135GHz CMOS/LTCC MIMO Receiver Array Tile Modules

We report 135GHz MIMO receiver array tile modules. The module integrate four or eight RF channels on an LTCC carrier, each channel having a 22nm SOI CMOS IC for RF-baseband and a linear microstrip patch antenna array; DC, baseband IQ and LO reference signal connections are by printed circuit board connected to the LTCC carrier. Digital beamforming is demonstrated with the 8-element array, showing 12 degrees 3-dB beam width and 56 degrees angular steering range, and with the 4-element array, showing 12 degrees 3-dB beam width and 20 degrees angular steering range before the appearance of grating lobes. The 4-element arrays, in single-beam operation, shows -15.7 dB RMS error vector magnitude receiving 1.34Gb/s QPSK data, and shows -15.6dB error vector magnitude receiving 1.92Gb/s 16QAM data.