This proposal leverages the advancements made on electromagnetic devices developed by the semiconductor industry by exploiting new time-reversal symmetry breaking using an acoustic wave platform to develop innovative devices more compact and efficient compared to electromagnetic devices. These new acoustic devices are capable of routing waves in specified directions and/or amplifying them without generating additional noise while also being compatible with existing acoustic devices to form acoustic ?chips?. The proposed innovative research combines concepts from electrical engineering and mechanical engineering to develop new solutions for important problems facing our future industries. This hybrid research program develops an entirely new paradigm for future wireless components by emphasizing system level figures of merit and system integration concepts necessary for the next generation electromagnetic devices. This approach requires cross-disciplinary interactions between traditionally dissimilar fields of electromagnetic waves and acoustic waves yielding a hybrid team capable of significant advancements. The proposed efforts also include educational emphasis for both undergraduate and K-12 students focusing on student educational experiences promoting systems level hybrid engineering concepts. Undergraduate students will be introduced to RF engineering applications closely aligned with this program. Additional students from underrepresented urban high schools in the Los Angeles area will be incorporated into ongoing summer research programs available at UCLA that incorporate system-level engineering concepts. The potential discoveries present in this research can bring a new revolution to wireless communication and sensor technologies. This advancement represents an order of magnitude miniaturization in the RF front-end while benefiting the entire system from extremely small form factors to substantially reduced costs. These advancements facilitate a wider deployment of electromagnetic sensors and devices necessary for future autonomous vehicles and environmental protection. A sensitive, interference resilient RF front-end also meets the ultimate need of wireless communications in cluttered environments, as interference and jamming have been primary challenges in many wireless communication scenarios.
By breaking time-reversal symmetry of acoustic wave propagation with parametric modulation, non-reciprocity is obtained on an acoustic wave platform. The proposed effort will yield a new class of acoustic devices based on this principle, such as acoustic amplifiers, mixers and circulators providing orders of magnitude improvement in efficiency while dramatically reducing sizes. This is achieved by leveraging (1) the slow velocity and small wavelength of acoustic waves at RF to reduce the transmission lines footprint and (2) the high quality factor of mechanical resonances and acoustic wave propagation as well as a reduction in resistive losses to increase energy efficiency and (3) innovative designs of grating structures allowing electro-acoustic coupling of the energy to unidirectional propagating waves. Combining this fundamentally new non-reciprocal concept with the well established field of Surface Acoustic Wave and Bulk Acoustic Wave filters and delay lines, a new generation of acoustic wave based integrated circuits will be developed. Furthermore, this approach provides novel signal processing functionalities such as performing time correlations and multipath equalizations directly at RF with almost no noise penalty, which are presently unavailable. These integrated circuit devices, once successfully made, will help the future wireless system to be more sensitive and have higher efficiency, yet with an extremely small form factor.
