A complete 400-Mb/s burst-mode data OEIC receiver

A fully integrated burst-mode GaAs MESFET optoelectronic integrated circuit (OEIC) receiver, 215 mil×109 mil, that has been designed and implemented for point-to-point data links for application as a phased-array antenna controller is described. The chip provides a low-cost means for passing 400-Mb/s antenna control information using fiber optics with a very low bit-error rate (BER). Approximately 350 source-coupled FET logic gates are present on the chip. A new data coding and timing recovery scheme that is highly tolerant to jitter over a wide bandwidth has been developed. The OEIC uses an on-chip metal-semiconductor-metal (MSM) photodiode with 0.12-A/W responsivity measured at 780 nm and was fabricated in a 1.0-mm GaAs MESFET manufacturing technology. The low capacitance semi-insulating GaAs substrate minimizes the coupling between analog and digital circuitry. The circuit operates from a single 5-V supply, consumes 1 W of power, and provides an 8-b CMOS output bus together with various utility flags. Optical sensitivity is estimated at -20 dBm for 10^-14 BER     

Clock and data recovery IC for 40-Gb/s fiber-optic receiver

The integrated clock and data recovery (CDR) circuit is a key element for broad-band optical communication systems at 40 Gb/s. We report a 40-Gb/s CDR fabricated in indium-phosphide heterojunction bipolar transistor (InP HBT) technology using a robust architecture of a phase-locked loop (PLL) with a digital early-late phase detector. The faster InP HBT technology allows the digital phase detector to operate at the full data rate of 40 Gb/s. This, in turn, reduces the circuit complexity (transistor count) and the voltage-controlled oscillator (VCO) requirements. The IC includes an on-chip LC VCO, on-chip clock dividers to drive an external demultiplexer, and low-frequency PLL control loop and on-chip limiting amplifier buffers for the data and clock I/O. To our knowledge, this is the first demonstration of a mixed-signal IC operating at the clock rate of 40 GHz. We also describe the chip architecture and measurement results.     

Single-MMIC four-channel transmitter module for multichannelRF/optical subcarrier multiplexed communications applications

Presents a compact single monolithic microwave integrated circuit (MMIC) transmitter module for four-channel RF/optical subcarrier multiplexed (OSCM) communication applications. The developed module consists of one fully monolithic four-channel OSCM transmitter integrated circuit (IC) and four coupled-line filters. The MMIC is designed and implemented in a commercial 0.6-μm GaAs MESFET process and five-stage coupled-line filters are fabricated for each of the four channels on the module board. The module design and bit-error-rate performance are considered. This is the first fully monolithic IC transmitter module for OSCM communications applications     

New GaAs-MMIC process technology using low-temperature depositedSrTiO3 thin film capacitors

The authors have developed a new GaAs-MMIC process technology using low-temperature deposited SrTiO₃ thin film capacitors which were combined with WSi-gate selfaligned FETs. The SrTiO₃ films were successfully deposited at 200°C by the RF magnetron sputtering method without degrading the FET characteristics. By integrating these on-chip SrTiO₃ bypass capacitors onto the GaAs IC, the parasitic inductance from the source to ground interconnection was successfully reduced and an enhanced gain characteristic was obtained for a self-biased amplifier circuit     

Miniaturised broadband on-chip transformer employing PPGM on MMIC for application to low impedance transformation

Using a microstrip line employing periodically perforated ground metal (PPGM) on a GaAs monolithic microwave integrated circuit (MMIC), a highly miniaturised and broadband impedance transformer was developed for application to low impedance matching in broadband. Its size was 0.132 mm/sup 2/ on GaAs substrate, which was 2.3% of the one fabricated by a conventional microstrip line. The transformer showed good RF performance over a broadband including ultra-wideband. This is the first report of an on-chip broadband impedance transformer fabricated on MMIC.     

A single-chip GaAs RF transceiver for 1.9-GHz digital mobilecommunication systems

A 1.9-GHz single-chip GaAs RF transceiver has been successfully developed using a planar self-aligned gate FET suitable for low-cost and high-volume production. This IC includes a negative voltage generator for 3-V single voltage operation and a control logic circuit to control transmit and receive functions, together with RF front-end analog circuits-a power amplifier, an SPDT switch, two attenuators for transmit and receive modes, and a low-noise amplifier. The IC can deliver 22-dBm output power at 30% efficiency with 3-V single power supply, The new negative voltage generator operates with charge time of less than 200 ns, producing a low level of spurious outputs below -70 dBc through the power amplifier. The generator also suppresses gate-bias voltage deviations to within 0.05 V even when gate current of -144 μA flows. The IC incorporates a new interface circuit between the logic circuit and the switch which enables it to handle power outputs over 24 dBm with only an operating voltage of 3 V. This transceiver will be expected to enable size reductions in telephones for 1.9-GHz digital mobile communication systems     

A novel self-oscillating HEMT-HBT cascode VCO-mixer using an activetunable inductor

Here we describe a unique Ka-band self-oscillating HEMT-HBT cascode mixer design which integrates an active tunable resonator circuit. The VCO-mixer MMIC integrates GaAs HEMT's and HBT's using selective molecular beam epitaxy (MBE) technology. The HEMT-HBT cascode active mixer operates similarly to a dual-gate mixer. The HBT of the cascode is used to construct a VCO by presenting the base with an HEMT tunable active inductor. The VCO can be tuned from 28.5 to 29.3 GHz while providing ≈0 dBm of output power. Operated as an upconverter, the MMIC achieves 6-9 dB conversion loss over a 31-39 GHz output frequency band. Using these active approaches, both VCO and mixer functions were integrated into a compact 1.44×0.76 mm² chip area. The active RF integrated circuit (IC) techniques presented here have direct implications to future high complexity millimeter-wave monolithic integrated circuits (MIMICs) for ultrahigh-speed clock recovery and digital radio applications     

Integrated optoelectronic materials and circuits for optical interconnects

Conventional interconnect and switching technology is rapidly becoming a critical issue in the realization of systems using high speed silicon and GaAs based technologies. In recent years clock speeds and on-chip density for VLSI/VHSIC technology has made packaging these high speed chips extremely difficult. A strong case can be made for using optical interconnects for on-chip/on-wafer, chip-to-chip and board-to-board high speed communications. GaAs Integrated Optoelectronic Circuits (IOC's) are being developed in a number of laboratories for performing Input/Output functions at all levels. In this paper integrated optoelectronic materials, electronics and optoelectronic devices are presented. IOC’s are examined from the standpoint of what it takes to fabricate the devices and what performance can be expected.     

A Digital Receiver Architecture for Bluetooth in 0.25- μm CMOS Technology and Beyond

A digital receiver architecture for short-range communications systems like Bluetooth is presented. The architecture is tailored to a highly integrated Bluetooth single-chip integrated circuit (IC) and can easily be adapted to other communications systems using a Gaussian frequency-shift keying (GFSK ) modulation scheme. The single-chip IC integrates the complete digital baseband and radio frequency (RF) functionality on a single die and is realized in a 0.25-mum complementary metal-oxide-semiconductor (CMOS) technology targeted for cost efficiency. The superior performance of this digital receiver architecture compared to the state-of-the-art short-range communications receivers is shown. Simulation and measurement results are presented showing a receiver sensitivity of 87 dBm and excellent co-channel and adjacent channel interference performance.     

A GaAs high power RF single-pole dual throw switch IC fordigital-mobile communication system

A high power GaAs monolithic RF switch IC that can handle powers over 5 W (P1 dB: 37 dBm) with a positive 5-V control voltage was developed. This high power handling capability was achieved by using a novel circuit configuration that makes possible the feeding forward of the input-signal to the control gates. The implemented Single Pole Dual Throw switch IC integrated with the coupling capacitors using a high dielectric material, Barium Strontium Titanate, shows an insertion loss less than 0.8 dB at 1 GHz and an isolation over 25 dB in a frequency range of 0.5-1.5 GHz     

The package integration of RF-MEMS switch and control IC for wireless applications

The integration of microelectromechanical systems (MEMS) switch and control integrated circuit (IC) in a single package was developed for use in next-generation portable wireless systems. This packaged radio-frequency (RF) MEMS switch exhibits an insertion loss under -0.4 dB, and isolation greater than -45 dB. This MEMS switch technology has significantly better RF characteristics than conventional PIN diodes or field effect transistor (FET) switches and consumes less power. The RF MEMS switch chip has been integrated with a high voltage charge pump plus control logic chips into a single package to accommodate the low voltage requirements in portable wireless applications. This paper discusses the package assembly process and critical parameters for integration of MEMS devices and bi-complementary metal oxide semiconductor (CMOS) control integrated circuit (IC) into a single package.     

An implantable wireless bidirectional communication microstimulator for neuromuscular stimulation

This paper presents the integrated circuit design for a wireless bidirectional transmission microstimulator. This implantable device is composed of an internal radio-frequency (RF) front-end circuit, a control circuit, a stimulator, and an on-chip transmitter. A 2-MHz amplitude-shift keying modulated signal, including the power and data necessary for the implantable device, is received, and a stable 3-V dc voltage and digital data will be extracted to further execute neuromuscular stimulation. The current-mode microstimulator can produce a bidirectional output current with 8-bit resolution for stimulation. The maximum stimulation current is 1 mA while the stimulation frequency is from 20 Hz to 2 kHz and the pulsewidth of stimulation current is from 150 to 500 /spl mu/s. Furthermore, the system can acquire the biological sensing signal by means of an on-chip transmitter. Most of the signal processing circuits have been designed with low-power schemes to reduce the power consumption, and the performance is also conformed to the requirements of the microstimulator. All of the circuits except for the RF link are combined in a single chip and implemented in TSMC 0.35-/spl mu/m 2P4M standard CMOS process.     

16×16 optical-fiber crossbar switch operating at 0.85 μm

An optical-fiber crossbar switch has been constructed using fully integrated GaAs optoelectronic receivers, custom monolithic GaAs laser drivers, and an electrical 32×32 silicon crossbar switch. 470 Mb/s operation has been achieved with a bit error rate of less than 10^-12. The approach uses a monolithic GaAs optoelectronic integrated receiver to convert optical signals into electrical signals that are fed into an Si 32×32 electronic crossbar switch. The switch outputs are used to drive laser transmitters consisting of a custom monolithic GaAs IC laser driver and a 0.85 μm GaAs/AlGaAs laser. The system could be reconfigured in 1 μm, limited by the control logic, with the switch chip capable of reconfiguration in 35 ns. No errors are induced by reconfiguration     

A Multi-Carrier QAM Transceiver for Ultra-Wideband Optical Communication

The feasibility of a 40 Gb/s subcarrier modulated optical transmission system using low-cost optoelectronic components and CMOS IC technology is presented. The optical channel impairments are studied. A complete DSP framework is developed to cancel out the optical channel impairments as well as analog circuit imperfections. To validate that the 40 Gb/s system can be implemented in CMOS, an integrated QAM-16 transceiver with a carrier frequency of 13.32 GHz was designed and fabricated in a 0.14$muhbox m$, 1.5 V CMOS technology. The test chip occupies 3.6$hbox mm^2$of area and consumes 340 mW of power. Measurement results for a transmission link consisting of the CMOS QAM-16 modulator/demodulator, a directly modulated laser (DML), a 30 km single mode fiber and a p-i-n photo-detector are reported.     

The prospects for ultrahigh-speed VLSI GaAs digital logic

Recent advances in the state of GaAs integrated circuit fabrication technology have made possible the demonstration of ultrahigh performance (tau_{d} sim 100ps) GaAs digital IC's with up to 64 gate MSI circuit complexities and with gate areas and power dissipations sufficiently low to make VLSI circuits achievable. It is the purpose of this paper to evaluate, based on the current state of GaAs IC technology and the fundamental device physics involved, the prospects of achieving an ultrahigh-speed VLSI GaAs IC technology. The paper includes a performance comparison analysis of Si and GaAs FET's and switching circuits which indicates that, for equivalent speed-power product operation, GaAs IC's should be about six times faster than Si IC's. The state of the art in GaAs IC fabrication and logic circuit approaches is reviewed, with particular emphasis on those approaches which are LSI/VLSI compatible in power and density. The experimental performance results are compared for the leading GaAs logic circuit approaches, both for simple ring oscillators and for more complex sequential logic circuits (which have demonstrated equivalent gate delays as low astau_{d} = 110ps).     

The prospects for ultrahigh-speed VLSI GaAs digital logic

Recent advances of GaAs integrated circuit fabrication technology have made possible the demonstration of ultrahigh performance GaAs digital ICs with up to 64 gate MSI circuit complexities and with gate areas and power dissipations sufficiently low to make VLSI circuits achievable. The authors evaluate, based on the current state of GaAs IC technology and the fundamental device physics involved, the prospects of achieving an ultrahigh-speed VLSI GaAs IC technology. GaAs IC fabrication and logic circuit approaches is reviewed. The experimental performance results are compared for the leading GaAs logic circuit approaches, both for simple ring oscillators and for more complex sequential logic circuits.     

Design of a sensorless commutation IC for BLDC motors

This paper presents the design and realization of a sensorless commutation integrated circuit (IC) for brushless DC motors (BLDCMs) by using mixed-mode IC design methodology. The developed IC can generate accurate commutation signals for BLDCMs by using a modified back-EMF sensing scheme instead of using Hall-effect sensors. This IC can be also easily interfaced with a microcontroller or a digital signal processor (DSP) to complete the closed-loop control of a BLDCM. The developed sensorless commutation IC consists of an analog back-EMF processing circuit and a programmable digital commutation control circuit. Since the commutation control is very critical for BLDCM control, the proposed sensorless commutation IC provides a phase compensation circuit to compensate phase error due to low-pass filtering, noise, and nonideal effects of back-EMFs. By using mixed-mode IC design methodology, this IC solution requires less analog compensation circuits compared to other commercially available motor control ICs. Therefore, high maintainability and flexibility can be both achieved. The proposed sensorless commutation IC is integrated in a standard 0.35-/spl mu/m single-poly four-metal CMOS process, and the realization technique of this mixed-mode IC has been given. The proposed control scheme and developed realization techniques provide illustrative engineering procedures for the system-on-a-chip solution for advanced digital motor control. Simulation and experimental results have been carried out in verification of the proposed control scheme.     

Measurement of on-chip waveforms and pulse propagation in digital GaAs integrated circuits by picosecond electro-optic sampling

We demonstrate precise measurement of sub-100 ps rise time on-chip electrical waveforms and of pulse propagation in digital GaAs integrated circuits with the use of picosecond electro-optic sampling. These experiments yield the first non-invasive measurement of single-gate propagation delays via direct and precise observation of on-chip waveforms at the input and output of individual logic gates internal to an integrated circuit.     

Fully Integrated Broadband CPW Left-Handed Metamaterials Based on GaAs Technology for RF/MMIC Applications

A fully integrated broadband coplanar waveguide left-handed metamaterial medium using GaAs technology for radio frequency/monolithic microwave integrated circuit (RF/MMIC) applications is reported and validated by the full wave simulation and measured results. The unit cell of the fabricated structures has a size of 0.09 mm². The left handedness of the integrated left-handed structure extends from 2.3 to 17.5 GHz. The compactness and broad left-handed operating bandwidth make the presented left-handed metamaterial be well incorporated with RF/MMIC applications.     

Design and implementation of an FPGA-based control IC forAC-voltage regulation

This paper presents a field-programmable gate army (FPGA)-based control integrated circuit (IC) for controlling the pulsewidth modulation (PWM) inverters used in power conditioning systems for AC-voltage regulation. We also propose a multiple-loop control scheme for this PWM inverter control IC to achieve sinusoidal voltage regulation under large load variations. The control scheme is simple in architecture and thus facilitates realization of the proposed digital controller for the PWM inverter using the FPGA-based circuit design approach. Bit-length effect of the digital PWM inverter controller has also been examined in this paper. The designed PWM inverter control IC has been realized using a single FPGA XC4005 from Xilinx Inc., which can be used as a coprocessor with a general-purpose microprocessor in application of AC-voltage regulation. Owing to the high-speed nature of FPGA, the sampling frequency of the constructed IC can be raised up to the range that cannot be reached using a conventional digital controller based merely on microcontrollers or a digital signal processor (DSP). Experimental results show the designed PWM inverter control IC using the proposed control scheme can achieve good voltage regulation against large load variations