622-Mb/s Bidirectional SFP Optical Transceiver Using an Integrated WDM Optical Subassembly

The 1.3/1.55-mum bidirectional small form pluggable (SFP) optical transceiver with an integrated wavelength division multiplexing (WDM) subassembly using accurate ceramic blocks has been developed. The WDM subassembly on which a laser diode, a receiver photodiode, a WDM filter, and two microlenses are integrated is only 2.0 times 2.1 times 0.6 mm³ in size and inserted in a TO-CAN package. The SFP transceiver coupled with single-mode fiber has been operated at a 622-Mb/s data rate. The transmitted optical output power is -2.8 dBm and the measured value of sensitivity is -32 dBm at 10^-10 bit-error rate.     

An Energy-Efficient OOK Transceiver for Wireless Sensor Networks

A 1-Mb/s 916.5-MHz on-off keying (OOK) transceiver for short-range wireless sensor networks has been designed in a 0.18-mum CMOS process. The receiver has an envelope detection based architecture with a highly scalable RF front-end. Untuned RF circuits are leveraged and optimized in the receiver to achieve superior energy efficiency compared to tuned RF circuits. The receiver power consumption scales from 0.5 mW to 2.6 mW, with an associated sensitivity of -37 dBm to -65 dBm at a BER of 10 ^-3. The transmitter consumes 3.8 mW to 9.1 mW with output power from -11.4 dBm to -2.2 dBm. The receiver achieves a startup time of 2.5 mus, allowing for efficient duty cycling     

High-speed, burst-mode, packet-capable optical receiver andinstantaneous clock recovery for optical bus operation

This paper describes an enhanced performance version of a high-speed burst-mode compatible optical receiver and its application to 622-Mb/s optical bus operation in conjunction with an instantaneous clock recovery scheme. The receiver is fabricated in a 12 GHz f_t silicon bipolar technology and consists of a differential transimpedance amplifier with an auto-threshold level controller and a high-speed quantizer. Using an InGaAs avalanche photodiode, the typical burst mode sensitivity is around -34 dBm (10^-9 BER) at bit rates up to 1.5 Gb/s with a dynamic range of 26 db for both pseudorandom and burst signals. The results using a laser beam modulated by a high-speed external modulator indicate that the receiver can be operated at bit rates higher than 2 Gb/s. With a worst-case self-resetting time <50 ns for the threshold control circuit, the receiver is usable for optical packet communication where data signals with varying optical power are employed. This receiver was demonstrated in a 622-Mb/s optical bus application where the clock signal was recovered from the packet data signal using a novel high-speed CMOS instantaneous clock recovery IC     

A 1 V Wireless Transceiver for an Ultra-Low-Power SoC for Biotelemetry Applications

This paper presents a 1 V RF transceiver for biotelemetry and wireless body sensor network (WBSN) applications, realized as part of an ultra low power system-on-chip (SoC), the Sensiumtrade. The transceiver utilizes FSK/GFSK modulation at a data rate of 50 kbit/s to provide wireless connectivity between target sensor nodes and a central base-station node in a single-hop star network topology operating in the 862-870 MHz European short-range-device (SRD) and the 902-928 MHz North American Industrial, Scientific & Medical (ISM) frequency bands. Controlled by a proprietary media access controller (MAC) which is hardware implemented on chip, the transceiver operates half-duplex, achieving -102 dBm receiver input sensitivity (for 1E-3 raw bit error rate) and up to -7 dBm transmitter output power through a single antenna port. It consumes 2.1 mA during receive and up to 2.6 mA during transmit from a 0.9 to 1.5 V supply. It is fabricated in a 0.13 mum CMOS technology and occupies 7 mm² in a SoC die size of 4 times 4 mm².     

A Low-Power Fullband 802.11a/b/g WLAN Transceiver With On-Chip PA

A low-power fullband 802.11a/b/g WLAN transceiver in 0.15-mum CMOS technology is described. The zero-IF transceiver achieves a receiver noise figure of 4.4/4 dB for the 2.4-GHz/5-GHz bands, respectively. The corresponding sensitivity at 54-Mb/s operation is -72 dBm for 802.11g and -74 dBm for 802.11a using actual PER measurement. An on-chip PA delivers 20 dBm output P1-dB. A new I/Q compensation scheme is implemented in local oscillator (LO) and an image rejection of better than 52 dB is observed. The transmitter delivers 10/1.5 dBm (2.4-/5-GHz) EVM-compliant output power for a 64-QAM OFDM signal at 54-Mb/s. The power consumption is 117/135 mW (1.8-V) in the receive mode and 570/233.1 mW in the transmit mode for 2.4/5 GHz, respectively. The low power consumption, high integration and robustness (-40 to 140degC) make this transceiver suitable for portable applications     

Differential precoder IC modules for 20-and 40-Gbit/s opticalduobinary transmission systems

This paper reports on 20- and 40-Gbit/s differential precoder modules for optical duobinary transmission systems. These precoder modules overcome the speed limit of a conventional precoder by parallel processing. The proposed precoders handle two or four parallel signals before multiplexing with data rates of one-half or one-quarter the transmission bit rate, and the final preceded signal is obtained by multiplexing the precoder output bit by bit, production-level 0.2-μm gate-length GaAs MESFET's were used to fabricate the precoders. The precoders are mounted in an RF package. They successfully performed 20- and 40-Gbit/s precoding for the first time, and the 20-Gbit/s precoder achieved a maximum precoding rate of 22 Gbit/s, which is 76% faster than that of the conventional circuit using the same MESFETs. The 40-Gbit/s precoder performs 40-Gbit/s precoding when combined with a 40-Gbit/s multiplexer unit. Twenty-Gbit/s optical duobinary transmitter and receiver circuits using the 20-Gbit/s precoder module successfully generate fully encoded optical duobinary signal at this rate for the first time. These circuits show a receiver sensitivity of -28.6 dBm for a bit error rate of 1×10^-9     

A 1.7 Gb/s ASK and a 622 Mb/s incoherent FSK transmissionexperiment using a 1.55-μm multiquantum well distributed feedbacklaser

A multiple-quantum-well distributed-feedback (MQW-DFB) laser with narrow linewidth and low frequency chirp at low output power may experience linewidth rebroadening at high output power. the rebroadening is mostly due to a large carrier-induced change of refractive index, which also causes a large frequency modulation response for the MQW-DFB lasers. Using a 1.55-μm MQW-DFB laser, a 622-Mb/s amplitude-shift-keying (ASK) transmission experiment employing 200-km of fiber and an erbium-doped fiber amplifier has been demonstrated having a dispersion power penalty less than 9.8 dB. The receiver sensitivities at BER=10^-9 of the ASK system are -34.5 dBm and -42.5 dBm for 1.7-Gb/s and 622-Mb/s modulation, respectively. A 622-Mb/s incoherent frequency-shift-keying (FSK) transmission experiment using the same laser has also achieved a receiver sensitivity of -42.5 dBm     

High-performance compact optical WDM transceiver module for passivedouble star subscriber systems

High-performance transceiver-type optical WDM interface modules with a volume of only 36 cc have been developed for PDS subscriber systems. The new module comprises an optical WDM sub-module, hybrid-integrated transmitter and receiver circuits. In the WDM sub-module, a planar lightwave circuit chip was hermetically sealed together with laser and photodiode chips in order to minimize the size of the transceiver module. The lightwave circuit was formed on an optical-waveguide chip by adopting a high-silica based optical-waveguide technology. The circuit has a 3-dB directional coupler for bi-directional transmission with a 1.3-μm wavelength through a single fiber and a wavelength division multiplexer between both 1.3-μm and 1.55-μm wavelengths. The overall characteristics of the fabricated WDM sub-module achieved were a responsitivity of 0.25±0.05 A/W, an insertion loss approximately 3 dB at 1.55 μm and an isolation of 35 dB between both wavelengths. Optical output power of the fabricated transceiver module was -3.8 dBm. Also, receiver sensitivity of less than -35 dBm with an overload of over -14 dBm were obtained by introducing high-speed automatic gain and threshold control techniques. Thus, an allowable span loss of over 30 dB and an optical dynamic range of over 20 dB were attained. The preamble bit length required to reach stable receiver operation was confirmed to be within three bits     

The STARNET coherent WDM computer communication network:experimental transceiver employing a novel modulation format

We have designed, constructed, and investigated an experimental transceiver employing a novel combined PSK and ASK modulation format for the STARNET coherent WDM computer communication network. Using this experimental transceiver, we show that it is possible to transmit and receive 2.488 Gb/s PSK circuit-switched data and 125 Mb/s ASK packet-switched data on the same lightwave. The experimental transceiver employs a custom integrated-optic LiNbO₃ modulator with both phase and amplitude sections, a 2.488 Gb/s tunable PSK heterodyne receiver, and a 125 Mb/s ASK heterodyne receiver. Both receivers function properly with error rates less than 10^-9 and a sensitivity of -32.1 dBm; the corresponding optimum ASK modulation depth is 0.57. The resulting network power budget is 26.6 dB     

High-sensitivity and wide-dynamic-range 10 Gbit/s APD/preamplifieroptical receiver module

InAlAs avalanche photodiodes (APD) and SiGe-HBT preamplifier 10 Gbit/s optical receiver modules have been developed. The measured back-to-back minimum sensitivity and the optical overload with a pseudorandom binary sequence of 2³¹ - 1 at a bit error rate of 10^-9 are -29.5 and +0.4 dBm, respectively. The dynamic range is 29.9 dB. These results show the highest sensitivity and the widest dynamic range yet reported for 10 Gbit/s APD receivers     

Multigigabit multichannel optical interconnection module forbroadband switching system

This paper describes optical transmitter and receiver modules for package-to-package interconnection in broadband switching networks such as an asynchronous transfer mode switch fabric. These modules, which include the multiplexer and demultiplexer, can reduce the number of connections and the problem of skew between links. Five-channel optical transmitter and receiver modules were fabricated and demonstrated at 2.8 Gbit/s with a power dissipation of 4.5 W per channel. Moreover, temperature-insensitive optical interconnection was successfully demonstrated by driving a laser with a constant bias current over the threshold and by deducting the optical signal offset. The output power of the transmitter module was -4.2 dBm. Nonuniformity of the transmitter output powers across the range of optical channels was <2.1 dB. Receiver sensitivity for a bit error rate of 10^-11 was -9.3 dBm. Nonuniformity of the receiver sensitivities was <1.5 dB. The power penalty of the receiver sensitivity due to crosstalk was 1 dB. The connection distance was >250 m     

560 Mb/s optical PSK synchronous heterodyne experiment

A phase-locked optical heterodyne receiver constructed using a 1320-nm diode-pumped miniature Nd:YAG ring laser is discussed. Using this receiver and a transmitter based on another Nd:YAG laser, a 560-Mb/s phase-shift keying (PSK) synchronous heterodyne transmission was demonstrated over 78 km of single-mode fiber. With an optical phase-locked loop (PLL) natural frequency of 32 kHz and a damping factor of 1.46, the receiver sensitivity, measured at the output of the transmission link, was -48.7 dBm, or 159 photons/b. The corresponding detected sensitivity, measured on the surface of the p-i-n diode, was -51.8 dBm or 78 photons/b. This result suggests that the receiver sensitivity would have been about 82 photons/b if a balanced receiver with 0.2-dB excess coupler loss had been used. The impact of the finite intermediate frequency (IF) on heterodyne system performance was investigated; it was found that an IF of at least twice the bit rate is needed for a negligibly small penalty     

High-sensitivity FSK signal detection with an erbium-doped fiberpreamplifier and Fabry-Perot etalon demodulation

A report is presented on a 622-Mb/s optical transmission system with demodulation of alternate mark invert (AMI) encoded frequency shift keying (FSK) signals by a Fabry-Perot etalon. A 25-dB gain erbium-doped fiber preamplifier gave a receiver sensitivity of -40 dBm at 10^-9 BER, which was improved to -44 dBm with the addition of a narrowband optical filter. The theoretical sensitivity of the preamplified receiver and the effect of the etalon on the amplified spontaneous emission beat noise are discussed and related to experiment     

An optical PSK homodyne transmission experiment using 1320 nmdiode-pumped Nd:YAG lasers

A second-order optical phase-locked loop was constructed using 1320-nm diode-pumped miniature Nd:YAG ring lasers. Using the loop, a 140-Mb/s PSK homodyne transmission experiment was demonstrated over 28.6 km of single-mode fiber. With a loop natural frequency of 13 kHz and a damping factor of 0.6, the receiver sensitivity was -62.8 dBm, or 25 photons/bit. The authors believe this is the highest sensitivity obtained to date with any optical communication system     

A 10 Gb/s high sensitivity, monolithically integrated p-i-n-HEMToptical receiver

A high-sensitivity, monolithically integrated optical receiver, composed of a p-i-n-PD and high electron mobility transistors (p-i-n-HEMTs) is described. The receiver sensitivity is -17.3 dBm at a bit error rate of 1×10^-9 for a 10-Gb/s non-return-to-zero (NRZ) lightwave signal. This value is the best result yet reported for 10-Gb/s monolithically integrated receivers. The sensitivity is -30.6 dBm if an erbium-doped fiber amplifier (EDFA) is placed ahead of the p-i-n-NEMT receiver. A transmission experiment using a 150-km dispersion-shifted fiber (DSF) indicates no degradation in the bit error rate characteristics or the eye pattern. This verifies the practicality of the p-i-n-HEMT optical receiver for high-speed transmission systems     

2.488 Gb/s-318 km repeaterless transmission using erbium-dopedfiber amplifiers in a direct-detection system

The authors have achieved a 2.488 Gb/s, 318 km repeaterless transmission without any fiber dispersion penalty through a nondispersion-shifted fiber in a direct detection system. The system was loss limited with a T-R power budget of 57 dB. Three key components enabled the authors to achieve this result: (1) a Ti:LiNbO₃ external amplitude modulator enabling a dispersion-free transmission, (2) erbium-doped fiber amplifiers increasing the transmitting power to +16 dBm, and (3) an erbium-doped fiber preamplifier enabling a high-receiver sensitivity of -4.1 dBm for 10^-9 BER. To the author's knowledge, this result is the longest repeaterless transmission span length ever reported for direct detection at this bit rate. From the experimental results and a theoretical model, the authors identified the sources of the receiver sensitivity degradation from the quantum limit (-48.6 dBm) and estimated the practically achievable receiver sensitivity of ~-44 dBm (~-124 photons/bit) for 2.5 Gb/s optical preamplifier detection     

A highly integrated dual-band multimode wireless LAN transceiver

A fully integrated radio transceiver chip for the 2.4- and 5-GHz WLAN standards 802.11a/b/g is presented in a 0.25-/spl mu/m 40-GHz BiCMOS technology. The chip integrates the low-noise amplifiers, mixers, channel filters, programmable gain control, synthesizers with voltage-controlled oscillators and reference oscillator, transmitters, antialiasing filters, and voltage regulators. The key performances of the presented transceiver are a receive sensitivity of -85 dBm and -74 dBm for 11-Mb/s complementary code keying (CCK) and 54 Mb/s orthogonal frequency division multiplexing (OFDM) modes, respectively, and an error vector magnitude of -35 dB measured at the transmitter with an output power of -4 dBm at 54-Mb/s 802.11a mode. The transceiver exceeds all IEEE requirements for the 802.11a/b/g CCK and OFDM standards and supports a frequency range of 4.9 to 6 GHz for the future extensions of the 802.11a standard in different countries.     

A low-power 8-PAM serial transceiver in 0.5-μm digital CMOS

An 8-PAM CMOS transceiver is described in this paper. Pre-emphasis is implemented without an increase in DAC resolution or digital computation. The receiver oversamples with three fully differential 3-bit ADCs. The prototype transmits at up to 1.3 Gb/s and has a measured bit error rate of less than 1 in 10¹³ for an 810-Mb/s pseudorandom bit sequence transmission. The device, packaged in a 68-pin ceramic leadless chip carrier, is implemented in 0.5-μm digital CMOS, occupies 2 mm², and dissipates 400 mW from a 3.3-V supply     

A transimpedance APD optical receiver operating at 10 Gb/s

The authors report an optical receiver which uses a separate-absorption-and-multiplication avalanche photodiode (SAM-APD) to achieve high sensitivity at a bit rate of 10 Gb/s. A transimpedance front end incorporating HEMT devices is used for high bandwidth and low noise. The sensitivity (bit-error rate of 10^-9) is -28.7 dBm for a return-to-zero signal, and -27.0 dBm for a nonreturn-to-zero signal     

A direct-conversion CMOS transceiver for the 802.11a/b/g WLAN standard utilizing a Cartesian feedback transmitter

A fully integrated dual-band transceiver is implemented in 0.18-/spl mu/m CMOS and is compliant with the IEEE 802.11a/b/g standards. The direct-conversion transceiver occupies 12 mm/sup 2/ in a QFN-40 package. A fractional-N synthesizer operates at twice the channel frequency, covering continuously bands from 4.9 to 5.9 GHz, as well as the 2.4-GHz band. The 5- and 2.4-GHz receivers achieve a sensitivity level below -73 dBm in the 54-Mb/s mode and below -93 dBm in the 6-Mb/s mode, while consuming 230 mW. A fast RSSI-channel power-detection system allows to power-down signal processing in the listen mode. The 5- and 2.4-GHz transmitters implement a wideband Cartesian feedback loop for enhanced EVM performances and improved spectrum masks compliance. The transmitters deliver -2-dBm average power with an EVM of 3% in the 54-Mb/s mode while consuming 300 mW.