Development of large format, far infrared focal-plane arrays has been identified as a pressing need for future astronomical instruments. In particular, array sizes as large as 128x128 with sensitivities equal to or better than 10 -18 W/ Hz are the goals to be achieved within the next fifteen years. As part of our continuing effort to further this technology, we are developing a 32x32 Ge:Sb photoconductor FPA with a CTIA cryogenic readout multiplexer. A new, layered-hybrid architecture is employed to block the readout glow, improve heat dissipation and temperature uniformity across the array, and alleviate the potential problems associated with the large CTE mismatch between the Ge detector and the Si readout. This is the first 1k-pixel photoconductor FPA of its kind and is meant to be a pathfinder for future large format FPAs. Based on the test results of a prototype 2x16 Ge:Sb array of similar design, we expect the sensitivity of this FPA to be as low as 10 -18 W/ Hz. This paper presents the design, characteristics, and the expected performance of this array.Recent studies of technology needs for future NASA astronomical missions have highlighted the serious lack of capability to fabricate large format focal-plane arrays (FPAs) for the scientifically rich but relatively unexplored far IR and submillimeter region (40-1000 m) [1][2][3]. This important technology has not benefited from the latest advances in FPA development for near and mid-IR primarily because of the absence of commercial and defense drivers. The need for large format far IR FPAs has further been echoed in the specific assessments of SAFIR (Single Aperture Far Infrared Observatory) [4-6] and its subsequent design concept CALISTO (Cryogenic Aperture Large Infrared Space Telescope Observatory) [7,8]. SAFIR/CALISTO is conceptualized as a 10m cold-aperture far IR/sub-mm observatory requiring FPAs larger than 128x128 with sensitivities better than 10 -19 W/ Hz. In addition, such far IR FPAs will be of critical importance to advanced instrumentation for SOFIA (Stratospheric Observatory for Infrared Astronomy) -due to start its observing flights in 2009 -and SPICA (SPace Infrared Telescope for Cosmology and Astrophysics) -a Japanese 3.5m space telescope covering the 5-200 m wavelength range [9].Given this technology need, we have been making incremental progress in fabricating large format photodetector FPAs with the ultimate goal of developing the capability similar to that which currently exists for shorter wavelength IR arrays. The path to establishing such capability is not straightforward since practically all the principal components of such an FPA need to be developed and, due to significant differences between short and long wavelength photodetector materials, the technology for short wavelength FPAs cannot be extended routinely.Our effort has leveraged the rich heritage of the developmental work in this area, in particular the work of Erick Young et al. which culminated in construction of the Ge:Ga FPAs for Spitzer's MIPS instrument [10][11][12]...