## 3 Current Status of the Circuit Component in the MMW Regime
### Recent Works of SoC in MMW Regime
#### CMOS MMW Transceivers  
CMOS technologies are popular in implementing MMW ICs for various applications owing to their high-level integration with the baseband circuitry. This contributes to the prosperity of the research in CMOS MMW circuit designs. As a result, in recent years, MMW transmitters and receivers are reported in CMOS technologies including multi-port transceiver [199], direct-conversion transceiver [191, 200], Doppler radar transceiver [201, 202, 203], phased-array transceiver [204, 205] and differential transceiver [166]. The earliest 60 GHz CMOS transceiver for gigabit software-defined transceivers was demonstratedusing 0.13-\(\upmu\)m bulk CMOS technology in [199]. It has a 5 dB conversion gain and measured EVM of the BPSK signal is lower than 4% with an input power of \(-\)30 dBm. Based on 90 nm CMOS technology, an integrated, energy-efficient 60 GHz transceiver was implemented including baseband circuitry [191], it has a BER of \(<\)10\({}^{-11}\) was measured up to 6 Gb/s in QPSK mode. Wireless testing was also performed using 25 dBi horn antennas over 1 m distance, and the measured BER at 4 Gb/s is \(<\)10\({}^{-11}\). In [163], the 130 nm CMOS 280 GHz imager is reported with a measured NEP of 29 and a responsivity of 5.1 kV/W. LNAs and passive pixels are put outside. The fully integrated array incorporates with the pixels increases 20% NEP. With the backend process, the 130 nm CMOS 860 GHz single sideband detector has a measured NEP of 42 \(\mathrm{pW/Hz^{1/2}}\) by reducing the number of unit cells in the diode and using the efficiency improvement of patch antenna with frequency. In [201], the 90 nm direct-conversion transceiver has been implemented. The transmitter has an output power of 3.3 to 6.3 dBm in the frequency range from 73.5 to 77.1 GHz. The conversion gain of the receiver is \(2\pm 1.5\) dB in the RF input range from 76 to 77 GHz, and the output power at the 1 dB compression point is \(-\)17 dBm. In [203], a 90 nm CMOS V-band transceiver for sensing the vital signals was reported. It demonstrates the first-pass success of human vital-sign detection at 0.3 m. The small mechanical vibration with a displacement of 0.2 mm can be detected up to 2 m away. A 90 nm CMOS 60 GHz direct-conversion transceiver was reported [200]. In this work, the transceiver was implemented with both 90 nm and 40 nm CMOS technologies. The transmitter has a EIRP of \(+\)8.5 dBm and EVM of \(-\)22 dB. The carrier and image leakages are \(-\)39 dBc and \(-\)37.7 dBc, respectively. After the DC/IQ calibration, the transmitter provides more than 14 dB improvement. The receiver has a wide dynamic range of 53 dB (\(-\)78--25 dBm) with a noise figure of 7.1 dB at its peak gain. This chipset has the MAC throughput of 1.8 Gb/s for up to 40 cm and 1.5 Gb/s for up to 1 m. It also shows the capability for 60 GHz mobile applications. Regarding 65 nm CMOS technologies, some MMW transceivers has been implemented. For instances, in [205], a 65 nm CMOS 4-element phased array was reported. The measured peak output power of the transmitter is \(-\)5 dBm whereas the conversion gain of the receiver is 20 dB. In [204], a phased array transceiver was proposed. A 200 m detection with angular resolution below 2\({}^{\circ}\) and 60 m detection with FoV of \(\pm\)45\({}^{\circ}\) within one cycle time of 46 ms multi-slope FMCW waveform is designed and implemented. Figure 18 illustrates the system block diagram of the transceiver. It is composed of eight channel I/Q receivers and one channel transmitter with frequency generation/power divider block. The transceiver is implemented in 65 nm CMOS technology and the patch antenna array is implemented on LTCC substrate. The chip size of single channel and two transmitters are 1.8 \(\times\) 2.0 mm\({}^{2}\), 1.9 \(\times\) 0.93 mm\({}^{2}\) and 0.8 \(\times\) 0.6 mm\({}^{2}\), respectively. The LNA has a measured gain of 20.1 dB and NF of 8.7 dB (sim.) at 77 GHz and conversion gain of I/Q receiver is 22 dB with 134 mW power consumption.