A modified holographic technique for antenna measurements

This work describes an extension to the use of indirect holographic techniques for antenna measurements. Previous versions of this work have been restricted to the measurement of high gain antennas without reducing sample spacing and increasing measurement times. This work describes a technique whereby using both sum and difference signals from the complex near field and the reference signal cancellation of the unwanted term in the Fourier domain is achieved enabling measurements to be made on medium gain antennas. Measured results are compared to simulation results for a small pyramidal horn antenna and are shown to provide good agreement.