We present two types of Si photonics-wireless interface (PWI) integrated circuits (ICs) realized in standard Si technology. Our PWI ICs convert optical signals into radio-frequency (RF) signals for downlink remote antenna units in fiber-wireless networks. Characterization and modeling of Si avalanche photodetectors (APDs) fabricated in two different Si technologies are carried out and used for PWI IC design. A 5-GHz RF-over-fiber PWI IC composed of APD, preamplifier, and power amplifier (PA) is fabricated in 0.18-μm CMOS technology and its performance is verified by 54-Mb/s wireless local area network data transmission. A 60-GHz baseband-over-fiber PWI IC containing APD, baseband photoreceiver, 60-GHz binary phase-shift keying (BPSK) modulator, and 60-GHz PA is realized in 0.25-μm SiGe BiCMOS technology. Error-free transmission of 1.6-Gb/s BPSK data in 60 GHz with this PWI IC is successfully achieved.