Broad-band GaAs monolithic equalizing amplifiers formultigigabit-per-second optical receivers

The authors discuss the development of ICs (integrated circuits) for a preamplifier, a gain-controllable amplifier, and main amplifiers with and without a three-way divider for multigigabit-per-second optical receivers using a single-ended parallel feedback circuit, two (inductor and capacitor) peaking techniques, and advanced GaAs process technology. An optical front-end circuit consisting of a GaAs preamplifier and an InGaAs p-i-n photodiode achieves a 3-dB bandwidth of 7 GHz and -12-dBm sensitivity at 10 Gb/s. Moreover, a gain-controllable amplifier obtains a maximum gain of 15 dB, a gain dynamic range of 25 dB, and a 3-dB bandwidth of 6.1 GHz by controlling the source bias of the common-source circuit. Gain, 3-dB bandwidth, and output power of the main amplifier with the three-way divider are 17.4 dB, 5.2 GHz, and 5 dBm, respectively. These ICs can be applied to optical receivers transmitting NRZ signals in excess of 7 Gb/s     

High Gain Equalizing Amplifier Integrated Circuits for a Gigabit Optical Repeater

Equalizing amplifier circuits for a gigabit optical-fiber transmission system are integrated on two monolithic chips implementing an advanced silicon bipolar process. Several new circuit techniques such as a broad-band 50-/spl Omega/ matching amplifier and an electrically controlled and adjusted peaking technique are employed. It is clarified that the main degradation factors of circuit stability are parasitic capacitance between the input and output terminals, and the crosstalk occuring through the wire bonding inductance. The maximum gain and 3-dB down bandwidth of the equalizing amplifier IC's are 64 dB and 1.2 GHz, respectively. The noise figure obtained is 4.5 dB within the dc to 2-GHz range.     

Si-analog IC's for 20 Gb/s optical receiver

Two Si-Analog IC's, a preamplifier IC and a decision IC, for a 20 Gb/s optical receiver have been developed using SiGe-base bipolar transistors having a 60 GHz maximum cutoff frequency. The preamplifier employing a dual feedback loop increases the -3 dB bandwidth up to 19 GHz. A decision IC, composed of a gain controllable amplifier with a bias stabilization circuit and D-F/F, operated at up to 20 Gb/s with a 200-mVp-p input sensitivity     

Si bipolar chip set for 10-Gb/s optical receiver

Three Si bipolar ICs, a preamplifier, a gain-controllable amplifier, and a decision circuit, have been developed for 10-Gb/s optical receivers. A dual-feedback configuration with a phase adjustment capacitor makes it possible to increase the preamplifier bandwidth up to 11.2 GHz, while still retaining flat frequency response. The gain-controllable amplifier, which utilizes a current-dividing amplifier stage, has an 11.4-GHz bandwidth with 20-dB gain variation. A master-slave D-type flip-flop is also operated as the decision circuit at 10 Gb/s. On-chip coplanar lines were applied to minimize the electrical reflection between the ICs     

An 84 GHz Bandwidth and 20 dB Gain Broadband Amplifier in SiGe Bipolar Technology

This paper reports on the design, fabrication, and characterization of a lumped broadband amplifier in SiGe bipolar technology. The measured differential gain is 20 dB with a 3-dB bandwidth of more than 84 GHz, which is the highest bandwidth reported so far for broadband SiGe bipolar amplifiers. The resulting gain bandwidth product (GBW) is more than 840 GHz. The amplifier consumes a power of 990 mW at a supply of -5.5 V.     

SiGe bipolar transceiver circuits operating at 60 GHz

A low-noise amplifier, direct-conversion quadrature mixer, power amplifier, and voltage-controlled oscillators have been implemented in a 0.12-/spl mu/m, 200-GHz f/sub T/290-GHz f/sub MAX/ SiGe bipolar technology for operation at 60 GHz. At 61.5 GHz, the two-stage LNA achieves 4.5-dB NF, 15-dB gain, consuming 6 mA from 1.8 V. This is the first known demonstration of a silicon LNA at V-band. The downconverter consists of a preamplifier, I/Q double-balanced mixers, a frequency tripler, and a quadrature generator, and is again the first known demonstration of silicon active mixers at V-band. At 60 GHz, the downconverter gain is 18.6 dB and the NF is 13.3 dB, and the circuit consumes 55 mA from 2.7 V, while the output buffers consume an additional 52 mA. The balanced class-AB PA provides 10.8-dB gain, +11.2-dBm 1-dB compression point, 4.3% maximum PAE, and 16-dBm saturated output power. Finally, fully differential Colpitts VCOs have been implemented at 22 and 67 GHz. The 67-GHz VCO has a phase noise better than -98 dBc/Hz at 1-MHz offset, and provides a 3.1% tuning range for 8-mA current consumption from a 3-V supply.     

A 0.18μm CMOS 3-5 GHz broadband flat gain low noise amplifier

A 3-5 GHz broadband flat gain differential low noise amplifier (LNA) is designed for the impulse radio uitra-wideband (IR-UWB) system. The gain-flatten technique is adopted in this UWB LNA. Serial and shunt peaking techniques are used to achieve broadband input matching and large gain-bandwidth product (GBW). Feedback networks are introduced to further extend the bandwidth and diminish the gain fluctuations. The prototype is fabricated in the SMIC 0.18 μm RF CMOS process. Measurement results show a 3-dB gain bandwidth of 2.4-5.5 GHz with a maximum power gain of 13.2 dB. The excellent gain flatness is achieved with ±0.45 dB gain fluctuations across 3-5 GHz and the minimum noise figure (NF) is 3.2 dB over 2.5-5 GHz. This circuit also shows an excellent input matching characteristic with the measured S11 below-13 dB over 2.9-5.4 GHz. The input-referred 1-dB compression point (IPldB) is -11.7 dBm at 5 GHz. The differential circuit consumes 9.6 mA current from a supply of 1.8 V.     

应用于10Gb/s光接收机的全差分CMOS跨阻前置电路设计

设计了一种的低成本、低功耗的10 Gb/s光接收机全差跨阻前置放大电路。该电路由跨阻放大器、限幅放大器和输出缓冲电路组成,其可将微弱的光电流信号转换为摆幅为400 mVpp的差分电压信号。该全差分前置放大电路采用0.18 m CMOS工艺进行设计,当光电二极管电容为250 fF时,该光接收机前置放大电路的跨阻增益为92 dB,-3 dB带宽为7.9 GHz,平均等效输入噪声电流谱密度约为23 pA/(0~8 GHz)。该电路采用电源电压为1.8 V时,跨阻放大器功耗为28 mW,限幅放大器功耗为80 mW,输出缓冲器功耗为40 mW,其芯片面积为800 m1 700 m。     

Millileter-Wave Power-Combining Amplifier Using A Broadband Waveguide Combiner

A Millimeter-wave power-combining amplifier based on the multi-way rectangular-waveguide power-dividing/combining circuit has been presented and investigated. The equivalent-circuit approach has been used to analyze the passive power-dividing/combining circuits. An eight-device amplifier is designed and measured to validate the power-dividing/combining mechanism using this technique. Both the measured 10-dB return loss bandwidth and the 2-dB insertion loss bandwidth of the passive system are more than 10?GHz. The measured maximum small-signal gain of the millimeter-wave eight-device power amplifier is 22.5?dB at 26.8?GHz with a 3-dB bandwidth of more than 6?GHz, while the input and output return loss of the proposed eight-device power amplifier is around ?10?dB from 26?GHz to 36?GHz. The measured maximum output power at 1-dB compression from the power amplifier is 28 dBm at 29.5?GHz.     

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     

DC to 40-GHz broad-band amplifiers using AlGaAs/GaAs HBT's

In this paper, we report two types of broad-band amplifiers implemented with AlGaAs/GaAs HBT's. One is a Darlington feedback amplifier and the other is a transimpedance amplifier. In the former circuit, a dc gain of 9.5 dB and a -3-dB bandwidth of 40 GHz were achieved. In the latter circuit, a transimpedance gain of 50 dBΩ and a -3-dB bandwidth of 27 GHz were achieved. To our best knowledge, they are the highest speed in each circuit configuration     

Monolithic integrated amplifiers for 400 Mbit/s optical repeater

Introduction of monolithic integrated circuit technology to high bit rate optical repeater is studied. Monolithic integrated amplifiers are realised for a 400 Mbit/s optical repeater such as a preamplifier, AGC amplifier and postamplifier, using advanced silicon bipolar process technology. An equalising amplifier with four monolithic amplifiers got 66 dB maximum gain, 35 dB variable gain and 350 MHz band-width with 550 mW power consumption.     

A 50-GHz silicon IMPATT diode oscillator and amplifier

Recent experimental observations on a silicon impact avalanche transit-time diode oscillator and amplifier CW-operated at 50 GHz are presented. 1) CW oscillation power of 100 mW was obtained at an overall efficiency of 2 percent. The oscillation frequency was continuously tunable over a 1.3-GHz range by a sliding short. 2) Phase-locking has been achieved with a maximum normalized gain-bandwidth product of 0.1. The minimum locking signal power required for a 500-MHz locking bandwidth was 20 dB below the oscillator output. 3) Electronic tuning of the oscillator frequency was demonstrated by placing a millimeter-wave varactor diode in the tuning circuit. The output frequency versus the bias voltage on the varactor diode was linear with maximum frequency deviation of 300 MHz. Frequency modulation of the oscillator by driving the varactor with a sinusoidal source was obtained at a modulation frequency of 50 MHz. 4) Stable amplification with 13-dB gain was obtained, centered at 52.885 GHz with a 3-dB bandwidth of 1 GHz. The maximum output power obtained was 16 mW. Higher gain of about 17 dB was obtained at a reduced bandwidth. The noise figure of the amplifier was 36 dB. Equivalent circuits for the oscillator and the amplifier are derived. The calculated results agree reasonably well with the experimental observations.     

A broad-band amplifier using GaAs/GaAlAs heterojunction bipolartransistors

A compact wideband amplifier (or gain block) designed around a Darlington pair of GaAs/GaAlAs heterojunction bipolar transistors (HBTs) is discussed. This circuit has been fabricated by an ion-implanted process with a transistor f_t of 40 GHz. Two variants of the circuit gave either a 8.5-dB gain with a DC-to-5-GHz 3-dB bandwidth or a 13-dB gain with a DC-to-3-GHz bandwidth. These amplifiers gave 11.8- and 18.3-dBm output, respectively, at 1-dB gain compression     

Wideband variable peaking AGC amplifier for high-speed lightwave digital transmission

A variable peaking AGC amplifier with a new circuit configuration is proposed and monolithically integrated by using 1 ?m Si-bipolar technology. The amplifier exhibits characteristics of l.8 GHz bandwidth, 9 dB maximum gain and 15 dB gain dynamic range, and is 1.8 times superior to nonpeaking amplifiers.     

Design of a 32.7-GHz bandwidth AGC amplifier IC with wide dynamicrange implemented in SiGe HBT

A wide-bandwidth automatic gain control (AGC) amplifier IC was developed using a self-aligned selective-epitaxial SiGe heterojunction bipolar transistor (HBT). A transimpedance load circuit was used, and its damping factor was optimized to achieve a wide bandwidth of 32.7 GHz. Capacitor peaking was introduced to the second variable-gain amplifier in order to obtain a wide gain dynamic range of 19 dB. The amplifier IC has a noise figure of 18 dB and an eye pattern at 25 Gb/s     

Gigahertz-band high-gain low-noise AGC amplifiers in fine-line NMOS

The design and test results of a single-chip NMOS automatic gain control (AGC) amplifier are described. The amplifier has a maximum flat gain of 50 dB, dynamic range of 70 dB, and a noise figure of 11 dB. The flat response from near DC to a 3-dB bandwidth of 1 GHz does not require tuning of any peaking circuits. The chip is also capable of operating at 3 GHz with unity gain delivering -8 dBm into a 50-/spl Omega/ load. The global feedback scheme designed for this chip stabilizes it against large shifts in threshold voltage and ambient temperature variation of 170/spl deg/C. This feedback scheme can provide stable DC feedback for a forward amplifier gain of at least 60 dB. Application of this application in the design of low-noise high-speed fibre-optic systems is envisaged.     

A high-gain GaAs amplifier with an AGC Function

A high-gain amplifier consisting of three GaAs monolithic IC chips, a preamplifier, an automatic gain control (AGC) amplifier, and a postamplifier, is developed. The fabricated low-noise low-VSWR amplifier has a 45-dB gain, a 13-dB AGC range, and a 1.6-GHz bandwidth with a power consumption of 2.5 W. It is a promising candidate for use in high-speed data rate transmission systems.     

0.1-42 GHz InP DHBT distributed amplifiers with 35 dB gain and 15 dBm output

An InP double hetero-junction bipolar transistor (DHBT) distributed power amplifier MMIC with 35 dB gain, 42 GHz bandwidth and 15 dBm output power is reported. This represents the highest power and largest gain reported over this bandwidth from a single chip HBT amplifier. A lumped preamplifier with a novel distributed output is used to obtain high gain and wide bandwidth at these power levels.     

X- and Ku-band amplifiers with GaAs Schottky-barriers field-effect transistors

During recent years significant progress has been made in GaAs technology and the GaAs Schottky-barrier field-effect transistor now shows outstanding microwave gain and noise properties. Two experimental microwave amplifiers demonstrate that the device is very well suited for broad-band applications and that large bandwidth in the X- and Ku-band can be obtained with simple circuits. The first of the two three-stage amplifiers realized was optimized with respect to noise and a noise figure of 3.8 dB was obtained at 8 GHz; the maximum gain is 17.5 dB at 8.3 GHz and the 3-dB bandwidth is 1.3 GHz. The second amplifier has a maximum gain of 11.5 dB at 11.5 GHz. The gain is greater than 8.5 dB in the range 9.5-14.3 GHz.