Microwave transmission lines

This research refers to a proof-of-concept study concerning the development of a
noninvasive blood-glucose monitoring system. The biosensor being considered is a
microwave-based transducer (that can be rendered compatible for ISM band of 2450
MHz and hence Zigbee™ and/or BluetoothTM compliant). The goal of this study is
tailored to develop eventually a unit for home-based healthcare and/or personalized
wellness monitoring of diabetic patients. This pilot effort is expected to culminate in
future in a wireless hyper/hypoglycemic risk-alert system and possible automatic insulin
infusion pump activation efforts.
The thesis addressed thereof provides details on the fundamentals of sensing
glucose content noninvasively across a finger. The underlying principle of biosensing
refers to detecting the change in the dielectric property of blood with differential changes
in the glucose influx in the finger by sensing microwave (such as 2450 MHz) absorption
and/or reflection so as to assay the glucose content of interest. Preliminary experimental
and theoretical results are presented and discussed.

PIN diodes and microstrip have found widespread use in modern
microwave systems. A design theory for the design of microwave
PIN diode switches and limiters is presented. Resonant
mi crostrip transmission line networks are shown to improve the
performance of packaged diodes. A systematic approach is used
to analyze the transmission line networks. Four types of
resonant diode switches are presented: an unmatched reverse
mode switch, a matched reverse mode switch, a series forward
mode switch, and a shunt forward mode switch. The utility of
this approach is illustrated by designing and testing several
PIN diode modules at both C and X-Band.