Three antennas have been made so far. The first operated at a base frequency of about 500MHz and was constructed at the Clarendon (Physics) Laboratory, Oxford. It was completed in 2000.
The second was made at the Los Alamos National Laboratory (LANL) in the USA and was completed in late 2009. It operates at about 2.6GHz
The third was made at LANL in late 2010. It is has a straight array of elements with accelerated excitation.
The buttons below show the machines and give some early results from the full-circle machine. The demonstration of the non-spherical decay of the emitted power was a dramatic indication of the potential of the antenna.