Millimeter-Wave Quadrature Mixed-Mode Transmitter With Distributed Parasitic Canceling and LO Leakage Self-Suppression

In this article, a 2
$\times $
9-bit millimeter-wave quadrature mixed-mode transmitter (TX) with distributed parasitic canceling and LO leakage self-suppression is proposed. The mixed-mode architecture uses both digital switched capacitor power amplifier (SCPA) and analog amplifier to achieve high output power and enhanced peak/average efficiency at millimeter-wave. In addition, the distributed parasitic canceling with 3-D shielded horizontal capacitor (3-D SHCAP) is adopted to decrease the passive loss for improved efficiency. Besides, the LO leakage self-suppression is introduced, which benefits to linearity and dynamic range. The proposed quadrature mixed-mode TX is implemented and fabricated in the 40-nm CMOS technology. With 1.1/2.2-V supply, it achieves saturated output power of 24.03 dBm with peak system efficiency (SE) of 31.5% at 24 GHz. It also exhibits 23.6% SE for 6-dB PBO at 24 GHz due to Doherty operation. It supports 400-MHz 64QAM signal with an average output power (i.e.,
$P_{\mathrm{ avg}}$
) of 16.37 dBm, an EVM of −29.6 dB, and an ACLR
$\leqslant \,\,-$
29.98 dBc. For 200-MHz 256QAM, it exhibits 15.21 dBm
$P_{\mathrm{ avg}}$
with an EVM of −30.9 dB and an ACLR
$\leqslant \,\,-$
31.71 dBc at 24 GHz.