A Ka-Band CMOS 4-Beam Phased-Array Receiver With Symmetrical Beam-Distribution Network
Na Peng, Peng Gu, Xiaohu You, Dixian Zhao
Abstract
This letter demonstrates a Ka-band 4-beam phased-array receiver in 65-nm CMOS. To generate four balanced beams from two inputs, a passive 4-beam symmetrical differential network is employed to achieve balanced signal distribution. With the use of passive vector-modulated phase shifter and switched-type attenuator, the receiver consumes a current of only 40 mA under 1-V supply voltage. The 4-beam receiver shows 3-dB gain per channel. From 27 to 31 GHz, the RMS gain error and phase error are .0.4 dB and .4°, respectively. Beam-to-beam couplings are investigated, and the measured beam-to-beam isolation is better than -32 dB from 27 to 31 GHz. The chip size is 2.6 × 4 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> with pads included. To author's knowledge, this letter reports the first CMOS phased-array receiver with four balanced beams.