William Ernest Engeler

Parallel architectures for multirate superresolution spectrum analyzers

The authors develop parallel architectures for implementing matrix-based superresolution spectral estimation algorithms for situations that required high levels of resolution commensurate with large coherent apertures and large sample orders. The featured architectures couple matrix-based superresolution algorithms together with a front-end multirate decimation processor. This procedure creates parallel pseudo-apertures corresponding to different subbands of the temporal (or spatial) frequency spectrum. The overall superresolution of the large aperture is maintained. Simulations applying the large array architectures to the Tufts-Kumaresan reduced-rank modified covariance algorithm and the linear-minimum-free-energy/regularized form of the modified covariance algorithm are given for 1024-element coherent apertures. >

High frequency MOS digital capacitor

A MOS digital capacitor capable of operation at VHF and UHF frequencies is described. This new device is made up of a parallel combination of MOS capacitors on a single chip each of which can be individually switched and statically maintained at two distinct RF capacitance values, the maximum binary state being the high frequency MOS inversion capacity and the minimum being that of a deep depletion MOS device. Switching is accomplished by on chip MOSFETs.

Parallel Multirate Preprocessors for Large Aperture Superresolution Systems

This work develops parallel architectures for implementing matrix based superresolution spectral estimation algori thm for situations that require high levels of resolution commensurate with large coherent apertures and large sample orders. The featured architectures couple matrix based superresolution algorithm together with front-end multirate decimation preprocessor. This procedure creates parallel pseudo apertures corresponding to different subbands of the temporal (or spatial) frequency spectrum. The overall superresolution of the large aperture is maintained. Single snapshot simulations are presented featuring the TuftsKumaresan reduced rank modified covariance algorithm, the Linear Minimum Free Energy/regularized form of the modified covariance algorithm, and the MUSIC algorit,hm using a spatially smoothed form of the covariance matrix.