A Fully-Integrated Reconfigurable Dual-Band Transceiver for Short Range Wireless Communications in 180 nm CMOS

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.A fully-integrated reconfigurable dual-band (760-960 MHz and 2.4-2.5 GHz) transceiver (TRX) for short range wireless communications is presented. The TRX consists of two individually-optimized RF front-ends for each band and one shared power-scalable analog baseband. The sub-GHz receiver has achieved the maximum 75 dBc 3rd-order harmonic rejection ratio (HRR3) by inserting a Q-enhanced notch filtering RF amplifier (RFA). In 2.4 GHz band, a single-ended-to-differential RFA with gain/phase imbalance compensation is proposed in the receiver. A ΣΔ fractional-N PLL frequency synthesizer with two switchable Class-C VCOs is employed to provide the LOs. Moreover, the integrated multi-mode PAs achieve the output P1dB (OP1dB) of 16.3 dBm and 14.1 dBm with both 25% PAE for sub-GHz and 2.4 GHz bands, respectively. A power-control loop is proposed to detect the input signal PAPR in real-time and flexibly reconfigure the PA's operation modes to enhance the back-off efficiency. With this proposed technique, the PAE of the sub-GHz PA is improved by x3.24 and x1.41 at 9 dB and 3 dB back-off powers, respectively, and the PAE of the 2.4 GHz PA is improved by x2.17 at 6 dB back-off power. The presented transceiver has achieved comparable or even better performance in terms of noise figure, HRR, OP1dB and power efficiency compared with the state-of-the-art.Peer reviewe

LOW POWER SI-BASED POWER AMPLIFIER FOR HEALTHCARE APPLICATION

Objective: The objective of this research was to design a 2.4 GHz class B Power Amplifier (PA), with 0.18um Semiconductor Manufacturing International Corporation (SMIC) CMOS technology by using Cadence software, for health care applications. The ultimate goal for such application is to minimize the trade-offs between performance and cost, and between performance and low power consumption design.Methods: This paper introduces the design of a 2.4GHz class B power amplifier designed as dual gate topology. This class B power amplifier could transmit 26dBm output power to a 50Ω load. The power added efficiency was 60% minimum and the power gain was 90dB, the total power consumption was 6.9 mW.Results: Besides, accurate device modeling, is needed, due to the leakage and process variations.Conclusion: The performance of the power amplifier meets the specification requirements of the desired

Key Parameters of Pulsed Laser Deposition for Solid Electrolyte Thin Film Growth

The pulsed laser deposition (PLD) technique has been a common method to grow thin films such as solid electrolyte (SE). The effects of substrate temperature and laser fluence on the thin film properties and the device performance are analyzed. For the first time, a quantitative analytical model dealing with the energy conversion in the process when laser hits the target is presented, which provides a solution that is crucial in correlating the formation of high quality and uniform thin films to the experimental design. The migration speed of the ablated particles, which determines the quality of the deposited films, is found to be directly related with the laser fluence. Specifically, a threshold fluence is required to generate high purity single form thin film. This model provides the opportunities to improve experimental design and quality control

RF Integrated Circuits for Energy Autonomous Sensor Nodes.

The exponential growth in the semiconductor industry has enabled computers to pervade our everyday lives, and as we move forward many of these computers will have form factors much smaller than a typical laptop or smartphone. Sensor nodes will soon be deployed ubiquitously, capable of capturing information of their surrounding environment. The next step is to connect all these different nodes together into an entire interconnected system. This “Internet of Things” (IoT) vision has incredible potential to change our lives commercially, societally, and personally. The backbone of IoT is the wireless sensor node, many of which will operate under very rigorous energy constraints with small batteries or no batteries at all. It has been shown that in sensor nodes, radio communication is one of the biggest bottlenecks to ultra-low power design. This research explores ways to reduce energy consumption in radios for wireless sensor networks, allowing them to run off harvested energy, while maintaining qualities that will allow them to function in a real world, multi-user environment. Three different prototypes have been designed demonstrating these techniques. The first is a sensitivity-reduced nanowatt wake-up radio which allows a sensor node to actively listen for packets even when the rest of the node is asleep. CDMA codes and interference rejection reduce the potential for energy-costly false wake-ups. The second prototype is a full transceiver for a body-worn EKG sensor node. This transceiver is designed to have low instantaneous power and is able to receive 802.15.6 Wireless Body Area Network compliant packets. It uses asymmetric communication including a wake-up receiver based on the previous design, UWB transmitter and a communication receiver. The communication receiver has 10 physical channels to avoid interference and demodulates coherent packets which is uncommon for low power radios, but dictated by the 802.15.6 standard. The third prototype is a long range transceiver capable of >1km communication range in the 433MHz band and able to interface with an existing commercial radio. A digitally assisted baseband demodulator was designed which enables the ability to perform bit-level as well as packet-level duty cycling which increases the radio's energy efficiency.PhDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/110432/1/nerobert_1.pd

Architecture for ultra-low power multi-channel transmitters for Body Area Networks using RF resonators

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 99-103).Body Area Networks (BANs) are gaining prominence for their use in medical and sports monitoring. This thesis develops the specifications of a ultra-low power 2.4GHz transmitter for use in a Body Area Networks, taking advantage of the asymmetric energy constraints on the sensor node and the basestation. The specifications include low transmit output powers, around -10dBm, low startup time, simple modulation schemes of OOK, FSK and BPSK and high datarates of 1Mbps. An architecture that is suited for the unique requirements of transmitters in these BANs is developed. RF Resonators, and in particular Film Bulk Acoustic Wave Resonators (FBARs) are explored as carrier frequency generators since they provide stable frequencies without the need for PLLs. The frequency of oscillation is directly modulated to generate FSK. Since these oscillators have low tuning range, the architecture uses multiple resonators to define the center frequencies of the multiple channels. A scalable scheme that uses a resonant buffer is developed to multiplex the oscillators' outputs to the Power Amplifier (PA). The buffer is also capable of generating BPSK signals. Finally a PA optimized for efficiently delivering the low output powers required in BANs is developed. A tunable matching network in the PA also enables pulse-shaping for spectrally efficient modulation. A prototype transmitter supporting 3 FBAR-oscillator channels in the 2.4GHz ISM band was designed in a 65nm CMOS process. It operates from a 0.7V supply for the RF portion and 1V for the digital section. The transmitter achieves 1Mbps FSK, up to 10Mbps for OOK and BPSK without pulse shaping and 1Mbps for OOK and BPSK with pulse shaping. The power amplifier has an efficiency of up to 43% and outputs between -15dBm and -7.5dBm onto a 50Q antenna. Overall, the transmitter achieves an efficiency of upto 26% and energy per bit of 483pJ/bit at 1Mbps.by Arun Paidimarri.S.M

Dispositivo de Deteção do Bruxismo do Sono

This thesis aims to explore and, ultimately, develop a system capable of monitoring physiological signals to detect bruxism events. Bruxism is a disorder characterized by the habit of pressing and grinding the teeth. These events can either occur during the day (Awake Bruxism) or during the night (Sleep Bruxism). Studies suggest that 20% of the adult population suffer from Awake Bruxism, and 8-16% from Sleep Bruxism. The consequences of this disorder are several, ranging from tooth wear, dental fractures, or abfraction, resulting in headaches, or facial myalgia. This dissertation focuses on the Sleep Bruxism type since it’s harder to detect and treat. First, a study about the evolution of technology in healthcare is carried out, fundamentally about how it was introduced and how did it get to the point it is now. The topic of wearable devices is also explored, in the sense that it’s where the market is going and how these devices can transform healthcare. Then, the study converges on the devices developed especially for bruxism, namely which devices, and what type of techniques are used. Subsequently, the general concept for the system is elaborated, exploring several options both in terms of devices and physiological data to be parameterized. However, some restrictions exist for the construction of the system. For the construction of an intraoral system, the device has to be of small dimensions and with low energy consumption. With these constraints, the system has implemented an Inertial Measurement Unit to estimate the orientation of the patient’s sleeping position, and force sensors to measure the force exerted between the teeth. For compactness, a Systemon-Chip is used, since it includes an ARM Cortex M4 processor, several peripherals, and an RF transceiver in one package. The system is not only responsible for the data acquisition, but also the data transmission. This is accomplished by using Bluetooth Low Energy, which is one of the most common protocols for low-power devices. Customized service is developed for this purpose, consisting of three different characteristics: the force characteristic, the accelerometer characteristic, and the gyroscope characteristic. The reason is for maximizing efficiency. The last step was to develop the prototype, testing its functionalities and try to project next iterations of the prototype

Design of Low-Power Short-Distance Transceiver for Wireless Sensor Networks

Ph.DDOCTOR OF PHILOSOPH