Integration and Characteristics of 40-Gb/s Electroabsorption Modulator Integrated Laser Module With a Driver Amplifier and Bias Tees

Integration of a 40-Gb/s electroabsorption modulator integrated distributed feedback (DFB) laser (EML) module with a driver amplifier and bias tee was investigated. For the EML fabrication the selective area growth (SAG) technique was adopted for the first time. It is shown that, with the SAG technique, the 3-dB bandwidth of about 45 GHz was measured in the electrical to optical response, and the return loss (S11) of below $-$10 dB was achieved for up to 50 GHz . To integrate a bias tee within the module, a right-angle bent coplanar waveguide (CPW) was developed. The right-angle bent CPW was characterized with S11 of below $-$ 10 dB for up to 35 GHz and insertion loss (S21) of about $-$1.4 dB for up to 40 GHz . The whole integrated module including the EML, a driver amplifier, and bias tee was characterized under the conditions of an operating temperature of 25 $^{circ}{rm C}$, the modulator bias of 1.4 V, and the DFB laser current of 40 mA. S11 of below $-$10 dB was obtained for up to 14 GHz and the measured electrical-to-optical response has 3-dB bandwidth of about 20 GHz.      

A 60-dB gain, 55-dB dynamic range, 10-Gb/s broad-band SiGe HBTlimiting amplifier

A limiting amplifier IC implemented in a silicon-germanium (SiGe) heterojunction bipolar transistor technology for low-cost 10-Gb/s applications is described. The IC employs 20 dB gain limiting cells, input overload protection, split analog-digital grounds, and on-chip isolation interface with transmission lines. A gain enhancement technique has been developed for a parallel-feedback limiting cell. The limiting amplifier sensitivity is less than 3.5 mV_pp at BER=10^-9 with 2-V_pp maximum input (55-dB dynamic range). The total gain is over 60 dB, and S₂₁ bandwidth exceeds 15 GHz at 10-mV_pp input. Parameters S₁₁ and S₂₂ are better than -10 dB in the 10-GHz frequency range. The AM to PM conversion is less than 5 ps across input dynamic range. The output differential voltage can be set from 0.2 to 2 V_pp with IC power dissipation from 250 mW to 1.1 W. The chip area is 1.2×2.6 mm². A 10-Gb/s optical receiver, built with the packaged limiting amplifier, demonstrated -19.6-dBm sensitivity. The IC can be used in 10-Gb/s fiber-optic receivers requiring high sensitivity and wide input dynamic range     

3–10-GHz Ultra-Wideband Low-Noise Amplifier Utilizing Miller Effect and Inductive Shunt–Shunt Feedback Technique

In this paper, we demonstrate an SiGe HBT ultra-wideband (UWB) low-noise amplifier (LNA), achieved by a newly proposed methodology, which takes advantage of the Miller effect for UWB input impedance matching and the inductive shunt-shunt feedback technique for bandwidth extension by pole-zero cancellation. The SiGe UWB LNA dissipates 25.8-mW power and achieves S₁₁ below -10 dB for frequencies from 3 to 14 GHz (except for a small range from 10 to 11 GHz, which is below -9 dB), flat S₂₁ of 24.6 plusmn 1.5 dB for frequencies from 3 to 11.6 GHz, noise figure of 2.5 and 5.8 dB at 3 and 10 GHz, respectively, and good phase linearity property (group-delay variation is only plusmn28 ps across the entire band). The measured 1-dB compression point (P₁ dB) and input third-order intermodulation point are -25.5 and -17 dBm, respectively, at 5.4 GHz.     

Design optimization and characterization of high-gain GaInP/GaAsHBT distributed amplifiers for high-bit-rate telecommunication

The design methodology, processing technology, and characterization of high-gain GaInP/GaAs heterojunction-bipolar-transistor-based distributed amplifiers are described in this paper. Distributed amplifiers with different active cells and number of stages have been compared for high-gain (>12 dB) and high-bandwidth (>25 GHz) performance. Based on the results, a three-stage attenuation-compensated distributed amplifier with a flat gain (S₂₁) of 12.7 dB over a bandwidth of 27.5 GHz was successfully fabricated and tested. Eye-diagram tests at 10 Gb/s show very open eye characteristics with no signal skewing. The amplifier achieves a minimum noise figure of 4 dB at 3 GHz and a sensitivity of -25 dBm for 10-Gb/s nonreturn-to-zero 2¹⁵-1 pseudorandom bit sequence with a bit error rate of 10^-9     

Right‐Angle‐Bent CPW for the Application of the Driver‐Amplifier‐Integrated 40 Gbps TW‐EML Module

In this letter we present a right‐angle‐bent coplanar waveguide (CPW) which we developed for the application of the driver amplifier‐integrated (DAI) 40 Gbps traveling wave electroabsorption modulated laser module. The developed CPW realized parallel progression of the radio frequency (RF) and light using a dielectric overlay structure and wedge bonding on the bending section. The measured S₁₁ and S₂₁ of the developed CPW were kept below ?10 dB up to 35 GHz and ?3 dB up to 43 GHz, respectively. These measured results of the CPW were in good agreement with the simulation results and demonstrated the applicability of the CPW to the 40 Gbps communication module.     

A Low-Power Wideband CMOS LNA for WiMAX

In this brief, the design of a low-power inductorless wideband low-noise amplifier (LNA) for worldwide interoperability for microwave access covering the frequency range from 0.1 to 3.8 GHz using 0.13-mum CMOS is described. The core consumes 1.9 mW from a 1.2-V supply. The chip performance achieves S₁₁ below -10 dB across the entire band and a minimum noise figure of 2.55 dB. The simulated third-order input intercept point is -2.7 dBm. The voltage gain reaches a peak of 11.2 dB in-band with an upper 3-dB frequency of 3.8 GHz, which can be extended to reach 6.2 GHz using shunt inductive peaking. A figure of merit is devised to compare the proposed designs to recently published wideband CMOS LNAs     

A 10-Gb/s Inductorless CMOS Limiting Amplifier With Third-Order Interleaving Active Feedback

This paper presents an inductorless circuit technique for CMOS limiting amplifiers. By employing the third-order interleaving active feedback, the bandwidth of the proposed circuit can be effectively enhanced while maintaining a suppressed gain peaking within the frequency band. Using a standard 0.18-mum CMOS process, the limiting amplifier is implemented for 10-Gb/s broadband applications. Consuming a DC power of 189 mW from a 1.8-V supply voltage, the fabricated circuit exhibits a voltage gain of 42 dB and a -3-dB bandwidth of 9 GHz. With a 2³¹-1 pseudo-random bit sequence at 10 Gb/s, the measured output swing and input sensitivity for a bit-error rate of 10^-12 are 300 and 10 mV_pp, respectively. Due to the absence of the spiral inductors, the chip size of the limiting amplifier including the pads is 0.68times0.8 mm² where the active circuit area only occupies 0.32times0.6 mm²     

First demonstration of monolithic InP-based HBT amplifier with PNPactive load

An InP-based integrated HBT amplifier with PNP active load was demonstrated for the first time using complementary HBT technology (CRBT). Selective molecular beam epitaxy (MBE) regrowth was employed and a merged processing technology was developed for the monolithic integration of InP-based NPN and PNP HBTs on the same chip. The availability of PNP devices allowed design of high gain amplifiers with low power supply voltage. The measured amplifier with PNP HBT active load achieved a voltage gain of 100 with a power supply (V_CC) of 1.5 V. The corresponding voltage swing was 0.9 V to 0.2 V. The amplifier also demonstrated S₂₁ of 7.8 dB with an associated S₁₁ and S₂₂ of -9.5 dB and -8.1 dB, respectively, at 10 GHz     

Low insertion loss and low dispersion penalty InGaAsP quantum-well high-speed electroabsorption modulator for 40-Gb/s very-short-reach, long-reach, and long-haul applications

We present a metal-organic-chemical-vapor-deposition-grown low-optical-insertion-loss InGaAsP/InP multiple-quantum-well electroabsorption modulator (EAM), suitable for both nonreturn-to-zero (NRZ) and return-to-zero (RZ) applications. The EAM exhibits a dynamic (RF) extinction ratio of 11.5 dB at 1550 nm for 3 Vp-p drive under 40-Gb/s modulation. The optical insertion loss of the modulator in the on-state is -5.2 dB at 1550 nm. In addition, the EAM also exhibits a 3-dB small-signal response (S21) of greater than 38 GHz, allowing it to be used in both 40-Gb/s NRZ and 10-Gb/s RZ applications. The dispersion penalty at 40 Gb/s is measured to be 1.2 dB over /spl plusmn/40 ps/nm of chromatic dispersion. Finally, we demonstrate 40-Gb/s transmission performance over 85 km and 700 km.     

8-element linear array monolithic p-i-n MODFET photoreceivers usingmolecular beam epitaxial regrowth

An 8-element linear array of single-stage integrating front-end photoreceivers using molecular beam epitaxial (MBE) regrowth was investigated. Each element consisted of a p-i-n In_0.53Ga_0.47As photodiode integrated with a selectively regrown pseudomorphic In_0.65Ga_0.35As/In_0.52Al_0.48 As MODFET. Cutoff frequencies of 1.0-μm discrete regrown MODFETs were f_t=24 GHz and f_max=50 GHz. Transconductance of the regrown MODFETs was as high as 495 mS/mm with a current density (I_ds) of 250 mA/mm. The 3-dB bandwidth of the photoreceiver was measured to be 1 GHz. The bit rate sensitivity at 1 Gb/s was -31.8 dBm for BER 10^-9 using 1.55 μm excitation for a photoreceiver with an anti-reflection coating. The single-stage amplifier exhibited up to 25 dB flatband gain of the photocurrent, and a two-stage amplifier was up to 31 dB of gain. Good uniformity between each photoreceiver element in the array was achieved. Electrical crosstalk between photoreceiver elements was estimated to be ~-34 dB     

A 4 Gb/s 2-level to 2 Gsymbol/s 4-level converter GaAs IC forsemiconductor optical amplifier QPSK modulators

The design of a 50 Ω impedance matched two-to-four level converter GaAs IC for two-electrode semiconductor optical amplifier (SOA) modulators is presented. The designed IC exhibits eye diagrams with eye openings of better than 0.30 V and a spacing between adjacent output signal levels of 0.33 V for output symbol rates of up to 2 Gsymbol/s corresponding to input bit rates of up to 4 Gb/s. A novel differential super buffer output driver is applied, for which output reflection coefficients |S₂₂| of less than -12 dB for frequencies up to 10 GHz are obtained. A 1 Gb/s optical QPSK microwave link transmission experiment using a packaged sample of the designed IC and a two-electrode semiconductor optical amplifier phase modulator has been conducted     

A Large Swing, 40-Gb/s SiGe BiCMOS Driver With Adjustable Pre-Emphasis for Data Transmission Over 75 $Omega$ Coaxial Cable

A fully differential 40-Gb/s cable driver with adjustable pre-emphasis is presented. The circuit is fabricated in a production 0.18 mum SiGe BiCMOS technology. A distributed limiting architecture is used for the driver employing high-speed HBTs in the lower voltage predriver, and a high-breakdown MOS-HV-HBT cascode, consisting of a 0.18 mum n-channel MOSFET and a high-voltage HBT (HV-HBT), for the high voltage output stages. The circuit delivers up to 3.6 V peak-to-peak per side into a 75 Omega load with variable pre-emphasis ranging from 0 to 400%. S-parameter measurements show 42 dB differential small-signal gain, a 3-dB bandwidth of 22 GHz, gain peaking control up to 25 dB at 20 GHz and input and output reflection coefficients better than -10 dB up to 40 GHz. Additional features of the driver include output amplitude control (from 1 V_pp to 3.6 V_pp per side), pulse-width control (35% to 65%) and an adjustable input dc level (1.1 V to 1.8 V) allowing the circuit to interface with a SiGe BiCMOS or MOS-CML SERDES. The transmitter is able to generate an eye opening at 38 Gb/s after 10 m of Belden 1694 A coaxial cable which introduces 22 dB of loss at 19 GHz. Measurement results also demonstrate that the transmitter IC operates as a standalone equalizer for 10-Gb/s data transmission over 40 m of Belden cable without the need for receiver equalization.     

Jitter considerations in the design of a 10-Gb/s automatic gain control amplifier

The effects of noise on random jitter in multistage broad-band amplifiers are analyzed. Limiting amplifiers are compared to automatic gain control (AGC) amplifiers with different gain profiles. Results are presented for a 10-Gb/s AGC amplifier implemented in an SiGe process with f_T of 45 GHz. Active peaking techniques were used to achieve a maximum gain of 48 dB with 7.8 GHz of bandwidth. The amplifier demonstrates low jitter and less than 0.5 dB of peak-to-peak output amplitude variation over a 50-dB input amplitude range. It consumes 30 mW of power from a 3.3-V supply. The amplifier core occupies 0.1 mm² and requires no external components     

0.18 μm 21-27 GHz CMOS UWB LNA with 9.3 ± 1.3 dB gain and 103.9 ± 8.1 ps group delay

A 21-27 GHz CMOS ultra-wideband low-noise amplifier (UWB LNA) with state-of-the-art phase linearity property (group delay variation is only ± 8.1 ps across the whole band) is reported for the first time. To achieve high and flat gain (S₂₁) and small group delay variation at the same time, the inductive series peaking technique was adopted in the output of each stage for bandwidth enhancement. The LNA dissipated 27 mW power and achieved input return loss (S₁₁) of 213 to 220.1 dB, output return loss (S₂₂) of 28.2 to 230.2 dB, flat S21 of 9.3 ± 1.3 dB, reverse isolation (S₁₂) of 252.7 to 273.3 dB, and noise figure of 4.9?6.1 dB over the 21-27 GHz band of interest. The measured 1 dB compression point (P_1dB) and input third-order intermodulation point (IIP3) were 214 and 24 dBm, respectively, at 24 GHz.     

DC to 2.5 Gb/s×4 p-i-n/HBT optical receiver array with lowcrosstalk

A multichannel optical receiver with an In_0.53Ga_0.47As p-i-n photodetector array and a monolithic transimpedance amplifier array fabricated in AlGaAs/GaAs HBT (heterojunction bipolar transistor) technology were demonstrated. Both flip-chip rear-illuminated and wire-bonded front-illuminated detector configurations were implemented. The transimpedance was 65 dBΩ, and the 3-dB bandwidth was measured to be 2.3 GHz. By using series feedback, the transimpedance gain of each cell was matched to within 0.5 dB, and the entire array operated from a single 5-V supply. A low interchannel crosstalk of less than -40 dB was measured up to a data rate of 2 Gb/s     

40 Gb/s Traveling‐Wave Electroabsorption Modulator‐Integrated DFB Lasers Fabricated Using Selective Area Growth

In this paper, we present the fabrication of 40 Gb/s traveling‐wave electroabsorption modulator‐integrated laser (TW‐EML) modules. A selective area growth method is first employed in 40 Gb/s EML fabrication to simultaneously provide active layers for lasers and modulators. The 3 dB bandwidth of a TW‐EML module is measured to be 34 GHz, which is wider than that of a lumped EML module. The 40 Gb/s non‐return‐to‐zero eye diagram shows clear openings with an average output power of +0.5 dBm.     

3-D CMOS Circuits Based on Low-Loss Vertical Interconnects on Parylene-N

parylene-N is used as a dielectric layer to create ultra low-loss 3-D vertical interconnects and coplanar waveguide (CPW) transmission lines on a CMOS substrate. Insertion loss of 0.013 dB for a 3-D vertical interconnect through a 15-$mu$ m-thick parylene-N layer and 0.56 dB/mm for a 50- $Omega$ CPW line on the parylene-N layer (compared to 1.85 dB/mm on a standard CMOS substrate) are measured at 40 GHz. L-shaped, U-shaped, and T-junction CPW structures are also fabricated with underpasses that eliminate the discontinuities arisen from the slot-line mode and are characterized up to 40 GHz. A 3-D low-noise amplifier using these post-processed structures on a 0.13-$mu$ m CMOS technology is also presented along with the investigation of parasitic effects for accurate simulation of such a 3-D circuit. The 3-D circuit implementation reduces the attenuation per unit length of the transmission lines, while preserving the CMOS chip area (in this specific design) by approximately 25%. The 3-D amplifier measures a gain of 13 dB at 2 GHz with 3-dB bandwidth of 500 MHz, noise figure of 3.3 dB, and output 1-dB compression point of ${+}$ 4.6 dBm. Room-temperature processing, simple fabrication, low-loss performance, and compatibility with the CMOS process make this technology a suitable choice for future 3-D CMOS and BiCMOS monolithic microwave integrated circuit applications that currently suffer from high substrate loss and crosstalk.      

2.5 dB NF 3.1-10.6 GHz CMOS UWB LNA with small group-delay variation

A 3.1-10.6 GHz ultra-wideband low-noise amplifier (UWB LNA) with excellent phase linearity property (group-delay variation is only plusmn 16.7 ps across the whole band) using standard 0.13 mum CMOS technology is reported. To achieve high and flat gain and small group-delay variation at the same time, the inductive peaking technique is adopted in the output stage for bandwidth enhancement. The UWB LNA achieved input return loss (S₁₁) of -17.5 to -33.6 dB, output return loss (S₂₂) of -14.4 to -16.3 dB, flat forward gain (S₂₂) of 7.92 plusmn 0.23 dB, and reverse isolation (S₁₂) of -25.8 to -41.9 dB over the 3.1-10.6 GHz band of interest. A state-of-the-art noise figure (NF) of 2.5 dB was achieved at 10.5 GHz.     

Design and Fabrication of Low-Driving-Voltage Electroabsorption Modulators Operating at 40 Gb/s

In this paper, a design for low-driving-voltage InGaAlAs/InAlAs electroabsorption modulators (EAMs) operating at 40 Gb/s is described. The theoretical calculation clarified that the tensile-strained InGaAlAs/InAlAs multiquantum-well layers with thin wells provide large and steep extinction characteristics. This was experimentally confirmed. We modeled an EAM with a low-loss coplanar waveguide for both the input and output ports and designed an optimized core structure that assures a sufficient extinction ratio and electrical-to-optical bandwidth for 40-Gb/s operation, in terms of well number and core length. A fabricated device driven by a peak-to-peak voltage as low as 1.1 V shows a 3-dB bandwidth of over 50 GHz and an RF extinction ratio of 10 dB. Error-free operation at 40 Gb/s is confirmed.     

Analysis, design, and optimization of InGaP-GaAs HBTmatched-impedance wide-band amplifiers with multiple feedback loops

The realization of matched impedance wide-band amplifiers fabricated by InGaP-GaAs heterojunction bipolar transistor (HBT) process is reported. The technique of multiple feedback loops was used to achieve terminal impedance matching and wide bandwidth simultaneously. The experimental results showed that a small signal gain of 16 dB and a 3-dB bandwidth of 11.6 GHz with in-band input/output return loss less than -10 dB were obtained. These values agreed well with those predicted from the analytic expressions that we derived for voltage gain, transimpedance gain, bandwidth, and input and output impedances. A general method for the determination of frequency responses of input/output return losses (or S₁₁, S₂₂) from the poles of voltage gain was proposed. The intrinsic overdamped characteristic of this amplifier was proved and emitter capacitive peaking was used to remedy this problem. The tradeoff between the input impedance matching and bandwidth was also found