Abstract: A two-arm delta mode spiral antenna includes a dielectric substrate having an upper side, a lower side, and an outward edge. A flat top cone with cylinder sidewall is attached to the lower side of the dielectric substrate, forming a scalable feed cavity. Two spiraling conductive radiator arms are mounted on the dielectric substrate. A magic-T is electrically connected to the two spiraling conductive radiator arms.

Abstract: Terahertz quantum cascade structures employing multiple steps per periodic section. Terahertz quantum cascade structures employing no more than one step per periodic section.

Abstract: A Quantum Cascade (QC) structure(s) for use in Quantum Cascade Lasers (QCLs) that use step quantum well(s) in which the radiative and LO-phonon transitions are both vertical transitions and within the same step well. This approach allows for a high oscillator strength and uses LO-phonon scattering for fast depopulation of the middle state (lower lasing state) for maintaining a population inversion. The step also reduces unwanted injection into the lower lasing state due to spatial separation of the wavefunctions. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope of the claims.

Abstract: A target object motion estimation method using at least one subset of a complex SAR image. Coarse range cell alignment is performed on at least one subset of a complex SAR image. At least one subset is autofocused, thereby providing an estimated phase error function. The estimated phase error function yielded by autofocusing (or a manipulated version of the phase error function) may be analyzed to detect, characterize, and estimate target object motion.

Abstract: An impedance matching feed is disclosed for use in a ridge waveguide which allows a coaxial transmission line, generally having an impedance of fifty ohm, to be matched to a ridge waveguide of arbitrary impedance. The matching feed consist of a transformer which is located inside the ridge of the waveguide, a probe and a quarter wave choke.

Abstract: A short ridge waveguide load is described which absorbs and cancels non-radiated electromagnetic energy in continuous slot or discrete slotted antennas. The load achieves a small physical size by using a resonant structure which includes an absorbing ferrite front section positioned within the interior of the waveguide antenna below the slot and a back section of ferrite material also positioned in the interior of the waveguide antenna. This allows for energy to be radiated from the slot while absorbing and canceling the non-radiated energy using a relatively small size load. In a rectangular ridge waveguide configuration, the front section consists of a pair of posts having a trapezoidal, rectangular or triangular shape.

Abstract: An impedance matching feed is disclosed for use in a ridge waveguide which allows a coaxial transmission line, generally having an impedance of fifty ohm, to be matched to a ridge waveguide of arbitrary impedance. The matching feed consist of a transformer which is located inside the ridge of the waveguide, a probe and a quarter wave choke.

Abstract: A short ridge waveguide load is described which absorbs and cancels non-radiated electromagnetic energy in continuous slot or discrete slotted antennas. The load achieves a small physical size by using a resonant structure which includes an absorbing ferrite front section positioned within the interior of the waveguide antenna below the slot and a back section of ferrite material also positioned in the interior of the waveguide antenna. This allows for energy to be radiated from the slot while absorbing and canceling the non-radiated energy using a relatively small size load. In a rectangular ridge waveguide configuration, the front section consists of a pair of posts having a trapezoidal, rectangular or triangular shape.

Abstract: An impedance matching feed is disclosed for use in a ridge waveguide which allows a coaxial transmission line, generally having an impedance of fifty ohm, to be matched to a ridge waveguide of arbitrary impedance. The matching feed consist of a transformer which is located inside the ridge of the waveguide, a probe and a quarter wave choke.

Abstract: An impedance matching feed is disclosed for use in a ridge waveguide which allows a coaxial transmission line, generally having an impedance of fifty ohm, to be matched to a ridge waveguide of arbitrary impedance. The matching feed consist of a transformer which is located inside the ridge of the waveguide, a probe and a quarter wave choke.

Abstract: An antenna array includes two pairs of linear polarized antennas mounted to a perimeter portion of an airframe with one pair having a polarization normal to the airframe and the other pair having a polarization tangential to the airframe. The antenna array eliminates the cross-polarization problem of an electromagnetic wave incident upon the array when using linear polarized perimeter mounted antennas.