Alejandro Álvarez Melcón

A simple low-cost coplanar twin-slot active antenna oscillator for wireless applications

This paper presents a compact, simple, low-cost coplanar waeguide actie antenna oscillator which can be used for wireless communication applications. The circuit uses the actie MGA86576 MMIC amplifier, which is biased through its output port using simple lumped elements. A closed feedback loop is implemented with two slot antennas fed by coplanar waeguide transmission lines. The paper pre- sents a design procedure to systematically dimension the different parts of the structure until the oscillation condition is satisfied. An actie antenna oscillator has been designed, manufactured, and tested, and measured results are in good agreement with predictions. The circuit exhibits aery clean, stable oscillation, and the radiation patterns are smooth and quasiomnidirectional. The measured gain of the actie antenna is 3.2 dBi. Q 1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 18)25, 1999.

An Efficient Procedure for the Optimization of Cavity Backed Printed Antennas for Broadband Communications

This paper presents an efficient technique for the optimization of cavity backed printed antennas which could be used in broadband communication applications. The method is applied to several antenna cases and the results obtained are validated with measured data. Results show that the technique is efficient and can be used to systematically optimize the antennas treated for maximum frequency bandwidth.