Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Engineering

Circuit Modules For Six-Port Reflectometer On Chip, Chaojiang Li Dec 2008

Circuit Modules For Six-Port Reflectometer On Chip, Chaojiang Li

All Theses

Broadband signal generator is an indispensable module for broadband Six-Port Reflectometer (SPR). To integrate a whole SPR system on a chip, the source must be compact. In this thesis, a three-stage voltage-controlled oscillator (VCO), using two parallel weak invertor-chain oscillators and sense amplifiers, is proposed and designed in a 0.13 µm CMOS process. These two parallel weak inverter-chain oscillators extend the low frequency operating range and the sense amplifiers expand the high frequency operation. The measurement results show that the oscillator can be tuned from 430 MHz to 12 GHz, which satisfies the targeted SPR operating frequency range.
In order …


Optically Powered Logic Transistor, Hanho Cho Jul 2008

Optically Powered Logic Transistor, Hanho Cho

Theses and Dissertations

This thesis presents the modeling and fabrication of a new solid-state device meant to be used for digital logic circuits. Most current logic circuits are based on MOSFETs. The new logic device uses some of the same operating principles, but also relies on optical illumination to provide input power. In order to obtain the desired current-voltage behavior of the new device, the Silvaco (Atlas) device simulation was used to give some insight into the correct doping levels in the semiconductor and device geometries. Prototypes were fabricated on p-type silicon wafers using CMOS fabrication processes including oxide growth, photolithography, precise plasma …


Design Of A Cmos Rf Front End Receiver In 0.18Μm Technology, Vishwas Kudur Sastry Jan 2008

Design Of A Cmos Rf Front End Receiver In 0.18Μm Technology, Vishwas Kudur Sastry

Browse all Theses and Dissertations

An RF front end receiver system refers to the analog down conversion stages of the wireless communication system. The Digital base-band signals cannot be transmitted directly through wireless channels due to the properties of electromagnetic waves. The baseband signals need to be converted to analog through a digital-to-analog converter (DAC), up converted to higher frequency using an up conversion mixer and then transmitted through the channel. The received signals are down converted to base band frequency and then converted to digital again using the analog to digital converter (ADC). The processes which the analog signal undergoes at the RF front …