Mohammad-Reza Nezhad-Ahmadi

Optimized Microstrip Antenna Arrays for Emerging Millimeter-Wave Wireless Applications

Two compact planar antennas operating in the unlicensed 60 GHz frequency band are presented based on the physical layer specifications of IEEE 802.15.3c and ECMA 387 standards for different classes of wireless applications. Each antenna is an array of 2 × 2 microstrip antennas covering at least two channels of the 60 GHz spectrum. The first antenna is optimized to achieve the highest gain, while the second antenna is optimized to give the largest beamwidth. The maximum measured radiation gain of the first antenna is 13.2 dBi. The measured beamwidth and gain of the second antenna are 76° and 10.3 dBi, respectively. The areas of these two antenna are only 0.25 and 0.16 cm2. The variation of radiation gain of each antenna over the frequency range of 57-65 GHz is less than 1 dB.

High-Efficiency On-Chip Dielectric Resonator Antenna for mm-Wave Transceivers

A high radiation efficiency on-chip antenna is presented in a low-resistivity silicon technology. The proposed antenna configuration consists of a high-permittivity rectangular dielectric resonator excited by an H-slot antenna implemented in a silicon integrated circuit process. Using the Wheeler method an efficiency of 48% has been measured for the integrated antenna at 35 GHz. The maximum size of this low profile antenna (h = 0.5 mm) is close to λ0/5 (considering the dielectric resonator), and its radiation gain is around 1 dBi at 35 GHz. Moreover, the bandwidth of this antenna is 4.15 GHz (12%). Simulations and measurements show that by removing the passivation layer on top of the H-slot aperture the radiation efficiency increases by 10%.

CMOS Phased Array Transceiver Technology for 60 GHz Wireless Applications

Based on the indoor radio-wave propagation analysis, and the fundamental limits of CMOS technology it is shown that phased array technology is the ultimate solution for the radio and physical layer of the millimeter wave multi-Gb/s wireless networks. A low-cost, single-receiver array architecture with RF phase-shifting is proposed and design, analysis and measurements of its key components are presented. A high-gain, two-stage, low noise amplifier in 90 nm-CMOS technology with more than 20 dB gain over the 60 GHz spectrum is designed. Furthermore, a broadband analog phase shifter with a linear phase and low insertion loss variation is designed, and its measured characteristics are presented. Moreover, two novel beamforming techniques for millimeter wave phased array receivers are developed in this paper. The performance of these methods for line-of-sight and multipath signal propagation conditions is studied. It is shown that one of the proposed beamforming methods has an excess gain of up to 14 dB when the line of sight link is obstructed by a human.

The impact of psychological factors on self-reported sleep disturbance among people living in the vicinity of wind turbines.

Canadas wind energy capacity has grown from approximately 137MW (MW) in 2000 to over 9700MW in 2014, and this progressive development has made Canada the fifth-largest market in the world for the installation of new wind turbines (WTs). Although wind energy is now one of the fastest growing sources of power in Canada and many other countries, the growth in both number and size of WTs has raised questions regarding potential health impacts on individuals who live close to such turbines. This study is the first published research using a prospective cohort design, with noise and sleep measurements obtained before and after installation of WTs to investigate effect of such turbines on self-reported sleep disturbances of nearby residents. Subjective assessment of sleep disturbance was conducted in Ontario, Canada through standard sleep and sleepiness scales, including the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Epworth daytime Sleepiness Scale (ESS). Both audible and infra-sound noises were also measured inside the bedroom. Descriptive and comparison analyses were performed to investigate the effect of WT exposure on sleep data. Results of the analysis show that participants reported poorer sleep quality if they had a negative attitude to WTs, if they had concerns related to property devaluation, and if they could see turbines from their properties. This study provides evidence for the role of individual differences and psychological factors in reports of sleep disturbance by people living in the vicinity of WTs.

Before-after field study of effects of wind turbine noise on polysomnographic sleep parameters.

Wind is considered one of the most advantageous alternatives to fossil energy because of its low operating cost and extensive availability. However, alleged health-related effects of exposure to wind turbine (WT) noise have attracted much public attention and various symptoms, such as sleep disturbance, have been reported by residents living close to wind developments. Prospective cohort study with synchronous measurement of noise and sleep physiologic signals was conducted to explore the possibility of sleep disturbance in people hosting new industrial WTs in Ontario, Canada, using a pre and post-exposure design. Objective and subjective sleep data were collected through polysomnography (PSG), the gold standard diagnostic test, and sleep diary. Sixteen participants were studied before and after WT installation during two consecutive nights in their own bedrooms. Both audible and infrasound noises were also concurrently measured inside the bedroom of each participant. Different noise exposure parameters were calculated (LAeq, LZeq) and analyzed in relation to whole-night sleep parameters. Results obtained from PSG show that sleep parameters were not significantly changed after exposure. However, reported sleep qualities were significantly (P = 0.008) worsened after exposure. Average noise levels during the exposure period were low to moderate and the mean of inside noise levels did not significantly change after exposure. The result of this study based on advanced sleep recording methodology together with extensive noise measurements in an ecologically valid setting cautiously suggests that there are no major changes in the sleep of participants who host new industrial WTs in their community. Further studies with a larger sample size and including comprehensive single-event analyses are warranted.

Optimized patch array antenna for 60 GHz wireless applications

The recently developed 60 GHz standard provides a 7 GHz license-free band around 60 GHz for high data-rate wireless communications at the rate of gigabits per second [1,2]. Due to huge interest in broadband Wireless Personal Area Network (WPAN) applications, a low cost, miniaturized and high performance radio technology at 60 GHz is on high demand. Antenna is a key element and several antennas have been introduced for an increasing number of applications [3–5]. Patch antennas are among the best candidates for implementing in mm-wave band due to their low profile and cost. In this paper, considering system requirements of an indoor wireless link to comply with IEEE 802.15.3c and ECMA 60GHz standards, a 2×2 array of patch antennas has been optimized, fabricated and measured.

Efficiency measurement of millimeter wave on-chip antennas

This paper describes a simple and accurate method to measure the radiation efficiency of millimeter-wave on-chip antennas. Based on the Wheeler method a cap is designed which is compatible with the coplanar waveguide feed of the antenna. This method is applied to a 35 GHz on-chip antennas. the measured efficiency is compared with the simulated radiation e

A 60 GHz on-chip slot antenna in silicon integrated passive device technology

One important application of 60 GHz spectrum is transferring data in a Line-of-Sight (LOS) path over a distance less than 1 m [1]. Fast downloading and live video streaming with very low power and compact implementation for data rates up to 3.4 Gbps are two widely advertised examples [2]. Link budget design for these applications shows that high efficiency antennas with minimum gain of 2dBi and a minimum bandwidth of 2 GHz can satisfy the radiation gain requirement. Use of an on-chip antenna significantly simplifies the matching network and improves the system performance through reducing the front end loss and noise figure. The above gain requirement can not be achieved on standard silicon substrate such as CMOS and SiGe due to low resistivity requirement of the substrate for active devices. Techniques such as micro machining to remove the low resistivity substrate under the antenna [3] or on-chip dielectric resonator antenna [4] have been proposed to increase the efficiency of the on-chip antenna but fabrication complexity, cost and packaging are the remaining issues for high volume production using such techniques. Reduction in the antenna area and the fabrication cost of the antenna as well as increase in the antenna efficiency and gain are necessary. This paper presents a microstrip-fed slot antenna implemented in ON Semiconductors Integrated Passive Device (IPD) technology. The antenna has been designed and optimized to operate in the frequency range of 58 to 63 GHz with 3.5 dBi radiation gain. The entire size of the antenna is 2 mm × 3 mm. The proposed antenna can be integrated with other active elements of the mm-wave systems in the same package as a flip-chip antenna die to obtain a fully integrated 60 GHz radio.

The effect of human body on indoor radio wave propagation at 57–64 GHz

Seven GHz bandwidth around 60 GHz frequencies has been released to develop high-rate short-range wireless data communication for a small area such as an office or a research lab. A regular propagation phenomenon in such environment is the shadowing of the Line-of-Sight (LOS) link caused by moving people. One research shows this phenomenon disconnects the LOS link for 2% of the time [1]; however, the blockage ratio could be higher depending on the number of people, geometry of the room, and transmitter-receiver (TX-RX) configuration. Moreover, it must be determined that how much attenuation is caused by a human body obscuring the LOS path. In this paper first the accurate ray-tracing analysis is used to answer this question. Next, a test set-up is developed to verify the accuracy of the simulation results by field tests.

Direct matching of a miniaturized antenna to an on-chip low noise amplifier

In this short communication, we will demonstrate the feasibility of designing a miniaturized antenna featuring direct matching to a low noise amplifier chipset. Our proposed design approach is verified by matching a small antenna directly to a chipset designed to operate at the ISM band. Such design methodology is applicable to many commercial applications extending its applicability to systems such as RFIDs and GPS receivers.