A baseband LPF for GSM,TD-SCDMA and WCDMA multi-mode transmitters

This paper describes a low-pass reconfigurable baseband filter for GSM,TD-SCDMA and WCDMA multi-mode transmitters.To comply with 3GPP emission mask and limit TX leakage at the RX band,the out-of -band noise performance is optimized.Due to the distortion caused by the subthreshold leakage current of the switches used in capacitor array,a capacitor bypass technique is proposed to improve the filter’s linearity.An automatic frequency tuning circuit is adopted to compensate the cut-off frequency variation.Simulation results show that the filter achieves an in-band input-referred third-order intercept point(IIP3) of 47 dBm at 1.2-V power supply and the out-of-band noise can meet TX SAW-less requirement for WCDMA & TD-SCDMA.The baseband filter incorporates -40 to 0 dB programmable gain control that is accurately variable in 0.5 dB steps.The filter’s cut-off frequency can be reconfigured for GSM/TD-SCDMAAVCDMA multi-mode transmitter.The implemented baseband filter draws 3.6 mA from a 1.2-V supply in a 0.13μm CMOS process.     

A continuously and widely tunable analog baseband chain with digital-assisted calibration for multi-standard DBS applications

This paper presents a continuously and widely tunable analog baseband chain with a digital-assisted calibration scheme implemented on a 0.13μm CMOS technology.The analog baseband is compliant with several digital broadcasting system（DBS） standards,including DVB-S,DVB-S2,and ABS-S.The cut-off frequency of the baseband circuit can be changed continuously from 4.5 to 32 MHz.The gain adjustment range is from 6 to 55.5 dB with 0.5 dB step.The calibration includes automatic frequency tuning（AFT） and automatic DC offset calibration （DCOC） to achieve less than 6%cut-off frequency deviation and 3 mV residual output offset.The out-of-band IIP2 and IIP3 of the overall chain are 45 dBm and 18 dBm respectively,while the input referred noise（IRN） is 17.4 nV/Hz^1/2.All circuit blocks are operated at 2.8 V from LDO and consume current of 20.4 mA in the receiving mode.     

一种新型指数增益控制60dB可变增益放大器

A CMOS variable gain amplifier（VGA） that adopts a novel exponential gain approximation is presented.No additional exponential gain control circuit is required in the proposed VGA used in a direct conversion receiver.A wide gain control voltage from 0.4 to 1.8 V and a high linearity performance are achieved.The three-stage VGA with automatic gain control（AGC） and DC offset cancellation（DCOC） is fabricated in a 0.18-μm CMOS technology and shows a linear gain range of more than 58-dB with a linearity error less than ±1 dB.The 3-dB bandwidth is over 8 MHz at all gain settings.The measured input-referred third intercept point（IIP3） of the proposed VGA varies from-18.1 to 13.5 dBm,and the measured noise figure varies from 27 to 65 dB at a frequency of 1 MHz.The dynamic range of the closed-loop AGC exceeds 56 dB,where the output signal-to-noise-and-distortion ratio（SNDR） reaches 20 dB.The whole circuit,occupying 0.3 mm^2 of chip area,dissipates less than 3.7 mA from a 1.8-V supply.     

LC voltage controlled oscillator in 0.18-μm RF CMOS

An integrated low-phase-noise voltage-controlled oscillator(VCO) has been designed and fabricated in SMIC 0.18μm RF CMOS technology.The circuit employs an optimally designed LC resonator and a differential cross-coupling amplifier acts as a negative resistor to compensate the energy loss of the resonator.To extend the frequency tuning range,a three-bit binary-weighted switched capacitor array is used in the circuit.The testing result indicates that the VCO achieves a tuning range of 60%from 1.92 to 3.35 GHz.The phase noise of the VCO is -117.8 dBc/Hz at 1 MHz offset from the carrier frequency of 2.4 GHz.It draws 5.6 mA current from a 1.8 V supply.The VCO integrated circuit occupies a die area of 600×900μm~2.It can be used in the IEEE802.11 b based wireless local network receiver.     

一种带宽为3.8GHz，增益步长为0.1dB的可编程增益放大器

A broadband programmable gain amplifier（PGA） with a small gain step and low gain error has been designed in 0.13 m CMOS technology. The PGA was implemented with open-loop architecture to provide wide bandwidth. A two-stage gain control method, which consists of a resistor ladder attenuator and an active fine gain control stage, provides the small gain step. A look-up table based gain control method is introduced in the fine gain control stage to lower the gain error.The proposedPGAshows a decibel-linear variable gainfrom4 to20 dB with a gain step of 0.1 dB and a gain error less than˙0.05 dB. The 3-dB bandwidth and maximum IIP3 are 3.8 GHz and 17 dBm, respectively.     

Wide band low phase noise QVCO based on superharmonic injection locking

A wide band, injection-coupled LC quadrature voltage control oscillator is presented. In the proposed circuit, two oscillators are injection locked by coupling their second-order harmonics in anti-phase, forcing the outputs of two oscillators into a quadrature phase state. As the common-mode point sampling the second harmonic frequency, flicker noise of the tail current is suppressed, the phase noise is reduced.The proposed design accomplishes a wide tuning frequency range by a combination of using a 5-bit switch capacitor array (SCA) for discrete tuning in addition to linearly varying AMOS varactors for continuous tuning. The proposed design has been fabricated and verified in a 0.18 μ m TSMC CMOS technology process. The measurement indicates that the quadrature voltage controlled oscillator has a 41.7% tuning range from 3.53 to 5.39 GHz. The measured phase noise is 127.98 dBc/Hz at 1 MHz offset at a 1.8 V supply voltage with a power consumption of 12 mW at a carrier frequency of 4.85 GHz.     

A novel analog/digital reconfigurable automatic gain control with a novel DC offset cancellation circuit

An analog/digital reconfigurable automatic gain control(AGC) circuit with a novel DC offset cancellation circuit for a direct-conversion receiver is presented.The AGC is analog/digital reconfigurable in order to be compatible with different baseband chips.What’s more,a novel DC offset cancellation(DCOC) circuit with an HPCF(high pass cutoff frequency) less than 10 kHz is proposed.The AGC is fabricated by a 0.18μm CMOS process.Under analog control mode,the AGC achieves a 70 dB dynamic range with a 3 dB-bandwidth larger than 60 MHz.Under digital control mode,through a 5-bit digital control word,the AGC shows a 64 dB gain control range by 2 dB each step with a gain error of less than 0.3 dB.The DC offset cancellation circuits can suppress the output DC offset voltage to be less than 1.5 mV,while the offset voltage of 40 mV is introduced into the input.The overall power consumption is less than 3.5 mA,and the die area is 800×300μm~2.     

A 0.18μm CMOS single-inductor single-stage quadrature frontend for GNSS receiver

This paper presents an improved merged architecture for a low-IF GNSS receiver frontend,where the bias current and functions are reused in a stacked quadrature LNA-mixer-VCO.Only a single spiral inductor is implemented for the LC resonator and an extra 1/2 frequency divider is added as the quadrature LO signal generator. The details of the design are presented.The gain plan and noise figure are discussed.The phase noise,quadrature accuracy and power consumption are improved.The test chip is fabricated though a 0.18μm RF CMOS process. The measured noise figure is 5.4 dB on average,with a gain of 43 dB and a IIP3 of-39 dBm.The measured phase noise is better than -105 dBc/Hz at 1 MHz offset.The total power consumption is 19.8 mW with a 1.8 V supply. The experimental results satisfy the requirements for GNSS applications.     

一种集成二进制权精确对数线性可编程增益放大器的卫星导航接收机数字自动增益控制环路

A novel digitally controlled automatic gain control(AGC) loop circuitry for the global navigation satellite system(GNSS) receiver chip is presented. The entire AGC loop contains a programmable gain amplifier(PGA),an AGC circuit and an analog-to-digital converter(ADC), which is implemented in a 0.18 m complementary metal–oxide–semiconductor(CMOS) process and measured. A binary-weighted approach is proposed in the PGA to achieve wide d B-linear gain control with small gain error. With binary-weighted cascaded amplifiers for coarse gain control, and parallel binary-weighted trans-conductance amplifier array for fine gain control, the PGA can provide a 64 dB dynamic range from4 to 60 dB in 1.14 dB gain steps with a less than 0.15 dB gain error. Based on the Gaussian noise statistic characteristic of the GNSS signal, a digital AGC circuit is also proposed with low area and fast settling. The feed-backward AGC loop occupies an area of 0.27 mm2 and settles within less than165 s while consuming an average current of 1.92 mA at 1.8 V.     

A △∑ fractional-N frequency synthesizer for FM tuner using low noise filter and quantization noise suppression technique

A △∑ fractional-N frequency synthesizer fabricated in a 130 nm CMOS technology is presented for the application of an FM tuner. A low noise filter, occupying a small die area and decreasing the output noise, is integrated on a chip. A quantization noise suppression technique, using a reduced step size of the frequency divider, is also adopted. The proposed synthesizer needs no off-chip components and occupies an area of 0.7 mm2. The in-band phase noise （from 10 to 100 kHz） below -108 dBc/Hz and out-of-band phase noise of -122.9 dBc/Hz （at 1 MHz offset） are measured with a loop bandwidth of 200 kHz. The quantization noise suppression technique reduces the in-band and out-of band phase noise by 15 dB and 7 dB respectively. The integrated RMS phase error is no more than 0.48°. The proposed synthesizer consumes a total power of 7.4 mW and the frequency resolution is less than 1 Hz.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks