Seungtae Ko

Millimeter-Wave 5G Antennas for Smartphones: Overview and Experimental Demonstration

For the first time to the best of our knowledge, this paper provides an overview of millimeter-wave (mmWave) 5G antennas for cellular handsets. Practical design considerations and solutions related to the integration of mmWave phased-array antennas with beam switching capabilities are investigated in detail. To experimentally examine the proposed methodologies, two types of mesh-grid phased-array antennas featuring reconfigurable horizontal and vertical polarizations are designed, fabricated, and measured at the 60 GHz spectrum. Afterward the antennas are integrated with the rest of the 60 GHz RF and digital architecture to create integrated mmWave antenna modules and implemented within fully operating cellular handsets under plausible user scenarios. The effectiveness, current limitations, and required future research areas regarding the presented mmWave 5G antenna design technologies are studied using mmWave 5G system benchmarks.

Multi-polarized antenna array configuration for mmWave 5G mobile terminals

Novel antenna design technologies are devised at 28 GHz to realize vertical and horizontal polarizations and its combined radiation characteristics using ultra-thin printed circuit board (PCB) substrates. Details of the design methodologies, simulation and measurement results are presented and discussed in relation to the targeted mmWave 5G mobile application.

OLED-embedded antennas for 2.4 GHz Wi-Fi and bluetooth applications

This is the first paper that demonstrates the possibility of utilizing transparent antennas to devise antennas with active display panels such LCDs and OLEDs with full invisibility. By using the entire region of an OLED of a smartwatch to devise a patch antenna, the radiation efficiency is confirmed to be maximized.

Optically Invisible Antenna Integrated Within an OLED Touch Display Panel for IoT Applications

Future electronics and Internet of Things devices with the capability of high-speed wireless communication will increasingly rely on efficient and intelligent antennas. However, conventional wireless communication systems for small wireless electronics devices suffer from low radiation efficiencies of miniaturized antennas implemented within less-than ideal locations and real estates. Here, we introduce the original concept of utilizing the entire transparent region of high-resolution organic light-emitting diode (OLED) touch displays to render an antenna that is invisible to the human eye. A transverse magnetic resonant mode antenna is formulated based on transparent conductive polymers, which are precisely realized using mesoscale formation of electromagnetic boundary conditions. Simultaneously, these electromagnetic patterns achieve optical invisibility. We show that the transparent antenna film can be integrated inside an OLED touch display and feature efficient radiation properties at 2.4 GHz. The presented theory and measurement studies of the fabricated prototype for smartwatch application for Wi-Fi and Bluetooth connectivity inspire a broader range of integration of microwave and display technologies.

Design and empirical investigation of miniaturized mmWave antenna array modules within cellular devices

Millimeter-wave (mmWave) wireless technologies are projected to play an integral role in sustaining the ongoing explosive growth of worldwide data traffic in the next decade. Significant research and development efforts in silicon and compound silicon technology have enabled various forms of mmWave broadband wireless communication applications over the past decade. For example, fixed, point-to-point mmWave communications are increasingly being deployed for fronthaul and backhaul scenarios. For close-range communication applications, the 60 GHz-based IEEE 802.11ad/WiGig standard supports up to 6.75 Gbps. It is mainly targeted to be used in conjunction with legacy radios to support use cases such as extreme high resolution video streaming and high speed data transfers between user equipments (UE) or to a nearby base stations. Furthermore, mmWave mobile broadband (MBB) technology denoted as 5G is being conceived to enhance the capacity of 4G LTE.

A planar, via-less zeroth-order antenna for wearable electrocardiography

Summary form only given. Wireless medical telemetry service is one of the fastest emerging technologies in healthcare industries worldwide. In addition, the proliferation of smartphones is currently serving as a catalyst to the increasing growth in this sector. Based on a secure, close-range wireless body area network (WBAN) which relays the patients physiological information to a nearby cellular device, a real-time monitoring system for those who require a relatively close medical attention can be realized. Among the physiological parameters, the pulse and the respiration rates are important indicators for wide range of healthcare applications ranging from recreational sports to wireless medical monitoring. Despite the significant advantages, the technical challenges of devising a wearable, sturdy health monitoring device with a reliable radio must be fully resolved. When operating at the industrial, medical and scientific (ISM) radio band, the antenna is expected to be one of the largest components within the device. It is imperative for the antenna to remain low-profile and yet be capable of exhibiting efficient radiation characteristics albeit the detrimental effects of the users body on the antenna matching and radiation. In this paper, a planar, zeroth-order resonance (ZOR) antenna is proposed for a wearable and detachable electrocardiography (ECG) sensor device. The profile of the proposed antenna topology is minimized using two distinctive techniques: 1.The elimination of vias unlike the conventional mushroom-shaped ZOR topologies. 2. Modeling of the radiator, series capacitance, shunt inductance and the ground on a single printed circuit board (PCB) layer. An air-bridge employed co-planar waveguide (CPW) structure is designed as the antenna feed network between the antenna element and the in-house low power 2.4 GHz RFIC. The overall dimension of the planar ZOR antenna is 15 mm × 9.6 mm × 3 mm when fabricated using a flexible PCB (İr = 2.2, tan = 0.02). The antenna is placed above the main board PCB of the ECG device and subsequently covered with flexible polycarbonate chassis. The radiation properties of the ZOR antenna within the assembled ECG device is studied by placing the device on the surface of the human body model with electrical properties as follows: Skin (ı=1.46 S/m, h=0.5mm), Body fat (ı=0.27 S/m, h=10.5mm), Muscle (ı=1.74 S/m, h=20mm) where h is denoted as the thickness. Simulation and measurements confirm a -10 dB S11 bandwidth of more than 80 MHz and a radiation efficiency of more than 30% in the presence of the human body. Overall, the ZOR antenna is confirmed to feature more than 3.5 m enhanced communication coverage and more than 20% higher antenna radiation efficiency in comparison to that using conventional chip antennas and monopoles under identical measurement conditions.