HP/Agilent 778D详细介绍：
Features * Multi-octave frequency range: 100 to 2000 MHz * High directivity: 36 dB to 1 GHz, 32 dB to 2 GHz * Reflection coefficient measurement: Over 4 octaves with 1 coupler Broadband 20 dB Dual Directional Coupler This dual directional 20 dB coupler has a frequency range extending over 4 octaves from 100 MHz to 2 GHz. The multi-octave capability makes measurements easier–setup and calibration time are reduced, since normally several couplers are required over this frequency band. The coupling factor increases about 6 dB per octave below 100 MH
