Efficient modeling of the wireless power transfer efficiency for varying positions and orientations between transmitter and receiver

A method that efficiently calculates the Power Transfer Efficiency (PTE) of a Wireless Power Transfer (WPT) system is described in this paper. It allows for arbitrary relative positions and orientations between devices in the system, both in far-field and radiative near-field configurations. The method uses a single simulation or measurement of the radiation patterns of the antennas employed in the WPT system, from which the interaction between devices at any relative position and orientation can be modeled. A spherical harmonics decomposition, together with Wigner-D rotation matrices, is applied to perform efficient translations and rotations of the devices used in the WPT system

Efficient full-wave modeling of radiative near-field interactions in semi-anechoic conditions

In this paper, a full-wave method to efficiently compute the electromagnetic interaction between two devices placed in semi-anechoic conditions is proposed. The aim of this research is the accurate and efficient reproduction of radiated immunity and emission tests in simulation. The employed technique relies on a single simulation (or measurement) of the radiation pattern of each device and allows an arbitrary relative position between the devices. The resulting procedure is practical, has a low computational cost, and shows good agreement with reference solutions

Efficient full-wave modeling of electromagnetic interference in the presence of multiple non-collocated noise sources

In this contribution a novel method is discussed that is of practical use for analyzing the electromagnetic compatibility behavior of electronic systems. The aim is to develop an efficient technique that mimics radiated immunity and emission tests in the presence of multiple non-collocated noise sources in simulation. The proposed method is simple in that it only relies on the simulated (or measured) radiation pattern of the devices in the system while allowing arbitrary positions. Rotation of the devices is performed by a spherical harmonics decomposition of the radiation patterns together with the application of Wigner-D rotation matrices. The adopted assumption is that the devices are spaced sufficiently far from each other such that there is no coupling via the reactive near-field. The proposed procedure shows good agreement with measurements and full-wave simulations while at the same time it has a low computational cost

EMC-aware analysis and design of a low-cost receiver circuit under injection locking and pulling

In low-cost receiver applications, the preselect filter is often omitted in order to reduce the footprint of the total system. However, the immunity of the receiver can be severely compromised by this approach. This paper focuses on the effects of co-located sources on the local oscillator (LO), specifically injection locking and pulling. To this end, a low-cost radio receiver (RF) front-end is designed for operation in the 2 : 4 5 GHz industrial, scientific and medical (ISM) radio band. In addition to the effects on the oscillator, the consequences on the receiver's performance are evaluated as well. For the first time in literature, this work demonstrates the critical necessity to take the potentially detrimental effects caused by injection locking and pulling into account during Electromagnetic Compatibility (EMC)-aware design

Full-wave modeling of interacting multiport devices with arbitrary relative positions and orientations for efficient EMI assessment

A novel method to accurately and efficiently model the interaction between radiating devices is proposed. Whereas previous work of the authors dealt with singleport devices (antennas), this paper constitutes an important extension to actual multiport devices, as such paving the way for electromagnetic interference assessment of real-life (sub) systems early in their design cycle. The method solely relies on the knowledge of the radiation patterns of the different ports of the devices, which can either be measured or simulated using a solver of choice. These patterns are then used to compute the electromagnetic interaction between the devices that may be positioned in each other's radiative near-field (Fresnel region) or far-field (Fraunhofer region). Furthermore, in the model, their relative positions and orientations can be altered at a very low computational cost. The technique is thoroughly validated and illustrated, demonstrating its appositeness to study the electromagnetic compatibility behavior of the multiport devices

A through wall doppler radar system: active textile antenna design, prototyping and experiment

Using garments as a platform for electronic sensing and communication systems opens up a wide range of novel and exciting applications. By carefully tailoring the antenna properties and by adopting a dedicated design strategy, a robust wearable antenna system can be obtained onto which all necessary electronics are integrated. In this contribution, the dedicated design for approach of a low-weight, wearable Doppler radar system fabricated on textile materials is presented. The system, fully integrated into a rescue worker's garment, is capable of detecting moving objects behind a barrier. It relies on an array of four textile transmit antennas to scan the surroundings. At the receiving end, an active wearable receive antenna is deployed to capture the reflected signals. It is demonstrated that the on-body system is capable of detecting moving subjects in indoor environments, including through-wall scenarios

Active textile antennas in professional garments for sensing, localisation and communication

New wireless wearable monitoring systems integrated in professional garments require a high degree of reliability and autonomy. Active textile antenna systems may serve as platforms for body-centric sensing, localisation, and wireless communication systems, in the meanwhile being comfortable and invisible to the wearer. We present a new dedicated comprehensive design paradigm and combine this with adapted signal-processing techniques that greatly enhance the robustness and the autonomy of these systems. On the one hand, the large amount of real estate available in professional rescue worker garments may be exploited to deploy multiple textile antennas. On the other hand, the size of each radiator may be designed large enough to ensure high radiation efficiency when deployed on the body. This antenna area is then reused by placing active electronics directly underneath and energy harvesters directly on top of the antenna patch. We illustrate this design paradigm by means of recent textile antenna prototypes integrated in professional garments, providing sensing, positioning, and communication capabilities. In particular, a novel wearable active Galileo E1-band antenna is presented and fully characterized, including noise figure, and linearity performance

Active textile antennas in professional garments for sensing, localisation and communication

New wireless wearable monitoring systems integrated in professional garments require a high degree of reliability and autonomy. Active textile antenna systems may serve as platforms for body-centric sensing, localization and wireless communication systems, in the meanwhile being comfortable and invisible to the wearer. New design strategies combined with dedicated signal processing techniques greatly enhance the robustness of these systems. On the one hand, the large amount of real estate available in public regulated services' garments may be exploited to deploy multiple textile antennas. On the other hand, the size of each radiator may be designed large enough to ensure high radiation efficiency when deployed on the body. This antenna area is then reused by placing active electronics directly underneath and energy harvesters directly on top of the antenna patch. We illustrate this design paradigm by means recent textile antenna prototypes integrated in professional garments, providing sensing, positioning and communication capabilities