I am using Q'ltf in the model of an amplifier, with the numerator and denominator declared as constant num : real_vector := (0 => gain*F_3db*math_2_pi); constant den : real_vector := (F_3db*math_2_pi, 1.0); and the simultaneous statement is voutL == voutdq'ltf(num, den); where voutL and voutdq are quantities. ncvhdl compiles this without problems, however when I elaborate it I get the following error, ncelab: 05.00-p001: (c) Copyright 1995-2003 Cadence Design Systems, Inc. ncelab: *E,ELABUNSUPPLTF: Unsupported LTF parameter type; must be aggregate of scalars: ./amp.vhd:126: voutdq'LTF_126_16. Error found by spectre. Error: VHDL-AMS SAM generation failed ncelab: *F,SSIGF: Spectre Simulation Image generation failed!. Any help would be appreciated Mark