No description available.

Thesis (M. Eng.)--Carleton University, 1988. / Also available in electronic format on the Internet.

Surface Acoustic Wave (SAW) devices are manufactured using standard metallization and photolithographic techniques that have been established by the semiconductor industry. The facilities in the newly developed Microelectronics laboratory at the University of Central Florida will be utilized in the fabrication of a SAW device. This thesis will outline the complete procedure beginning with the initial design from given specifications, up to mask generation, fabricating and testing of the device. This will serve to calibrate the fabrication process for future work in SAW device and semiconductor fabrication. The models that are used in the SAWCAD design software will be verified by comparing the theoretical and experimental results.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Thin Film bulk acoustic wave devices have the advantages of low loss, low temperature coefficient of the resonant frequency, and high power handling. These excellent characteristics are suitable for the applications on high frequency communication systems. In this study, thin film bulk acoustic wave filters using the ladder-type filter and stacked crystal filter configurations were investigated. Platinum was chosen as the top and bottom electrodes. To improve the platinum adhesion on SiNx/SiO2/Si substrates, a seeding layer of titanium is used. Highly c-axis oriented piezoelectric zinc oxide thin films were deposited by two-step deposition method under room temperature. As resonant area decreases, the band rejection of ladder-type filter will increase. Because the resonant area decreased, the distance between signal and ground will increase the results in an increased insertion loss. On the other hand, stacked crystal filters have larger band rejection and less 3dB bandwidth, which are suitable for the application of narrow band filters.

No description available.

<p> A two-part scheme for the design of wideband linear phase SAW filters is proposed. The design uses curved finger interdigital transducers, and extension of slanted finger design, to compensate for circuit effects and eliminate the need for matching. Theory is combined with distortion minimizing techniques to realize devices which satisfy INTELSAT filter specifications. </p> <p> Basic SAW theory is reviewed. and curved finger theory presented, while methods of distortion minimization are both reviewed and proposed. Experimental results which illustrate and support the theory given are included. </p> / Thesis / Master of Engineering (MEngr)

A general, non-iterative design technique for low shapefactor, transversal filters is presented. This design approach uses two cosine series to specify appropriate eigenfunctions. An infinite set of such eigenfunctions are defined and the method for choosing the coefficients is discussed. The total filter response is specified as the product of two individual frequency responses. The impulse response of each is then determined by applying the superposition of appropriate eigenfunctions. The criteria for choosing the appropriate eigenfunctions is discussed. A synthesis procedure for designing surface acoustic wave filters is presented. The effects of truncating the impulse response are also explored. A design example is shown for a filter with 10 percent fractional bandwidth and a shapefactor of 1.15.

Matched filter detectors are used to detect known signal waveforms transmitted under noisy conditions. Moving-average matched filters (MAMF's) are a class of digital filters whose performance is measured in terms of Signal to Noise Ratio (SNR). The overall performance of a MAMF is described by the SNR Improvement (SNRI) which is the ratio of Output SNR (OSNR) to Input SNR (ISNR). The OSNR and ISNR are the SNR at the output and input of the MAMF respectively. SNRI is maximized by maximizing OSNR since ISNR is fixed for a received signal and noise. The OSNR of a MAMF is a function of the noise autocorrelation sequence and the transmitted signal vector. The maximum OSNR of a MAMF is produced when the signal vector is the eigenvector associated with the smallest eigenvalue of the Toeplitz matrix formed from the noise autocorrelation sequence. If the noise autocorrelation is not known in advance of transmission, or not stationary, then it must be estimated at the receiver. Since autocorrelation estimators derive their estimates from noise samples, i.e. a random process, the estimates are probabilistic. In a practical implementation wherein the signal vector is fixed, the noise is stationary over short periods of time, and the noise autocorrelation sequence is estimated, the SNRI or performance of the MAMF varies and can even become less than unity if either the estimates are poor or the noise characteristics differ from those expected when the signal vectors were selected. A SNRI less than unity is highly undesirable as processing, which is done with the objective of obtaining higher OSNR than ISNR, i.e. a SNRI greater than unity, has become counterproductive. This thesis proposes a variation to the classical MAMF communication system and investigates the performance of the resulting MAMF. In the classical MAMF communication system the N-dimensional signal vector is treated as a single vector. In the proposed MAMF communication system, the N-dimensional signal vector is composed of two or more linearly independent basis vectors spanning a signal vector subspace of dimension M. By combining the linearly independent basis vectors in the receiver, one can effectively change the transmitted signal vector to any signal vector in the signal vector subspace to maximize OSNR. The OSNR of a MAMF is a function of the autocorrelation of the noise as well as the signal vector. The autocorrelation of the noise is estimated in both the classical and proposed systems. For relatively few noise samples, the estimated autocorrelation of the noise deviates from the actual autocorrelation. The proposed system is formed from the classical system by proceeding the MAMF with a processor that extracts the received linearly independent basis vectors with additive colored Gaussian noise from the received transmission and combines them to yield maximum OSNR assuming the estimated autocorrelation of the noise is exact. Since the autocorrelation of the noise is estimated from the random noise process, the autocorrelations themselves are probabilistic and hence the maximum OSNR is too. As the estimated noise autocorrelation approaches the actual noise autocorrelation, the OSNR approaches the absolute maximum OSNR for the M-dimensional system. The theoretical aspects of both the classical and proposed MAMF communication systems are developed in this thesis. The performance of the proposed MAMF communication system is investigated for a practical implementation wherein the signal vector is composed of two linearly independent basis vectors and the noise characteristics vary over time. The performance of the proposed system is first compared to that of the classical system with both systems using various signal vectors, over various noise colors, and with the exact noise autocorrelation given. The performance comparison between the classical and proposed systems is then repeated with the noise autocorrelation, as in a practical implementation, estimated using either the classical biased or Burg estimator. The performance is measured by SNRI and the results are tabulated and graphed. Finally, the proposed system is implemented and its performance measured by bit error rates as a function of ISNR. This will show whether SNRI performance is a good prediction of bit error rate performance. The color of the stationary Gaussian noise is kept constant during transmission of a particular bit. The color of the stationary Gaussian noise is changed between bit transmissions to observe the robustness of the system under different colored noise conditions while maintaining the same signal vectors, or signal subspace. The results are again tabulated and graphed. / Master of Science

Τα φίλτρα λογαριθμικού πεδίου (log-domain filters) είναι μια οικογένεια φίλτρων συνεχούς χρόνου στην οποία γίνεται χρήση της μη-γραμμικής I/V χαρακτηριστικής των ενεργών στοιχείων (BJT τρανζίστορ, MOSFET τρανζίστορ σε ασθενή αναστροφή) για να επιτευχθεί γραμμική συμπεριφορά από είσοδο σε έξοδο. Επιπρόσθετα τα log-domain φίλτρα, προσφέρουν και άλλα πλεονεκτήματα, όπως την ηλεκτρονική ρύθμιση της συχνότητας αποκοπής, την λειτουργία σε υψηλές συχνότητες και την δυνατότητα λειτουργίας με χαμηλή τάση τροφοδοσίας. Στην παρούσα διατριβή προτείνεται μια καινούρια τεχνική σχεδιασμού log-domain φίλτρων, η οποία στηρίζεται στη κυματική μέθοδο (log-domain wave filters). Με αυτή την τεχνική, log-domain φίλτρα μπορούν να σχεδιαστούν είτε με την χρήση των κυματικών παραμέτρων σκέδασης (wave scattering parameters), είτε με την χρήση κυματικών τερματιστών θύρας (wave port terminator). Έτσι αρχικά, προτείνονται δομές log-domain κυματικών φίλτρων με χρήση των κυματικών παραμέτρων σκέδασης. Σε αυτήν την προσέγγιση, το log-domain κυματικό ισοδύναμο ενός επαγωγού σε σειρά κλάδο μετασχηματίζεται από το γραμμικό στο λογαριθμικό πεδίο. Τα log-domain κυματικά ισοδύναμα των υπολοίπων βασικών στοιχείων του παθητικού πρωτοτύπου φίλτρου προκύπτουν από το κυματικό ισοδύναμο του επαγωγού σε σειρά κλάδο με την εναλλαγή των εξόδων του ή/και την προσθήκη αντιστροφέων τάσης. Χρησιμοποιώντας μια διαφορετική προσέγγιση, προτείνονται δομές log-domain κυματικών φίλτρων με χρήση του log-domain κυματικού τερμαστιστή θύρας. Με την χρήση του σχεδιάζεται το κυματικό ισοδύναμο στο log-domain ενός πυκνωτή σε παράλληλο κλάδο, το οποίο χρησιμοποιείται ως το βασικό κυματικό ισοδύναμο δομικό στοιχείο. Τα κυματικά ισοδύναμα των υπολοίπων στοιχείων του παθητικού κυκλώματος προκύπτουν με χρήση των παραπάνω κυματικών ισοδυνάμων. Τέλος γίνεται μελέτη της επίδρασης των μη-ιδανικών χαρακτηριστικών του BJT τρανζίστορ και της επίδρασης των θερμοκρασιακών μεταβολών στην συμπεριφορά των προτεινόμενων φίλτρων, ενώ προτείνονται μέθοδοι τόσο για την επιμέρους όσο και την συνολική αντιστάθμισή τους. / Log-domain filters are a family of continuous time filters that instead of being designed using locally linearized components, directly exploit the non-linear nature of a BJT, or a MOSFET transistor operating in weak inversion, in order to obtain a system with overall linear performance. This way they exhibit high linearity even for large signal to bias ratios. In addition they have some other interesting features like tunability and the ability to work at high frequencies even with low voltage supplies. In the present dissertation a new method for the design of log-domain filters is proposed, based on the well-known wave method. According to this method log-domain filters can be designed using the wave scattering parameters or using the wave port terminator block. Structures of log-domain wave filters using wave scattering parameters are initially proposed. In this approach the log-domain wave equivalent of a series inductor is transformed from linear to log-domain. Log-domain wave equivalents of the other basic elements of a passive prototype are then derived by the interchange of its outputs or/and the addition of voltage inverters. These equivalents are then connected together forming the actual filter. Log-domain differential wave filters can be designed by the introduction of the log-domain differential wave equivalent of the series inductor. Using a different approach, log-domain wave filters have been designed, introducing the block of a log-domain wave port terminator. Using this block, the log-domain wave equivalent of a shunt capacitor is derived as the based structure element. The wave equivalents of other basic elements of the passive prototype are derived as before interchanging its outputs or/and adding voltage inverters. Finally the influence of the non-ideal characteristics of the BJT transistor on the frequency response of the derived filters is analyzed and efficient methods are proposed for their compensation.