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The efficacy of the three-dimensional, rectangular magnetic EZ antenna for use with mesoband high power microwave (HPM) sources has been demonstrated previously. It overcomes the typical bulky and massive impedance matching components found currently in most HPM systems, making it an attractive option when space is very limited. However, its extremely compact nature presents practical challenges when dealing with extremely high power sources due to the associated local field enhancements near the feed and the near field resonant parasitic element. This letter presents a fully integrated, highvoltage source and radiating system that has several improvements in the antenna, source, and power system that have not before been demonstrated. The full system includes a ferroelectric generator, standing wave oscillator source, and electrically small antenna (ka = 0.37) operating at 510 MHz that can be packaged inside a 15-cm diameter tube. This small diameter results in a quarter-wavelength-diameter ground plane, and the effects of this small ground plane on the radiation characteristics are explored. The development of a pressurized radome allows for operation at 73.6 kV, significantly higher than previous studies. The results in this letter demonstrate that several disparate parts can be brought together to make a self-contained, compact, HPM system. the performance characteristics obtained through numerical simulations.

Previously we reported on the integration of an electrically small EZ antenna with a mesoband HPM source based on a coaxial, quarter-wave oscillator. In our previous work, we demonstrated through modeling and experiment the use of an antenna with ka = 0.47 for radiation of HPM signals. In the present paper, we present a design that allows the oscillator to function as a dual-frequency source by including multiple trigger points. We further adapt the EZ-antenna to be dually resonant with no increase in size through the use of orthogonal polarization coupling. I. INTRODUCTIONHigh Power Microwave (HPM) systems are used for a variety of applications ranging from radar to intentional electromagnetic interference [1]. In most applications the antennas are made as large as possible in order to maximize the gain and the effective radiated power. However, in some applications, the space available for an external antenna is extremely limited. In these cases, it can be useful to develop electrically small antennas that are adapted for the field levels associated with HPM systems.Our group has worked with two seperate strategies for this problem in the realm of mesoband (MB) sources[2], [3]. Mesoband sources have bandwidths on the order of 10%, and often leverage ultra-wideband technology to excite weakly resonant oscillators. This strategy allows for an increase in both total radiated energy and the energy spectral density from the system, which can be advantageous in many applications. In our previous work [2], we coupled a quarter-wave, coaxial standing-wave oscillator (SWO) [4] with an electrically small magnetic antenna called the EZ-Antenna[5] to achieve a reasonable MB HPM concept in the UHF region of the spectrum (500 -600 MHz).In some applications it is desirable to have a source that can radiate at multiple frequencies. The SWO sources we have used previously have bandwidths on the order of 10%, while the EZ-antenna has a bandwidth on the order of 1%, so a dualfrequency system would need multiple resonant structures to function, and it would be desirable to obtain this in the same working volume. In this paper, we discuss adapting the SWO and EZ antennas to obtain simultaneous resonance at 500 MHz and 750 MHz by providing multiple trigger points in the SWO and using multiple, orthogonally-polarized radiating elements for the EZ antenna.

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