280 INTRODUCTION Accurate collection and processing of electromagnetic information is critical to a wide variety of applications. Present day RF and microwave sensor systems must cover many frequency bands, detect and identify a large range of signal powers, and analyze the signal information on an ever-decreasing time scale. Simultaneously achieving these attributes typically requires multiple...

The novel digital-to-analog conversion technique studied in this paper, is founded on the digital duty-cycle modulation principle. It consists of a simple digital duty-cycle modulation program loaded in the flash memory of a microcontroller and an external analog low pass filter. Both pulse width and modulation period, simultaneously evolve according to the variation of the modulating input. Th...

This paper presents a multi-mode receiver concept for different transmission standards like UMTS and IS95. Due to the use of a Digital-Front-End (DFE) the requirements for the analog part of the well known direct conversion receiver (DCR) architecture decrease because channelization and fine frequency tuning are shifted from the analog into the digital domain. The adaptation of the channelizati...

In a growing number of applications, there is need to digitize signals whose spectral characteristics are challenging for traditional Analog-to-Digital Converters (ADCs). Examples, among others, include systems where the ADC must acquire at once very wide but sparsely and dynamically occupied bandwidth supporting diverse services, as well signal interest subject strong narrowband co-channel int...