Silicon photonics-wireless interface ICs for micro-/millimeter-wave fiber-wireless networks

Abstract

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.

A Highly Linear Low-Noise Transimpedance Amplifier for Indoor Fiber-Wireless Remote Antenna Units

“…In this work, we present the first IFoF TIA with a linear in dB gain control that is able to extend the input dynamic range for which high linearity is achieved. It shows a better linear performance than RoF receivers, as our proposal achieves an EVM lower than 2% through a wider input dynamic range of 10 dB optical power, compared to the 3 and 5 dB ranges reported in [6] and [8], respectively. Another advantage of this design is the adaptability of its response to higher input capacitances by adjusting the transimpedance and open-loop gain.…”

“…Another advantage of this design is the adaptability of its response to higher input capacitances by adjusting the transimpedance and open-loop gain. This design is compatible with commercially available external PIN photodiodes, which can present a much higher junction capacitance, of the order of pF, compared to the greatly low 35 fF and 140 fF capacitances of the integrated PD presented in [8] and [9], respectively. As shown in Table 1, the TIAs aimed for IFoF achieve a much better FoM than those designed for RoF applications, mainly due to the higher transimpedance and the lower power consumption.…”

“…Therefore, the design of the TIA requires a low input impedance in order to compensate the high PD capacitance to exhibit a wide BW to amplify the incoming signal accordingly. Recent publications report the use of integrated avalanche photodiodes (APDs), which show very low junction capacitances [6,8]. However, these PDs are lacking in linear performance in comparison with PIN PDs.…”

“…These systems, however, require much higher linearity than BBoF to transmit the signal properly and they show distance limitations when transmitting several WLAN standards due to the high chromatic dispersion of the fiber at such frequencies [5]. Several attempts to design RAUs for RoF have been made in recent years with promising results and performance, transmitting RF at 2.5 GHz [6,7], 5 GHz [8], or 12 GHz [9]. However, RoF systems require high-speed circuit design and high-performance photonic devices, therefore increasing the power consumption and the overall cost of the DAS significantly.…”

Single Stage Low Noise Inductor-Less TIA for RF Over Fiber Communication

“…Apart from high-speed data transmission, siliconphotonics [6], [7] is also being explored for on-chip or chipto-chip or within an RF-over-fiber (RFoF) communication system [8]. This is due to the inherent properties of fiber such as low leakage, low interference and better signal VOLUME 4, 2016 confinement at very high frequencies with a small form factor.…”