The RTP5318 from Boonton is a Power Sensor with Frequency 50 MHz to 18 GHz, Power Range -34 to 20 dBm, Peak Power Range 30 dBm, Dynamic Range 54 dB, Measurement Speed 100K meas/sec (buffered mode) over USB 800 meas/sec (continuous). More details for RTP5318 can be seen below.