Farran Technology Ltd (FTL) has developed a rnage of Frequency Extension products to satisfy the demand for extending the measurement capability of customer owned Vector Network Analysers to 170GHz. Together with the FTL Frequency Extension Controller (FEC-01 or FEC-02) they allow measurements in the range 75GHz to 170GHz (D -band) using Agilent PNA/PNA-X or Anritsu 37XXXD/Vector Star. The Rohde and Schwarz ZVA does not require a Controller.