volume | PIER Journals

Abstract

A modified three-antenna gain measurement method is proposed to significantly simplify, and thereby to reduce the costs of, uncertainty estimation. Unlike the three-antenna method, the new method employs a standard antenna whose gains and uncertainty limits have been established through absolute calibration. The measurements are carried out as in the three-antenna method, with the reference antenna also analysed as presumed unknown. An overall uncertainty figure for the measurement is obtained only from the resulting data in conjunction with the uncertainty on the reference antenna gain values. The proposal is verified by using a rigorous experimental study on the gains of three pyramidal horns in the frequency range 5.8 GHz-8.2 GHz. First, the gains and error limits of the antennas are estimated by using the three-antenna method. One of the antennas is then used as reference antenna and the modified method employed on the measured data to determine the gains of a test antenna. It emerges that the new method substantially simplifies the secondary calibration and gain measurement of antennas.

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Prof. Krishnasamy Selvan