CMOS-based Bi-directional T/R chipsets for phased array antenna

This paper presents the bi-directional CMOS-based T/R circuits. X-band bi-directional gain amplifier shows the gain of > 12 dB and the reverse isolation of > 35 dB at 8–12 GHz. X-band 5-bit phase shifter shows the insertion loss of < 17 dB, the RMS phase error of < 2.6°, and the RMS amplitude error of < 0.5 dB at 8–12 GHz. For wideband applications, true time delay circuit is developed to enable a time delay up to 198 ps with the LSB of 1.6 ps. The insertion loss of < 40 dB is achieved at 8–15 GHz. To compensate the losses of the TTD, the distributed bi-directional gain amplifier shows the gain of > 8.5 dB and the P1dB of 7 dBm at 8–15 GHz. The 6-bit digital step attenuator with the maximum attenuation of 31 dB shows the insertion loss of < 13 dB, the RMS phase error of < 3.5°, and the amplitude error of < 0.8 dB at DC-15 GHz.