Integrated reconfigurable RF MEMS antenna using artificial magnetic conductor and defected ground structure for 5G applications

This thesis investigates the reconfigurable microstrip patch antennas using RF MEMS switch for 5G applications. As 4G is nearly achieved its maximum capacity, 5G is estimated to replace the current technology. To be applied for 5G applications, the antenna has to be small in size and offers a wide bandwidth and high gain. Therefore the reconfigurable antenna is chosen and to reconfigure its pattern and frequency, RF MEMS switch has been used. Then to boost the performance, the Artificial Magnetic Conductor (AMC) is implemented to overcome the problem of narrow bandwidth and low gain created by the conventional microstrip patch antenna. Besides that, the implementation of Defected Ground Structure (DGS) onto the antenna design helps also in bandwidth enhancement and multiple bands creation. In this research, the frequency bands for above and below 6 GHz have been tested. For the band above 6 GHz, the operated frequency is set to be 11 GHz while for the bands below 6 GHz, the frequency bands are ranging from 3.3 to 3.6 GHz, 4.4 to 4.6 GHz and 4.8 to 4.9 GHz. This thesis proposes three antennas which are reconfigurable microstrip patch antenna, reconfigurable microstrip patch antenna using AMC and reconfigurable multiband antenna using DGS. All antennas are designed on Rogers RT/Duroid 5880 substrate with dielectric constant of 2.2 which integrated with RF MEMS as switching to realize their reconfigurable ability. The first antenna consists of three antenna designs with different orientations of slot. These antennas are dedicated to control the radiation pattern at 11 GHz. For the second antenna, AMC is added onto the antenna design in order to improve the bandwidth and gain of the antenna at 11 GHz. Lastly, the combination of RF MEMS and DGS is designed onto the third antenna for bandwidth enhancement and to create the multiple frequency bands at 3.45, 4.5 and 4.85 GHz. All proposed antennas are successfully designed, simulated, fabricated, measured and analyzed. The configuration of RF MEMS switch is depending on two states which are ON and OFF states. The first antenna is capable in steering towards the angles of ±29° at 11 GHz, with a maximum measured gain of 7.93 dB when one of the switches is turned ON. For the second antenna, the overall impedance bandwidth is enhanced to 333 MHz with the highest measured gain of 7.6 dB by adding AMC structure. Finally, by adding the DGS at the ground plane of the third antenna design, the antenna resonated at 3.45 and 4.85 GHz when the switch is turned ON. On the contrary, the antenna resonated at 4.5 GHz when the switch is turned OFF. The highest measured gain of 4.37 dB is obtained by ON state at 4.85 GHz. These capabilities in the proposed antennas are very favorable to be used for future 5G applications.