An Area-Efficient 21- to 23-GHz Analog Beamformer With Pseudo-Distributed Amplifier Architecture

This article presents an area and power-efficient pseudo-distributed amplifier (Pseudo-DA) beamforming architecture capable of supporting two simultaneous beams. The proposed receiving beamformer is constructed by removing the input transmission line of a distributed amplifier (DA) to directly connect the gain cells to the antenna elements of a phased array and utilizing tunable artificial transmission line (Tunable-ATL) cells of DA’s output transmission line for creating the required progressive phase shifts. Using both ends of the output transmission line, two simultaneous beams can be obtained. The first beam can be steered independently while the other one is formed as an image of the first one. In this article, the theory of operation and the design methodology of the proposed beamformer are presented. In addition, to verify the efficacy of the proposed solution a
$K$
-band four-element prototype is fabricated in a standard 65-nm complementary metal–oxide–semiconductor (CMOS) technology, and the measurement results are reported. The fabricated beamformer provides 110° beam steering over a 21–23 GHz frequency range. The measured gain, noise figure, and 1 dB compression point (P1dB) are 18 dB, 5.1 dB, and −18.5 dBm, respectively, with 90-mW dc power consumption and a chip area of
$2.05 \text {mm}^{2}$
.