The United States of America as represented by the Secretary of the Army - Washington DC
International Classification:
H04B 700
US Classification:
343100SA
Abstract:
According to the invention, a receive-transmit steerable null antenna prosor includes incrementally adjustable delay lines and a variable ratio power network (amplitude balance control) for adjusting the relative phase and amplitude in two or more antenna branches to steer a null on an interference source. A digital controller compares a signal which includes a representation of the interference level to a previously sampled value to note improvement or not and adjusts the delay lines and amplitude balance accordingly.
Adaptive Steerable Null Antenna Processor With Null Indicator
The United States of America as represented by the Secretary of the Army - Washington DC
International Classification:
G01S 502
US Classification:
342417
Abstract:
An adaptive antenna array system steers a plurality of antennas to direct e null toward an undesired source of interference to reduce noise and enhance detection of desired signals. A null indication processing system adjusts the phase and amplitude of the antenna branches to steer the null and provide a null angle indication and display. Digital controller and memory circuits provide automatic operation.
Eugene L. Roberts - Maitland FL Thomas J. Steffancin - Orlando FL
Assignee:
The United States of America as represented by the Secretary of the Army - Washington DC
International Classification:
H04B 700
US Classification:
343100LE
Abstract:
A system employing broadband radio frequency vector multipliers in a balang process for nulling out unwanted radio frequency signals. The nulling is achieved by adjustment of both the desired and interference signals as they pass through the system. The adjustment is accomplished by using vector multipliers which shift the phase by equal amounts and vary the amplitude by proportionate amounts of one or more radio frequency signals in response to separate phase shift and amplitude control forces. To obtain a desired phase shift, an incoming radio frequency signal is split into 0. degree. and 90. degree. components. By multiplying the 0. degree. component by the cosine of the desired phase shift angle, multiplying the 90. degree. component by the sine of the desired phase shift angle, and then summing the results, the signal can be phase shifted by any amounts through all four quadrants. The phase shift and amplitude control forces may be operator initiated or may be initiated through control processing to maximize the relative strength of the desired signal with respect to the interference signal.
Switched Delay Line For Steerable Null Antenna System
The United States of America as represented by the Secretary of the Army - Washington DC
International Classification:
H03K 514 H03K 1766
US Classification:
307603
Abstract:
The delay line has a number of sections in tandem. Each section comprises o line segments in parallel, one of which is relatively short and the other of a length to provide a given differential delay for the section. Each segment has a PIN diode at each end, poled in one direction for the short segment and in the other direction for the other. The bias arrangement for the PIN diodes includes four transistor switches in a bridge, with a selected pair in opposite legs turned on to cause a polarity which permits it to flow through only that segment in which the PIN diodes are forward biased. The given differential delay for the several sections has a binary relation.
Isbn (Books And Publications)
Problems in GABA Research, from Brain to Bacteria: Proceedings of an International Symposium on Recent Advances in GABA Study-GABA in Neural and Non-Neural Tissues, Hakone, Japan, July 15-18, 1981
Propranolol and Schizophrenia: Proceedings of a Conference Sponsored by the Kroc Foundation, Held December 1976, at Its Headquarters in the Santa Ynez Valley, California