Model WMC-6-18-10dB-S from Werbel Microwave is a directional coupler that covers 6 to 18 GHz with broadband flat coupling response, high directivity, and excellent return loss performance.  Coupling flatness response, also referred to as frequency sensitivity, is typically ±0.3 dB or better across the band.  Directivity 15dB typical.  Return loss 18dB typical.  Insertion loss 0.82dB typical.  The enclosure is compact, measuring 1.00 x 0.60 x 0.38 inches, with SMA-Female connectors.  The unique approach at creating a coupled line structure results in a super flat coupling response.  This allows for highly accurate and dependable measurements.  The device covers both X and Ku bands in one compact size enclosure.  Our own design, assembled and tested in the USA.