating in the Ku-band.

Low frequency analog and digital electronic circuits are susceptible to radiofrequency interference (RFI). This disturbance is produced when the coupled RF signal is rectified by the nonlinear behavior of the semiconductors used in the small signal analog input stages of the electronic system. These circuits present an AM demodulation effect produced by nonlinearity of internal transistors, generating parasitic signals in the low-frequency range and undesired offset voltage. In this paper, an alternative to the current standard EMI filters is presented by combining the conventional printed circuit board layout with complementary split ring resonators (CSRRs), in order to reduce the output offset impact due to RFI. An operational amplifier circuit has been designed with a 4-stage CSRR filter, electromagnetically simulated and experimentally tested. Two prototypes have been implemented, with and without CSRRs, in order to compare the filter properties in standard FR4 substrate. The resonance frequency of the CSRRs has been designed in the vicinity of 2.4 GHz in order to prevent susceptibility in the ISM band. Electromagnetic and electrical equivalent circuit model simulations are also provided and compared with experimental results. Measurement data show an effective rejection of the undesired RF demodulation without affecting the signal integrity out of the filter band, and therefore a significant reduction concerning output offset voltage impact in terms of RFI amplitude, with no-extra cost in terms of the device area or manufacturing process.

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.

In this paper the switching noise of a CMOS ring oscillator has been analysed when their pFETs are subjected to negative bias temperature instability (NBTI). The impact of pFET under NBTI has been experimentally quantified whereas CMOS ring oscillator frequency and the switching noise has been analysed by means of electrical full-model simulation. The results show that the impact on the electromagnetic compatibility behaviour increases with NBTI wearout.

The continuous scaling of CMOS circuits has set the MOSFET transistor in the nanoelectronic era. In this context, the functionality and complexity of integrated circuits (ICs) are growing up. However, the operation voltage has been continuously reduced. The higher complexity of ICs has allowed including electronic systems in a lot of safety critical applications (i.e., automotive, aeronautics and/or medical applications). Therefore, the functionality of these electronic equipments must be assured and the risk of electromagnetic interference (EMI) must be reduced during their lifetime. Nowadays, circuits’ robustness to electromagnetic interference is checked in a burn-in component, without taking into account the impact of the natural devices’ aging. However, shrunk dimensions imply the appearance of several wear out mechanisms, which can limit the functionality of the circuits and modify their electromagnetic performance. Therefore, the time dependence of electromagnetic behaviour, which is known as Electromagnetic Robustness or Electromagnetic Reliability (EMR), should be evaluated. The switching noise is probably one of the main EMC emission problems in CMOS circuits. It is know that wear out mechanism affects the switching behaviour of CMOS circuits. Therefore, some effects on EMC performance of these circuits should be expected. In this work, the switching noise behaviour or CMOS circuits under one of the most important reliability problems are analysed by means of electrical simulation. In order to do that, a characterization of wear out mechanism on single MOSFET is presented and modelled. The results show a reduction on the frequency switching noise emission in circuits subjected to wear out, due to the reduction of the drain current of MOSFET.

In this work a flexible wearable PIFA antenna has been designed in order to operate according to the Bluetooth v4 standard (2400-2483.5 MHz) in healthcare applications designed for wireless sensor networks. The substrate design includes the textile and human skin effects as well as the antenna flexible substrate (Pyralux). The return losses results show a strong detuning (36.8 %) of the operation frequency of the antenna due to the outfit and human skin presence, instead of air, and therefore a redesign of the antenna dimensions has been done (42.2% of miniaturization of the antenna layer). Some antenna performance changes are observed in terms of the radiation pattern and gain reduction due to the body proximity

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.