RF limiter for -20dbm
Although not an answer this is the construction of a 2~22 GHz soft limiter (almost 1GHz) to give you an idea of the cascaded stages of limiting in order to  give you more dynamic range of compression.


  Qorvo’s TQGaN15 GaN on SiC process. GaN on SiC offers high input power survivability of 40 dBm, potentially eliminating the need for a power limiter.