RF switch and DSA under performance

Discussion created by Ranga@55 on Oct 20, 2016

I HAVE AN ISSUE WITH THE 6 BIT DIGITAL STEP ATTENUATOR (DSA) part no HMC 424ALP3E. I used a two layer 10 mil thick ROgers 4350B board and the schematic followed is as per the data sheet. I am not getting the performance as per the data sheet. I am only getting 6 dB attenuation instead of 31.5 dB. Same issue with HMC 232A RF switch . Isolation comes only 40 dB . Can any one help me in resolviing these issues. I have two questions- 1) Can I cascade three such DSAs to get 90 dB attenuation in the 9-10 GHz range.  2) Can I cascade two or more switches to improve isolation. WHat preccautions to be taken during the realisation of the above.