A Compact X-Band Bi-Directional Phased-Array T/R Chipset in 0.13 μm CMOS Technology

This paper presents an X-band bi-directional T/R chipset in 0.13 mu m CMOS. The T/R chipset consists of a bi-directional gain amplifier (BDGA), a 5-bit digital step attenuator with two BDGAs for compensating the switch losses, and a 6-bit phase shifter using DPDT switches. The phase and attenuation coverage is 360 degrees with the LSB of 5.625 degrees, and 31 dB with the LSB of 1 dB, respectively. The circuit has a reference state gain of > 3.5 db, and the return losses of > 11 db at 8.5-10.5 GHz. The T/R chipset has a phase shift accuracy with the RMS phase error of < 4.3 degrees, while the RMS amplitude error is < 0.8 db at 8.5-10.5 GHz. The attenuation accuracy is measured to be < 0.33 db, while the RMS phase error is < 7.4 degrees at 8.5-10.5 GHz. The output P1dB of the T/R chipset is > 6.5 dBm and the noise figure is < 7.5 db at 8.5-10 GHz. The chip size is 2.06 x 0.58 mm(2) including pads, and the DC power consumption is 154 mW only in the BDGAs. To authors' knowledge, this is the X-band CMOS T/R chipset with the competitive RF performance compared to other device technologies, which has the smallest size and the lowest power consumption to-date.