Abstract:
An arrangement for generating false echoes for ECM is characterized by providing identical magnetic environments for two paramagnetic samples for spin echo delay lines at microwave frequencies. A static magnetic field is formed by parallel faces of spaced-apart pole pieces having received therebetween two separate and independent waveguides. The two waveguides are arranged such that a common wall between them lies in the center plane of mirror symmetry of the magnetic field. A paramagnetic sample is disposed in each waveguide between the pole pieces such that the magnetic field distribution across the samples is substantially uniform but provides sufficient bandwidth for producing spin echoes of input microwave pulses. Circuitry is disclosed for directing an input pulse to one of the paramagnetic samples from which, at a time later, an echo is recalled and forms an input pulse to the second paramagnetic sample. A false echo is then provided by recalling the input pulse to the second paramagnetic sample at a selected time later.
Abstract:
A cancellation effect is obtained between the temperaturedependent phenomenon of the externally applied magnetic field and the crystallographic orientation of a gyromagnetic element by utilizing a temperature compensating magnetic shunt in combination with a permanent magnet used to establish a unidirectional or DC magnetic field through the gyromagnetic element comprising a YIG sphere and selectively orienting its axis to a predetermined angle defined by the direction of the DC magnetic field wherein the resonance frequency of the YIG sphere increases with temperature. Thus, any decrease in saturation magnetization as a function of temperature is exactly cancelled out by selective orientation of the YIG sphere.
Abstract:
Described is a small, lightweight ferrite phase shifter, constructed in a strip line wave energy transmission assemblage, which is small enough to fit into a steerable antenna array while at the same time providing good electrical isolation between adjacent phase shifters in the array.
Abstract:
A miniature electromagnetic wave apparatus or reciprocal phase shifter is disclosed. The apparatus comprises a wave guide structure having a longitudinal axis and at least first and second parallel elongated conductive members. The wave guide structure is dimensioned so as to support propagation of electromagnetic wave energy in a direction along the longitudinal axis of the wave guide structure. The electromagnetic wave energy as supported in said wave guide structure has longitudinally and transversely extending r.f. magnetic field components. A thin elongated body of gyromagnetic material is disposed between the conductive members so as to be traversed by the transversely extending magnetic field components. Means are associated with the wave guide structure for establishing a given state of magnetization within the body of gyromagnetic material and longitudinally thereof so as to effect negative phase shift of the wave energy propagated through the phase shifter.
Abstract:
A MULTIPLEXING DEVICE IS DISCLOSED EMPLOYING A PLURALITY OF FERROMAGNETIC RESONATORS WHICH COUPLE ALL WAVE ENENERGY WITHIN THEIR RESPECTIVE OPERATING BANDS FROM A BROAD BAND OF WAVE ENERGY PROPAGATING ALONG A PAIR OF PARALLEL WAVE ENERGY TRANSMISSION LINES AND TRANSMIT THE COUPLED ENERGY TO ASSOCIATED SECONDARY WAVE ENERGY TRANSMISSION LINES POSITIONED ADJACENT EACH OF THE RESONATORS.
Abstract:
DESCRIBED IS AN INTERGITITAL WAVE CIRCUIT DEPOSITED ON A FERRITE FILM AND HAVING A DIRECT CURRENT MAGNETIC FIELD APPLIED IN THE PLANE OF THE INTERDIGITAL CIRCUIT TO PROVIDE A MICROWAVE DEVICE EMPLOYING GYROMAGNETIC MEDIA FOR PHASE SHIFT, FREQUENCY TRANSLATION, CIRCULATION AND THE LIKE.
Abstract:
Apparatus is described for operation at high frequencies to convert analogue signals into corresponding digital signals. The high-frequency apparatus includes means such as an electron gun for producing a beam of electrons which is directed onto a target assembly of elements capable of providing a high degree of amplification of the incident electron beam. More specifically, the target assembly includes an apertured plate and semiconductor target elements disposed to receive the electron beam directed through the apertures of the plate. The analogue signal is applied to a suitable deflection mechanism for scanning the electron beam across the face of the target assembly. By arranging the apertures of the target assembly in defined array according to a suitable code for digital information, the semiconductor members may provide signals at separate output terminals corresponding to the desired quantization or levels of the analogue signals. For high-frequency operation, the electron deflection mechanism may assume the form of a traveling wave circuit such as a meander line to which is applied the highfrequency analogue input signal.
Abstract:
The phase shifter comprises a ferrite film structured to define a multiple toroid configuration and having deposited on one surface thereof a microwave transmission line defining the direction of propagation of microwave energy. Flux driving means are digitally controlled for selectively driving the film to remanent conditions of magnetization of predetermined orientations relative to the direction of microwave propagation. In a preferred embodiment, the flux driving means includes a conducting film deposited between two layers of the ferrite film, which layers are integrally formed about the boundaries of the conducting film to define the multiple toroid configuration. Energization of selected latching current paths defined by the film provides for the selective flux driving of the film. Where Beta is the propagation constant of the microstrip, relative differential phase shift is expressed as ( Delta Beta / Beta ), and is a function of the remanent field strength in the direction of propagation. Selective current pulsing of the conducting film to establish latching current in selected ones of the current paths permits rapid switching of each step of relative phase shift.
Abstract:
THE PHASE SHIFTER COMPRISES AN INTEGERAL STRUCTURE OF FIRST AND SECOND SEPARATELY DEPOSITED FERRITE LAYERS AND AN INTERMEDIATE CONDUCTING FILM DEFINING ORTHOGONAL LATCHING CURRENT CONDUCTING PATHS AND SERVING TO STRUCTURE THE FERRITE FILM IN A DOUBLE TORROID CONFIGURATION. A MICROWAVE TRANSMISSION LINE INCLUDES A MICROSTRIP DEPOSITED ON THE SECOND FERRITE LAYER DEFINING THE DIRECTION OF PROPAGATION OF MICROWAVE ENERGY. ENERGIZATION OF THE CONDUCTING FILM FOR ESTABLISHING A FLOW OF LATCHING CURRENT IN A SELECTED ONE OF THE CONDUCTING PATHS THEREIN PROVIDES FOR FLUX DRIVING THE FILM TO A REMANENT CONDITION OF MAGNETIZATION IN A CORRESPONDING, DESIRED ORIENTATION, PARALLEL OR PERPENDICULAR TO THE DIRECTION OF MICROWAVE PROPAGATION. WHERE B IS THE PROPAGATION CONSTANT OF THE MICROSTRIP, RELATIVE
DIFFERENTIAL PHASE SHIFT IS EXPRESSED AS $B/B, AND IS A FUNCTION OF THE REMEANENT FIELD STRENGTH IN THE DIRECTION OF PROPAGATION. ALTERNATE CURRENT PULSING OF THE CONDUCTING FILM TO ESTABLISH LATCHING CURRENT IN ALTERNATE ONES OF THE CURRENT PATHS PERMITS RAPID SWITCHING BETWEEN MINIMUM AND MAXIMUM RELATIVE PHASE SHIFT CONDITIONS.