Rca Inc.

David F Bowman

Bruce F Bogner

The configuration of a waveguide antenna feed is determined by a shaped body of solid dielectric material which is coated with a conductive material. The conductive material functions as a waveguide wall for constraining electromagnetic wave propagation within the dielectric body. The body includes a mode converter and a coupler to a lead-in structure. A polarization converter, if desired, can be integral with the dielectric body.

Antenna feed with mode conversion and polarization conversion means

A one-piece array antenna dipole radiating element is formed from a wide, thin conductor. This element is suitable for attachment to a microstrip or other feed circuit. The radiation element includes a dipole portion, a balanced transmission line portion and a balun portion. These various portions are formed by providing an appropriately shaped slot in the thin conductor.

Dipole radiating element

A mode converter is disclosed which selectively generates a predetermined higher order mode(s) from an incident fundamental mode. This mode converter comprises a dielectric region having an effective-dielectric-constant/thickness profile which is the same as the amplitude profile of the desired higher order mode(s).

Selective waveguide mode converter

A three-horn microwave feed produces a near ideal aperture width ratio of 2:1 for the difference and sum modes of aperture illumination. Three horns are utilized, each of which supports propagation of at least two modes. Sum and difference components are present in all three horns in response to signals applied to both sum and difference ports of the feed and sum illumination components are present in all three horns in response to signals applied to only the sum port of the feed.

Three horn E-plane monopulse feed

A power distribution network is disclosed for use in a frequency scan antenna element. A microwave signal applied to the input of the network is power divided and phase shifted so as to provide, at a plurality of output ports, signals of equal amplitude and, at a design frequency, phase equality. The signals appearing at the output ports are phase delayed relative to the signals at adjacent outputs such that an input signal frequency other than the design frequency presents a wave front across the output ports angled away from the normal to the output ports. The present invention discloses a series-parallel configuration of the power distribution network which provides improvements over both the pure-series and the pure-parallel configurations of the prior art.

Circuit for frequency scan antenna element

A transmission line hybrid junction which provides a power dividing and combining function between a first port and a pair of ports. In one embodiment it provides a well-matched, high-isolation, three-port, equal-power, equal-phase, power dividing junction with a bandwidth adequate for typical radio frequency applications. The hybrid junction comprises a single transmission line coupled to a pair of branch transmission lines, and a single resistive element coupled between the branch lines. The single transmission line comprises a quarter wavelength transforming section and each of the branch transmission lines comprises two cascaded quarter wavelength transforming sections. Coupling between two transforming sections of the branch transmission lines permits independent selection of the characteristic impedance of those sections in the odd and even modes of excitation.

Transmission line hybrid junction

A reflectarray antenna includes a primary feed that radiates a primary wave to a plurality of radiators where the wave is absorbed. A portion of the absorbed wave is resolved into first and second mutually orthogonal components at first and second feed ports, respectively, of a radiator. The first component is transmitted with a designated phase shift via a transmission phase shifter to the second feed port. Correspondingly, the second component is transmitted with the designated phase shift via the phase shifter to the first feed port. After the components are transmitted to the feed ports, they are re-radiated by the radiator in polarization states orthogonal to the ones in which they were absorbed.

Reflectarray antenna

A ridged rectangular launching waveguide and a ridged rectangular radiating waveguide have a common length-wise wall comprised of wall segments. A wave launched at the proximal end of the launching waveguide is coupled to the radiating waveguide through passageways between the segments. A cylindrical metal rod extends through a segment to the wavepaths of the waveguides. Additionally, the ridges of the waveguides have similar notches near the rod, the rod and the notches forming similar attenuators in the wavepaths. The passageways result in a formation of a pair of three-db, ninety-degree hybrids connected back-to-back through the attenuators. The hybrids and the attenuators couple a predetermined percentage of the energy of the wave to a radiating slot in a panel at the distal end of the radiating waveguide. The remainder of the wave energy is reflected by the attenuators and coupled by the hybrids through the radiating waveguide towards the proximal end thereof.

Frequency-scanned antenna

A pair of conductive circular plates are positioned in a parallel spaced relationship. A conductive ring-like band extending about the periphery of the plates forms an enclosed parallel plate transmission line. A coupling member is located at the center of this enclosed transmission line. A plurality of peripheral coupling members to the transmission line are spaced radially from and in a ring-like pattern about the center coupling member. A plurality of radio frequency (RF) power absorption members are coupled to the transmission line at the regions between the peripheral coupling members to reduce radio frequency signal coupling between the peripheral coupling members.

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Moorestown, NJ, United States of America

David F Bowman