BX
B.W. Xu
info
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2 records found
1
To support the exploration of the Moon, wireless sensor networks could be deployed. However, using a very large number of tiny sensing nodes to collect data in such a harsh environment has many challenges. Integrated circuits are exposed to a wide temperature range (-253 Β°C / +120 Β°C) during the lunar days and nights. To meet the very constrained power budget of an autonomous node, the node time references must consume ultra-low power while maintaining an accurate frequency. To allow accurate operation over the wide target temperature range and be robust to radiations, this thesis proposes to lock the frequency of a frequency locked loop (FLL) to an LC filter. In the FLL, a high-frequency low-power ring oscillator is locked to a separate LC filter to potentially save power with respect of a standard LC oscillator. To further save power, the FLL is heavily duty-cycled and turned on only to calibrate a lower-frequency oscillator to compensate its drift due to noise and environmental changes, thus achieving ultra-low-power dissipation. This thesis explores the design and implementation of the first LC-based FLL by proposing a system architecture, analyzing its limitations and proposing a transistor-level implementation. The resulting time reference, when implemented in TSMC 40-nm process, consumes 773.29ππ power and achieved an estimated 41.89πππ/ ππΆ temperature coefficient within an 0.389ππ2 chip area.
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To support the exploration of the Moon, wireless sensor networks could be deployed. However, using a very large number of tiny sensing nodes to collect data in such a harsh environment has many challenges. Integrated circuits are exposed to a wide temperature range (-253 Β°C / +120 Β°C) during the lunar days and nights. To meet the very constrained power budget of an autonomous node, the node time references must consume ultra-low power while maintaining an accurate frequency. To allow accurate operation over the wide target temperature range and be robust to radiations, this thesis proposes to lock the frequency of a frequency locked loop (FLL) to an LC filter. In the FLL, a high-frequency low-power ring oscillator is locked to a separate LC filter to potentially save power with respect of a standard LC oscillator. To further save power, the FLL is heavily duty-cycled and turned on only to calibrate a lower-frequency oscillator to compensate its drift due to noise and environmental changes, thus achieving ultra-low-power dissipation. This thesis explores the design and implementation of the first LC-based FLL by proposing a system architecture, analyzing its limitations and proposing a transistor-level implementation. The resulting time reference, when implemented in TSMC 40-nm process, consumes 773.29ππ power and achieved an estimated 41.89πππ/ ππΆ temperature coefficient within an 0.389ππ2 chip area.
Error model for beam-forming system
Antenna Dome 2.0
A new antenna measurement setup, the Antenna Dome, is being developed, which can provide real time antenna and beamformer measurements. In order to be able to validate this setup, an existing beamforming system will be will be extensively studied and characterized. Multiple measurement setups will be used, providing multiple measured characteristics. The result is an accurate statistical model for the steering system, and a comprehensive error model for the complete beamforming system, including the provided antenna array. This model will help in validating the functionality of the Antenna Dome, and ultimately will help in its further development.
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A new antenna measurement setup, the Antenna Dome, is being developed, which can provide real time antenna and beamformer measurements. In order to be able to validate this setup, an existing beamforming system will be will be extensively studied and characterized. Multiple measurement setups will be used, providing multiple measured characteristics. The result is an accurate statistical model for the steering system, and a comprehensive error model for the complete beamforming system, including the provided antenna array. This model will help in validating the functionality of the Antenna Dome, and ultimately will help in its further development.