Direct data distribution from low-Earth orbit

Budinger, James M.; Fujikawa, Gene; Kunath, Richard R.; Nguyen, Ngoc Tu; Romanofsky, Robert R.; Spence, Rodney L.

doi:10.1109/icc.1997.609934

Cited by 5 publications

References 6 publications

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Tunable Dielectric Materials and Devices for Broadband Wireless Communications

Mueller

Miranda

Dayton³

2000

Handbook of Thin Film Devices

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Wireless and satellite communications are a rapidly growing industries which are slated for explosive growth into emerging countries as well as countries with advanced economies.The dominant trend in wireless communication systems is towards broadband applications such as multimedia file transfer, video transmission and Internet access. These applications require much higher data transmission rates than those currently used for voice transmission applications. To achieve these higher data rates, substantially larger bandwidths and higher carrier frequencies are required. A key roadblock to implementing these systems at K-band (18-26.5 GHz) and is the need to develop hardware which meets the requirements for high data rate transmission in a cost effective manner. In this chapter, we report on the status of tunable dielectric thin films for devices, such as resonators, filters, phased array antennas, and tunable oscillators, which utilize nonlinear tuning in the control elements. Paraelectric materials such as Barium StrontiumTitanate ((Ba, Sr)TiO 3) have dielectric constants which can be tuned by varying the magnitude of the electric field across the material. Therefore, these materials can be used to control the frequency and/or phase response of various devices such as electronically steerable phased array antennas, oscillators, and filters. Currently, tunable dielectric devices are being developed for applications which require high tunability, low loss, and good RF power-handling capabilities at microwave and millimeter-wave frequencies. These properties are strongly impacted by film microstructure and device design, and considerable developmental work is still required. However, in the last several years enormous progress has occurred in this field, validating the

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