FPD'17

D2P8 - ARTES AT - Q-band High Power Isolator - Honeywell Aerospace (UK)

15 Feb 2017, 14:55

30m

Newton 1 & 2 (ESA/ESTEC)

Speaker

Dr Andreas Papanastasiou (Honeywell Aerospace (UK))

Description

A compact waveguide isolator has been developed, providing full reverse-power protection for TWTAs with 100W RF CW output, to be qualified for use in the next generation of Q-band multi-beam satellite missions. Using a classical quarter-wave coupled resonator Y-junction circulator design with a mixed metal housing and high conductivity material bonding allowed the full 100W of RF power to be handled in full reflection condition without overheating the junction ferrite discs. A dual-channel waveguide load was designed to dissipate the 100W RF power in ceramic absorber elements over a large area. Thermal analysis was employed to optimise the mechanical element design of the RF-characterised load material to average out the heat distribution over the elements whilst maintaining RF performance characteristics. Although RF finite element analysis was used in the design of the circulator, manufacturing tolerances were critical in realising the s-parameter performance over the desired bandwidth. The isolator design was targeted to achieve a 5GHz bandwidth centred on 40GHz with 22dB return loss and 23dB isolation over the -10 to +85°C temperature range, however the manufactured isolator was centred 2.5GHz lower in frequency. It was tested beyond the rated maximum power in TVAC at Honeywell’s Aylesbury facility and confirmed low loss, high isolation performance even under full reflection conditions.

Short Speaker Information

Andreas Papanastasiou received his B.Sc. in Electrical Engineering from the Pennsylvania State University, State College, PA, USA in 2001, his M.Sc. in electrical engineering from the Polytechnic Institute of NYU, Brooklyn, NY, USA in 2005 and his PhD in Electrical and Computer Engineering from the University of Cyprus in 2015. From 2001 to 2006, he worked for ARTEMIS, Inc. as and RF/ Microwave Design Engineer where he developed active and passive components for upconverters and receivers for the aerospace industry. From 2007 to 2013, he worked as a Lead Research Fellow for the Electromagnetics and Novel Applications Lab of the University of Cyprus, where he led the RF Engineering effort of the laboratory and worked on multiple European Defence Agency funded projects in radar applications. Since 2013 he works for Honeywell Aerospace (t/a COM DEV) in the UK and currently is involved in the design of various passive microwave subsystems and components for satellite and ground support instruments. He also acts as a regular reviewer for IEEE journals.