TY - SER AU - Elsdon,M. AU - Foti,S.J. AU - Leach,M. AU - Smith,D. TI - Indirect holographic techniques for determining antenna radiation characteristics and imaging aperture fields / D. Smith... [et. al.] KW - ANTENAS [ELECTRONICA] N1 - SOLICITAR EL ARTICULO EN EL PROGRAMA DE ELECTRONICA Y TELECOMUNICACIONES; Electrónica y Telecomunicaciones; Sistemas N2 - Indirect holographic techniques offer the potential of using simple and inexpensive near-field intensity-pattern measurements for the determination of the radiation characteristics of microwave antennas, and for the reconstruction of complex aperture fields. This work describes a practical method of applying indirect holographic techniques to microwave antennas. It describes how a technique originally developed at optical frequencies can be adapted to enable measurements to be taken on microwave antennas. The major difference is the replacement of a radiated reference signal by an electronically generated reference signal. This has enabled previous practical limitations to be overcome. Computer simulations and practical results are included for a large dish antenna at sample spacing similar to those employed in direct holographic techniques. This work also describes how reducing the sample spacing significantly below a half wavelength enables the radiation characteristics of smaller antennas to be determined ER -