Abstract: A holographic device and method encrypts a time dependent data signal, s(t), by a complex time dependent phase shifting signal. This produces a new signal whose modulus is equal the absolute value of the data signal, s(t), but has widely spread the frequency of the data signal. This new complex signal is mathematically transformed, producing an amplitude and phase spectrum (or a real and imaginary transform spectrum) of signal components. The amplitude and phase signals are modulated into a radio frequency carrier (or some other radiating source) as quadrature components and transmitted. At the receiver, the quadrature signals are separated into an amplitude and phase components which are then mathematically inverse transformed. The result is a complex signal with a real and imaginary components. The resulting signal is an accurate representation of the original data signal if a complete signal is recovered.

Abstract: The invention is directed to electromagnets for producing a high uniformity magnetic field or shielding a magnetic field by the use of passive compensation coils in the form of rings of superconductive material positioned perpendicularly adjacent to the electromagnet windings. Current induced into the rings of superconducting magnetic material establishing magnetic fields perpendicular to the electromagnetic magnetic field, thereby, depending on this size and quantity of the rings a highly uniform magnetic field or the cancelling of the magnetic field from the electromagnet adjacent to the surface of the rings remote from the electromagnet field occurs. High temeprature superconducting material can be used for the rings which lead to high temperature operation.