Multimode, multispectral antenna

Claim 1

A multimode detection arrangement for the detection of remote targets electromagnetically, comprising an active feed for transceiving electromagnetic radiation of a first selected radar spectrum bandwidth, said feed being effective for actively sourcing said radiation and receiving reflected portions of the actively sourced radiation, and refractive collimating lens means, having a collimating lens diameter, for directing and collimating radiation in said first selected radar spectrum bandwidth from said feed toward the region of said targets, wherein said arrangement further includes a detection means for detection of radiation from said targets at a second selected infrared spectrum bandwidth, said collimating lens being substantially transmissive to both of the spectrum bandwidths defining said forms of radiation; and wherein said arrangement includes a second refractive lens means disposed between said detection means and said collimating lens and substantially transmissive to radiation of said second selected infrared spectrum bandwidth and shaped and positioned to focus radiation in said second bandwidth on said detection means, and characterized in that: said collimating lens means is disposed on a lens axis and said active feed and said detection means are disposed along said lens axis at substantially the same position and displaced transversely from said lens axis by first and second predetermined amounts, respectively, whereby radiation focused by said collimating lens means or by said second refractive lens means into said active feed and said detection means makes corresponding first and second radiation angles with respect to said lens axis and at least one of said corresponding radiation angles is non-zero; said arrangement includes a mechanically rotatable dual-wedge optical beam steering means having a steering means diameter substantially equal to said collimating lens diameter and having first and second rotatable wedge prisms, centered on said lens axis and controllable, under stored program control, to direct radiation from a predetermined location having a predetermined polar and azimuthal angular orientation with respect to said lens axis, into one of said active feed and said detection means, said first and second rotatable wedge prisms being transmissive to radiation in both said first and second spectrum bandwidths and independently rotatable by mechanical rotation means about said lens axis, whereby said beam steering means may selectively steer radar radiation from a predetermined angular position into said active feed by assuming a first predetermined angular configuration dependent on said radar spectrum bandwidth and said predetermined angular position and may steer infrared radiation from said predetermined angular position into said detection means by assuming a second predetermined angular configuration dependent on said infrared spectrum bandwidth and said predetermined angular position, thereby obtaining information about an object at said predetermined angular position in both the infrared and radar spectral regions.