Do you need to design it from scratch - based on your quoted dimensions and degree of attenuation at the stated frequencies, you're after a pretty standard steel lined enclosure (or a 3 - 5mm steel box) with a knife edge door and a few honeycomb wave guide entries. Possibly jacked up on a frame to allow inspection underneath it, and robustly earthed to a reliable ground plane. Depending on what services you need you may have to use a few tempest filters on some of the incoming circuits, and consider the cable type (shielded with foil plus braiding would be usual) - generally keep as much out of the box as you can.


Basically, if you can define the E field and H field, then for any frequency you can quickly work out the shielding thickness required for a given material.


You could effectively buy (or specify) one "off the shelf" at 80dB attenuation. You may need a mix of ferrous and non ferrous linings if the 80dB is absolute at all specified frequencies, aluminium/steel composites are particularly effective at absorption and reflection techniques. There are a few companies listed via CPNI (but you may need a security consultant or similar to access the data) and a whole lot more knocking about for less secure applications


You can design from scratch but eventually, you'll run into performance certification problems if you have to satisfy the requirements of a Class consultant or similar acting for the ultimate client - for example, you usually won't have any drama with an enclosure certified to, say, MIL STD 285/IEEE-299


If Mapj1 rocks up, this will be right up his street if you do want some outlines for designing one. I'm a lazy sod, I'd just buy one ?


Regards


OMS

Do you need to design it from scratch - based on your quoted dimensions and degree of attenuation at the stated frequencies, you're after a pretty standard steel lined enclosure (or a 3 - 5mm steel box) with a knife edge door and a few honeycomb wave guide entries. Possibly jacked up on a frame to allow inspection underneath it, and robustly earthed to a reliable ground plane. Depending on what services you need you may have to use a few tempest filters on some of the incoming circuits, and consider the cable type (shielded with foil plus braiding would be usual) - generally keep as much out of the box as you can.


Basically, if you can define the E field and H field, then for any frequency you can quickly work out the shielding thickness required for a given material.


You could effectively buy (or specify) one "off the shelf" at 80dB attenuation. You may need a mix of ferrous and non ferrous linings if the 80dB is absolute at all specified frequencies, aluminium/steel composites are particularly effective at absorption and reflection techniques. There are a few companies listed via CPNI (but you may need a security consultant or similar to access the data) and a whole lot more knocking about for less secure applications


You can design from scratch but eventually, you'll run into performance certification problems if you have to satisfy the requirements of a Class consultant or similar acting for the ultimate client - for example, you usually won't have any drama with an enclosure certified to, say, MIL STD 285/IEEE-299


If Mapj1 rocks up, this will be right up his street if you do want some outlines for designing one. I'm a lazy sod, I'd just buy one ?


Regards


OMS