0.5 GHz-1.5 GHz Bandwidth 10W GaN HEMT RF Power Amplifier Design

With the current development in wireless communication technology, the need for a wide bandwith in RF power amplifier (RF PA) is an essential. In this paper, the design and simulation of 10W GaN HEMT wideband RF PA will be presented. The Source-Pull and Load-Pull technique was used to design the input and output matching network of the RF PA. From the simulation, the RF PA achieved a flat gain between 15dB to 17dB from 0.5GHz to 1.5GHz. At 1.5GHz, the drain efficiency is simulated to achieve 36% at the output power of 40 dBm while the power added efficiency (PAE) was found to be 28.2%

Architecture of Micro Energy Harvesting Using Hybrid Input of RF, Thermal and Vibration for Semi-Active RFID Tag

This research work presents a novel architecture of Hybrid Input Energy Harvester (HIEH) system for semi-active Radio Frequency Identification (RFID) tags. The proposed architecture consists of three input sources of energy which are radio frequency signal, thermal and vibration. The main purpose is to solve the semi-active RFID tags limited lifespan issues due to the need for batteries to power their circuitries. The focus will be on the rectifiers and DC-DC converter circuits with an ultra-low power design to ensure low power consumption in the system. The design architecture will be modelled and simulated using PSpice software, Verilog coding using Mentor Graphics and real-time verification using field-programmable gate array board before being implemented in a 0.13 µm CMOS technology. Our expectations of the results from this architecture are it can deliver 3.3 V of output voltage, 6.5 mW of output power and 90% of efficiency when all input sources are simultaneously harvested. The contribution of this work is it able to extend the lifetime of semi-active tag by supplying electrical energy continuously to the device. Thus, this will indirectly  reduce the energy limitation problem, eliminate the dependency on batteries and make it possible to achieve a batteryless device.This research work presents a novel architecture of Hybrid Input Energy Harvester (HIEH) system for semi-active Radio Frequency Identification (RFID) tags. The proposed architecture consists of three input sources of energy which are radio frequency signal, thermal and vibration. The main purpose is to solve the semi-active RFID tags limited lifespan issues due to the need for batteries to power their circuitries. The focus will be on the rectifiers and DC-DC converter circuits with an ultra-low power design to ensure low power consumption in the system. The design architecture will be modelled and simulated using PSpice software, Verilog coding using Mentor Graphics and real-time verification using field-programmable gate array board before being implemented in a 0.13 µm CMOS technology. Our expectations of the results from this architecture are it can deliver 3.3 V of output voltage, 6.5 mW of output power and 90% of efficiency when all input sources are simultaneously harvested. The contribution of this work is it able to extend the lifetime of semi-active tag by supplying electrical energy continuously to the device. Thus, this will indirectly  reduce the energy limitation problem, eliminate the dependency on batteries and make it possible to achieve a batteryless device

Litar penuai tenaga hibrid mikro untuk aplikasi bioperubatan

Penggunaan penuai tenaga sebagai bekalan kuasa mendapat perhatian tinggi terutamanya untuk peranti berskala mikro. Ianya memanfaatkan sumber tenaga ambien untuk menghasilkan tenaga elektrik. Kajian yang mendalam telah dilakukan bagi memperolehi penuai tenaga dengan kecekapan dan kepekaan yang tinggi. Tiga sumber tenaga digunakan sebagai masukan iaitu tenaga haba, getaran dan Frekuensi Radio (RF). Masukan tenaga haba adalah dalam bentuk voltan DC manakala masukan getaran dan RF adalah dalam bentuk voltan AC. Kesemua masukan ini masing-masing ditetapkan pada nilai 0.02 V, 0.5 V dan -20 dBm. Frekuensi operasi yang digunakan bagi masukan getaran adalah 10 Hz manakala bagi masukan RF adalah 915 MHz. Litar penerus gelombang penuh digunakan bagi menukarkan isyarat getaran AC kepada DC. Sementara itu, litar pendarab voltan dibina dengan mengaplikasikan teknik modulasi substrat bagi menggandakan voltan masukan. Kesemua litar penuai tenaga tunggal ini digabungkan menggunakan litar penambah voltan untuk membentuk satu sistem penuai tenaga hibrid yang lengkap. Litar-litar penuai tenaga ini dibina dan disimulasi menggunakan perisian PSPICE dengan menyambungkan perintang beban 1 MΩ. Litar lengkap penuai tenaga dengan masukan hibrid berjaya mencapai voltan keluaran lebih kurang 2.12 V dan sesuai digunakan sebagai alternatif bekalan kuasa kepada aplikasi peranti bioperubatan. Peranti tersebut adalah Peranti Pemantau Kesihatan yang memerlukan bekalam masukan minimum 1.7 V

Architecture of an efficient dual band 1.8/2.5 GHz rectenna for RF energy harvesting

This paper presents a highly efficient rectenna of RF energy harvesting systems operating at 1.8 GHz and 2.5 GHz bands for battery-less sensor application. The antenna is designed by CST-MWS. The Schottky diode used for rectifying circuit is HSMS 286B in which designed by Agilent ADS. The key finding of the paper is that the simulated DC output voltage of the rectenna is 1.35 V for low input power of -25 dBm at a high resistance load of 1M Ω. Correspondingly, the RF-DC conversion efficiency of the rectification process is 59.51% and 45.75% at 1.8 GHz and 2.5 GHz, which are high efficiency and much better compared to literature respectively. The rectenna is capable to produce 1.8 V from an input power of -20 dBm. Thus, the proposed RF energy harvesting system offers a promising solution designed for efficient functionality at a low power level of RF energy in the dual band

Feature Selection Analysis of Chewing Activity Based on Contactless Food Intake Detection

This paper presents the feature selection methods for chewing activity detection. Chewing detection typically used for food intake monitoring applications. The work aims to analyze the effect of implementing optimum feature selection that can improve the accuracy of the chewing detection.  The raw chewing data is collected using a proximity sensor. Pre-process procedures are implemented on the data using normalization and bandpass filters. The searching of a suitable combination of bandpass filter parameters such as lower cut-off frequency (Fc1) and steepness targeted for best accuracy was also included. The Fc1 was 0,5Hz, 1.0Hz and 1.2H, while the steepness varied from 0.75 to 0.9 with an interval of 0.5. By using the bandpass filter with the value of [1Hz, 5Hz] with a steepness of 0.8, the system’s accuracy improves by 1.2% compared to the previous work, which uses [0.5Hz, 5Hz] with a steepness of 0.85. The accuracy of using all 40 extracted features is 98.5%. Two feature selection methods based on feature domain and feature ranking are analyzed. The features domain gives an accuracy of 95.8% using 10 features of the time domain, while the combination of time domain and frequency domain gives an accuracy of 98% with 13 features. Three feature ranking methods were used in this paper: minimum redundancy maximum relevance (MRMR), t-Test, and receiver operating characteristic (ROC). The analysis of the feature ranking method has the accuracy of 98.2%, 85.8%, and 98% for MRMR, t-Test, and ROC with 10 features, respectively. While the accuracy of using 20 features is 98.3%, 97.9%, and 98.3% for MRMR, t-Test, and ROC, respectively. It can be concluded that the feature selection method helps to reduce the number of features while giving a good accuracy

Development of a Hybrid Solar and Waste Heat Thermal Energy Harvesting System

This research aims to develop a Hybrid Solar and Waste Heat Thermal Energy Harvesting System that integrates Thermoelectric Generator (TEG) with a solar PV system. The main focus is given to the development of the hybrid solar and waste heat released from the solar panel by using the TEG system. This hybrid system consists of photovoltaic (PV) cells to absorb the solar energy and the TEG attached to the back of the panel to absorb heat waste and convert it into usable electricity. The PV cell and the TEG are integrated with each other in order to obtain maximum energy and increased system efficiency. The experimental results show that the maximum output voltage produced from the solar PV is 20.37V and the maximum output current generated is 203.72mA. The maximum output voltage obtained from the TEG is 18.92V and the maximum current produced is 189.265mA. This experimental result shows that the maximum voltage and current produced from solar and waste thermal heat from PV panels can be used to charge and to power up portable electronic devices. More efficiency is accomplished by combining the TEG to absorb waste heat loss from the PV cell, thus improving the performance of the PV panel system

Analisis prestasi penuai tenaga mikro frekuensi radio berkuasa rendah menggunakan antena MEMS bagi rangkaian sensor tanpa wayar

Kebelakangan ini, terdapat kecenderungan minat yang semakin meningkat dari para penyelidik menggunakan tenaga ambien bagi menghidupkan peralatan elektronik menggunakan pelbagai teknik penuaian tenaga. Penuaian tenaga mikro adalah teknik yang berpotensi untuk menukar tenaga ambien dari persekitaran kepada tenaga elektrik. Rangkaian sensor tanpa wayar memerlukan sumber tenaga elektrik yang berterusan untuk mengaktifkannya dan sumber tenaga ambien frekuensi radio (RF) yang sentiasa wujud dipersekitaran sangat sesuai digunakan. Oleh itu, penuai tenaga mikro RF yang direkacipta dan dibangunkan terdiri dari litar padanan galangan, pendarab voltan dan litar pengatur tidak memerlukan sumber tenaga luar untuk mengaktifkannya. Litar penuai tenaga mikro RF ini dibina dan disimulasi menggunakan perisian PSPICE dengan menyambungkan perintang beban 1 MΩ. Pada kuasa masukan -20 dBm atau 10 μW yang ditangkap oleh antena MEMS, nilai voltan dan arus keluaran yang dihasilkan dalam litar penuai tenaga ini masing-masing adalah 2.36 V dan 1.7 mA. Manakala, peratusan kecekapan maksimum bagi keseluruhan litar penuai tenaga mikro RF ini adalah 55.7%. Nilai kuasa keluaran yang dihasilkan iaitu 40.12 mW adalah lebih tinggi berbanding nilai kuasa masukan iaitu 10 μW. Penuai tenaga mikro RF ini mampu untuk mengaktifkan rangkaian sensor tanpa wayar dengan keperluan arus masukan minimum 1 mA. Susunatur litar bersepadu menggunakan teknologi CMOS 180 nm bagi litar pendarab telah berjaya dibangunkan dengan saiz yang sangat kecil iaitu 22.48 x 56.96 μm2 sebagai pembuktian litar boleh difabrikasi sebagai cip litar bersepadu

Architecture of Low Power Energy Harvester Using Hybrid Input of Solar and Thermal for Laptop or Notebook: A Review

Abstract: This paper aims to develop and design the architecture of Low Power Hybrid Energy Harvester (LPHEH) using the hybrid input of solar and thermal that can be harvested for self-powered laptop or notebook. This research will focus on the development of the high performance boost power converter to power up any laptop or notebook and design power management system of the hybrid input of solar and waste heat that has been released. The main function of the boost converter is to generate a sufficient DC power supply for laptop or notebook. The second stage focuses on investigation, design and development of the architecture to convert the solar and waste heat energy to reusable energy. The solar energy harvesting elements such as solar panels and energy storage components are used and to be matched to each other with sufficient energy required to increase the energy harvesting efficiency. The proposed design performances will be described using PSPICE software simulation and experimental results. The final stage is to integrate the first stage and second stage, power management module and charge controller module. Then, the developed LPHEH will be simulated, synthesis using Mentor Graphics and coding using Verilog and then download the LPHEH modules into FPGA board for real time verification. The layout architecture of LPHEH will be tested and analyzed using CALIBRE tools from Mentor Graphics. The expected result from this LPHEH is to get 12 V to 20 V of the regulated output voltage from minimum input voltage sources range from 5 V to 12 V with efficiency more than 90%