Optical beam forming for phased-array antennas

The activities of the Telecommunication Engineering (TE) group span the communications spectrum from copper cables, optical fibres, microwaves, radio and electromagnetic compatibility. Our research concentrates on optical signal processing and networks, mobile communications, microwave techniques and radiation from ICs and PCBs [1]. A considerable (and particularly interesting) part of it is related to optical beam forming for phased array antennas, using optical ring resonators.\ud In this article the theoretical basics and practical challenges of this interesting research topic will be summarized.\u

Radial microstrip slotline feed network for circular mobile communications array

In mobile and satellite communications there is a need for low cost and low profile antennas which have a toroidal pattern. Antennas that have been developed for mobile communications include a L-Band electronically steered stripline phased array, a Ka-Band mechanically steered elliptical reflector antenna and a Ka-Band printed dipole. In addition, a L-Band mechanically steered microstrip array, a L-Band microstrip phased array tracking antenna for mounting on a car roof and an X-Band radial line slotted waveguide antenna have been demonstrated. In the above electronically scanned printed arrays, the individual element radiates normally to the plane of the array and hence require a phase shifter to scan the beam towards the horizon. Scanning in the azimuth is by mechanical or electronic steering. An alternate approach is to mount microstrip patch radiators on the surface of a cone to achieve the required elevation angle. The array then scans in the azimuth by beam switching

A low profile radiating element with nearly hemispheric coverage for satellite communications on-the-move hybrid array antenna

A novel design solution of a dual-linearly polarised Ku-band low-profile radiating element for low elevation angle coverage (down to 10° above horizon) is presented. Such an element is suitable for full-duplex Satellite Communications On-The-Move (SCOTM) hybrid scanned phased array antenna applications. Standard designed radiating elements for array applications with low profile physical structure suffer poor low elevation angle coverage as the element pattern reduces by sine of the elevation angle. The element design demonstrated in this paper features unique louvered array element geometry incorporating a spatial “ray bending” lens facilitates the shaping of the element pattern to increase gain at low elevation angles. Preliminary modelling results using ray tracing analysis shows that the desired low angle coverage can be achieved. Currently in progress full 3D electromagnetic simulations which include the interaction between the basic radiator and the spatial lens indicates that using an ideal tilted element with novel louvered reflector in addition with proposed lens, low angular coverage can potentially be realised in a low profile structure

Performance of a family of omni and steered antennas for mobile satellite applications

The design and performance of a family of vehicle antennas developed at JPL in support of an emerging US Mobile Satellite Service (MSS) system are described. Test results of the antennas are presented. Trends for future development are addressed. Recommendations on design approaches for vehicle antennas of the first generation MSS are discussed

Rationale for and design of a generic tiled hierarchical phased array beamforming architecture

The purpose of the phased array beamforming project is to develop a generic flexible efficient phased array receiver platform, using a mixed signal hardware/software-codesign approach. The results will be applicable to any radio (RF) system, but we will focus on satellite receiver (DVB-S) and radar applications. We will present a preliminary mapping of beamforming processing on a tiled architecture and determine its scalability.\ud \ud The functionality, size and cost constraints imply an integrated mixed signal CMOS solution. For a generic flexible multi-standard solution, a software defined radio approach is taken. Because a scalable and dependable solution is needed, a tiled hierarchical architecture is proposed with reconfigurable hardware to regain flexibility. A mapping is provided of beamforming on the proposed architecture. The advantages and disadvantages of each solution are discussed with respect to applicability and scalability.\ud \ud Different beamforming processing solutions can be mapped on the same proposed tiled hierarchical architecture. This provides a flexible, scalable and reconfigurable solution for a wide application domain. Beamforming is a data-driven streaming process which lends itself well for a regular scalable architecture. Beamsteering on the other hand is much more control-oriented and future work will focus on how to support beamsteering on the proposed architecture as well