Abstract: A helical antenna for radiating waves in both orthogonal states of circular olarization that is fed at the base by a first feed and at the tip by a second feed. The amplitude and phase of the signal from the first feed controls the amplitude and phase of the wave in the first orthogonal polarization while the amplitude and phase of the second signal from the second feed independently controls the amplitude and phase of the wave in the second polarization state. Radiated waves of any arbitrary polarization state are formed by adjusting the amplitude and phase of the feed signal. Alternative embodiments are disclosed and claimed.

Abstract: A high frequency antenna achieves low signal-levels in far-out sidelobe and acklobe antenna pattern regions through utilization of a corrugated feed-horn acting as a non-axial source for a cooperating parabolic reflector.

Abstract: The architecture of this invention makes multiple use of switched time-delay circuits to reduce the complexity of both series and parallel feed antenna arrays. Each time-delay circuit can give a delay that can be switched to values between 0 and 2d/c, where d is the inter-element spacing and c is the velocity of light. At the highest frequency of the series feed array, the elements are spaced by .lambda./2 to avoid grating lobes and the maximum delay corresponds to 360.degree. of phaseshift. When the time-delays are set half way (d/c), the various lines feeding the elements of the array at the aperture have bias delays that make them all equal in length, thereby giving a broadside beam, independent of frequency. At the highest frequency, the switchable time delay gives some excess in available delay. If additional excess time-delay is needed it can be obtained by increasing the time delay circuit range. Insertion loss is proportional to the number of bits used.