Abstract: An improved method and system for generating quadrature phase shift keying signals for use in data transmission is provided. A pair of oscillators are slaved to the transmit frequency and produce two quadrature signal components with the same frequency but 90 degrees out of phase. The two signal components are carried to separate bi-phase switches by mirrored waveguides. Each bi-phase switch has a reflective waveguide coupler which directs the received signal into a waveguide terminated by a hard short and has a controllable shorting plane spaced approximately one-quarter wavelength from the termination point. The shorting planes are controlled by the output data signals and each introduces a 180 degree phase shift in the respective signal component when activated. The reflective couplers direct the selectively phase shifted signal components to an in-phase combiner, where they are combined to produce the quadrature phase shift keyed output signal.

Abstract: A parabolic reflective antenna having a front concave surface and a rear convex surface. The reflective antenna including a heating assembly for preventing and removing ice and snow during cold weather. The heating assembly includes first and second woven supporting structures. A heating element is supported between the first and second supporting structures, the first and second woven supporting structures being interposed between the front and rear surfaces of the antenna. Heat generated from the heating element emanates to the front concave surface of the reflective antenna.

Abstract: An improved dipole antenna array with high radiation directivity and broad bandwidth is disclosed. Each dipole antenna is driven by a balun structure composed of an unbalanced J-shaped transmission line placed over a pair of ground plane extensions that are separated by a channel. The dipole antenna arms are connected to an intermediate point on the ground plane extensions so that the balun structure extends beyond the dipole antenna. The length of the dipole arms, their position on the ground plane extensions, and the extent to which the balun extends beyond the dipole antenna can be chosen to determine the desired operating frequency range. The antennas are fabricated on ground and circuit planes separated by a dielectric material and composed of conducting material deposited on dielectric sheets. A planar array of dipole antennas is formed with the ground plane circumscribing each antenna in the array to improve directivity.