Najim  Abdallah Jazea, 
    Design and Implementation of Reconfigurable Microstrip Patch Antenna for Cognitive Radio
Applications,
    Journal of Engineering and Applied Sciences,
    Volume 15,Issue 22,
    2020,
    Pages 3697-3707,
    ISSN 1816-949x,
    jeasci.2020.3697.3707,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2020.3697.3707)
    Abstract: This study focuses on the design and analysis
of a reconfigurable antenna that can be integrated into the
CR systems. A dual-port “interweave” CR antenna system
in which an antenna structure is proposed and designed.
This design is composed of an elliptical disk radiator
sensing antenna that covers a frequency range of
(1.8-11) GHz and a dual-band reconfigurable
communicating antenna in the form of a modified
dual-band rectangular radiator. By controlling the length
of a stub attached to the communicating antenna with the
aid of two PIN diodes, the dual-band antenna can
reconfigure its resonant frequencies to (2, 2.2 GHz),
(3.25, 3.8 GHz) and (4.3, 5.6 GHz).
    Keywords: Reconfigurable;cognitive radio;MSPA;broadband antenna