Fernando Las-Heras

By Javier Gutiérrez-Meana, José Á. Martínez-Lorenzo and Fernando Las-Heras

Part of the book: Electromagnetic Waves

By María Elena De Cos and Fernando Las-Heras

Part of the book: Current Trends and Challenges in RFID

By Javier Gutiérrez-Meana, José Á. Martínez-Lorenzo and Fernando Las-Heras

Part of the book: Electromagnetic Waves

By Yuri Álvarez, Fernando Las-Heras and Cebrián García

Part of the book: Solutions and Applications of Scattering, Propagation, Radiation and Emission of Electromagnetic Waves

By Jaime Laviada, Fernando Las-Heras and Marcos R. Pino

Part of the book: Solutions and Applications of Scattering, Propagation, Radiation and Emission of Electromagnetic Waves

By Ana Arboleya, Jaime Laviada, Juha Ala-Laurinaho, Yuri Álvarez, Fernando Las-Heras and Antti V. Räisänen

Phase acquisition in antenna measurement, especially at millimeter- and submillimeter-wave frequencies, is an expensive and challenging task. The need of a steady phase reference demands not only a very stable source but unvarying temperature conditions and strong positioning accuracy requirements. Indirect off-axis holography is an interferometric technique that allows for characterization of an unknown field by means of a simple filtering process of the hologram or intensity interference pattern in the spectral domain, provided that the reference field, employed to interfere with the unknown field, is known in amplitude and phase. This technique can be used to avoid the effect of the errors related to the phase acquisition and to further develop new efficient and robust techniques capable of phase retrieval from amplitude-only acquisitions allowing for cost and complexity reduction of the measurement setup. A short review of the state-of-the-art in antenna metrology is presented in this chapter, as well as a description of conventional indirect off-axis techniques applied to this field. Last sections are devoted to the description of novel measurement techniques developed by the authors in order to overcome the main limitations of the conventional methods.

Part of the book: Holographic Materials and Optical Systems