K. C. Gupta

Optimum thickness of metal in waveguiding structures, ground planes and reflectors

Reflection of a wave incident on a metal sheet of finite thickness is considered. It is found that the reflectivity is increased and conductor losses are reduced by about 9% when the thickness of the conductor is π/2 times the skin depth.

Narrow-beam antennas using cylindrical columns of isotropic plasma†

It has been reported earlier (Gupta 1970) that a radiation pattern with single or multiple narrow beams may be obtained when a column of isotropic plasma is excited by a ring source of electromagnetic waves placed inside the column. This investigation has been extended to the case where the waves on plasma column are excited by a waveguide source. Also the TE- and TM-modes of propagation for both the excitation schemes have been discussed. Narrow beams of radiation may be obtained in all these four eases. It is observed that the small beamwidths (1° to 5°) are obtained for high plasma densities (∊p = 01) and large plasma column radii (k 0b≥15.0)

Slow leaky waves

A new type of leaky wave called a alow leaky wave is reported. The slow leaky waves have a phase velocity less than the velocity of light but radiate in a direction away from end-fire. This type of wave ia supported by a metal-dielectric-thin conductor plate when

Design Of Microwave Integrated Circuits: Part 2

This three part serial discusses basic design considerations for microwave integrated circuits using distributed circuit approach. Various circuit elements include transmission line sections, coupled line section, resonators, junctions, bends, transitions etc. Design data for these elements is included. Of these elements, Part 1 presents available transmission line sections and coupled line sections. Part 2 includes resonators, various discontinuities and transitions.The design method of microwave integrated circuit is illustrated by considering three examples: a pin diode phase shifter, a Gunn oscillator and a hybrid branchline directional coupler. The role of discontinuity and junction reactances in the exact design of these circuits is emphasized. This portion constitutes last part of the serial.