stepped attenuator in RF chain justification

Your drawing indicates that the input frequency is 8 GHz. HMC424 is specified to operate form dc to 3 GHz. So you are going to need a higher frequency attenuator.  I'm not sure of your question "is the use of this attenuator in this schematic" justifiable. From a signal balancing perspective, I would probably move the attenuator more to the center of the signal chain. There are models for all of these components in ADIsimRF (you can make a custom model for the Qorvo part). The software allows you to do frequency and DSA attenuation sweeps (www.analog.com/adisimrf)

Your drawing indicates that the input frequency is 8 GHz. HMC424 is specified to operate form dc to 3 GHz. So you are going to need a higher frequency attenuator.  I'm not sure of your question "is the use of this attenuator in this schematic" justifiable. From a signal balancing perspective, I would probably move the attenuator more to the center of the signal chain. There are models for all of these components in ADIsimRF (you can make a custom model for the Qorvo part). The software allows you to do frequency and DSA attenuation sweeps (www.analog.com/adisimrf)

Hi enash 

thank you for replying

but based on the datasheet of HMC424 this IC worked in 8 GHz to 13 GHz

www.analog.com/.../hmc424alh5.html

HMC424AG16 is specified from DC to 3 GHz. HMC424ALH5 is specified from DC to 13 GHz. I'm surprised that two parts with the same root part number (HMC424) have such different frequency ranges. Anyway, if you use HMC424ALH5, then it will, as you say, cover your 8 GHz operating frequency.