FPGA implementation of a phased array DBF using a latch method

Abstract

Timing resolution plays significant role in generating digital phased array beams. In this paper we present a latch method for FPGA implementation of digital heamforming (DBF') for an ionospheric radar. The radar requires a constant phasing vector to steer the beam over a specified region of the ionosphere. Sixteen digital beams are derived from the vector with beam resolution of approximately three degrees. The phasing weights can be employed either in the time domain or in the frequency domain. Comparison of phase delay and time delay methods is presented for broadband frequencies of the radar. Performance of the proposed DBF system is presented including speed limitations.

Improving energy efficiency in massive MIMO: joint digital beam‐steering and tone‐reservation PAPR reduction

“…In this section, we introduce the issue of digital time‐domain beam‐steering with phase shifts (time delays) but constant amplitude. This strategy has been widely used in the recent past, mainly associated to beam‐steering in microwaves for radar applications [21, 22]. First, we show how the phase shift , where is the desired beam direction, is traduced into a delay in the discrete time domain for a given sampling frequency.…”