Abstract: An RF transparent antenna shield structure is disclosed particularly useful for missile nose cone radome and other severe environment applications. The structure comprises a solid metal wall member perforated to form a triangular grid array of windows each of which has fitted within it a dielectric plug member the end faces of which are flush with the opposite surfaces of the metal wall member. The thickness of the wall member and the dielectric constant of these plug members are chosen such as provide a resonant radome thickness. The waveguide-space junction susceptances are tuned out by capacitive iris members concentrically disposed on the plug member end faces, to yield acceptable uniformity of insertion phase and attenuation even at relatively extreme incidence angles.

Abstract: A digital phase bit is provided for microwave operation, comprising a pair of FET switches and at least three transmission lines. The FETs when operated in a digital switching mode, present a small impedance when on and a high impedance when off. Each of two of the transmission lines exhibits a series inductive impedance over the operating frequency band and shunts a FET switch, two shunt combinations being interconnected by the third transmission line. When the switches are on, the signal path is effectively through the FET switch alone (and not branched) and a reference phase shift is produced. When the FET switches are off, a signal applied to the phase bit branches at each shunt combination. The inductive reactance of the transmission line and the capacitive reactance of the FET switch of each shunt combination then jointly produce a resonantly enhanced reactance over the band, causing a reflection and a maximum differential phase shift.

Abstract: Antenna arrays with more than one radiating element often require a calibration or adaptive technique to monitor the individual antenna currents and provide some form of correction. This invention is directed to a system of directional couplers and transmission lines usually placed between the transmitter and element matching network that develops a signal which is proportional to the actual antenna element radiating current. This includes mismatches and mutual impedance effects. A knowledge of the matching network is required. The system can be used in any guided transmission line system (i.e., waveguide, coax, stripline, microstrip, etc.

Abstract: Transmission line directional coupler directivity is improved by providing compensation for even and odd mode phase velocity differences. Teeth are added to the edges of the coupler electrodes remote from the coupling region separating the electrodes, so that the phase velocity of even mode and odd mode waves is made similar over a wide frequency band. The compensation approach is applicable to both suspended substrate and stripline type directional couplers, where the uncompensated odd mode velocity is less than the even mode velocity.

Abstract: Digital phase shifter bits of predetermined phase shift capability and lumped element network component fabrication arrangement are described. A variety of phase shifter bits including the capability of eleven and one-quarter, twenty-two and one-half, forty-five, ninety, and one hundred eighty degrees of phase shift are included. Also included are a number of high-pass/low-pass and switching transistor inclusive phase shifter bit arrangements. Both electrical schematic diagram and integrated circuit embodiments of the phase shifting networks are also disclosed.