Did you look at the "Verilog-AMS" link at the top of the page?

Note that Verilog A won't simulate in a Verilog (digital) simulator - you need to use either an analog simulator (such as Cadence's spectre), or a mixed signal simulator (such as Cadence's AMS Designer).

Also, in Cadence's IC tools, you should have libraries (such as ahdlLib, rfLib) which have both SpectreHDL ("ahdl" - no longer supported in spectre) and VerilogA views.

http://www.designers-guide.org/VerilogAMS/

Regards,

Andrew.