High-gain Amplifier Research Articles

High-Gain Nanosecond Vortex Laser

We demonstrate a high-gain vortex power amplifier with the double-pass configuration based on the rod Nd:YAG crystal. In the experiments, a nanosecond vortex seed beam is converted from a conventional Q-switched Nd:YAG laser output with a spiral phase plate and then amplified with the Nd:YAG amplifier stage. A maximum amplification output energy up to 163.5 mJ is achieved at 20 Hz with a 3.2-ns pulse, corresponding to an amplification factor of 81.8. Further discussions are provided to find ways of increasing the power scaling.

Design and analysis of high gain and low noise figure CMOS low noise amplifier for Q-band nano-sensor application

A high gain, low power, low Noise figure (NF) and wide band of milli-meter Wave (mmW) circuits design at 50 GHz are used for Radio Frequency (RF) front end. The fundamental necessity of a receiver front-end includes perfect output and input impedance matching and port-to-port isolation with high gain and low noise over the entire band of interest. In this paper, a design of Cascade-Cascode CMOS LNA circuit at 50 GHz for Q-band application is proposed. The design of Low noise amplifier at 50 GHz using Agilent ADS tool with microstrip lines which provides simplicity in fabrication and less chip area. The low off-leakage current Ioff can be maintained with high K-dielectrics CMOS structure. Nano-scale electronics can be achieved with increased robustness. The design has overall gain of 11.091 dB and noise figure of 2.673 dB for the Q-band of 48.3 GHz to 51.3 GHz. Impedance matching is done by T matching network and the obtained input and output reflection coefficients are S11 = <−10 dB and S22 = <−10 dB. Compared to Silicon (Si) material, Wide Band Gap semiconductor materials used attains higher junction temperatures which is well matched to ceramics used in packaging technology, the protection and reliability also can be achieved with the electronic packaging. The reverse transmission coefficient S21 is less than −21 dB has shown that LNA has better isolation between input and output, Stability factor greater than 1 and Power is also optimized in this design. Layout is designed, power gain of 4.6 dB is achieved and area is optimized which is nearly equal to 502 740 μm2. The observed results show that the proposed Cascade-Cascode LNA design can find its suitability in future milli-meter Wave Radar application.

80-kb Logic Embedded High-K Charge Trap Transistor-Based Multi-Time-Programmable Memory With No Added Process Complexity

This paper describes the design and implementation of an 80-kb logic-embedded non-volatile multi-time programmable memory (MTPM) with no added process complexity. Charge trap transistors (CTTs) that exploit charge trapping and de-trapping behavior in high-K dielectric of 32-/22-nm Logic FETs are used as storage elements with logic-compatible programming voltages. A high-gain slew-sense amplifier (SA) is used to efficiently detect the threshold voltage difference ( $\Delta V_{\textrm {DIF}}$ ) between the true and complement FETs in the twin cell. Design-assist techniques including multi-step programming with over-write protection and block write algorithm are used to enhance the programming efficiency without causing a dielectric breakdown. High-temperature stress results show a projected data retention of 10 years at 125 °C with a signal loss of <30% that is margined in while programming, by employing a sense margining logic in the SA. Scalability of CTT has been established by the first demonstration of CTT-based MTPM in 14-nm bulk FinFET technology with read cycle time of 40 ns at 0.7-V VDD.

An Injection- and Frequency-Locked Loop for Reducing Phase Noise of Wideband Oscillators

High-performance microwave oscillators often exploit feedback loop methods such as those that involve a frequency-locked loop (FLL) or a self-injection-locked loop to improve phase noise. This paper proposes a novel injection- and frequency-locked loop (IFLL) for reducing phase noise of wideband oscillators, which uses an injection-locked oscillator instead of a high-gain amplifier and a variable phase shifter in the FLL to amplify and phase-shift the feedback signal. In this paper, the frequency domain analysis is presented to characterize the proposed IFLL and compared with the experimental results. Consequently, the oscillators that use the IFLL exhibit remarkable phase-noise reduction, which is 5.5–9.3 dB better than that achieved using conventional FLLs at 1-MHz offset frequency, over a wide tuning range of about 53%.

A Sampling Holder Using A Bootstrapped Switch

This paper describes the design of a sampling holder, Using a higher linearity bootstrapped switch, by using the bottom plate sampling to offset the effect of charge injection effect, By using the capacitance flip type structure to reduce power consumption, designing a high gain and high speed operational trans-conductance amplifier to improve gain and speed.

Cusp Guns for Helical-Waveguide Gyro-TWTs of a High-Gain High-Power W-Band Amplifier Cascade

The evaluation, design, and simulations of two different electron guns generating the beams for W-band second cyclotron harmonic gyro-TWTs forming a high-gain powerful amplifier cascade are presented. The optimum configurations of the systems creating nearly axis-encircling electron beams having velocity pitch-factor up to 1.5, voltage/current of 40 kV/0.5 A, and 100 kV/13 A with acceptable velocity spreads have been found and are presented.

Light amplification by seeded Kerr instability.

Amplification of femtosecond laser pulses typically requires a lasing medium or a nonlinear crystal. In either case, the chemical properties of the lasing medium or the momentum conservation in the nonlinear crystal constrain the frequency and the bandwidth of the amplified pulses. We demonstrate high gain amplification (greater than 1000) of widely tunable (0.5 to 2.2 micrometers) and short (less than 60 femtosecond) laser pulses, up to intensities of 1 terawatt per square centimeter, by seeding the modulation instability in an Y3Al5O12 crystal pumped by femtosecond near-infrared pulses. Our method avoids constraints related to doping and phase matching and therefore can occur in a wider pool of glasses and crystals even at far-infrared frequencies and for single-cycle pulses. Such amplified pulses are ideal to study strong-field processes in solids and highly excited states in gases.

Fiber-Optic Pyrometer with Optically Powered Switch for Temperature Measurements.

We report the experimental results on a new infrared fiber-optic pyrometer for very localized and high-speed temperature measurements ranging from 170 to 530 °C using low-noise photodetectors and high-gain transimpedance amplifiers with a single gain mode in the whole temperature range. We also report a shutter based on an optical fiber switch which is optically powered to provide a reference signal in an optical fiber pyrometer measuring from 200 to 550 °C. The tests show the potential of remotely powering via optical means a 300 mW power-hungry optical switch at a distance of 100 m, avoiding any electromagnetic interference close to the measuring point.

A 12-Gb/s -16.8-dBm OMA Sensitivity 23-mW Optical Receiver in 65-nm CMOS

Optical interconnects are being increasingly deployed in data centers to meet growing bandwidth requirements under tight power constraints. Therefore, there has been renewed focus on increasing data rates and improving power efficiency of optical links. Among all the link components, laser diodes typically consume the most power. Their power dissipation is dictated by the amount of signal power that needs to be transmitted to meet the bit error rate requirements under given channel loss and receiver sensitivity conditions. Consequently, improving receiver sensitivity directly helps lowering laser diode power consumption. In this paper, we present design techniques to implement such high sensitivity optical receivers. To this end, we identify noise–bandwidth tradeoffs of a shunt feedback transimpedance amplifier (SF-TIA) and elucidate how they limit the maximum achievable sensitivity at a given data rate and process technology. We then propose to combine a low-bandwidth SF-TIA with a four-tap decision feedback equalizer to overcome this noise–bandwidth tradeoff. The proposed SF-TIA uses high-gain multistage amplifier and large feedback resistance and achieves greatly improved noise performance. Fabricated in a 65-nm CMOS technology and heterogeneously integrated with a photonic IC, the proposed optical receiver achieves optical modulation amplitude sensitivity of −16.8 dBm with 1.9-pJ/bit efficiency at 12 Gb/s.

High-gain, low-threshold and small-footprint optical parametric amplifier for photonic integrated circuits

A new model of an optical parametric amplifier is proposed based on a silicon-slab slotted photonic crystal waveguide (SPCW). The slot is considered to be filled with silicon nanocrystal material (SiNC/SiO2) having a high Kerr nonlinearity. The extreme optical confinement (spatial and temporal) of the SPCW has enhanced the optical nonlinearity, and thus, a high parametric gain is attained in a small length of the waveguide. Further, for analyses of pulse propagation, the coupled nonlinear Schrodinger’s equations have been modified to incorporate the enhancements in the linear and the nonlinear coefficients due to the slow-light effect. Simulations have been performed on both the high group index region and the low-dispersion regions of the guided band. The simulations on the high group index region, centered at ≈1584 nm, depict a 22.6 dB parametric gain and a 20.9 dB conversion efficiency at a waveguide length of 152 μm, with an effective pump power and peak input signal power of 700 mW and 0.25 Mw, respectively. The pulsating signal, with a pulse width of 5 ps, also experienced a negligible deterioration in its pulse shapes in this length of the SPCW. On the other hand, the simulations on the region of negligible dispersion, centered at 1530 nm, have produced an over 10 dB parametric gain and conversion efficiency through a long range of wavelengths, i.e., 1490–1568 nm, which covers half of the S-band and the complete C-band of the optical communication windows. The significant gain at a micrometer scale length of the waveguide is expected to advance the possibility of on-chip integration of a high-speed all-optical amplifier in photonic integrated circuits.

Influence on the saturable absorption of the induced losses by photodeposition of zinc nanoparticles in an optical fiber.

In this work, the influence of induced losses on the saturable absorption by zinc nanoparticles photodeposited onto the core of an optical fiber end is reported. Samples with different losses were obtained by the photodeposition technique using a continuous wave laser at 1550 nm. The nonlinear absorption of the saturable absorber was characterized by the P-scan technique using a high-gain pulsed erbium-doped fiber amplifier. The results have demonstrated that for optical fibers with variable induced losses by deposited nanoparticles, the modulation depth increases proportionally based on the nonlinear absorption coefficient. With induced losses fixed at 3 dB, it was demonstrated that the modulation depth increased as a function of the optical power used in the photodeposition process. The saturation intensity of the saturable absorber presents small shifts for higher intensities.

High-Gain Transimpedance Amplifier for Flexible Radiation Dosimetry Using InGaZnO TFTs

This paper presents a novel high-gain transimpedance amplifier for flexible radiation sensing systems that can be used as large-area dosimeters. The circuit is implemented with indium-gallium-zinc-oxide thin-film-transistors and uses two stages for the amplification of the sensor signal (current). The first stage consists of cascode current mirrors with a diode connected load that performs current amplification and voltage conversion. Then, the first stage is followed by a voltage amplifier based on a positive feedback topology for gain enhancement. The proposed circuit converts nano-ampere (10 nA) currents into hundreds of millivolts (280 mV), showing a gain around 149 dB and a power consumption of 0.45 mW. The sensed radiation dose level, in voltage terms, can drive the next stages in the radiation sensing system, such as analog to digital converters. These radiation sensing devices can find potential applications in real-time, large area, flexible health, and security systems.

Weak laser pulse signal amplification based on a fiber Brillouin amplifier

We propose a high-gain and frequency-selective amplifier for a weak optical signal based on stimulated Brillouin scattering in a single mode fiber. To be able to satisfy the needs of high gain and high signal-to-noise ratio laser pulse amplification, different fiber lengths and core diameters are used to fulfill this experiment. In the experiment, a 430 nW (peak power) pulsed signal is amplified by 70 dB with a signal-to-noise ratio of 14 dB. The small size, high gain, low cost, and low noise of the fiber Brillouin amplifier make it a promising weak signal amplification method for practical applications such as lidar.

Development of Bi/Er co-doped optical fibers for ultra-broadband photonic applications

Targeting the huge unused bandwidth (BW) of modern telecommunication networks, Bi/Er co-doped silica optical fibers (BEDFs) have been proposed and developed for ultra-broadband, high-gain optical amplifiers covering the 1150–1700 nm wavelength range. Ultrabroadband luminescence has been demonstrated in both BEDFs and bismuth/erbium/ytterbium co-doped optical fibers (BEYDFs) fabricated with the modified chemical vapor deposition (MCVD) and in situ doping techniques. Several novel and sophisticated techniques have been developed for the fabrication and characterization of the new active fibers. For controlling the performance of the active fibers, post-treatment processes using high temperature, g-radiation, and laser light have been introduced. Although many fundamental scientific and technological issues and challenges still remain, several photonic applications, such as fiber sensing, fiber gratings, fiber amplification, fiber lasers, etc., have already been demonstrated.

Application of 1013 ohm Faraday cup current amplifiers for boron isotopic analyses by solution mode and laser ablation multicollector inductively coupled plasma mass spectrometry.

Boron isotope ratios (δ11 B values) are used as a proxy for seawater paleo-pH, amongst several other applications. The analytical precision can be limited by the detection of low intensity ion beams from limited sample amounts. High-gain amplifiers offer improvements in signal/noise ratio and can be used to increase measurement precision and reduce sample amounts. 1013 ohm amplifier technology has previously been applied to several radiogenic systems, but has thus far not been applied to non-traditional stable isotopes. Here we apply 1013 ohm amplifier technology for the measurement of boron isotope ratios using solution mode MC-ICP-MS and laser ablation mode (LA-)MC-ICP-MS techniques. Precision is shown for reference materials as well as for low-volume foraminifera samples. The baseline uncertainty for a 0.1 pA 10 B+ ion beam is reduced to <0.1 ‰ for a typical measurement period. The external precision is better than 0.2 ‰ (2SD) for δ11 B measurements for solution samples containing as little as 0.8 ng total boron. For in situ microanalyses with LA-MC-ICP-MS, the external precision of 11 B/10 B from an in-house calcite standard was 1 ‰ (2SD) for individual spot analyses, and 0.3 ‰ for the mean of ≥10 replicate spot analyses. 1013 ohm amplifier technology is demonstrated to offer advantages for the determination of δ11 B values by both MC-ICP-MS and LA-MC-ICP-MS for small samples of biogenic carbonates, such as foraminifera shells. 1013 ohm amplifier technology will also be of benefit to other non-traditional stable isotope measurements.

High-dynamic-range programmable gain amplifier with linear-in-dB and DAC gain control

This paper presents a high dynamic range programmable gain amplifier (PGA) with linear-in-dB and digital to analog converter (DAC) gain control using a BiCMOS process. The proposed PGA is composed of a folded Gilbert variable gain amplifier cell, a DC offset cancellation circuitry, two inductorless fixed gain amplifiers with bandwidth extension, a symmetrical exponential voltage generator, a novel buffer amplifier with active inductive peaking for testing purposes and a 10 bit R-2R DAC. The linear-in-dB and DAC gain control scheme facilitate the analog baseband gain tuning accuracy and stability, which also provides an efficient way for digital baseband automatic gain control. The PGA chip is fabricated using 0.13 μm SiGe BiCMOS technology. With a power consumption of 80 mA@1.2 V supply voltage, the fabricated circuit exhibits a tunable gain range of − 30–27 dB (DAC linear gain step guaranteed), a 3 dB bandwidth of around 3.5 GHz and a gain resolution of better than 0.07 dB.

Universal design of a microcontroller and IoT system to detect the heart rate

Heart rate analysis provides vital information of the present condition of the human body. It helps medical professionals in diagnosis of various malfunctions of the body. The limitation of vision impaired and blind people to access medical devices cause a considerable loss of life. In this paper, we intended to develop a heart rate detection system that is usable for people with normal and abnormal vision. The system is based on a non-invasive method of measuring the variation of the tissue blood flow rate by means of a photo transmitter and detector through fingertip known as photoplethysmography (PPG). The signal detected is firstly passed through active low pass filter and then amplified by a two stages high gain amplifier. The amplified signal is feed into the microcontroller to calculate the heart rate and displays the heart beat via sound systems and Liquid Crystal Display (LCD). To distinguish arrhythmia, normal heart rate and abnormal working conditions of the system, recognition is provided in different sounds, LCD readings and Light Emitting Diodes (LED).

A Comparative Analysis on Fully Integrated Spectral Broadening of Kerr Frequency Combs

Microresonator-based frequency combs have potential to achieve on-chip frequency metrology. To obtain high-power comb lines at f and 2f for self-referenced stabilization, we evaluate the feasibility of building a fully integrated comb generator with spectral broadening. Comparing two types of nonlinear waveguides based on Si and chalcogenides, we find that the system feasibility relies on integrated waveguide amplifiers. If with a high-gain amplifier, a dispersion-engineered chalcogenide waveguide is preferred. Otherwise, an Si waveguide performs better. Considering the immaturity of both on-chip amplification technologies for ultrafast pulses and hybrid integration of multiple nonlinear materials, it could be concluded that in near future it is not practical to achieve fully on-chip f-2f self-referenced comb stabilization via subsequent spectral broadening of a Kerr frequency comb. Alternatively, direct generation of octave-spanning Kerr combs via dispersion engineering still remains attractive.

Enhancement of spectroscopic and luminescence properties of Er3+ doped tellurite glasses by adding P2O5 for lasing materials

Er3+-doped phosphor-tellurite glasses has been synthesized by conventional melting method. Results of differential scanning calorimetry (DSC) measurements indicate a good thermal stability of tellurite glasses. The DSC measurements show an improvement of thermal stability of glass hosts after adding P2O5. The structures of glasses were investigated by X-ray diffraction (XRD) and Raman spectroscopy to understand their dependence of structure on composition. Absorption spectrum from near infrared to visible was obtained and the Judd–Ofelt (J-O) intensity parameters (Ω2, Ω4, and Ω6) were determined. Spontaneous emission probabilities of some relevant transitions, branching ratio, and radiative lifetimes of several excited states of Er3+ have been predicted using intensity J-O parameters. Up-conversion luminescence characteristics, under 977 nm excitation wavelength, have been investigated at room and low temperature in these glasses. Intense green and red emissions from Er3+ centered at 534 nm, 548 nm and 660 nm, corresponding to the transitions 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2, respectively, were simultaneously observed. The quadratic dependence of the up-conversion emission on the excitation power indicates that two-photon steps are involved for the three visible emission bands. The PL lifetimes is found to decrease in the temperature range 77–300K. Using the Mc-Cumber method, emission cross-section (σe), Absorption cross-section (σa), and gain cross-section (G(λ)) for the 4I13/2→4I15/2 transition, were calculated. By analyzing obtained data based to all advantages after adding P2O5, the tellurite glasses can be used as potential host material for developing optical amplifiers applied for 1.53 µm band broad and high-gain erbium-doped fiber amplifiers (EDFA).

A 152-GHz OOK Transmitter With 3-dBm Output Power in 65-nm CMOS

A high output power 152 GHz ON-OFF keying transmitter in 65-nm CMOS is presented. The transmitter consists of a high dc-RF efficiency push-push voltage-controlled oscillator followed by a high-speed and high-gain switched-mode power amplifier. The transmitter achieves the highest output power (3 dBm) beyond 140 GHz in silicon process, with high on-off ratio (>39 dB) and high dc-RF efficiency (3.7%). The transmitter could support 10-Gb/s data rate communication with a bit-error rate of less than 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup> .