• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 4
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 34
  • 34
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Measurement of Balanced Devices Using Vector Network Analyzers

Tsai, Di-Chi 12 July 2002 (has links)
This thesis presented a complete measurement method for accurate characterization of balanced devices using two-port vector network analyzer. Combining renormalization and mixed-mode transformation techniques, this method is good for coaxial components. At first, the feasibility of the method was confirmed with the help of ADS simulation. Then a real example of Marchand balun fabricated on FR4 substrate was measured with calibrated mixed-mode S-parameters that have been further verified by full-wave simulations. The measurement system developed based on this method does not require any additional hardware to the vector network analyzer. This system can be also applied to the measurement of on-wafer components with the help of some microwave switches.
2

Fabrication and characterization of high-speed through silicon via

Huang, Shu-Ting 28 July 2012 (has links)
The target of this thesis is to fabricate through Silicon via (TSV) structures based on Si-bench technology for high-speed transmission interface. In this process, Si via with a depth of 250 £gm were formed by dry etching on a 500 £gm thick <111> Si wafer. The TSV were then obtained by removing the bottom of the silicon wafer using grinding technique. To reduce microwave loss of high frequency signal transmission, we oxidized the TSV by oxygen wet oxidation at a temperature of 1000 oC. Finally, conductive paths through the TSV were formed by filling silver epoxy into the via and dry at a temperature of 200 oC for 1 hour. The s parameters of the high speed TSV structure was characterized by a Vector Network Analyzer. Si-bench technology can effectively improve system integration and performance while reducing cost and size of the module package. . Key words: Through silicon via, microwave loss, s parameters
3

EMI/EMC analysis of electronic systems subject to near zone illuminations

Khan, Zulfiqar A. 10 December 2007 (has links)
No description available.
4

Large-signal characterization and modeling of nonlinear devices using scattering parameters

Call, John B. 07 November 2002 (has links)
Characterization and modeling of devices at high drive levels often requires specialized equipment and measurement techniques. Many large-signal devices will never have traditional nonlinear models because model development is expensive and time-consuming. Due to the complexity of the device or the size of the application market, nonlinear modeling efforts may not be cost effective. Scattering parameters, widely used for small-signal passive and active device characterization, have received only cursory consideration for large-signal nonlinear device characterization due to technical and theoretical issues. We review the theory of S-parameters, active device characterization, and previous efforts to use S-parameters with large-signal nonlinear devices. A robust, calibrated vector-measurement system is used to obtain device scattering parameters as a function of drive level. The unique measurement system architecture allows meaningful scattering parameter measurements of large-signal nonlinear devices, overcoming limitations reported by previous researchers. A three-port S-parameter device model, with a nonlinear reflection coefficient terminating the third port, can be extracted from scattering parameters measured as a function of drive level. This three-port model provides excellent agreement with device measurements across a wide range of drive conditions. The model is used to simulate load-pull data for various drive levels which are compared to measured data. / Master of Science
5

In-situ S-Parameter Analysis and Applications

Hershberger, Kyle M 22 May 2014 (has links)
This thesis will begin with an investigation on the limitations associated with the predominate two-port stability analysis techniques with respect to multi-stage RF amplifier design. The primary focus will be to investigate and develop network analysis techniques that allow internal ports to be created within a RF circuit. This technique will facilitate the application of existing stability analysis techniques in ways that are not commonly known. Examples of situations where traditional network and stability analysis is insufficient will be presented, and the application of the newly developed techniques will be examined.
6

On the Metrology of Nanoscale Silicon Transistors above 100 GHz

Yau, Kenneth Hoi Kan 12 January 2012 (has links)
This thesis presents the theoretical and experimental framework for the development of accurate on-wafer S-parameter and noise parameter measurements of silicon devices in the upper millimetre-wave frequency range between 70 GHz and 300 GHz. Novel integrated noise parameter test setups were developed for nanoscale MOSFETs and SiGe HBTs and validated up to 170 GHz. In the absence of accurate foundry models in this frequency range, the experimental findings of this thesis have been employed by other graduate students to design the first noise and input impedance matched W- and D-band low-noise amplifiers in nanoscale CMOS and SiGe BiCMOS technologies. The results of the D-band S-parameter characterization techniques and of the new Y-parameter based noise model have been used by STMicroelectronics to optimize the SiGe HBT structure for applications in the D-band. In the first half of the thesis, theoretical analysis indicates that, for current silicon devices, distributive effects in test structure parasitics will become significant only beyond 300 GHz. This conclusion is supported by experiments which compare the lumped-element based open-short and the transmission line based split-thru de-embedding techniques to the multiline thru-reflect-line (TRL) network analyzer calibration algorithm. Electromagnetic simulations and measurements up to 170 GHz demonstrate that, for microstrip transmission lines with metal ground plane placed above the silicon substrate, the line capacitance per unit length remains a weak function of frequency. Based on this observation, the multiline TRL algorithm has been modified to include a dummy short de-embedding structure. This allowed for the first time to perform single step calibration and de-embedding of silicon devices using on-silicon calibration standards. The usefulness of the proposed method was demonstrated on the extraction of the difficult-to-measure SiGe HBT and nanoscale MOSFET model parameters, including transcondutance delay, tau, gate resistance, source resistance, drain-source capacitance, and channel resistance, Ri. Building on the small-signal characterization technique developed in the first half, a new Y-parameter based noise model for SiGe HBTs, that includes the correlation between the base and collector shot noise currents, is proposed in the second half of the thesis along with a method to extract the noise transit time parameter. With this model, the high frequency noise parameters of a SiGe HBT can be calculated from the measured Y-parameters, without requiring any noise figure measurements. Finally, to validate the proposed noise model, the first on-wafer integrated noise parameter measurement systems were designed and measured in the W- and D-bands. The systems enable millimetre-wave noise parameter measurements with the multi-impedance method by integrating the impedance tuner and an entire millimetre-wave noise receiver on the same die as the device-under-test. Good agreement was obtained between the noise parameters calculated from the Y-parameter measurements and those obtained from direct noise figure measurements with the integrated systems. The results indicate that the minimum noise figure of state-of-the-art advanced SiGe HBTs remains below 5 dB throughout the D-band, making them suitable for a variety of commercial products in this frequency range.
7

On the Metrology of Nanoscale Silicon Transistors above 100 GHz

Yau, Kenneth Hoi Kan 12 January 2012 (has links)
This thesis presents the theoretical and experimental framework for the development of accurate on-wafer S-parameter and noise parameter measurements of silicon devices in the upper millimetre-wave frequency range between 70 GHz and 300 GHz. Novel integrated noise parameter test setups were developed for nanoscale MOSFETs and SiGe HBTs and validated up to 170 GHz. In the absence of accurate foundry models in this frequency range, the experimental findings of this thesis have been employed by other graduate students to design the first noise and input impedance matched W- and D-band low-noise amplifiers in nanoscale CMOS and SiGe BiCMOS technologies. The results of the D-band S-parameter characterization techniques and of the new Y-parameter based noise model have been used by STMicroelectronics to optimize the SiGe HBT structure for applications in the D-band. In the first half of the thesis, theoretical analysis indicates that, for current silicon devices, distributive effects in test structure parasitics will become significant only beyond 300 GHz. This conclusion is supported by experiments which compare the lumped-element based open-short and the transmission line based split-thru de-embedding techniques to the multiline thru-reflect-line (TRL) network analyzer calibration algorithm. Electromagnetic simulations and measurements up to 170 GHz demonstrate that, for microstrip transmission lines with metal ground plane placed above the silicon substrate, the line capacitance per unit length remains a weak function of frequency. Based on this observation, the multiline TRL algorithm has been modified to include a dummy short de-embedding structure. This allowed for the first time to perform single step calibration and de-embedding of silicon devices using on-silicon calibration standards. The usefulness of the proposed method was demonstrated on the extraction of the difficult-to-measure SiGe HBT and nanoscale MOSFET model parameters, including transcondutance delay, tau, gate resistance, source resistance, drain-source capacitance, and channel resistance, Ri. Building on the small-signal characterization technique developed in the first half, a new Y-parameter based noise model for SiGe HBTs, that includes the correlation between the base and collector shot noise currents, is proposed in the second half of the thesis along with a method to extract the noise transit time parameter. With this model, the high frequency noise parameters of a SiGe HBT can be calculated from the measured Y-parameters, without requiring any noise figure measurements. Finally, to validate the proposed noise model, the first on-wafer integrated noise parameter measurement systems were designed and measured in the W- and D-bands. The systems enable millimetre-wave noise parameter measurements with the multi-impedance method by integrating the impedance tuner and an entire millimetre-wave noise receiver on the same die as the device-under-test. Good agreement was obtained between the noise parameters calculated from the Y-parameter measurements and those obtained from direct noise figure measurements with the integrated systems. The results indicate that the minimum noise figure of state-of-the-art advanced SiGe HBTs remains below 5 dB throughout the D-band, making them suitable for a variety of commercial products in this frequency range.
8

A study of NRD-guide basic structure and an integrated microstrip to NRD-guide transition

Tsai, Jin-lung 11 July 2004 (has links)
Comparing with other dielectric waveguides, NRD (nonradiative dielectric guides) presents advantages of ease of fabrication, low transmission loss, and absence of radiation from bends and discontinuities, making it suitable for realizing compact and high-performance millimeter wave integrated circuits. First, we study the EM theory of NRD to observe the characteristic affected by NRD geometric parameters and introduce multi-mode parameters to analyze mode coupling phenomena in bend and two-layer NRD structures. In order to promote NRD circuit application and transmission performance, we also study an integrated transition between microstrip line and NRD and mode suppressing technique. Finally, the structures mentioned above are all integrated in circuit application.
9

Design and development of a microwave multifrequency polarimetric scatterometer for biosphere remote sensing

Stjernman, Anders January 1995 (has links)
Microwave radar and radiometer techniques are used to gather crucial information about the earth and its atmosphere. The ERS-1, JERS-1, RadarSAT and NASA’s Mission to Planet Earth projects are designed to study the changing global environment. In all these endeavors, the key instrument is the radar or scatterometer. The advantage of microwave radar is that it is hindered very little by clouds, fog or solar radiation. Polarimetrie sensors like the shuttle-borne SIR-C radar, provides additional information compared to single polarization systems. Correct interpretation of polarimetrie data necessitates proper understanding of the scattering mechanism. Thus theory of polarization synthesis is discussed. Solution to the Kennaugh eigenvalue problem for point targets is derived. Polarimetrie signatures of point targets are shown as surfaces of spherical co-ordinates based on the Poincare sphere. Statistics of the covariance matrix elements for distributed targets are presented. The main topic of this research report is the design and development of a multifrequency, polarimetrie scatterometer for biosphere remote sensing. The system was developed using a standard HP network analyzer, a crossed log-periodic dipole antenna and a reflector. The scatterometer functions in a linear polarization basis between the L- and X-bands and gathers full-polarimetric information. The standard S-parameter measurements using the network analyzer were related to surface and volume scattering coefficients of rough surface, snow cover and vegetation media. The scatterometer measurements were carried out in the frequency domain to make use of narrow band filters in the receiver chain. The fast Fourier transform was used to convert the frequency domain measurements to the time domain. The range resolution of the system was 20 cm; azimuthal and elevation resolutions are determined by the antenna beam widths. Range side lobes were reduced by making use of appropriate weighting (Kaiser-Bessel window) functions. In the process of receiver design, we developed a number of signal processing techniques which are illustrated using appropriate numerical examples. The accuracy of target characterization depends on the quality of scatterometer calibration. A novel technique to estimate the absolute gain and crosstalk of the radar system was developed. Using a distortion matrix approach, the cross-polarization response of the system was improved by 10 to 25 dB. The radar measurements were validated by comparing point target radar observations with the corresponding theoretical values. Also, measurements of fading decorrelation distance and decorrelation bandwidth of rough surfaces were in good agreement with the theory. Backscatter observations of vegetation and snow cover were comparable to earlier published values for a similar environment. Based on initial test results and operations capability, we propose to use the present scatterometer for ground-truthing in support of ERS-1 missions. Direct comparisons of electromagnetic backscatter coefficients are possible between the ERS-1 and the present scatterometer. These joint studies are beneficial for developing inverse scattering techniques, designing new experiments and calibrating ERS-1 radar systems for distributed target environments. / <p>Diss. Umeå : Umeå universitet, 1995</p> / digitalisering@umu
10

End-launched coaxial and microstrip to partial H-plane waveguide adapters

Kloke, Kevin Hugh January 2015 (has links)
Conventional rectangular waveguides are commonly used for high power and millimetre wave microwave applications. However their use at lower frequencies has been limited by their bulky nature at these frequencies. A new type of compact waveguide called a partial H-plane waveguide has previously been proposed that has only one quarter of the cross sectional area of a conventional waveguide. However, only limited information relating to the feeding of such waveguides is available. This study focuses on the development of a practical end-launched coaxial and a microstrip to partial H-plane waveguide adapters with similar or larger achievable bandwidths compared to conventional waveguide probe feed adapters. The two proposed waveguide transition geometries are investigated to determine which parameters can be used to optimise the insertion and return losses. The prototype waveguide transitions were optimised using numerous simulations and fabricated in the back-to-back configuration. Simulated single ended and back-to-back S-parameters yield good performance over the entire H-band (3.95 to 5.85 GHz, also known as G-Band). De-embedding techniques are used to measure the approximate single ended response of the two waveguide adapters based on the back-to-back measurements. The measurement and simulation results compare favourably and validate the designs. / Dissertation (MEng)--University of Pretoria, 2014. / tm2015 / Electrical, Electronic and Computer Engineering / MEng / Unrestricted

Page generated in 0.05 seconds