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A low cost, small size, and tunable printed circuit antennas are in high demand for both civilian and military applications. The tunable antennas are a required feature in the most recent communication systems since these systems dramatically scale down in size and operate at various wireless communication frequencies. By employing the tunable antennas, a single antenna geometry can operate at different frequencies. Various methods and techniques were introduced in the recent years for this purpose of multi-frequency operation, such as optically and electrically tuned varacter diodes, but these solutions have high losses that degrade the performance of the tunable antenna. On the other hand, the tuning and switching functions are reported using ferrite structures, which are also lossy at microwave frequencies. Alternatively, ferromagnetic nanoparticles and ferroelectric have been demonstrated a high tuning sensitivity up to broad bandwidth at microwave frequencies, while as result of e_r>>1 and m_r>>1 in ferroelectric and ferromagnetic materials respectively, then a compact size antenna can be realized for a variety of wireless applications.

This thesis presents design and realization on FR4 substrate of ferromagnetic based composite annular ring antennas nanoparticle, where FeCo nanoparticles has demonstrated low coercive material and high permeability of 8 and high saturation magnetic moment. A 100MHz frequency tuning had been obtained by utilizing an external permanent magnet of 1.5kG. However, a high loss tangent of about 0.25 results in a lower efficiency than the baseline annular ring antenna realized without the ferromagnetic material. To improve the gain of FeCo composite based antenna, the parasitic element stacking technique is proposed to maintain a higher gain tunable annular ring antenna.