Jakob Helander

Performance Analysis of Millimeter-Wave Phased Array Antennas in Cellular Handsets

This letter discusses the usage of high-gain steerable antenna arrays operating at millimeter-wave (mmWave) frequencies for future cellular networks (5G). Based on the probable outline of the 5G networks, a method for characterizing phased array antennas in cellular handsets has been introduced. For analyzing the performance, the total scan pattern of the array configuration together with its respective coverage efficiency are essential to consider in order to compare different antenna designs and topology approaches with each other. Two design approaches and subarray schemes of these have been considered in order to illustrate the relevance of such a characterization method. The results show the importance of evaluating potential array antennas in such manners. The method can be applied to much more complex system models, where polarization diversity, hand and body effect, and statistical modeling of the channel may be included.

mmWave Phased Array in Mobile Terminal for 5G Mobile System with Consideration of Hand Effect

In this paper, the latest study of the millimeter wave (mmWave) phased array in mobile terminals for the 5G communication is presented. New parameters for evaluating the mmWave phased array in mobile terminals are introduced. Furthermore, the hand effect on the phased array in mobile terminal at 15 GHz is also investigated.

Wireless Body Area Network for Heart Attack Detection [Education Corner]

This article describes a body area network (BAN) for measuring an electrocardiogram (ECG) signal and transmitting it to a smartphone via Bluetooth for data analysis. The BAN uses a specially designed planar inverted F-antenna (PIFA) with a small form factor, realizable with low-fabricationcost techniques. Furthermore, due to the human bodys electrical properties, the antenna was designed to enable surface-wave propagation around the body. The system utilizes the users own smartphone for data processing, and the built-in communications can be used to raise an alarm if a heart attack is detected. This is managed by an application for Android smartphones that has been developed for this system. The good functionality of the system was confirmed in three real-life user case scenarios.

Compressive Sensing Techniques for mm-Wave Nondestructive Testing of Composite Panels

This paper presents imaging results from measurements of an industrially manufactured composite test panel, utilizing two introduced algorithms for data postprocessing. The system employs a planar near-field scanning setup for characterizing defects in composite panels in the 50–67-GHz band, and can be considered as a complementary diagnostic tool for nondestructive testing purposes. The introduced algorithms are based on the reconstruction of the illuminating source at the transmitter, enabling a separation of the sampled signal with respect to the location of its potential sources, the scatterers within the device under test or the transmitter. For the second algorithm, an

Characterization of millimeter wave phased array antennas in mobile terminal for 5G mobile system

L_{1}

Synthesis of Large Endfire Antenna Arrays Using Convex Optimization

-minimization problem formulation is introduced that enables compressive sensing techniques to be adapted for image retrieval. The algorithms are benchmarked against a more conventional imaging technique, based on the Fourier transform, and it is seen that the complete imaging system provides increased dynamic range, improved resolution, and reduced measurement time by removal of a reference measurement. Moreover, the system provides stable image quality over a range of frequencies.

A Comparison of Macro Basis Function Methods for Interconnected Endfire Antenna Arrays

This paper presents a characterization method for millimeter wave (mmWave) phased array antennas in the mobile terminal for 5G communication. Arrays of different antenna designs, operating at 28 GHz, are evaluated according to novel characterization methods in this context - the total scan pattern of the phased array and its respective coverage efficiency. The results show the relevance of evaluating antenna array designs according to these characteristics, and illustrate, by introducing pattern diversity through sub-array schemes, that the coverage efficiency can be enhanced.

On the issue of simulating very large endfire arrays with complex antenna geometries

An innovative approach utilizing convex optimization to simultaneously conduct pattern synthesis and improve the matching of large-scale endfire antenna arrays is proposed in this paper. A fast full-wave analysis tool facilitates the computation of the necessary data for running the optimization routine and enables analysis on arrays with dimensions

60 GHz imaging of panels for defect detection using planar scanning

100\lambda \times 6\lambda

User Body Effect on Phased Array in User Equipment for the 5G mmWave Communication System

for the highest simulated frequency. Simulated results are provided for various array configurations of bowties, and the results show that improved matching can be obtained while maintaining a clear endfire far-field pattern analogous to the pattern obtained with the classical Hansen–Woodyard excitation. The spatial dependence on the amplitude of the optimized input waves in the antenna ports indicates that a considerable fraction of the input power is fed to the antennas at the array’s front, in the direction in which the main lobe is launched.