Initial demonstration of an X-band digital beamforming (DBF) receive array

This paper presents the architecture and initial measured performance of an X-band digital beamforming (DBF) plug-and-play receive array. This processor was designed to steer four independent simultaneous beams over the entire X-band with 32 independent channels, an instantaneous bandwidth of 15 MHz, and a spur-free dynamic range of at least 65 dB. Designed using commercial-off-the-shelf (COTS) components, we achieved a vast decrease in size of the DBF processor. When compared to previous DBF systems, the system's ease in mobility and measurement accuracy greatly increases DBF's applicability towards smaller airborne platforms. Using AFRL-SNHA's in house facilities, we have begun to measure and test the plug-and-play processor's current capabilities. These measured capabilities include not only the ability to form multi-beam, uniformly illuminated broadside and scanned array patterns, but also its ability to reduce the array sidelobes, using tapered illuminations. Measurements to date have been taken using only 8 to 12 channels, but work is currently underway to utilize the processor's mil capacity. However, these initial measurements and results demonstrate that this DBF processor exhibits exceptional array processing capabilities, while possessing an overall small system footprint.