Jan Velim

Wideband Skin-Equivalent Phantom for V- and W-Band

In this letter, a wideband semisolid skin-equivalent phantom with dielectric properties close to human skin in the V- and W-band is proposed. The constituents of the phantom are deionized water, agar, and gelatin powder. The phantom has been fabricated and validated by an open-ended waveguide method. Since it comprises low-cost constituents and its fabrication does not require special equipment, the phantom can be easily reproduced. The proposed skin-equivalent phantom can be used in the field of on-body antenna and propagation measurement at millimeter waves.

Slot loop antennas printed on 3D textile substrate

In the paper, planar slot loop antennas are presented. The antennas radiate electromagnetic waves which are polarized perpendicularly to a conductive surface. Therefore, the antennas can be used for on-body or off-body communication. The role of the substrate is played by a three-dimensional textile material. Conductive parts of antennas are fabricated by a screen-printing technology using a silver paste. Walls of waveguides integrated into the textile substrate are created by sewing with a conductive thread. Functionality of antennas was verified by computer simulations and measurements.

3D-textile integrated corrugated horn antenna

The paper describes a corrugated substrate integrated horn antenna designed for surface wave excitation in the UWB band groups 3, 4, 5 and 6 (6-10 GHz). The antenna is optimized for integration into 3.4 mm thick textile of relative permittivity of 1.2. The corrugated substrate integrated waveguide is fed by a microstrip line and for connectivity a transition from microstrip line to coaxial line is designed. In order to enhance the impedance matching, we utilize thin strip lines placed in front of the aperture. The directivity of the antenna is 12.5 dBi at the 8 GHz and the antenna efficiency is about 70 %.

Wireless power transmission in small airplanes

In the paper, we describe results of experimental investigations of in-plane wireless power transmission supported by a 3D textile material. The 3D textile upholstery is fed by planar horn antennas optimized for the frequency band from 7.5 GHz to 8.5 GHz. Using screen printing by a silver paste, slot ring antennas are created on the upholstery to deliver electromagnetic energy to passengers on seats below. Functionality of the described concept has been verified experimentally.

On-roof wireless link operating at 60 GHz

The paper discusses possible ways of building a wireless link along an inner part of a roof of a car at 60 GHz. The investigation is mainly based on experimental measurements. A vector network analyzer, horn antennas integrated into substrate and open-ended rectangular waveguide antennas are key components of measurement setup. For an appropriate positioning of the antennas and an adjustment of used materials, suggested mechanical equipment was designed to improve repeatability of measuring the transmission coefficient.

Wireless power transfer along a car body at 60 GHz: Experimental investigations

The paper summarizes first experimental results related to the wireless transfer of electromagnetic power along a conductive surface of a car body. The investigated power transfer is aimed to supply sensors connected by a wireless network. The experimental system was designed at 60 GHz. The electromagnetic energy is transmitted and received by substrate integrated waveguide (SIW) planar horn antennas. Influence of the curvature of the car body is described. A 3D textile material is used as upholstery to improve efficiency of power transfer.

Transition adapters for 3D textile substrates

The paper presents transition adapters to be used between conventional RF connectors (SMA, 2.92 mm, etc.) and 3D textile transmission lines (microstrips at 5.8 GHz and textile integrated waveguides at 8 GHz). Proposed transitions could be used for other multilayer structures. The insertion losses of designed transition adapters are lower than 0.6 dB. The transition adapters are suitable for the excitation of antennas integrated into 3D textile substrates or similar textile materials.

Reply to “Comments on ‘Wideband Skin-Equivalent Phantom for V- and W-Band’ ”

Presents a reply to comments on the paper, ”Comments on Wideband Skin-Equivalent Phantom for V- and W-Band,”(Aminzaech, R., et al),IEEE Antennas Wirel. Propag. Letters.

Wireless body area networks numerical, experimental and approximate characterization

For the numerical design of on-body communication components, accurate and reliable models of a communication channel of a wireless body area network (WBAN) are needed. Whereas numerical models (volume-pixel ones, layered ones) can be very detailed, experimental models consist of a single layer of an agar gelatin usually. In the paper, an analytical model based on Norton surface waves is used to describe the surface wave propagating along the interface between the agar phantom and environment. For the frequency band of interest, electrical parameters of the analytical model of the agar phantom are optimized so that the propagation properties of the phantom can agree with properties computed by numerical layered models, volume-pixel models, or experiments.

Neural modeling of in-vehicle wireless channels: Wave propagation along the vehicle body at 60 GHz

In the paper, we discuss an exploitation of artificial neural networks for modeling wireless channels inside a car. Neural models are based on feed-forward architecture and radial basis function architecture of neural networks. In the paper, we briefly explain the concept of experimental measurements of in-car channels. Then, we explain the process of creating and training a neural network. Finally, we discuss a neural model validation.