High Performance Continuous-time Filters for Information Transfer Systems. (August 2003) Ahmed Nader Mohieldin, B.Sc., Cairo University, Egypt; M.Sc., Cairo University, Egypt; Chairs of Advisory Committee: Dr. Edgar Sánchez-Sinencio Vast attention has been paid to active continuous-time filters over the years. The changes in technology have required new approaches. Thus as cheap, readily availa...

A chemical sensor for ozone based on an array of microfabricated tuning forks is described. The tuning forks are highly sensitive and stable, with low power consumption and cost. The selective detection is based on the specific reaction of the polymer with ozone. With a mass detection limit of ∼2 pg/mm(2) and response time of 1 second, the sensor coated with a polymer sensing material can detec...

A new concept for quadrature coupling of oscillators is introduced and demonstrated on a 5-GHz CMOS voltagecontrolled oscillator (VCO). It uses the second harmonic of the outputs to couple the oscillators. The technique provides quadrature over a wide tuning range without introducing any increase in phase noise or power consumption. The VCO is tunable between 4.57 and 5.21 GHz and has a phase n...

A CMOS 80–200-MHz fourth-order continuous-time 0.05 equiripple linear phase filter with an automatic frequency tuning system is presented. An operational transconductance amplifier based on transistors operating in triode region is used and a circuit that combines common-mode feedback, common-mode feedforward, and adaptive bias is introduced. The chip was fabricated in a 0.35m process; filter e...

This paper presents the design of a new four-stage ring oscillator with quadrature outputs using a 0.13μm CMOS 1P8M technology. The oscillator utilizes feed-forward technique and negative resistance to reduce the delay per stage and provides high frequencies. Employing single PMOS transistor to vary the load impedance allows reaching ultra-wide tuning range. The output frequency ranges from 0.8...

A frequency tunable planar inverted F antenna (PIFA) is presented for use in the following bands: DCS, PCS, and UMTS. Initially, the tuning was achieved by placing a lumped capacitor, with values in the range of 1.5 to 4 pF, along the slot of the radiator. The final tuning circuit uses a varactor diode, and discrete lumped elements are fully integrated with the antenna. The antenna prototype is...

This paper demonstrates the feasibility of implementing wide tuning band low phase noise oscillators in low cost Sibased integration technologies. For that, it is necessary to use radio-frequency switched capacitors arrays (RFSCA) and differentially tuned anti-parallel varactors. To corroborate this idea, a voltage controlled oscillator (VCO), designed in a low cost 0.35 μm CMOS technology, is ...

An analog line driver for video applications is presented. Utilizing a class-AB error amplifier structure, the design achieved 1.2–V peak-to-peak output swing with better than 42-dB linearity for frequencies up to 5 MHz. An adaptive tuning scheme for output impedance matching using peak detection is used to provide uniform performance across line impedance variations. The circuit is designed in...

This paper introduces a new type of CMOS-based current conveyor: current controlled fully balanced second generation current conveyor (CFBCCII) element which has a pair of differential Y terminals, a pair of differential X terminals and two pairs of Z terminals. The proposed circuit offers electronic tuning possibilities by means of a current adjustable intrinsic resistance at its X terminal. A...

We demonstrate a cortical circuit based on known anatomical details and cellular properties which achieves sharp orientation tuning despite poorly tuned thalamo-cortical input. Sharp tuning arises emergently from excitatory interactions between similarly tuned neurons, which also receive broadly tuned inhibition. This model accounts for data obtained from intracellular recording and pharmacolog...