Computational Electromagnetic Studies for Low-Frequency Compensation of the Reflector Impulse-radiating Antenna.

摘要

The reflector impulse-radiating antenna (IRA) is considered to meet the requirement for a wideband, directional antenna with short temporal response and small electrical footprint. Standard reflector IRA designs are modeled and performance is simulated using full-wave computational electromagnetic (CEM) software. Characterization of the standard designs reveals the possible existence of wide, frequency-independent backlobes containing nearly 40% of the radiated power at high frequencies. These undesirable backlobes have never been hypothesized, predicted or measured, likely due in part to their alignment outside the primary measurement planes. At the lowest operating frequencies, the reflector IRA is unaffected by backlobes, but is characterized by low radiation efficiency and high resistive losses. Simulated studies are conducted to identify options for enhancing the low-frequency performance of the reflector IRA, including novel multi-arm feed structures and varied resistor distributions and values in the matching circuit component of the antenna design. Both techniques are predicted to provide viable options for enhancing and tuning the performance of the reflector IRA at low frequencies.