Low Cost,Low Power Magnetic IEDs Detection Method Using Biaxial Magnetometry Digital Sensors

The magnetic improvised explosive devices （IEDs）, also commonly known as a type of a sticky bomb, is simply constructed devices yet very lethal. This paper puts forward the idea of an electronic compass that is capable of sensing the change of a magnetic field generated by a magnet and translating it into interpretable data, which could act as the base for the further studies and assist in developing a greener automated system for detecting this device. The electronic compass is specifically chosen for reducing power consumption of systems in addition to the fact that it is available at a low cost.

Low-cost low-power UHF RFID tag with on-chip antenna

This paper presents an EPC Class 1 Generation 2 compatible tag with on-chip antenna implemented in the SMIC 0.18 μm standard CMOS process.The UHF tag chip includes an RF/analog front-end, a digital baseband, and a 640-bit EEPROM memory.The on-chip antenna is optimized based on a novel parasitic-aware model.The rectifier is optimized to achieve a power conversion efficiency up to 40% by applying a self-bias feedback and threshold compensation techniques.A good match between the tag circuits and the on-chip antenna is realized by adjusting the rectifier input impedance.Measurements show that the presented tag can achieve a communication range of 1 cm with 1 W reader output power using a 1 × 1 cm2 single-turn loop reader antenna.

A 4.2-5GHz,low phase noise LC-VCO with constant bandwidth and small tuning gain

As the tuning frequency of an integrated LC-voltage controlled oscillator （LC-VCO） increases, it is difficult to co-design the active negative resistance core and the varactor to achieve wideband frequency range, low phase noise, constant bandwidth and small tuning gain together. The presented VCO solves the problem by designing a set of changeable varactor units. The whole VCO was implemented in a 0.18μm CMOS process. The measured result shows -120 dBc/Hz phase noise at 1 MHz offset. The measured tuning range is from 4.2 to 5 GHz and the tuning gain is 8-10 MHz/V. The VCO draws 4 mA from a 1.5 V supply voltage.

Analysis and design of power efficient semi-passive RFID tag

The analysis and design of a semi-passive radio frequency identification（RFID） tag is presented.By studying the power transmission link of the backscatter RFID system and exploiting a power conversion efficiency model for a multi-stage AC-DC charge pump,the calculation method for semi-passive tag＇s read range is proposed.According to different read range limitation factors,an intuitive way to define the specifications of tag＇s power budget and backscatter modulation index is given.A test chip is implemented in SMIC 0.18μm standard CMOS technology under the guidance of theoretical analysis.The main building blocks are the threshold compensated charge pump and low power wake-up circuit using the power triggering wake-up mode.The proposed semi-passive tag is fully compatible to EPC C1G2 standard.It has a compact chip size of 0.54 mm^2,and is adaptable to batteries with a 1.2 to 2.4 V output voltage.