Design of Energy Harvester Module with a Low RF Power Input for UHF RFID Tag

An UHF RFID system is required to be able to operate at long range coverage, typically at 1-4 m. As a result, the RF signal power received at RFID Tag is very low, typically at -10 dBm. Moreover, practically most of commercially used RFID Tag is passive, which means that it solely relies on the RF signal transmitted from the RFID reader as the power source. Therefore, it is mandatory and critical to design an efficient and low input power RFID Tag system. In this paper, an energy harvester module for UHF RFID Tag, which is able to work at low RF input signal power and generate a stable DC voltage output, is designed. The module is able to operate at a very low RF input power as low as -10 dBm or equal to 100 mVpeak of induced voltage. To obtain such performance, a modified and optimized rectifier-using a Dynamic Vth Cancellation technique, is designed. By using this technique, the rectifier is able to produce an efficient and a high output voltage. Additionally, bandgap reference and voltage regulator circuits are designed to be independent of power supply and temperature variation. As the result, a stable DC power supply output is able to be generated. All the circuits are designed on Silterra 130nm CMOS technology. This technology allows us to design the transistor to operate at a low threshold voltage of 0.1 V, which is very suitable for the application of low input power UHF RFID Tag system

Empirical Mode Decomposition (EMD) Based Denoising Method for Heart Sound Signal and Its Performance Analysis

In this paper, a denoising method for heart sound signal based on empirical mode decomposition (EMD) is proposed. To evaluate the performance of the proposed method, extensive simulations are performed using synthetic normal and abnormal heart sound data corrupted with white, colored, exponential and alpha-stable noise under different SNR input values. The performance is evaluated in terms of signal-to-noise ratio (SNR), root mean square error (RMSE), and percent root mean square difference (PRD), and compared with wavelet transform (WT) and total variation (TV) denoising methods. The simulation results show that the proposed method outperforms two other methods in removing three types of noises

Virtual Labs of Analog Oscillator

This paper discusses the functional system of a learning media product development; the design and implementation of a virtual lab with analog oscillator comprised of the following: i) Wien Bridge oscillator, ii) Colpitts oscillator, iii) Hartley oscillator and, iv) Astable Multivibrator. The virtual laboratory was built using Adobe Flash CS6 Action Script 3.0. This media can be accessed offline on a computer standalone based on the extension .exe or .swf and constructed with 24 frames per second (fps). This media can be operated by changing the Resistor (R), Inductor (L) and Capacitor (C) components via ‘plug and play’ to the tool-kit, or trainer kit, while the output can be seen in the measuring devices, namely: the frequnecy counter and oscilloscope. The second product is a digital jobsheet as a supplementary element for the practical, which contains prequisites for conducting practical use, introductory, and anatomic information of the virtual lab, as well as the directions for using the e-jobsheet and virtual lab, the practical procedures, and the test items for evaluation