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Wireless sensor chips have many applications including biomedical monitoring, distributed
sensors within civil infrastructure and for sensors implanted within the body. Wireless
communication and powering of sensors has been accomplished in small modules, but not
completely on chip as traditional power sources are too large and bulky. One approach to a
chip sized wireless power source is a telemetry system to power the sensor. Wireless telemetry
systems require the use of an antenna which will inductively couple power onto the chip.
Previous work in this field includes that done by Huang et. al [1], Marschner et. al [2] and
Schuylenbergh & Puers [3]. Marschner separates the transmitter and energy reception into two
different off-chip antennas. Huang and Schuylenbergh & Puers both condense their design to
use only one antenna, but in both cases they are still off-chip and the frequency of operation is
very low. At high enough frequencies the antenna length requirement decreases, enabling it to
be placed entirely on chip. This section of the paper contains the design and test of a circuit to
be used at these very high frequencies with all on-chip components. Circuit simulation was done
through spectre with layout and fabrication through the spring 2002 and beginning of fall 2002
semesters. Fabrication was completed in February 2003, with chip characterization completed
by summer 2003. The results showed a constant regulated voltage output that was higher than
expected due to process variations. The bandgap circuit showed a constant voltage output that
matched simulation data, though the startup voltage necessary to obtain this functionality was
higher than expected. Future work includes using high breakdown voltage transistors as well as
larger transistors and capacitors for operation at both low and high input voltages.
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