Objectives: With the rapid development of microelectronics and micro-power source, wireless telecommunications have become ubiquitous in our daily lives in the last decade (mobile phones, RFID, wireless sensor networks, private networks, WiFi, Bluetooth, ZigBee...). However, optimization of the energy consumption of wireless telecommunication systems remains a major research area for applications. As part of its research on circuits and systems applied to these interfaces, RF platform also wants to develop a new focus on the modification of wireless communication systems. It supports the optimization of antenna design and integration of sensors on wireless communication devices.
Besides, RF platform is fully equipped with primary RF research facilities including RF microwave measurement, high frequency characterization and computer simulation software. With these in hand, the design, simulation and integration of radio and millimeter-wave components and devices are able to be implemented and validated.
Activities: RF platform focuses on the development of high frequency devices and systems for wireless communications:
Smart antenna is a digital wireless communications antenna system that takes advantage of diversity effect at the source (transmitter), the destination (receiver), or both. Diversity effect involves the transmission and/or reception of multiple radio frequency (RF) waves to increase data speed and reduce the error rate.
RF energy harvesting makes use of available RF source such as mobile telephones, handheld radios, mobile base stations, and television/ radio broadcast stations. The ability to harvest RF energy, from ambient or dedicated sources, enables wireless charging of low-power devices and has resulting benefits to product design, usability, and reliability. Battery-based systems can be trickled charged to eliminate battery replacement or extend the operating life of systems using disposable batteries. Battery-free devices can be designed to operate upon demand or when sufficient charge is accumulated. In both cases, these devices can be free of connectors, cables, and battery access panels, and have freedom of placement and mobility during charging and usage.
Wireless sensor networks (WSNs) are playing more and more a key role in several application scenarios such as healthcare, agriculture, environment monitoring, and smart metering. Furthermore, WSNs are characterized by high heterogeneity because there are many different proprietary and non-proprietary solutions. This wide range of technologies has delayed new deployments and integration with existing sensor networks. The current trend, however, is to move away from proprietary and closed standards, to 5G wireless communication and using IP to identify the network components. This allows native connectivity between WSN and Internet, enabling smart objects to participate to the Internet of Things (IoT). Building an all-IP infrastructure from scratch, however, would be difficult because many different sensors and actuators technologies (both wired and wireless) have already been deployed over the years. The Building Automation use case has been chosen to discuss potential benefits of the proposed framework.
Design and Fabrication
RF platform has the capability of developing standard and advanced high frequency components and circuits. With the collaboration with international laboratory, even the high-speed, low-power and monolithic microwave integrated circuits can be modeled and fabricated. Previous design experience of active and passive RF components (power amplifiers, multipliers, phase shifters, LNAs…) can be leveraged to assist in the development of wireless systems. The design is always validated by the leading microwave design software including CST Microwave Studio, Agilent Technologies’ ADS, Ansoft’s HFSS. Several materials for RF based devices are also available in the platform such as Roger 4003, Roger 5880, FR4.
Measurement Service
The Radio Frequency platform has top notch radiofrequency equipments at its disposal, in order to measure antenna characteristics, radio frequency spectrun, S-parameters as well as time-varying signals. The equipment assortiment includes RF spectrum analyzer up to 6 GHz, vector network analyzer up to 26.5 GHz, scalable ânlyzer of circuits up to 8 GHz and different RF sources up to 8 GHz. For direct time-domain measurements, oscilloscope tup to 6 GHz is also available. To measure radiation characteristics of antennas, the platform has developed and implemented an open-air professional measuring spot with associated equipment on the roof of B1 Building. The equipment allows measuring of full antenna parameters, i.e. return loss, radiation patterns, gain and polarisation.
Education and Training
The platform is also involved into the student teaching process at School of Electrical Engineering and delivers different courses on Master Programs of Hanoi University of Science and Technology in subjects that cover radio communications, antennas and propagation and basic microwave phenomena. Furthermore, it also supports a wide spectrum of interesting, dynamical and educational laboratory training and workshops.
Facilities
Series | Model | Range of operation | Option |
N5222A | Performance Network Analyzer (PNA) | 10 MHz to 26.5 GHz | 080-400 |
N9030A | X-Series Signal Analyzer (PXA) | 3 Hz to 8.4 GHz | 508 |
N5172B | X-RF Vector Signal Generator (EXG) | 9 kHz to 6 GHz | 506-653 |
U2001A | U2000 USB Power Sensors | 10 MHz to 6 GHz | 100 |
33509B | Waveform Generators, 1-Channel | 1 Hz to 20 MHz | |
8495B | Step Attenuator | DC to 18 GHz | 001 |
90604A | Infiniium 9000 Series Oscilloscopes | 6 GHz bandwidth |
Completed projects
LORELA (Localisation Relative personnes/objets en environnements perceptifs pour l'assistance aux personnes Aveugles)
Contacts Nguyen Thanh Huong Nguyen Viet Tung Duong Huu Tung Nguyen Cong Thuan |
Partners IMEP-LAHC (France) Post & Telocommunication Institute (Vietnam) Keysight Technology |