Abstract: A reflectarray antenna element includes a first dielectric layer, a conductive ground layer mounted to the first dielectric layer and including an aperture formed therethrough, a second dielectric layer mounted to the conductive ground layer, a radiating patch layer mounted to the second dielectric layer, a delay line layer mounted to the first dielectric layer and comprising a first delay line connected to an open-circuit termination and a second delay line connected to a short-circuit termination, and a first switch and a second switch electrically connected to the first delay line and the second delay line. The first delay line and the second delay line are positioned to couple electromagnetically with the aperture, and each switch is switchable between an ON state and an OFF state.

Abstract: A method for validating expansion ROM cards which are loaded into a Personal Computer. A ROM image is signed (encrypted) using a private key and an encryption algorithm to create a digital signature. The digital signature is stored along with the ROM image on an expansion ROM. The system BIOS scans the system for the presence of an expansion ROM and when one is detected, the digital signature is verified (decrypted) using a public key corresponding to the private key. If the decrypted digital signature matches the ROM image (or a hash digest thereof), then the BIOS loads the ROM image.