No abstract

Nonlinearity in the electrical-to-optical conversion limits the dynamic range for transmitting analog and multilevel signals over fiber-optic channels. We describe a complementary metal-oxide-semiconductor (CMOS) predistortion linearizer that extends the dynamic range of both direct and externally modulated links. The linearizer achieves 13-24-dB suppression for both second-and third-order distortions.

and yields a good SNR in the cyc measurements of milliwatt signals with 25 fl sampling pulses (4 pW average power). This small power requirement allows a simpler sampling setup. Finally, thc optical bandwidth of the sampling setup is 350 GHr.

A digitally-controlled switched-capacitor RF power amplifier (SCPA) that uses a dual-supply voltage, class-G architecture is implemented in 65nm CMOS. It implements signal envelope digital-to-analog conversion using switching functions controlled by digital logic to achieve superior efficiency and linearity at output power backoff. The SCPA delivers a peak (average) output power of 24.3 (16.8) dBm with a peak (average) PAE of 44% (33%) for an IEEE 802.11g signal (64 QAM OFDM) with a measured EVM of 2.9 % in the 2.4 GHz band. No digital predistortion was necessary because of the superior linearity.