Graduation Year
2022
Document Type
Dissertation
Degree
Ph.D.
Degree Name
Doctor of Philosophy (Ph.D.)
Degree Granting Department
Electrical Engineering
Major Professor
Gokhan Mumcu, Ph.D.
Committee Member
Huseyin Arslan, Ph.D.
Committee Member
Nathan Crane, Ph.D.
Committee Member
Rasim Guldiken, Ph.D.
Committee Member
Jing Wang, Ph.D.
Keywords
Microfluidics, Reconfigurability, Piezoelectric Actuation, Phased Arrays
Abstract
Microfluidically reconfigurable radio-frequency (RF) devices, in general, are found attractive for low-loss, wide-frequency tunability, low hardware complexity, and high-power-handling capabilities. More recently, microfluidic actuation has also been proposed as an alternative to semiconductors and micro-electromechanical systems-based approaches to realize new and compact reconfigurable devices operating in mm-Wave bands. This research expands the knowledge base on low-loss and compact mm-Wave reconfigurable devices. The reconfiguration approach relies on utilizing a microfluidically actuated selectively metalized plate (SMP) within proximity of the RF device to alleviate the practical issues arising from the traditional usage of liquid metals in microfluidically reconfigurable devices.
The first novel concept is a microfluidically actuated spatially adaptive antenna array (MRSA) that can be used to achieve control of the mm-Wave wireless communication channel. MRSA concept is realized with a new compact RF feed network so that spatial adaptation on the order of several wavelengths can be accomplished without unnecessarily increasing the microfluidic system's size that enables this spatial adaptation. MRSA allows the improvement of the link-level performance of a wireless channel by 24%, from 8.5 bps/Hz to 10.5 bps/Hz. 100% improved system-level average spectral efficiency, and a 5 dB improvement in the average signal-to-interference ratio was achieved without additional antenna elements.
The second concept is a novel frequency reconfigurable antenna with integrated microfluidic actuation for the 28 GHz or 38 GHz mm-Wave bands. The device's novelty resides in a new multilayer integrated microfluidic actuator that can reposition multiple metalized plates simultaneously within the microfluidic channel performing complex mechanical reconfigurations with reduced hardware complexity to achieve the desired functionality. It exhibits a realized gain of 5.6 dBi and 4.9 dBi at 28 GHz and 38 GHz, respectively, with improved loss compared to alternatives such as liquid metals, which exhibit challenges associated with actuation and liquid metal oxidization within channels that require lossy solutions for encapsulation.
The integrated actuation approach is subsequently utilized in a novel microfluidically reconfigurable mm-wave slow-wave phase shifter. The phase shifter achieves better loss and compactness when compared to other microfluidic technologies such as liquid metals and dielectric liquid loadings by utilizing a selectively metalized plate (SMP) repositionable within a microfluidic channel placed in close proximity to a microstrip line, creating a variable capacitive loading that alters the speed of its propagating wave. The device achieves total reconfiguration in approximately 50 ms, which is 39\times higher than its predecessor.
Finally, by combining multiple phase shifters through a new design approach a mm-wave beamforming network is introduced to achieve beam steering antenna arrays. The beam steering is performed with a single microfluidic actuator and a circuit model is introduced to facilitate the design of the beamforming network. The design example presented is for a four-element antenna array operating at 28 GHz exhibiting continuous beam steering capability within \pm{30}^\circ when its SMP is actuated within its -100 to 100 \mum displacement range. Unlike beaming steering antennas using beamforming ICs, they do not require active amplification to compensate for high loss and have reduced hardware complexity associated with control bits and bias lines. Compared to previously investigated microfluidically actuated beam steering antennas, it offers the advantage of not relying on switched beam techniques and bulky lenses.
Scholar Commons Citation
Mendoza Sandoval, Jonas J., "Mm-Wave Reconfigurable Antenna Arrays, Phase Shifters and Beamforming Networks With Reduced Hardware Complexity Using Integrated Microfluidic Actuation" (2022). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/10328
