A 127mW SAW-less LTE transmitter with LC-load bootstrapped quadrature voltage modulator in 130nm RFCMOS

摘要

In this paper, using relative low cost 130nm RFCMOS, a high linearity, SAW-less, LTE transmitter with quadrature passive voltage mixer driven by bootstrapped 25% duty-cycle LO is presented. A tunable LC tank is added between mixer and Pre-PA amplifier (PPA). As the result, requirement on linearity of reconstruction lowpass filter (LPF), mixer and PPA are reduced. The linearity of mixer is further improved by programmable bootstrap voltages. Sideband leakage and LO Feedthrough (LOFT) can be calibrated by these bootstrap voltages. 54dB of total 84dB gain dynamic range is implemented in PPA by using binary gm cells and C-2C voltage division. 25% duty-cycle LO is generated with IQ-AND gating scheme. Delivering +1.3dBm power at 2.5GHz carrier, the transmitter achieves −46.5dB adjacent ACLR, −60.5dB LO leakage and −35.3dB sideband leakage, while consuming 127mW. The out-of-band noise is −156.2dBc/Hz at 120 MHz offset and the measured EVM is 2.4%.