A novel calibration scheme is presented that is especially suited for complex digital beamforming (DBF) antenna arrays at millimeter-wave frequencies. Calibration data is extracted by sampling the field of each radiator at certain locations near the array by fixed probe antennas. A scalable calibration model for evaluation of the measured data is described. First tests are performed on a small passive array representing a unit cell of larger arrays. The calibration scheme is subsequently applied to and tested on a 64 element DBF transmit antenna array.

An External Calibration Scheme for DBF Antenna Arrays

This paper presents the design, implementation, and test of a compact antenna array providing polarization multiplexing at 30 GHz. The array elements are realized as open-ended substrate-integrated waveguides (SIW). Focus of this paper is on the far field analysis of the array for different steering angles and polarizations. Simulation as well as measurement data is presented and discussed.

Far field measurement on Ka-band substrate-integrated waveguide antenna array with polarization multiplexing

The increasing demand for mobile access to fast data services is one of the drivers for future broadband satellite systems. In-flight data exchange between aircraft and satellites for real-time Internet access is a prominent example for this kind of satellite link. Antennas employing digital beam-forming provide the fast and flexible reconfigurability required in such a system without the necessity for moving mechanical parts. The antenna presented is a circularly polarised, 4/spl times/4 element array building block. This module can be used for a digital beam forming terminal transmitting system operating at 29.75 GHz (Baggen, L. et al., IEEE Phased Array Systems and Technology, p.571-76, 2003). The array features a calibration network as well as transmitting circuitry for each single element. This high density integration task is achieved by the vertical integration of antenna and circuitries in an LTCC multilayer module.

A 30 GHz highly integrated LTCC antenna element for digital beam forming arrays

Embodiments of the present invention provide an antenna apparatus, a base station and a communications system. The antenna apparatus includes: an antenna part, including a common radome; an active part, connected to the antenna part and including at least one active module, where each active module includes at least one antenna element, and an element reflector and a phase shifter and a radio frequency module that are corresponding to each antenna element, where the element reflector of the at least one active module is configured to implement an antenna function; and a common part, connected to the active part and the antenna part, and shared by the at least one active module in the active part, where the common part includes at least one common module. By using the above antenna apparatus, each radio frequency module can be flexibly configured, so as to simplify onsite replacement and maintenance operations.

Antenna apparatus, base station and communications system

In this paper several components for a highly integrated digital beamforming (DBF) antenna array for Ka-band satellite systems are presented. The general concept of array construction based on a modular approach is introduced and the construction of a constituent array module discussed. Following this outline, different components, designed and tested to later be incorporated into the array module, are treated with the focus set on the Ka-band receiver and transmitter frontends.

Components of a highly integrated DBF terminal antenna for mobile Ka-band satellite communications

Results of a concept study dealing with a smart Digital Beam Forming (DBF) satellite terminal in Ka-band are presented. The objective of this study was to investigate systems, concepts and technologies for active DBF terminal antennas operating with future broadband satellite systems. The results were intended and are now being used as a basis for an ongoing project dealing with the development and realization of a DBF terminal demonstrator.Conformal antennas, discrete mode matching, numerical methods, network analysis

M. Thiel

Papers

Ka-band DBF terminal concepts for broadband satellite communications

Components of a highly integrated DBF terminal antenna for mobile Ka-band satellite communications

Modular DBF Terminal Antennas for Broadband Mobile Satellite Communications in Ka-Band