A sampling gate comprising a first frequency input coupled to a first frequency path from a broadband photodiode. The sampling gate also includes a positive bias input coupled to a positive offset portion of a second frequency path from the broadband photodiode. The sampling gate also includes a negative bias input coupled to a negative offset portion of the second frequency path from the broadband photodiode. The sampling gate combines a first frequency signal from the first frequency path and a second frequency signal from the second frequency path to create a combined broadband frequency signal from the broadband photodiode.