Aircraft Interference Suppressors-Passive and Active

Control Technology in collaboration with the Royal Aircraft Establishment have developed range of active and passive suppressors suitable for airborne use. The work was undertaken to make available an approved range from which suppressors could be selected either for incorporation in new equipment to enable it to comply with the relevant procurement specification or for retrofitting existing aircraft systems. The design of the passivè suppressors is based largely on the work presented at the 1972 IEEE EMC Symposium in the paper "An Improved Design and Measurement of Attenuation Characteristics of RF Suppressors" by M L Jarvis. Initially, development was of suppressors having cut-off frequencies which would enable equipment to meet the conducted emission requirements of MIL-STD-461 and BS.3G.100. Both 28 V dc and 200 V 400 Hz ac versions have been produced with a variety of current ratings - up to 10A for the ac suppressors and up to 100A for the dc suppressors. Both "T" and "H" versions are available. Details will be given in the paper of a BASIC program to evaluate prototype suppressor designs for minimum voltage attenuation or for insertion loss.