Li-Rong Zheng

An innovative fully printable RFID technology based on high speed time-domain reflections

In this paper, we present an innovative, chipless and fully printable RFID technology. The proposed tag is a fully passive device. Neither power supply nor chip assembly is required. In our design, information data is embedded in the tag as impedance mismatches along a transmission line. The RFID-reader sends a short time pulse modulated at high frequencies. The reflections due to the impedance mismatches in the tag are transmitted back and detected by the reader. A prototype of the tag has been constructed and tested. The idea has been successfully proven both by simulations and experimental measurements

CMOS UWB IR Non-Coherent Receiver for RF-ID Applications

Ultra wide band impulse-radio (UWB-IR) brings the opportunity of increased bitrates in RFID systems. This paper presents the implementation of a CMOS non-coherent UWB impulse receiver targeted for readers in RFID applications. The receiver consists of an RF-front-end and an on-off keying (OOK) 10 Mbps demodulator, which is implemented using a 0.18mum CMOS process. The receiver works for 3.1GHz-5GHz, has a sensitivity of -70dBm, and consumes 31mW from a 1.8V supply

Analysis, design and development of novel, low profile 2.487 GHz microstrip antenna

International Telecommunication Union Radio Communication Sector (ITU-R) has assigned 1.176 GHz and 2.487 GHz respectively in L and S band to Regional Navigational Satellite System (RNSS) for satellite navigation purpose. In this paper attempt has been made to design a novel, low profile compact microstrip antenna which achieves required specification such as gain of −4dBi up to ±50° and bandwidth of 30 MHz. The design of S band antenna was carried out using Ansoft Designer software, was fabricated and the required performance of antenna was measured in terms of its return loss, VSWR and gain radiation pattern. The return loss of the developed antenna was measured with the vector network analyzer and its gain radiation pattern in anechoic chamber and the performance of its measurements were compared with the analyzed results.

Design and implementation of system-on-package for radio and mixed-signal applications

Emerging wireless applications for logistics, intelligent home networks, smart dusts, wireless body area networks (WBAN) will need integration and fusion of a diversity of technologies, which may include digital CMOS circuits, analog/RF circuits, sensors/MEMS, embedded software and memories, antenna, displays, polymer, packaging and interconnections, new materials and new integration process. System-on-package (SoP) is considered as a promising solution for the fundamental integration platform for such applications. In this paper, we show how SoP technology can address the integration platform for these applications and how this can be done in a better way than system-on-chip integration. We first demonstrate the integration process off SoP in liquid-crystal polymer materials. We see that liquid-crystal-polymer is a promising material for low cost RF SoP. We then demonstrate some design examples. The first one is an integrated 5GHz RF receiver front-end in liquid crystal polymer. Due to high quality of passive components in SoP, superior RF performance is found in this module. In the second example, we address several critical design issues for on-chip versus off-chip passives in a multi-band multi-standard radio for beyond 3G applications. We find that not only RF performance can be improved. Cost benefits are also obvious for such a complex radio. Chip-package co-design for smart parasitic absorption is demonstrated through an RF module for an ultra-wide band radio in gigabit wireless. Concept of a SoP pacemaker in a WBAN is shown. Finally, we discuss some system level integration issues and we show how a system can be smartly partitioned for SoP so that we can obtain an optimal total solution for low-cost and good-performance wireless integration.