Miniaturized ultra-wideband multifunction antenna via multi-mode traveling-waves (TW)

摘要

A miniaturized ultra-wideband multifunction antenna comprising a conducting ground plane at the base, a plurality of concentric feed cables, one or more omnidirectional one-dimensional (1-D) normal-mode and two-dimensional (2-D) surface-mode traveling-wave (TW) radiators, frequency-selective internal and external couplers, and a unidirectional radiator on top, stacked and cascaded one on top of the other. Configured as a single structure, its unidirectional radiator and plurality of omnidirectional TW radiators can cover, respectively, most satellite and terrestrial communications, with unidirectional and omnidirectional radiation patterns, respectively, needed on various platforms. This new class of multifunction antenna is ultra-wideband, miniaturized and low-cost, thus attractive for applications on automobiles and other small platforms. As a multifunction antenna, a continuous bandwidth up to 1000:1 or more is reachable for terrestrial communications and a continuous bandwidth of 10:1 or more is feasible for satellite communications.

主权项

1. A multifunction antenna comprising:
a unidirectional radiator, a plurality of traveling-wave (TW) structures comprising stacked ultra wideband low-profile two-dimensional (2-D) surface-mode TW structures, wherein the surface-mode TW structure is excited in mode-0 and comprises a 2-D surface-mode TW radiator for omnidirectional radiation, a dual-mode feed network consisting of at least two separate feed networks, and a conducting ground plane; wherein the plurality of TW structures and feed networks being cascaded in a stack, with the appropriate frequency-selective coupler or decoupler between adjacent radiators; wherein the 2-D surface-mode TW structures being further configured to have a diameter less than λL/2and a thickness less than λL/10, where λL is the free-space wavelength at the lowest frequency of operation of the 2-D surface-mode TW structures; wherein the multi-mode feed network consisting of at least two separate feed networks, one for the unidirectional radiator and one for each mode-0 2-D TW structure; and wherein the conducting ground surface is of a canonical shape, the conducting ground surface further being positioned at a bottom side of the antenna, and having a surface area covering at least the projection of the antenna.