Sardine Can Antenna. is a BiQuad or Bi circle – wire length each side (8 x 1/4 waves ) 31 mm
Sardine cans have quite standard dimensions around the world, although the oval one shown here is lightweight aluminium & does seem (perhaps by chance ?)to have enhanced directivity compared with more normal steel Canadian “Brunswicks ” etc. It’s an ex. Latvian RICHTER “Smoked RIGA SPRATS” & perhaps first received publicity in the Nov. 2002 Australian “Silicon Chip” monthly ( author Stan. SWAN => firstname.lastname@example.org ), when it was first called a “Kipper Can”. ( For those readers who don’t recall Monty Python, Kippers are smoked herrings http://www.deliaonline.com/ingredients/ingredientsatoz/i_0000000135.asp. See refs & further construction dimensions/views/insights => http://www.manuka.orcon.net.nz <= Even an old CD can act as the reflector, exploiting the metalised layer of course, but the sardine version prooved far superior, no doubt due to the focusing side walls.
The hot melt glue shown here is not really needed if a rigid N connector is used, although a recent enhancement has been to form the radiating bow tie as tracks on a small PCB secured via nylon spacers. Gain is great -typically 10dB ( links to 10km LOS made & typically 2km more normal built up areas !).
Need a quickee antenna ? Got 10 minutes & simple tools ? You won’t get a simpler, cheaper or more compact design. The unit can be neatly hidden in a pencil case or plastic bag beside your road warrior notebook so it’s not intimidating for field use. It’s directional enough to even pin point the signal location ( using NetStumbler etc )in a multilevel building. RECOMMENDED !
Originally publihed at http://www.seattlewireless.net/SardineCanAntenna