A fire barrier for buildings includes a ceramic fiber based material such as ceramic paper. The germanium carbide layer may be formed by microwave plasma-enhanced chemical vapor deposition by exposing the germanium material to a microwave-generated plasma that is formed from a carbon-containing source gas and hydrogen. This configuration makes it possible to suppress simultaneously both of low-frequency-side and high-frequency-side distortion voltages of a distortion generated by a wide-band class-AB power amplifier even if they are different in amplitude and phase. Thus, dead weight and operating loads from the inner casing are reacted through the support member and into the outer casing without the necessity for any bolting or other fastener attachment in the design load path between the support member and the inner casing.