Simulation of charge-trapping in nano-scale MOSFETs in the presence of random-dopants-induced variability

The growing variability of electrical characteristics is a major issue associated with continuous downscaling of contemporary bulk MOSFETs. In addition, the operating conditions brought about by these same scaling trends have pushed MOSFET degradation mechanisms such as Bias Temperature Instability (BTI) to the forefront as a critical reliability threat. This thesis investigates the impact of this ageing phenomena, in conjunction with device variability, on key MOSFET electrical parameters. A three-dimensional drift-diffusion approximation is adopted as the simulation approach in this work, with random dopant fluctuations—the dominant source of statistical variability—included in the simulations. The testbed device is a realistic 35 nm physical gate length n-channel conventional bulk MOSFET. 1000 microscopically different implementations of the transistor are simulated and subjected to charge-trapping at the oxide interface. The statistical simulations reveal relatively rare but very large threshold voltage shifts, with magnitudes over 3 times than that predicted by the conventional theoretical approach. The physical origin of this effect is investigated in terms of the electrostatic influences of the random dopants and trapped charges on the channel electron concentration. Simulations with progressively increased trapped charge densities—emulating the characteristic condition of BTI degradation—result in further variability of the threshold voltage distribution. Weak correlations of the order of 10-2 are found between the pre-degradation threshold voltage and post-degradation threshold voltage shift distributions. The importance of accounting for random dopant fluctuations in the simulations is emphasised in order to obtain qualitative agreement between simulation results and published experimental measurements. Finally, the information gained from these device-level physical simulations is integrated into statistical compact models, making the information available to circuit designers

Prototype development of a smart voice-controlled audio system based on the Raspberry Pi platform

We report a prototype audio system that can be controlled by means of voice commands. The operations of this audio player – such as song playback and volume control – can be effectively controlled by verbal commands alone without requiring any button-press or dial-turn, enabling a user to operate it with full hands. This feature could be particularly useful in situations when the user’s view and attention are pre-occupied, as in the case of driving or cycling. A voice-command device also has the advantage of a smaller form factor and simpler product casing, due to fewer dials and buttons. While there are a wide variety of commercial audio systems, only very limited few allow voice-control operations. This voice-controlled audio system is low-cost, open-source, and capable of “smart” features that include notifying weather forecasts, automatic volume control, and automatic shutdown. Its platform is the single-board computer Raspberry Pi, which runs speech-to-text processes that record and transcribe a given voice command, such as “Play music” and “Volume up.” The Raspberry Pi also connects to cloud-based services – and upon voice requests – can check and tell real-time information such as date, time, and weather. The system’s average response time to a given voice command was measured to be about 5 seconds. A simple circuit of LED indicators was also designed to prompt users to give voice commands at the right window of time, therefore improving system responsiveness and overall user experience. This prototype can be extended to voice-control other appliances in an integrated smart home environment

A multiband 130nm CMOS second order band pass filter for LTE bands

With increasing consumer demand for wireless devices to support multiple air standards and applications, there have been increased trends for implementation multimode multiband (MMMB) devices in the RF front-end of wireless handsets. This paper presents a design of multiband band pass filter (BPF) in 130nm standard CMOS technology that can operates in 12 different LTE bands (band 1, 2, 3, 4, 5, 8, 9, 11, 18, 19, 21 and 25). The filter response is tuned by employing switched capacitors in parallel with LC resonant circuit; and Q-factor of the filter is tuned using cross-coupled differential pair connected across the resonant circuit. The gain of 30dB with maximum bandwidth of 145 MHz at 900MHz center frequency, 328MHz at 1.5GHz center frequency and 594MHz at 2GHz center frequency is achieved at 3.3V supply. The Q-factor of the filter is tunable through 2.1 to 8.1. The 1-dB compression point (P1dB), third order intercept point (IP3), and noise figure achieved are -39dBm, -25dBm and 3.83dB respectively. The designed filter has the features of less BOM count and smaller area making it suitable for integration in modern wireless applications

A multiband 130nm CMOS low noise amplifier for LTE bands

With increasing consumer demand for wireless devices to support multiple air standards and applications, there have been increased trends for the implementation of multiband (MB) devices in the RF front-end of the wireless handsets. This paper presents the design of multiband low noise amplifier (LNA) in the 130nm Silterra CMOS technology. The proposed LNA operates in five major LTE bands (band 1, 2, 3, 4 and 8) used in the smartphone transceiver. The proposed design uses a transistor based shunt feedback to lower the noise figure of the LNA. It uses switched capacitors and MOS varactors that are controlled externally to achieve multiband operation. The gain, noise figure, IIP3 achieved are 20dB, 2.9-4.35dB and -15dBm respectively. The proposed circuit consumes 20.7mW power at 1.2V operation. Notably, the proposed LNA operates at both low-band and high-band making it more suitable for the multiband requirement of modern wireless transceiver frontends

Evaluating final-year student classroom communication at the faculty of engineering and built environment, Universiti Kebangsaan Malaysia

Classroom communication is a very important and complex aspect in teaching and learning. The complexity of a communication process is attributed to a host of components that include the participants, messages, encoding, decoding, and transmission channels. Not much is currently known concerning classroom communication in the context of engineering education in Malaysian universities. This paper evaluates classroom communication of final-year students of the Electrical and Electronic engineering degree programs at Universiti Kebangsaan Malaysia. Four important aspects of classroom communication were investigated to understand student abilities and issues in classroom communication. One hundred and four students undertook the self-administered survey, yielding a response rate of 92.8%. The majority of the students exhibited good non-verbal communication practices, and scored favourably in the aspect of adapting the way they communicate to others. However, 42.3% of the respondents seemed to have difficulties to explain and express ideas confidently via classroom presentations. Additionally, 43 students (41.3%) appeared to be handicapped in participating actively in class discussions. Finally, at least 40 respondents (38.5%) reported difficulties to express ideas in English, but not to the extent of hindering them in participating in classroom discussions. Further studies are needed to uncover classroom communication issues in student learning among engineering students at Universiti Kebangsaan Malaysia

Perbandingan keberkesanan kaedah mendokumentasikan maklumat bangunan warisan melalui perwakilan digital BIM dan CAD

Dokumentasi merupakan proses utama dalam pemuliharaan bangunan sebelum sebarang keputusan dalam kerja-kerja pemuliharaan dibuat terhadap bangunan warisan. Warisan umumnya didefinasikan sebagai sesuatu yang bernilai yang diwariskan dari satu generasi ke satu generasi yang baru. Oleh itu, pendokumentasian maklumat bangunan warisan memerlukan kaedah dan teknik yang inovatif supaya data maklumat bangunan dapat diuruskan dengan baik bagi memastikan sebarang perubahan, pembaikan, penambahan atau perobohan bahagian aset dicatat dengan betul dalam usaha mengekalkan kesahihan aset. Building Information Modelling (BIM) merupakan salah satu kaedah pendokumentasian bangunan yang sedang digunapakai pada era teknologi kini selain daripada kaedah mendokumentasikan bangunan menggunakan Computer-Aided Drafting (CAD). Walau bagaimanapun, penggunaan BIM di Malaysia masih di peringkat awal pertumbuhan. Kaedah mendokumentasikan bangunan ke dalam bentuk lukisan menggunakan CAD pula telah lama digunakan, namun kos penyelengaraan agak tinggi. Oleh itu, kajian ini dijalankan bertujuan untuk membandingkan keberkesanan kaedah mendokumentasikan maklumat bangunan warisan menggunakan teknologi BIM dan CAD. Hasil kajian melalui temu bual terhadap syarikat yang menggunakan teknologi BIM dan CAD mendapati bahawa teknologi BIM lebih berkesan dalam mendokumentasikan bangunan warisan kerana ianya memiliki tetapan fungsi yang dapat menghasilkan lukisan yang lebih tepat berbanding CAD. Pengurusan aktiviti pendokumentasian juga lebih mudah dijalankan melalui BIM kerana ianya memiliki sistem koordinasi data yang bersepadu dan jitu. BIM dapat meningkatkan ketepatan maklumat model lukisan dan seharusnya digunapakai dalam aktiviti pemuliharaan bangunan warisan

Multimode multiband power amplifier with tapped transformer for efficiency enhancement in low power mode

Multimode multiband connectivity has become a defacto requirement for smartphones with 3G WCDMA/4G LTE applications. In this research, a two-stage multimode multiband (MMMB) power amplifier (PA) with multiple gated transistor (MGTR) and configurable tapped transformer is designed and analysed in view of enhancing the efficiency in low power mode. The designed MMMB PA offers a 900MHz of operating bandwidth starting from the frequency of 1400MHz up to 2300MHz, covering 16 LTE FDD bands with peak output power of 27.8dBm and peak PAE of 31% in the high power mode. In low power mode, the PA offers the same bandwidth with peak output power of 25.5dBm and PAE of 30%. Use of the multiple gated transistor with tapped transformer for matching has increased the PAE in low power mode by 19% compared with that PAE in the high power mode

Wireless power transfer with on-chip inductor and class-E power amplifier for implant medical device applications

The popular use of biomedical implants has been going on in numerous applications that include the use of pacemakers and emerging retina prostheses, together with brain-computer interfaces. Other popular uses include drug delivery and smart orthopaedic implants. The avoidance of batteries or piercing wirings has made the wireless powering of these implantable devices highly attractive. In this paper, a design of a class-E power amplifier which has inductive loading appropriate for implant application was made using 130nm Silterra CMOS process at 2.4V supply. A presentation of high-Q on-chip inductors is made as a way of improving the efficiency of the wireless power transfer (WPT) system at 37.5MHz industrial, scientific and medical (ISM) band. Wireless power transfer efficiency of 59-89% is obtained for distance variation up to 10mm of the implant coil from the transmit power coil. DC voltage of more 3V is obtained for distance up to 10mm of the implant coil; and the on-chip implant inductor measures a smaller size of 10mm×10mm making the design more suitable for the application of medical implant

Evaluation of architecture student classroom communication at Universiti Kebangsaan Malaysia

Classroom communication is a very important and complex aspect in teaching and learning. Its complexity is attributed to a host of factors that include participants, messages, encoding, decoding, and channels. Not much is currently known concerning classroom communication in the context of architecture education in Malaysian universities. This paper evaluates classroom communication of students undertaking architecture degree programs at Universiti Kebangsaan Malaysia. Four factors of student classroom communication were investigated to understand student abilities and issues in classroom communication. Forty-four students undertook the self administered survey. The majority of the students exhibited good non-verbal communication practices, and scored favourably in the aspect of adapting the way they communicate to others. However, students seemed to have some difficulty to express ideas in class presentations. Additionally, some students appeared to be handicapped in actively participating and leading class discussions. Last but not least, a number of students were not comfortable in using English in the classroom, but not to the extent of hindering them in participating in classroom discussions. Further studies are needed to uncover classroom communication issues in student learning among architecture students at Universiti Kebangsaan Malaysia

A low power multiplexer based pass transistor logic full adder

In this paper, a high-speed low-power full adder design using multiplexer based pass transistor logic featuring full-swing output is proposed. The adder is designed and simulated using the industry standard 130 nm CMOS technology, at a supply voltage of 1.2 V. The obtained Power Delay Product (PDP) of its critical path is 29×10-18 J and its power consumption is 2.01μW. The proposed full adder is also capable to function at lower supply voltages of 0.4 V and 0.8 V without significant performance degradation. The proposed adder when cascaded in a 4-bit ripple carry adder configuration, its power, delay and PDP performance are better than the other adders making it suitable for larger arithmetic circuits