Frequency domain measurement of the reflector impulse radiating antenna (IRA)

Abstract

This paper focuses on the frequency domain measurement of the reflector impulse radiating antenna (IRA). To measure the time domain characteristics of an IRA, we had two options. The first method uses short pulses with a time domain setup. The second method applies different frequencies in a wide frequency band and then uses the inverse Fourier transformation for the construction of the time domain results. In this work, we used frequency domain measurement setup to find out the antenna characteristics. We show the 0.6 m reflector IRA constructed at UCLA. The far-field region for this antenna at 2 GHz is 4.8 m and at 10 GHz is 24 m. To survey the radiated field of the reflected IRA over the entire frequency range we would need a huge anechoic chamber. In this paper, it is shown that a typical size chamber can be used for measurements and the results can be corrected using physical optics simulation. Our simulation for the reflector antenna shows that the main lobe does not distort dramatically in the radiating near-field region but there is some reduction in the field strength as a function of frequency. To calculate the time domain radiated field of the antenna using the inverse Fourier transform, measured results can be adjusted with PO simulation results. The time domain radiated field of the reflector IRA is calculated with and without this correction and the results show that they are almost identical. The measured results have good agreement with the radiated field of an ideal IRA.