Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet VGA.
Sammanfattning : The main aim of this work is to demonstrate the easibility of designing and characterizing monolithic microwave integrated circuit (MMIC) variable gain amplifiers (VGA) and small signal amplifiers in III-V (GaAs) and 90 nm CMOS technologies, respectively. The VGA is studied at the IFfrequency of 2. LÄS MER
Sammanfattning : Variable Gain Amplifier finds extensive use in the high frequency demonstrators specially those operating in the millimeter-wave regions and beyond where the incoming RF signal level can have wide variations. To maintain a constant signal level an IF VGA has been designed that can offer a dynamic variation of gain as much as 45 dB together with a high maximum gain and a low noise figure. LÄS MER
3. Quantifying the quality of medical x-ray images. An evaluation based on normal anatomy for lumbar spine and chest radiography
Sammanfattning : Optimisation in diagnostic radiology requires accurate methods for determination of patient absorbed dose and clinical image quality. Simple methods for evaluation of clinical image quality are at present scarce and this project aims at developing such methods. LÄS MER
4. Methods Used in Quality Assurance and Optimization in Nuclear Medicine Imaging and Imaging Systems
Sammanfattning : .... LÄS MER
Sammanfattning : This doctoral dissertation presents a study of linear radio transmitters based on the combined analog locked loop universal modulator (CALLUM) approach. Linear architectures such as CALLUM are very attractive for power-efficient operations, since they have no fundamental limitations prohibiting a 100% efficiency for all envelope levels, without sacrificing the potential of a linear transmission. LÄS MER