A Software-Defined Frequency-Reconfigurable Meandered Printed Monopole

In this letter, a frequency-reconfigurable printed meandered monopole structure is presented. The antenna structure is composed of three radiating parts that are connected through two integrated PIN diodes. Such integration allows the antenna to reconfigure its operation within four frequency bands that correspond to various LTE, UMTS, and GSM channels. A graphical user interface (GUI) using Java is employed to control the states of the switches. The interface allows the control of a microcontroller to supply appropriate current to each of the two diodes. The GUI also simulates a cognitive radio environment where the activation of the corresponding PIN diodes is determined by the users' activities. A prototype is fabricated and tested as a proof of concept where measured results agree with simulated data.