[IEEE 1999 Symposium on High Performance Electron Devices for Microwave and Optoelectronic Applications. EDMO - London, UK (22-23 Nov. 1999)] 1999 Symposium on High Performance Electron Devices for Microwave and Optoelectronic Applications. EDMO (Cat. No.99TH8401) - High order mode planar resonators for mm-wave applications