Shanti Garman

Research Abstract:

My doctoral research focuses on wireless energy for emerging power and communications scenarios for Earth and Space. Over the past four years, I have investigated three primary areas: wireless power for Lunar and planetary applications, ambient energy harvesting from high-power sources, and modulated noise communication, which is ultra-low-power because it is based on thermal noise rather than generated radio frequency carriers. Summaries: (1) Most recently, I have published a journal article on magnetic coupling with Lunar regolith (soil) simulants. This work is in support of a NASA-sponsored project to incorporate wireless charging in Lunar surface vehicles such as landers and rovers. In this work, I investigate the magnetic coupling between a wireless power transfer field which uses magnetically coupled resonators (MCR) and a regolith simulant enriched with iron nanoparticles to represent the actual regolith returned by NASA’s Apollo missions. My findings suggest particle size and skin depth of the metallic iron content are critical parameters for the resultant electromagnetic coupling, which has important implications for future Lunar and planetary missions and their modeling accuracy. (2) In the field of energy harvesting, I recently published and presented a paper at the 2023 IEEE Wireless Power Transfer conference on ambient energy harvesting from high-power sources in our terrestrial environment, such as cell towers. This work is based on Earth, but is exciting because of its potential to enable interesting scenarios where we harvest larger amounts of wireless energy to power small devices. While RF harvesters are already well-established when it comes to powering low-power sensors with inputs at the microwatt to milliwatt level, this work is motivated by asking what new charging scenarios are possible if we can harvest watt-level power. In this work, I investigate the unique challenges of harvesting at ultra-high frequency (UHF) and high power levels (<120W radiated power). My research contributions to date include identifying the RF Schottky diode as a key limitation in UHF high-power harvesters and developing prototype architectures which circumvent these component limitations. An early prototype delivers ~3W to a load in a lab setup, and a real-world demonstration of harvesting from an active cell site is presented. This is almost enough to power a Starlink base station or a small drone. (3) My third research area concerns wireless energy for communications, including emerging scenarios such as Modulated Noise Communication. At the 2023 IEEE RFID conference, I published and presented work demonstrating how thermal noise of electronic components on an RFID tag may be modulated and used for the wireless transmission of data. While early, the introduction of a new ultra-low-power communications scheme is promising, particularly for target applications where power is limited, such as biomedical, space, and stealth scenarios.

Bio:

Shanti Garman is a 5th-year PhD student interested in using established electromagnetics (EM) and antenna theory to investigate new systems and methodologies for Earth- and space-based wireless power transmission and ultra-low-power wireless communications. She is advised by Prof. Joshua R. Smith, PI for the UW Sensor Systems Lab, where she works on wireless power transfer for lunar & planetary missions, RF energy harvesting from high-power sources on Earth, and modulated noise communication. Before UW, Shanti completed her BSEE and MSEE at Stanford, launched satellites with Space Systems/Loral, earned an MBA, and continued launching services and programs for for-profit (Microsoft) and nonprofit (Rainier Scholars) institutions. As a first-generation college student and underrepresented minority woman in STEM, Shanti has first-hand experience navigating institutional obstacles related to race and gender, and she actively participates in the UW ECE department’s DEI efforts. Personal Website: https://sites.google.com/uw.edu/shantigarman