Zbynek Raida

Influence of car panorama glass roofs on Car2Car communication (poster)

The Car2Car communication will use a reserved frequency band at 5.9 GHz. One of the key requirements for a Car2Car antenna is that the gain is concentrated in the horizontal plane, which is a problem due to the limited ground plane of a car roof. The influence of roof curvature, roof racks and panorama glass roofs were investigated to quantify them. To the authors knowledge such measurements have not been published yet. Three different antennas were simulated and measured on round ground planes and real car roofs in different configurations. The configuration with a panorama glass roof showed an unexpected high loss of gain in the direction of the glass roof in the range of 15 to 20 dB which result in a drastically reduced communication range to the front direction. This phenomenon is still under investigation.

Enhanced-Gain Dielectric Resonator Antenna Based on the Combination of Higher-Order Modes

The combination of two higher-order hybrid electromagnetic modes ( HEM133 and HEM123) in a simple cylindrical dielectric resonator is exploited in the presented letter to enhance antenna gain. Both modes were excited by the same feeding aperture in the ground plane of a microstrip line. A linearly polarized, broadside radiation pattern with maximum realized gain of about 11.6 dBi was successfully obtained. The antenna was designed for the ISM band with central frequency 5.8 GHz and relative bandwidth of at least 2.6%. For fabrication, we used a layered Arlon AR600 substrate of relative permittivity 6.15. Experimental results showed reasonable agreement with simulations and validated the new concept of the high-gain dielectric resonator antenna.

Steering an adaptive antenna array by the simplified Kalman filter

Adaptive antenna arrays controlled by the Kalman filter excel in high rate of convergence, low misadjustment and independence on a priori information about interference statistics. High computational requirements and potential numerical non-stability are drawbacks of the Kalmans steering. The author describes a way of reducing computational requirements and improving numerical stability of the steering algorithm based on a Kalman filter. Rate of convergence and misadjustment of the resultant algorithm (simplified Kalman filter, (SKF)) are better in comparison with the optimal LMS and worse than the pure Kalman filter. Computational requirements of the SKF are approximately three times higher in comparison with the LMS. SKF does not require any a priori information about interference statistics and is totally numerically stable. >

High-Gain Dielectric-Loaded Vivaldi Antenna for

In this letter, a novel concept of a high-gain Vivaldi antenna operating in the Ka frequency band is proposed. The antenna is fed by the substrate integrated waveguide. The concept overcomes shortcomings of conventional antipodal Vivaldi antenna using dielectric load with printed metal transition and transverse ripples. The added parts are optimized to obtain a wideband high-gain antenna with low cross polarization. The fabricated antenna shows very good performance over the entire Ka band where the measured gain is more than 10.5 dBi.

K_{a}

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.

-Band Applications

In this letter, we describe the design and simulation of on-body antennas for wireless body area network (WBAN) communication operating in the 61-GHz ISM frequency band. We developed a disc-like concept of an antenna. Instead of a direct connection between a circular disc and a feeding pin, the electromagnetic coupling is used. This concept enables us to obtain relatively broadband characteristics with omnidirectional radiation pattern and vertical polarization suitable for on-body communication. Impedance properties and radiation of the antenna were studied in open space and on a tissue-equivalent phantom representing the human body. Fabricated prototype is well matched from 59.3 to 63.4 GHz. The bandwidth of the antenna is about 7%. An antenna analyzed close to body tissue exhibits efficiency of at least 25% and the maximum gain 5.2 dB in the horizontal plane.

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

This article presents European-based contributions for wireless power transmission (WPT), related to applications ranging from future Internet of Things (IoT) and fifth-generation (5G) systems to high-power electric vehicle charging. The contributors are all members of a European consortium on WPT, COST Action IC1301. WPT is the driving technology that will enable the next stage in the current consumer electronics revolution, including batteryless sensors, passive RF identification (RFID), passive wireless sensors, the IoT, and machine-to-machine solutions. The article discusses the latest developments in research by some of the members of this group.This article presents recent European-based contributions for wireless power transmission (WPT), related to applications ranging from future Internet of Things (IoT) and fifth-generation (5G) systems to highpower electric vehicle charging. The contributors are all members of a European consortium on WPT, COST Action IC1301 (Table 1). WPT is the driving technology that will enable the next stage in the current consumer electronics revolution, including batteryless sensors, passive RF identification (RFID), passive wireless sensors, the IoT, and machine-to-machine solutions.

Wearable Disc-Like Antenna for Body-Centric Communications at 61 GHz

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.

Europe and the Future for WPT: European Contributions to Wireless Power Transfer Technology

The paper is focused on a design of a three-element filtering patch antenna array using an equivalent-circuit approach. The array is requested to exhibit a prescribed frequency response of a realized gain which corresponds to the output signal of a band-pass filter. When implementing the antenna, no filter elements are allowed to be used. Such an antenna can become a good candidate for the design of filtering antennas (filtennas). We present an equivalent circuit of such an antenna array. The equivalent circuit is validated by a full-wave model of the antenna. The equivalent circuit is transformed to a low-pass prototype filter. The low-pass prototype filter is intended to be exploited for the synthesis of filtering antenna arrays.

Slot loop antennas printed on 3D textile substrate

In the paper, we describe the design of a slot antenna array, which is placed on the top of a circular substrate integrated waveguide (SIW) resonator. The structure is analyzed from the viewpoint of modes excited in the resonator, and from the viewpoint of the following optimization of an antenna array. The array consisting of four circular slots is intended to operate in the ISM frequency band 5.725 GHz to 5.875 GHz (ITU - R5.138, 5.150 and 5.280). The study shows impedance and radiation properties of the antenna. The slot antenna is shown to be suitable for use in proximity of human body due to a proper formation of surface waves and creeping waves.