Holographic techniques have proved useful -for the determination of antenna radiation patterns and imaging antenna fields. Traditionally this has been achieved mainly by the direct measurement of complex near fields of the antenna over a measurement plane located close to the antenna under test.[l] This is a slow and expensive process requiring equipment capable of determining both amplitude and phase of the sampled antenna near field. An alternative approach has been to use an indirect technique, as often employed at optical frequencies, and record the scalar intensity pattern produced by the interference of the antenna near field and a radiated phase coherent reference wave , A limitation of this technique is the requirement that the antenna must have a radiation pattern of small angular extent, restricting this method to the measurement of high gain antennas. This work describes the further development of a recently reported technique whereby an intensity pattern is formed using an electronically derived reference signal.  A significant advantage of this technique is that it allows an unlimited phase difference to be applied to adjacent samples. This overcomes the practical limitation imposed using a radiated reference signal and enables the radiation patterns of medium gain antennas to be determined.
|Title of host publication||ISAPE 2003 - 2003 6th International Symposium on Antennas, Propagation and EM Theory, Proceedings|
|Number of pages||4|
|Publication status||Published - 30 Mar 2004|
|Event||6th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2003 - Beijing, China|
Duration: 28 Oct 2003 → 1 Nov 2003
|Conference||6th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2003|
|Period||28/10/03 → 1/11/03|