This paper compares numerical simulation results, from CST MWS R ©, with the experimental results published in [1] for the 5-10-5 MAX1 antenna configuration. This comparison is used to validate and establish the accuracy of the simulation software.

This paper reminisces about the final years of Dr. Carl E. Baum's life and career as a distinguished Research Professor at the University of New Mexico, Department of Electrical and Computer Engineering. It focuses on Carl's most significant research projects during this time, in his capacity as an advisor and mentor to his graduate students, and as a colleague.

This paper briefly reviews the design of a prolate-spheroidal impulse-radiating hyperband antenna system to launch and focus fast (100 ps) high-voltage ( >; 100 kV) pulses onto biological targets. Design and experiments on a graded five-layer dielectric lens, designed to match the pulses into the target medium, are outlined. The design and numerical simulations of a switch system to launch high-voltage spherical TEM pulses are also presented.

A prolate-spheroidal reflector antenna focusing sub-nanosecond pulsed electromagnetic radiation in the near field is studied. This antenna reflector is fed by a pair of balanced, conical-plate transmission lines and the radiated pulse consists of a prepulse, an impulse, and a postpulse. Whereas the prepulse amplitude decreases inversely with distance, the impulse is maximum near the geometric focus, and its power density distribution has a full-width at half-maximum (FWHM) width of 32 cm in the axial direction and 10 cm in the lateral direction.

Four switch designs are explored using numerical simulations. These configurations are then compared based on the focal impulse amplitude, beam width and ease-of-fabrication

In this paper, numerical simulations are used to explore the peak focal impulse amplitude and the beam width as a function of the feed-arm and loft lengths, height of the cylindrical support structure and the radius of the pressure vessel for the T4FASC-CSS-SPVSHC configuration. The feed-arm and loft lengths of the T4FASC-CSS-CPVCHC structure are also explored in a similar manner. The results are used to identify practically suitable ranges which yield reasonable electric field amplification with a small compromise in the spot size.

This paper extends the concept of an array of THz resonant elements to sets of distributed elements that can be used as the rows of an array.

In this paper we present the experimental results for a five layer electromagnetic focusing lens. This lens is used to match the spherical TEM wave converging at the second focal point of a prolate-spheroidal impulse radiating antenna (PSIRA) into a biological target.

In this paper, numerical simulations are used to investigate the 150 Ω impedancematched bicone switch configuration with a spherical pressure vessel. The near-field electric field responses and the focal impulse waveforms are compared for cylindrical and spherical hydrogen chamber geometries.

This paper considers four feed-arms with a bicone switch. Spherical TEM waves are launched from the switch center and guided by the feed arms. Numerical simulations are used to examine the time-of-arrival of electric fields in the near field.

This paper investigates a vertical bicone antenna as a source and guide for the spherical TEM waves originating from the center. Numerical simulations are used to obtain near-field time-of-arrival measurments for the electric field. Results examining the effect of the switch cone impedance on the focal impulse amplitude and beam width are presented.

Design, simulations, and experiments on a radially inhomogeneous spherical dielectric lens, that is used at the second focal point of a prolate-spheroidal impulse radiating antenna, are presented. This lens is designed to match 100-ps pulses into a biological medium. The higher field amplitude and smaller spot size obtained with such a lens are useful for various bioelectric applications.

The shorter duration of the pre-pulse observed in the focal response of the T4FASC-CSS-SPVSHC and T4FASC-CSS-CPVCHC configurations allows one to scale down the size of the reflector. In this paper, the peak focal impulse amplitude and the beam width are explored as a function of the reflector size.

This paper presents experimental results for the focal waveform and beam width in air with a 100 ps filter. The filter is characterized to ensure that it performs within the desired specifications. The focal impulse waveform and the beam width are compared to the rescaled results in [1]. The experimental results are found to agree well with analytical calculations and numerical simulations.

Numerical simulations are used to compare important electromagnetic parameters, such as the electric field enhancement and spot size reduction, at the second focus, for the T4FASC-CSS-SPVSHC and T4FASC-CSS-CPVCHC configurations with the focusing lens.

In this paper, total incident electron dose as an inherent parameter in secondary electron emission is experimentally demonstrated. A completely automated experimental setup allows for measuring of secondary electron yield (SEY) as a function of beam energy, angle of incidence of primary electrons, electron dose, and time. SEY data are presented for copper, plasma-sprayed boron carbide, and titanium nitride samples with principal focus on dose dependence. Experiments were conducted in the low-energy range (5-1000 eV) and direct-current regime. Experimental results have been compared with formulas in literature, and good agreement was observed. Modified empirical formulas incorporating the dose effect have also been proposed.

The 100 ps time dispersion obtained in all our previous simulation results is a cause of concern. This paper presents simulation results for two cases : 1) Uniform launching lens and 2) Switch and feed arm (without lens), in an attempt to diagnose the cause for observed discrepancies. These cases have been chosen as analytical results are known exactly and hence would easily help identify any errors.

This paper presents the numerical simulation results of a 60 ◦ four feed-arm PSIRA with a focusing lens. Observations are made on the focal waveform inside the lens. The beam width inside the focusing lens is compared to the beam width in air (without the lens). The focal waveforms and beam widths are compared to analytical approximations in [1]. Some additional notes are made on the focal waveforms inside the lens and in air.

This paper establishes scaling relationships for electric field, displacement, and magnetic field for focusing graded dielectric lenses. This accompanies the reduction in spot size. Examples are given in tabular form.

Simulation results for the pressure vessel surrounded by a dielectric sphere are presented. It is observed that the time spread is reduced. Rough calculations for predicting the effect of variation of the pressure vessel height and pressure vessel dielectric on the time of arrival of waves are also presented.