M. R. T. de Oliveira

Instantaneous Frequency Measurement Subsystem implementation using low-cost microcontroller

This paper presents a practical implementation of a S-Band 4-bit Digital Instantaneous Frequency Measurement Subsystem based on microstrip multibandstop filters. The outputs are converted using RF detectors and digitized using an Arduino® board. Filter design is based on open-loop resonators. Sub-band is determined by calculating the average value of m measures and standard deviation is used to further improve reliability. This paper discusses the key requirements for this design and presents experimental results for the sub-band determination.

Modeling microwave devices using genetic algorithms

This paper proposes a methodology for modeling microwave devices based on Genetic Algorithms (GA). This technique allows electromagnetic parameters be related to the physical dimensions of device, making it easier to perform adjustment to obtain a certain response. To demonstrate the validity, the method was applied in double-H resonator bandpass filter and results were then compared with those offered by traditional full-wave simulators. This filter was then fabricated and measured in the Microwave Laboratory of the Department of Electronics and Systems, UFPE and experimental results were compared with simulated.

Recent trends and considerations for high speed data in chips and system interconnects

This paper discusses key issues related to the design of large processing volume chip architectures and high speed system interconnects. Design methodologies and techniques are discussed, where recent trends and considerations are highlighted.

New compact interferometer based on fractal concept

The authors present a novel compact 3-bit interferometer based on Hilbert fractal geometry for application to Instantaneous Frequency Measurement (IFM) system operating in the range 4.66-6.38 GHz. The interferometers use two-way Wilkinson power dividers connected to two microstrip line with different signal delays, where one of these microstrip lines is based on Hilbert fractal curve. A full wave EM simulator is used to obtain the frequency response. Simulated responses are presented and compared to theoretical results.