Ponce de Leon, Lorenzo Angel.

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.

A theory of the circular loop antenna constructed from finite conductivity wire is developed via a Fourier series expansion of the currents in the loop. Models for a family of small loop antennas are also presented. A new high sensitivity and selectivity heterodyne fiber optic based electromagnetic field detector is developed compatible with open antenna range measurements made at low signal levels and in the presence of strong interfering signals. A new analytical solution pertaining to the response of a disk loaded dipole antenna representing a dipole configured on a lossy dielectric medium is developed using a field compensation theorem and a geometrical theory of diffraction. The multipole expansions for the scattered fields of a multilayered infinite cylinder illuminated by oblique incidence plane wave are formulated and programmed for numerical analysis. The response of cylinders with constitutive parameters reflecting those used in human phantoms are calculated. The response of a small antenna proximal to a multilayered cylinder is analyzed. The scattered fields from multilayered bodies are coupled to a small wire antenna using a combined methods induced electromagnetic force (EMF) technique. New results concerning the response of a loop antenna near a multilayered body obtained via a zero and first phase current model are presented. The new technique is applied in the analysis of human phantoms tested in an open field antenna range. Validation of the theory of multilayered human phantoms with measurements using the new detector is demonstrated.