Tunable Electrically Small Conical Folded Dipole Antenna Used as a Mesoband High-Power Microwave Source
High-power microwave (HPM) moderate-band (MB) sources combine simple design concepts seen in ultrawideband (UWB) sources, but with longer pulses to produces higher energy spectral densities. These factors allow the designs to be more compact and less complicated than many narrowband HPM sources. In this letter, we will demonstrate from both simulation and experimental results the operation of a electrically small, tunable, self-resonant, mesoband source utilizing a conical folded dipole antenna as the energy storage and radiating element. The system is based on a previous design for an HPM folded helix antenna that has a resonant frequency of 46 MHz and is charged to 70 kV. The design presented here utilizes a tunable capacitance that allows the resonant frequency to be tuned between 52 and 87 MHz with ka =0.58 at the lowest resonant frequency.
The SWO Box, a Portable Resonant Source for High-Power Electromagnetic Applications
Experimental results of a portable and compact high power electromagnetic, mesoband radiator, working in the lower-UHF band, are presented. The radiator is a self-contained unit, comprising a quarter-wave switched oscillator (SWO), antenna, high-voltage source, pneumatic system, and battery bank. The TEM horn antenna acts a mechanical support and partially houses the components of the system. The bounding box of the system is 0.44 λ at the central frequency of operation. Measurements of the radiated electric field are presented, and the overall performance of the system is discussed.
Interaction Between Geometric Parameters and Output Waveforms in High-Power Quarter-Wave Oscillators
Quarter-wave switched oscillators (SWOs) are an important technology for the generation of high-power mesoband waveforms. The operation of these SWOs has been discussed for the past several years, but a detailed discussion of the design of these sources for particular waveforms has been lacking. In this paper, we relate several important parameters such as gap spacing, oscillator shape, and antenna to the properties of the radiated waveform.