We present a two-stage digitally controlled ring oscillator designed mainly for impulse-radio ultra-wideband (UWB) applications. Each basic stage utilizes a local positive feedback, allowing to achieve steady oscillation at low current consumption levels, and to extend the frequency tuning over an ultra-wide range. The frequency tuning is achieved via the control of the tail resistor in each st...

--The All-Digital Phase-Locked Loop (ADPLL) is digital electronic circuit that are used in modern electronic communication systems like frequency synthesizer, modulator/demodulator etc. This paper presents a review of various ADPLL techniques. The range of input frequency of ADPLL is 40 to 98 MHz; the output frequency may be up to 2.92 to 4 GHz range. The components of ADPLL such as phase detec...

This paper presents a comprehensive case study on electro-mechanical analysis of MEMS[1] variable capacitors. Using the fundamental mechanical and electrical equations, static and dynamic behaviors of the device are studied. The analysis is done for three different modes, namely: dc (static mode), small signal ac and large signal regime. A complete set of equations defining dynamic behavior of ...

In this paper, a Single resistance controlled Sinusoidal Oscillators is presented using a single current feedback operational amplifier (CFOA). The main feature of this circuit configuration is that frequency of oscillation (FO) and condition of oscillation (CO) can be controlled by single resistance. It uses single CFOA and minimum passive components that are three voltage controlled resistors...

A design for a voltage-controlled ring oscillator (VCO) is presented. The design allows an implementation of low frequency ring oscillator using relatively small devices and less stage. It is implemented using .18um technology provided by TSMC technology using 3.3V power supply. The VCO topology exhibits a very wide tuning range from few Hz to 368.9 MHz. It also features the rapid voltage swing...