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Non-squinting wideband analog multi-beamformer is proposed using true time delay (TTD) element delay Vandermonde matrix (DVM). Efficient realization of the DVM is achieved by sparse factorization, which leads to low-complexity hardware implementations (i.e. less number of delay blocks). It is shown that the proposed approach saves 36 TTD elements in a 5-beam multi-beamformer (4-beams corresponding...
This paper introduces a new method for computing matrix exponential based on truncated Neumann series. The efficiency of the method is based on smart factorizations for evaluation of several Neumann series that can be done in parallel and divided across different processors with low communication overhead. A physical realization on FPGA is provided for proof-of-concept. The method is verified to be...
An intermediate frequency (IF) squinting-free multi-beamforming method is proposed for multi-antenna systems. The proposed approach uses a low-complexity factorization of a true-time-delay (TTD) multi-beam matrix, which is proposed to be realized using an analog integrated circuits approach. A TTD realization of multi-beams at intermediate frequency is achieved following amplification and synchronous...
The presented work explores novel methods for synthesizing approximately frequency independent array factors at lower hardware complexity for wideband beamforming applications. The proposed approach employs 2-D infinite impulse response (IIR) digital beam filters together with nested uniform linear arrays (ULAs). The array is designed to have multiple levels of nesting. Each level of nesting consists...
A delay-and-sum wideband beamforming architecture is proposed employing digital fractional delays realized via Thiran recursive all-pass filters. FIR filter based fractional delay approximation blocks that are used in standard delay-and-sum beamformers are replaced by Thiran all-pass fractional delay filters. Thiran filters — which are of IIR type — provide maximally flat group delay compared to other...
The synthesis of approximately frequency independent array factors at low hardware complexity using 2-D infinite impulse response (IIR) digital beam filters and nested uniform linear arrays is proposed. The array is designed to have multiple levels of nesting. Each level consists of a uniform linear array (ULA) covering a separate subband of the incident wideband signal. The use of nested arrays allows...
A current-mode CMOS design is proposed for realizing receive mode multi-beams in the analog domain using a novel DFT approximation. High-bandwidth CMOS RF transistors are employed in low-voltage current mirrors to achieve bandwidths exceeding 4 GHz with good beam fidelity. Current mirrors realize the coefficients of the considered DFT approximation, which take simple values in {0,±1,±2} only. This...
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