Survey of millimeter-wave propagation measurements and models in indoor environments

The millimeter-wave (mmWave) is expected to deliver a huge bandwidth to address the future demands for higher data rate transmissions. However, one of the major challenges in the mmWave band is the increase in signal loss as the operating frequency increases. This has attracted several research interests both from academia and the industry for indoor and outdoor mmWave operations. This paper focuses on the works that have been carried out in the study of the mmWave channel measurement in indoor environments. A survey of the measurement techniques, prominent path loss models, analysis of path loss and delay spread for mmWave in different indoor environments is presented. This covers the mmWave frequencies from 28 GHz to 100 GHz that have been considered in the last two decades. In addition, the possible future trends for the mmWave indoor propagation studies and measurements have been discussed. These include the critical indoor environment, the roles of artificial intelligence, channel characterization for indoor devices, reconfigurable intelligent surfaces, and mmWave for 6G systems. This survey can help engineers and researchers to plan, design, and optimize reliable 5G wireless indoor networks. It will also motivate the researchers and engineering communities towards finding a better outcome in the future trends of the mmWave indoor wireless network for 6G systems and beyond

Two-segments compact dielectric resonator antenna for UWB application

A new compact two-segments dielectric resonator antenna (TSDR) for ultrawideband (UWB) application is presented and studied. The design consists of a thin monopole printed antenna loaded with two dielectric resonators with different dielectric constant. By applying a combination of U-shaped feedline and modified TSDR, proper radiation characteristics are achieved. The proposed antenna provides an ultrawide impedance bandwidth, high radiation efficiency, and compact antenna with an overall size of 18 × 36 × 11 mm 3. From the measurement results, it is found that the realized dielectric resonator antenna with good radiation characteristics provides an ultrawide bandwidth of about 110%, covering a range from 3.14 to 10.9 GHz, which covers UWB application. © 2002-2011 IEEE

A grounded CPW transparent UWB antenna for UHF and microwave frequency application

A grounded CPW transparent ultra-wideband (UWB) antenna for Ultra High Frequency (UHF) and microwave frequency application is proposed in this paper. The proposed antenna covers a bandwidth starting from as low as 500MHz to the upper limit of the FCC UWB bandwidth of 10.6 GHz. This enables the antenna to be used for a very wide range of applications ranging from narrow band UHF devices to high data rate UWB transceivers. The antenna is fabricated using AgHT-8 for the CPW and radiator patch on a 1mm thick glass substrate with an Indium Tin Oxide (ITO) ground. The AgHT-8 has a sheet resistance of 8 Ω . m while the ITO, a sheet resistance of 4Ω . m. The overall size of the antenna is 64 × 67mm2. The antenna has a consistent flat 10 dB return loss across the entire bandwidth. The antenna is suitable for integrating onto window glass of homes and buildings as it does not affect the aesthetics of the building. The AgHT-8 layer of the antenna additionally provides sun-shielding from harmful sun-rays and keeps the building cool thus conserving energy required for air-conditioning in hot climates. As such the antenna provides an integrated wireless communication and energy conservation solution for modern day homes and buildings. Copyright © 2013 The Electromagnetics Academy.link_to_OA_fulltex

Ultra wideband dielectric resonator antenna design

An ultra-wideband dielectric resonator antenna (DRA) is studied and investigated for wireless application. The dielectric resonator is fed by a microstrip line. The overall size of the proposed DR antenna is 20 × 35 mm2, and the thickness of the dielectric resonator is only 5.12 mm, which is suitable for mobile device. The design simulation is done by using computer simulation Technology Microwave studio suite 2012 (CST). The results represent that by using N-shaped dielectric resonator, a wideband impedance bandwidth of 111% for VSWR≤ 2 covering a frequency range from 3.59 to 12.61 GHz. A parametric study is presented. © 2013 IEEE

CPW-Fed transparent antenna for extended ultrawideband applications

A novel coplanar waveguide-fed transparent antenna for ultrawideband applications with enhanced bandwidth is presented. In this design, different techniques have been used to broaden the bandwidth. The rectangular radiator of the antenna is equipped by the staircase technique to increase the overlapped resonant frequencies. Moreover, two major and minor symmetrical rectangular stubs are mounted on top of the quarter-circle slot ground by using a dual axis to significantly increase the bandwidth between 3.15 and 32 GHz for VSWR< 2. AghT-8 transparent thin film is used in the design of the proposed antenna to obtain a very compact size and lightweight structure. © 2014 IEEE

Ultrawideband dielectric resonator antenna with WLAN band rejection at 5.8 GHz

A novel compact ultrawideband (UWB) dielectric resonator antenna (DRA) with a band rejection at 5.8 GHz is proposed and studied. The antenna is composed of a thin monopole printed antenna loaded with DR that is housed into a dielectric substrate and an L-shaped parasitic strip connected to the ground plane. The L-shaped strip andmetallic sheet are utilized to improve impedance bandwidth. A modified metallic sheet underneath the dielectric resonator has been applied to create a band rejection at frequency 5.8 GHz. The measurement results exhibit acceptable performances in terms of reflection coefficient, radiation pattern, efficiency, and realized gain. © 2013 IEEE