Integral Equation Modeling of Waveguide-Fed Planar Antennas

This paper presents a method for the analysis of planar multilayered waveguide-fed antennas. The method combines mixed-potential integral equations (for laterally open regions) and modal field integral equations (for laterally closed regions) with a seamless transition between the two domains. The method has been implemented in a numerical tool and the simulation results of two waveguide-fed microstrip structures have been presented. The results are in good agreement with both measurements and simulations obtained with other commercial electromagnetic tools. Comparisons in terms of memory occupation and simulation time have also been performed

Miniaturised DBF Communication Modules for Broadband Mobile Satellite Access at Ka-Band

This paper describes the implementation of and measurements on highly integrated transmitter and receiver modules featuring digital beamforming (DBF) at Ka-band frequencies. These modules can be used as building blocks for large receiver or transmitter terminal antennas. After a review of the essential parts of the receiver and transmitter modules like antenna elements, Ka-band frontends, miniaturised interfaces and IF / baseband circuitry, measurement results of one receiver and one transmitter module are presented and discussed

SANTANA – Smart Antenna Terminal for Broadband Mobile Satellite Communications at Ka-Band

Smart antennas employing Digital BeamForming (DBF) at Ka-band frequencies will be key elements for the next generation of broadband satellite communication systems. This frequency band offers high bandwidth, whereas DBF provides a high degree of system flexibility. Scope of the two-phase project Smart Antenna Terminal (SANTANA) is the development of advanced satellite communication terminals for mobile segments (e.g. aircrafts). The antenna consists of an Rx (20 GHz) and a separate Tx (30 GHz) array. In order to realise high gain DBF arrays, the Tx/Rx antennas are composed of 4x4 array modules which are used as basic building blocks. After a short introduction explaining the background and vision of the SANTANA project, a general system overview on the terminal-antenna concept will be given, followed by the presentation of measurement results. After that, the focus will be on novel concepts of an improved terminal architecture which is currently developed in the second project phase: • An enhanced RF-to-antenna interconnect design, which enables separate testing of RF- and antenna structures before integration and allows for a new architecture to enhance the thermal management. • An improved Rx-antenna element and feeding structure. • A new Tx antenna layout, based on a LTCC multilayer structure, featuring hybrid couplers, shielding cavities and a calibration network. An outlook on the fixed and mobile tests of a system, composed of 4 basic building blocks for high data rate planned to be carried out in 2006 will conclude this contribution

The SANTANA project

Smart antennas employing digital beamforming (DBF) at Ka-band frequencies will be key elements for the next generation of broadband satellite communication systems. This frequency band offers high bandwidth and therefore high data rate capability, whereas digital beamforming provides a high degree of system flexibility. Within the SANTANA (Smart Antenna Terminal) project, key elements of advanced DBF satellite communication terminals at Ka-band frequencies have been developed. SANTANA is a joint project of IMST GmbH and TU Hamburg-Harburg with DLR Oberpfaffenhofen, EADS Astrium GmbH. Industrial support is provided by Lewicki Microelectronics GmbH, RHe Microsystems, and EPAK GmbH. The project is funded and supported by the German Space Agency (DLR) on behalf of the German Ministry of Economics and Technology (BMWi). Within the SANTANA project framework of phase 1 (2001 - 2003) and phase 2 (2003 - 2007), a complete medium size DBF system has been realised. It consists of separate transmit (30 GHz) and receive (20 GHz) units with 64 antenna elements each. This DBF system has been successfully demonstrated by establishing bidirectional communication links to moving platforms (car and aircraft) equipped with a conventional transmit/receive unit. The aim of the current project phase 3 is the adaptation of the present technology towards large arrays, the verification of the terminal within a moving environment, and the further industrialisation of several building blocks. The paper describes the whole system and reports the essential experimental results obtained during the field tests

Smart antenna terminals for broadband mobile satellite communications at Ka-band

This paper deals with a modular Rx- and Tx-antenna terminal featuring digital beamforming (DBF) at Ka-band frequencies. Background and vision of the project SANTANA II and recent realizations are described. Different system components are outlined covering digital baseband, RF- and IF-level as well as software aspects. An outlook on mobile field tests, which will be reported at the conference, concludes this contribution

SANTANA: Advanced Electronically Steerable Antennas at Ka-Band

This paper presents the background, the vision, and the motivation of the SANTANA project (Smart Antenna Terminal). Recent realizations of electronically steerable receive (Rx) and transmit (Tx) antennas for satellite communications at Ka-Band are shown. In detail, the integration and packaging techniques of frontend modules, which combine the antenna, the RF circuitry, and the cooling system within one functional block, are discussed. In addition, a novel digital beam steering concept as well as a hybrid beam steering approach are addressed. It will be shown that these system concepts can be applied to large antenna arrays as needed to fulfill link budget requirements for the intended satellite communications