3GHz Handheld Frequency Counter - 

The PFM3000 offers high sensitivity frequency measurement from 3Hz to more than 3GHz in two overlapping ranges. Period measurement is also provided from 8ns to 330ms. The PFM3000 uses a continuous reciprocal measurement technique to provide high resolution at all frequencies with rapid update. It offers high sensitivity across the whole frequency range. A low pass filter can be selected to reduce high frequency signal noise at lower frequencies.