EP-4742451-A1 - A PHASED ARRAY EXCITED MULTI-MODE WAVEGUIDE WITH OMNIDIRECTIONAL COVERAGE AND BEAM STEERING

EP4742451A1EP 4742451 A1EP4742451 A1EP 4742451A1EP-4742451-A1

Abstract

An antenna for omnidirectional coverage and directional beam forming includes a multimode biconical waveguide with a first conical structure having a first base and a first apex, a second conical structure having a second base and a second apex, the first apex facing the second apex, and a radiation aperture. There is a coaxial interface between the first conical structure and the second conical structure that includes a coaxial waveguide to direct electromagnetic (EM) energy into the radiation aperture. An active electronic phased array (ASEA) included with the antenna controls independent sources of EM wave energy that excite multiple modes of the multimode biconical waveguide and provide omnidirectional radiation and directional beam steering.

Inventors

EDWARDS, RICHARD G.

Assignees

L3Harris Technologies, Inc.

Dates

Publication Date: 20260513
Application Date: 20251021

Claims (14)

An antenna for omnidirectional coverage and directional beam forming comprising: a multimode biconical waveguide including: a first conical structure having a first base and a first apex, a second conical structure having a second base and a second apex, the first apex facing the second apex, a radiation aperture, and a coaxial interface between the first conical structure and the second conical structure that includes a coaxial waveguide to direct electromagnetic (EM) energy into the radiation aperture, and an active electronic phased array (ASEA) configured to control independent sources of EM wave energy that excite multiple modes of the multimode biconical waveguide and provide omnidirectional radiation and directional beam steering.
The antenna in claim 1, wherein the omnidirectional coverage includes an omnidirectional antenna coverage pattern in azimuth with controllable gain near a horizon; and/or wherein the directional beam steering includes one or more radiation beams steerable in elevation; and/or wherein the ASEA is controllable to rapidly change radiation beams including nulling in some directions and focused in other directions; and/or wherein the multimode biconical waveguide includes a radiation cavity between facing surfaces of the first conical structure and the first conical structure that defines physical dimensions of the radiation aperture.
The antenna in claim 2, wherein the controllable gain near the horizon is in a range of about 0dB-20dB.
The antenna in claim 2, wherein the radiation cavity includes a dielectric having a relative permittivity in a range of about 1-5; and/or wherein the radiation cavity is a vacuum; and/or wherein the radiation cavity is at least partially filled with foam.
The antenna in claim 1, wherein the multimode biconical waveguide is a monolithic structure.
The antenna in claim 1, wherein the ASEA includes an array of radiating elements coupled to multiple modes in the coaxial waveguide.
The antenna in claim 6, wherein the array of radiating elements is formed within an area having a shape corresponding to a cross section of the coaxial waveguide.
The antenna in claim 6, wherein a number of radiating elements in the array of radiating elements includes a range of about 4 to 256 elements and are configured to excite a number of modes in a range of about 1 to 20 modes in the coaxial waveguide.
The antenna in claim 1, wherein the multiple modes of the multimode biconical waveguide include transverse electromagnetic (TEM), transverse electric (TE), and transverse magnetic (TM) modes.
A system comprising: an antenna for omnidirectional coverage and directional beam forming including a multimode biconical waveguide having a first conical structure having a first base and a first apex, a second conical structure having a second base and a second apex, the first apex facing the second apex, a radiation aperture, a coaxial interface between the first conical structure and the second conical structure that includes a coaxial waveguide to direct electromagnetic (EM) energy into the radiation aperture, and an active electronic phased array (ASEA) configured to control independent sources of EM wave energy that excite multiple modes of the multimode biconical waveguide; an amplitude and phase-shifting network configured to provide an amplitude control signal and a phase control signal to at least some of the independent sources of EM wave energy to generate a predetermined number of modes in the coaxial waveguide; and processing circuitry configured to generate input signals to the amplitude and phase-shifting network associated with a steerable radiation pattern such that the antenna provides omnidirectional radiation and directional beam steering.
The system in claim 10, wherein the omnidirectional coverage includes an omnidirectional antenna coverage pattern in azimuth with the processing circuitry configured to generate input signals to the amplitude and phase-shifting network to control a gain near a horizon.
The system in claim 11, wherein the gain near the horizon is in a range of about 0dB-20dB.
The system in claim 10, wherein the directional beam steering includes one or more radiation beams steerable in elevation.
The system in claim 10, wherein the processing circuitry is configured to generate input signals to the amplitude and phase-shifting network to control the ASEA to rapidly change radiation beams including nulling in some directions and focused in other directions.

Description

INTRODUCTION The inventor recognized that it is desirable to provide an antenna that offers both full azimuth omnidirectional coverage along with the ability to steer and form nulls and beams. SUMMARY Some example embodiments provide an antenna for omnidirectional coverage and directional beam forming. The antenna includes a multimode biconical waveguide including a first conical structure having a first base and a first apex, a second conical structure having a second base and a second apex, the first apex facing the second apex, and a radiation aperture. A coaxial interface between the first conical structure and the second conical structure includes a coaxial waveguide that directs electromagnetic (EM) energy into the radiation aperture. The antenna further includes an active electronic phased array (ASEA) configured to control independent sources of EM wave energy that excite multiple modes of the multimode biconical waveguide and provide omnidirectional radiation and directional beam steering. Example implementations may include one or more of the following features. The omnidirectional coverage of the antenna includes an omnidirectional antenna coverage pattern in azimuth with controllable gain near a horizon. The controllable gain near the horizon may be in a range of about [0 dB-20 dB] which depend on the final size of the aperture of the antenna. The directional beam steering includes one or more radiation beams steerable in elevation. The ASEA is controllable to rapidly change radiation beams including nulling in some directions and focused in other directions. The multimode biconical waveguide includes a radiation cavity between facing surfaces of the first conical structure and the first conical structure that defines physical dimensions of the radiation aperture. The radiation cavity may include a dielectric having a range of relative permittivity such as a range of about 1-5 that includes a relative permittivity of 1 where the radiation cavity is a vacuum. The radiation cavity may be partially or fully filled with foam. The multimode biconical waveguide may be a monolithic structure. In example implementations, the ASEA includes an array of radiating elements coupled to multiple modes in the coaxial waveguide. The array of radiating elements may be formed within an area having a shape corresponding to a cross section of the coaxial waveguide (although other shapes may be used). A number of radiating elements in the array of radiating elements may include a range of about 4 to 256 elements and may be configured to excite a number of modes in a range of about 1 to 20 modes in the coaxial waveguide. In one example embodiment, the array includes 56 elements and/or the number of modes is 8. The number of radiating elements and/or number of modes may vary. The multiple modes of the multimode biconical waveguide may include transverse electromagnetic (TEM), transverse electric (TE), and transverse magnetic (TM) modes. Some example embodiments provide a system that includes an antenna for omnidirectional coverage and directional beam forming including a multimode biconical waveguide having a first conical structure having a first base and a first apex, a second conical structure having a second base and a second apex, the first apex facing the second apex, a radiation aperture, a coaxial interface between the first conical structure and the second conical structure that includes a coaxial waveguide to direct electromagnetic (EM) energy into the radiation aperture, and an active electronic phased array (ASEA) configured to control independent sources of EM wave energy that excite multiple modes of the multimode biconical waveguide. The system also includes an amplitude and phase-shifting network configured to provide an amplitude control signal and a phase control signal to at least some of the independent sources of EM wave energy to generate a predetermined number of modes in the coaxial waveguide. The system also includes processing circuitry configured to generate input signals to the amplitude and phase-shifting network associated with a steerable radiation pattern such that the antenna provides omnidirectional radiation and directional beam steering. This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is intended neither to identify key features or essential features of the claimed subject matter, nor to be used to limit the scope of the claimed subject matter; rather, this Summary is intended to provide an overview of the subject matter described in this document. Accordingly, it will be appreciated that the above-described features are merely examples, and that other features, aspects, and advantages of the subject matter described herein will become apparent from the following Detailed Description, Figures, and Claims. BRIEF DESCRIPTION OF THE FIGURES These and other features and advantages will be better and