International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper proposes a modification of the high alphabet method of data transmission over an RF carrier. The system maps eleven characters into three tones. The three tones are Frequency Modulated onto an RF carrier. The 165 unique characters can be utilized for data transmission. The advantages of this system are: 1. Longer duration data words which have narrow bandwidth yielding a high signal to noise ratio. 2. Digital Signal Processing can be utilized to reconstruct characters from the tri-tone encoding. 3. The system will be less susceptible to external interference than normal Frequency Shift Keying system. The majority of the three tone burst would have to masked in order to loose a data word.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / An algorithm for automatic modulation recognition of ASK, PSK and FSK was developed by Azzouz and Nandi. The algorithm has some serious problems at SNR of 10 dB and below. This paper describes a modification to the algorithm that significantly improves the performance for detection of ASK and FSK at moderate and low SNR.

Multiple scattering effects from bubble clouds are investigated in this study. A high performance, general purpose numerical tool for multiple scattering calculations is developed. This numerical tool is applied in three computational scenarios in this study. The total scattering cross section of a bubble cloud is investigated. Numerical results indicate that the resonant frequency of the bubble cloud is much lower than that of a single bubble. The variation of resonant frequency of multiple scattering is also studied. It is found that the resonant frequency decreases as the number of bubbles increases, or as the void fraction of the bubble cloud decreases. Phase distributions of bubble oscillations in various multiple scattering scenarios are presented. It is found that, at resonance, the bubbles synchronize to the same phase, which is indicative of the lowest mode of collective oscillation. At wave localization, half of the bubbles oscillate at phase 0 while the other half oscillate at phase Pi. An intuitive interpretation of this behavior is given.

This thesis consists of two topics. A frequency-shift readout circuit is integrated for the rapid IgE measurement biomedical system in the first half. Secondly, we present a ROM-less DDFS (direct digital frequency synthesis) using a non-equal division parabolic polynomial interpolation method, which is used as the frequency generator in the measurement system. The first topic investigates the IgE concentration measurement system and realizes the readout circuit using TSMC 1P6M 0.18 £gm CMOS technology. We integrate the flexural plate wave (FPW) sensor chips and an ASIC comprising control block, digital to analog convertor (DAC), OTA-C oscillators, amplifiers, peak detectors, registers, and a subtractor. By taking advantages of the characteristics that the central frequencies of the loaded FPW sensors will be shifted, sine waves with various frequencies are generated and swept through one pair of FPW sensors. The frequency difference of these sensors is then readout to get concentration by look-up table. The second topic investigates the division method of a quarter sine wave to improve the spurious free dynamic range (SFDR) and realizes a ROM-less DDFS which is used as the frequency generator in the mentioned IgE measurement system. The proposed non-equal division parabolic polynomial interpolation method will generate a complete sine wave by a quarter of a sine digital signal owing to the symmetry. We combine the quasi-linear interpolation and an offset adjustment to derive the quarter sine wave digital signals. The proposed method not only reduces the absolute error between ideal sine wave and generated sine wave, it also improves SFDR.

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Space-time Coding (STC) for Multiple-Input Multiple-Output (MIMO) wireless communication systems is an effective technique for providing robust wireless link performance in telemetry systems. This paper investigates the degradation in system performance when synchronization errors between the transmitter and receiver are present. Specifically, expressions that quantify the increase in symbol-error-rate as a function of symbol synchronization error are derived for a two-transmit and single receive antenna MISO system using binary frequency shift keying waveforms. These results are then extended to the MIMO case. The analytic results are verified with simulation results that show close agreement between the theoretical expressions and Monte Carlo simulation runs.

This thesis consists of two topics. We proposed a low power half-run RC5 cipher for portable biomedical devices in the first part of this thesis. The second topic is to realize a frequency-shift readout system for FPW-based biosensors. In the first topic, a half-round low-power RC5 encryption structure is proposed. To reduce hardware cost as well as power consumption, the proposed RC5 cipher adopts a resource-sharing approach, where only one adder/subtractor, one bi-directional barrel shifter, and one XOR with 32-bit bus width are used to carry out the entire design. Two data paths are switched through the combination of four multiplexers in the encryption/decryption procedure. For the sake of power reduction, the clock in the key expansion can be turned off when all subkeys are generated. In the second topic, an IgE antigen concentration measurement system using a frequency-shift readout method for a two-port FPW (flexural plate-wave) allergy biosensor is presented. The proposed frequency-shift readout method adopts a peak detecting scheme to detect the resonant frequency. A linear frequency generator, a pair of peak detectors, two registers, and an subtractor are only needed in our system. According to the characteristics of the FPW allergy biosensor, the frequency sweep range is limited in a range of 2 MHz to 4 MHz. The precision of the measured frequency is proved to the 4.2 kHz/mV, which is for better than that of existing designs.

Surface acoustic wave sensors have been a focus of active research for many years. Its ability to respond for surface perturbation is a basic principle for its sensing capability. Sensitivity to surface perturbation changes with every inter-digital transducer (IDT) design parameters, substrate selection, metallization choice and technique, delay line length and working environment. In this thesis, surface acoustic wave (SAW) sensors are designed and characterized to improve sensitivity and reduce loss. To quantify the improvements with a specific design configuration, the sensors are employed to measure temperature. Four SAW sensors design configurations, namely bi-directional, split electrode, single phase unidirectional transducer (SPUDT) and metal grating on delay line (shear transvers wave sensors) are designed and then fabricated in Nanotechnology Research and Education Center (NREC) facility using traditional MEMS fabrication processes Additionally, sensors are then coated with guiding layer SU8-2035 of 40 m using spin coating and SiO2 of 6 m using plasma enhanced chemical vapor deposition (PECVD) process. Sensors are later diced and tested for every 5oC increment using network analyzer for temperature ranging from 30oC–0.5oC to 80oC–0.5oC. Data acquired from network analyzer is analyzed using plot of logarithmic magnitude, phase and frequency shift. Furthermore, to investigate the effect of metallization technique on the sensor performance, sensors are also fabricated on substrates that were metallized at a commercial MEMS foundry. All in-house and outside sputtered sensor configurations are compared to investigate quality of sputtered metal on wafer. One with better quality sputtered metal is chosen for further study. Later sensors coated with SU8 and SiO2 as guiding layer are compared to investigate effect of each waveguide on sensors and determine which waveguide offers better performance. The results showed that company sputtered sensors have higher sensitivity compared to in-house sputtered wafers. Furthermore after comparing SU8 and SiO2 coated sensors in the same instrumental and environmental condition, it was observed that SU8 coated di-directional and single phase unidirectional transducer (SPUDT) sensors showed best response.

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The Motorola Inc. paging protocol FLEX is discussed. The design and construction of a FLEX paging protocol decoder is discussed in detail. It proposes a decoding solution that includes a radio frequency (RF) receiver and a decoder board. The RF receiver will be briefly discussed. The decoder design is the main focus of this thesis as it transforms the RF frequency modulated (FM) data from the receiver and converts it to FLEX data words. The decoder is designed to handle bit sampling, bit clock synchronization, FLEX packet detection, and FLEX data word collection. The FLEX data words are then sent by the decoder to an external computer through a serial link for bit processing and storage. A FLEX transmitter will send randomly generated data so that a bit error rate (BER) calculation can be made at a PC. Each receiver'9s noise power and noise bandwidth will be measured so that noise spectral density may be calculated. A complete measurement set-up will be shown on how these noise measurements are made. The BER at a known power level is recorded. This enables Eb/No curves to be generated so that results of the decoding algorithm may be compared. This is performed on two different receivers. / Master of Science