Multi Channel Digital Equalization to Enable Wideband Digital Arrays
Abstract
In a digital beamforming system, equalization in the digital domain is utilized to help in calibration and reducing errors induced by the system processing chain. This is done by precisely matching amplitude and phase between elemental channels. Without this critical processing step, the desired beamforming (i.e., main beam and null) of next generation radar systems cannot be achieved. This paper addresses the problem of implementing equalization in real time to enable wideband digital arrays. Several equalization algorithms were evaluated and implemented to produce FIR coefficients including our polyphase based equalizer. To our knowledge this type of equalization implementation has not been utilized before in this way. These concepts were demonstrated on data collected from a benchtop four-channel RF system prototype. Additionally, a beamforming environment was created to show the importance of equalization in forming nulls and main lobes. A true-time delay (TTD) FIR filter was combined with the chosen minimum mean-square-error (MMSE) equalization FIR filter followed by a wideband adaptive digital beamforming (ADBF) FIR filter to display results.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 25, 2019
- Accession Number
- AD1076122
Entities
People
- Austin Saunders
- Mark Yeary
Organizations
- University of Oklahoma