PT Unknown AU Meledin, D Pantaleev, M Pavolotsky, A Risacher, C Belitsky, V Drakinskiy, V Cherednichenko, S TI Balanced waveguide HEB mixer for APEX 1.3 THz receiver SE Proc. 16[super:th] Int. Symp. Space Terahertz Technol. PY 2005 PI Göteborg, Sweden ER