US Patent 7149093 PXI chassis with backwards compatibility for existing PXI devices

The coupling apparatus couples two circuit cards to fit into a larger chassis. A coupling element can connect two similar sized circuit cards or two different sized circuit cards together by coupling the first circuit card and the second circuit card to effectively form a combined circuit card of a larger size. The larger size may allow for more features, may make it easier to dissipate heat, may make the circuit cards easier to shield, and/or may allow for the use of larger and less expensive components on the circuit cards.