The objective is to develop a steerable antenna such as could be used for satellite communications to high speed trains. Potential end users include 21Net Ltd.
Following successful proof-of-concept for a hemispherical lens antenna design, ESA have backed this project under their ‘Innovation Triangle Initiative’. The work is a collaboration between York Electronics Centre (a unit with the Electronics Department at University of York, tasked with the project management and design), the Communications Research Group, and satcomms consultants.
The requirements for a prototype scanning antenna for Ku band will be defined. This will capture the critical performance parameters including: gain, scan angle range, sidelobe level, polarisation, tracking rate and accuracy.
The properties of multi-layer hemisphere lenses operating at Ku band will be investigated using computer modelling techniques. Working to the requirements specification from WP1, multi-layer lens structures will be examined with the aim of maximising antenna performance with a minimum number of dielectric layers, thus seeking to minimise production costs. The WP will deliver the dimensions and required dielectric materials for a desired prototype antenna.
The antenna lens components will be fabricated. It is envisaged that these will comprise a multi-layer system of concentric hemispheres using low-loss dielectric materials. Means of manufacturing the lens antenna will be investigated with a view to recommending the most appropriate commercial fabrication process. For the breadboard antenna a representative lens system may be based on one or more of the following options (to be determined):
Fabricate a one-off item according to the optimum design output of WP2.
Procure a Luneburg-type lens from an external supplier.
Produce a scale-model for purposes of demonstration.
A ground plane and primary feed will complete the electromagnetic components of the antenna. An off-the-shelf primary feed with low noise block converter may be the most appropriate choice for a receive-only demonstration.
A steering mechanism for a single primary feed will be constructed. This will require control in azimuth and elevation, most probably by an electric motor in each case. Means of routing power supply and radio frequency cables will be considered, with the prototype hardware demonstrating solutions to the most critical issues. The electro-mechanical system will be interfaced with a computer and software for purposes of a closed-loop demonstration control-system.
This will comprise a programme of measurements using an anechoic chamber. Near field radiation patterns will be measured in the principle antenna planes (E-plane and H-plane). These will be compared with theoretical patterns predicted by computer modelling in WP2000. The gain will be measured by comparison with various reference antennas, using either a near-field range or an outdoor range for extended distance.
Members
- John Thornton
Funding
- ESA ARTES
Dates
- September 2007 to
April 2009
Research