THE DIGITAL AMPLITUDE MODULATOR

Timothy P. Hulick, Ph.D., W9QQ
886 Brandon Lane
Schwenksville, PA 19473


Abstract.
This paper is the first of two presenting the Digital Amplitude Modulator and the Digital Linear Amplifier. One leads to the other with the Digital Amplitude Modulator the precursor and the first theorized. Linear amplitude modulation in very high power full carrier systems still requires rather large solid state or vacuum tube devices in Medium Wave (MW) and Short Wave (SW), telephone and VHF and UHF ....etc

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Introduction

The proliferation of wireless products over past few years has been rapidly increasing. New wireless standards such as GPRS and HSCSD have brought new challenges to wireless transceiver design. One pivotal component of transceiver is frequency synthesizer.

Two major requirements in mobile applications are efficient utilization of frequency spectrum by narrowing the channel spacing and fast switching for high data rates. This can be achieved by using fractional- N PLL architecture. They are capable of synthesizing frequencies ....etc

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INTRODUCTION

The proliferation of wireless products over past few years has been rapidly increasing. New wireless standards such as GPRS and HSCSD have brought new challenges to wireless transceiver design. One pivotal component of transceiver is frequency synthesizer.

Two major requirements in mobile applications are efficient utilization of frequency spectrum by narrowing the channel spacing and fast switching for high data rates. This can be achieved by using fractional- N PLL architecture. They are capable of synthesizing frequencies ....etc

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presented by:
Vajoorbi Mohammad


ABSTRACT:
In this we concentrate on sigma delta modulator to produce high resolution with less power consumption and without change in conversion speed. low pass filter is used to get the band pass signal
Driven by the digital circuit technology, the feature size of transistors has shrunk into the sub-100nm range earlier than estimated. The working voltage is decreased as a consequence of the size reduction in order to avoid transistor breakdown. However, the dec ....etc

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ABSTRACT
Wide band Sigma-Delta PLL modulator is based on PLL fractional N synthesis techniques along with Sigma-Delta modulation to randomize fractional N spurs. A modified Sigma-Delta function allows for suppression of Sigma-Delta noise at low frequencies & hence allows wider bandwidth. This is achieved using a fractional-N PLL architecture. They are capable of synthesizing frequencies at channel spacings less than the reference frequency. This helps to increase the reference frequency & hence reduces PL ....etc

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Introduction

The proliferation of wireless products over past few years has been rapidly increasing. New wireless standards such as GPRS and HSCSD have brought new challenges to wireless transceiver design. One pivotal component of transceiver is frequency synthesizer.

Two major requirements in mobile applications are efficient utilization of frequency spectrum by narrowing the channel spacing and fast switching for high data rates. This can be achieved by using fractional- N PLL architecture. They are capable of synthesizing frequencies ....etc

[:=Read Full Message Here=:]

ABSTRACT

Wide band Sigma-Delta PLL modulator is based on PLL fractional N synthesis techniques along with Sigma-Delta modulation to randomize fractional N spurs. A modified Sigma-Delta function allows for suppression of Sigma-Delta noise at low frequencies & hence allows wider bandwidth. This is achieved using a fractional-N PLL architecture. They are capable of synthesizing frequencies at channel spacings less than the reference frequency. This helps to increase the reference frequency; hence reduces PLL’s locking time.
One of the ....etc

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Wideband Sigma Delta PLL Modulator

The proliferation of wireless products over past few years has been rapidly increasing. New wireless standards such as GPRS and HSCSD have brought new challenges to wireless transceiver design. One pivotal component of transceiver is frequency synthesizer.

Two major requirements in mobile applications are efficient utilization of frequency spectrum by narrowing the channel spacing and fast switching for high data rates. This can be achieved by using fractional- ....etc

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INTRODUCTION
Wireless communications are an essential and continuously expanding part of modern life. Smart phones presents a number of challenging requirements on the display module, such as low power consumption, video quality speed, and viewability in a broad range of lighting conditions.

The Interferometric Modulator (IMOD) is an electrically switched light modulator comprising a micro-machined cavity that is switched on and off using driver ICs similar to those used to ad ....etc

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DIRECT DIGITAL RF MODULATOR:A MULTI-FUNCTION ARCHITECTURE FOR A SYSTEM-INDEPENDENT RADIO TRANSMITTER
Sarath Kumar P.K
Roll No:57
S7 E&C



CONTENTS
Introduction
Communication system
RF Systems
Direct conversion modulator
DDRF Modulator
Conclusion
References

INTRODUCTION
Increase in number of radio systems in portable devices
High signal bandwidth and narrow channel bandwidth
Need for low cost,low power and low complexity transmitter architecture
Need for ad ....etc

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