Abstract: A novel antenna is disclosed which provides inherent filtering action by ch the frequency response curve of the antenna can be shaped. In the preferred inventive embodiment, the antenna comprises at least one elongated receiving element, and preferably two such elements in the form of a dipole, both elements being constructed, at least in part, of an electrically resistive material. A detector, such as a diode detector, is directly coupled to the receiving elements. The resistance of the receiving element and the capacitances of the receiving element and the detector form a distributed parameter RC filter, the values of which parameters can be carefully controlled so as to provide the desired frequency response curve shaping. In the preferred inventive embodiment, a conductive strip is disposed along the length of and preferably to both sides of each receiving element, with a layer of dielectric material being sandwiched therebetween, whereby the filtering action is enhanced.

Abstract: A Doppler radar device in which a detector diode is arranged in a flared horn which constitutes the aerial of the device. A metal sleeve is arranged in the flared horn perpendicular to the axis and parallel to the smaller sides of the horn, the said body being arranged behind the detector diode (viewed from the radiating side of the horn), and parallel to the diode.

Abstract: For use with radio receivers adapted to receive both frequency and amplitude modulated signals, a frequency modulated signal preamplifier adapted to be serially connected between the antenna input lead and antenna connector of such a radio, the pre-amplifier including means for separating the amplitude modulated and frequency modulated signals, amplifying the frequency modulated signals, and recombining the signals for input at the antenna input terminal of the receiver.

Abstract: A single element line scanner applicable to millimeter or submillimeter w beam steering which includes a semiconductor waveguide made of a high resistivity bulk single crystal intrinsic semiconductor material such as silicon. Parallel spaced radiator elements are disposed on one major or top surface of the semiconductor waveguide transverse to the direction of wave propagation along the waveguide. Parallel spaced PIN diodes are disposed on the other or bottom major surface of the semiconductor waveguide transverse to the direction of wave propagation. The PIN diodes are spaced close enough to prevent radiation from escaping outwardly from the bottom major surface and are provided with a variable forward bias to produce a conductivity sheet. The conductivity sheet on the bottom major surface is electronically modulated as a function of the bias current for a given frequency and the variation of such a conductivity sheet changes the wavelengths in the semiconductor waveguide.

Abstract: Control of the directivity, reflectivity, transparency and tuning of R.F. antenna array is accomplished by building antenna with short dipole segments with a switch between each two segments. The elements are properly connected to exhibit these electrical characteristics by remotely controlling the closing and opening of selected switches. The means for controlling the switches is isolated from the R.F. working frequencies of the antenna.

Abstract: A loop antenna system including a negative reactance circuit and having a bandwidth of several octaves in the low frequency bands.