Noise Figure Reduction Research Articles

Miniature Wide-Band Noise-Canceling CMOS LNA.

In this paper, a wide-band noise-canceling (NC) current conveyor (CC)-based CMOS low-noise amplifier (LNA) is presented. The circuit employs a CC-based approach to obtain wide-band input matching without the need for bulky inductances, allowing broadband performance with a very small area used. The NC technique is applied by subtracting the input transistor’s noise contribution to the output and achieves a noise figure (NF) reduction from 4.8 dB to 3.2 dB. The NC LNA is implemented in a UMC 65-nm CMOS process and occupies an area of only 160 × 80 μm2. It achieves a stable frequency response from 0 to 6.2 GHz, a maximum gain of 15.3 dB, an input return loss (S11) < −10 dB, and a remarkable IIP3 of 7.6 dBm, while consuming 18.6 mW from a ±1.2 V DC supply. Comparisons with similar works prove the effectiveness of this new implementation, showing that the circuit obtains a noteworthy performance trade-off.

On the phase fading effect in the dual-pulse heterodyne demodulated distributed acoustic sensing system.

Understanding signal fading effect is essential for the application of Rayleigh-scattering-based distributed acoustic fibre sensors (DASs) due to the nature of coherent beam interference within the pulse length. Statistical properties for the intensity of the Rayleigh backscattered light (i.e. intensity fading) and its impact on the sensitivity of DAS systems have been intensely studied over the last decades. Here we for the first time establish an analytical model for the phase signal retrieved from the dual-pulse heterodyne demodulated DAS system, which can be exploited to investigate the phase fading effect in this system. The developed model reveals that the phase fading phenomenon mainly originates from the randomness in the phase retardant of the Rayleigh scatters. The quantitatively resolved statistical features of the phase fading is confirmed by experimental results. Based on the analytical model, a noise figure is defined to characterize the global fading-induced noise level via taking into account contributions from all channels along the sensing fiber. The model also reproduces the anti-correlation relation between the power spectrum density of retrieved phase at the heterodyne frequency and the phase fading noise level. Following the analysis and the definition of the noise figure, an optimized real-time weighted-channel stack algorithm is developed to efficiently suppress the fading noise. Experimental results show that the algorithm can achieve a maximum noise figure reduction of 15.8 dB without increasing the system complexity.

Exploiting MOS Parametric Amplification to Suppress Noise in Switched-Capacitor RF Receivers

This article presents a technique to suppress noise in switched-capacitor (SC) radio frequency (RF) receivers (RXs). In the proposed technique, the sampling capacitor of a typical SC-RX is realized using a MOS capacitor. Furthermore, the same sampling MOS capacitor is switched between the inversion and depletion regions to act as a discrete-time parametric amplifier for downconverted signals. Due to the voltage gain at the front end, the noise of successive stages in the receiver chain is suppressed. Analytical expressions for the conversion gain, input impedance, and noise figure (NF) of the gain-boosted SC receiver are derived and verified through simulations. A prototype SC receiver is implemented in a CMOS 180-nm technology. In measurements, the receiver achieved 41-dB conversion gain and 3.1-dB NF over the tuning range of 0.2-to-0.95 GHz. The reduction in NF due to the parametric gain boost is >10 dB.

On-chip programmable microwave photonic filter with an integrated optical carrier processor

We demonstrate a programmable microwave photonic bandpass filter with a rectangular frequency response and a reconfigurable spectral resolution. We achieved these features through dual-sidebands processing of a phase modulated signal using a network of four optical ring resonators in a low-loss silicon nitride (Si3N4) circuit. Furthermore, we integrate a pair of optical ring resonators in the same circuit to precisely control the amplitude and phase of the optical carrier to enhance the noise performance of the filter. We achieved filtering with a tunable bandwidth from 2 to 7 GHz with optical carrier suppression up to 6 dB, a maximum RF gain of -10 dB, and a minimum noise figure of 27 dB. These experiments are expected to provide a feasible design to approach fully integrated microwave photonic filters with improved link gain and reduced noise figure.

On the Analysis and Comparison of Decoupled Modal Gain Equalization Systems for Four-Mode (4M)-EDFAs

SpaceDivision Multiplexing (SDM) has gained considerable interest as a promising means to increase transmission capacity per fiber. For proper use of this technology, optical components of transmission line including Erbium-Doped Fiber Amplifiers (EDFAs) need to be re-examined. In this work we analyze modal gain equalization systems obtained from extended Giles model for 4M-EDFA. We introduced a simpler method of calculation of two radial overlap factors extracted from the model using standard B–V curve thus proposing two decoupled systems for Modal Gain Equalization. In Decoupled Mode Specific Pump Combination (MSPC) system so obtained, Differential Modal Gain (DMG) was reduced to 1.55 dB with mean gain of about 28.72 dB. For Modified Erbium Doped Profile (MEDP) system we obtained an optimum Multi-Well Profile. The DMG here showed further reduction to 1.3254 dB with mean gain of about 24.24 dB. Further we report investigation on evolution of ASE for 4M-EDFA for the first time with new performance metric namely ASE ratio to indicate the deviation of noise between four modes. The ASE levels reached in MEDP are smaller than MSPC system thus enabling reduction in Noise Figure. Simulation results and comparison indicated that in MEDP, DMG is more sensitive to variation in length, concentration and wavelength. Each spatial channel in our designed MEDP and MSPC system as well as simple 4M-EDFA system gave good pre-amplification performance for data rates upto 15 Gb/s.

A Four-Phase Passive Mixer-First Receiver With a Low-Power Complementary Common-Gate TIA

This paper presents a four-phase passive mixer-first receiver using a common-gate (CG) trans-impedance amplifier (TIA), instead of a conventional shunt-feedback amplifier. The four-transistor TIA used in this work combines current-reuse with cross-coupled $g_{m}$ -boosting to achieve a reduced noise figure (NF) at low power levels. Moreover, complementary derivative-superposition (CDS) linearization within the TIA helps to improve the linearity with no additional power overhead. A prototype receiver is implemented in a 180 nm CMOS technology. The receiver operates from 0.3 to 1.3 GHz with a conversion gain of 21.9 dB. In measurements, the receiver achieved a noise figure of 5.8 dB and an in-band (IB) IIP3 of +7.2 dBm while consuming 0.34 mW power per TIA at 1 GHz. The measured spurious-free dynamic range (SFDR) at 1 GHz is 76.9 dB.

An N-Path Band-Pass Filter With Parametric Gain-Boosting

This paper presents a gain-boosting technique for two-port N-path band-pass filters (BPFs) based on the principle of discrete-time parametric amplification in MOS devices. The proposed technique also acts as a noise figure (NF) reduction technique due to the low-noise amplification before the output commutation. Analytical expressions for gain, NF, and input impedance of the proposed parametrically gain-boosted N-path BPF are derived using linear periodically time-variant (LPTV) network analysis and have been verified through simulations. The measurement results of a pseudo-differential eight-path BPF, implemented in a 180 nm CMOS technology, are presented. The center frequency of the implemented filter is tunable from 0.05 GHz to 0.4 GHz with a Q varying from 4 to 18. The gain of the filter is programmable with the input common-mode voltage. At 0.4 GHz, the filter achieves a variable gain of 2–8 dB over the input common-mode range of 0.55 V to 0.85 V. At every tuned frequency, the filter has a peak gain ≥8 dB, NF 0 dBm. It is also shown in simulations that the proposed gain-boosting technique reduced the NF of the filter by >2.2 dB while consuming a dynamic power in the range of 3.8-31 mW per filter.

Modified Gilbert-Cell Mixer With an LO Waveform Shaper and Switched Gate-Biasing for 1/f Noise Reduction in 28-nm CMOS

In this brief, we propose an active mixer based on a modified Gilbert-cell topology intended for radar applications, which uses an LO waveform shaper at mm-wave frequencies to decrease the high 1/f noise of MOS transistors. Compared to a reference mixer without an LO waveform shaper, measurement results show that this mixer achieves a significant 5 dB noise figure (NF) reduction at 100 kHz. The measured voltage conversion gain (CG) and input-referred 1-dB compression point (IP1dB) are 2 dB and −4 dBm, respectively. The core of the proposed modified Gilbert-cell draws 13 mA from a single 0.9-V supply, while it occupies an area of 0.5 mm $\times $ 0.94 mm. Additionally, an IF buffer drawing 12 mA has been added to drive a 50 $\Omega $ load for measurement purposes. To the best of author’s knowledge, we apply the principle of switched biasing for 1/f noise reduction of an active mixer at mm-wave frequencies for the first time.

A CMOS low-noise active mixer with enhanced linearity and isolation by exploiting capacitive neutralization technique

In this paper, a broadband complementary metal–oxide–semiconductor (CMOS) active down-conversion mixer is presented. Specifically, a capacitor cross-coupled (CCC) transconductor serves as the input stage to reduce noise figure of the mixer while providing wideband input matching. Moreover, a capacitive neutralization technique is used to compensate the source-drain parasitic of input stage and boost loop gain of the transconductor, resulting in improved isolation and linearity. The current-reuse technique applied to the developed transconductor by stacked nMOS/pMOS architecture efficiently saves power consumption of the circuit. Implemented in the TSMC 28-nm CMOS process, post-simulations show that the proposed mixer provides a maximal conversion gain of 11.4 dB and an NF of 3.9–4.7 dB across RF input frequency range of 2–9.6 GHz. The average IIP3 of 5 dBm are obtained while the mixer core consumes 6.2 mW from a 1 V supply.

Gain-controlled noise-reduction LNA design using source-bulk resistors and double common-source topology

This paper presents the design of a Low Noise Amplifier (LNA) using double common-source technique results in wideband input matching. Moreover, to reduce the noise figure, a resistor series to source-bulk substrate resistance is applied. One of the main problems of the common-source structure in LNA design is the narrow-band property. Using the proposed double common-source scheme, the narrow-band problem is solved and the desired wideband attributes can be achieved. In addition, using a resistor series to the source-bulk substrate resistance results in significant noise figure reduction. In the proposed scheme, the gain of LNA in frequency band of 3–12 GHz would be between 14.2 dB and 15.1 dB. Furthermore, the variation of gain in this band is 0.45 dB which is significant. The 3-dB bandwidth of the designed LNA is 10.2 GHz (from 2.4 to 12.6 GHz). The worst case of return loss of input port is −10 dB. The above mentioned series resistor causes the noise figure to decrease and set between 3.47 and 4.12 dB. Using 180-nm TSMC technology, the DC power is 11 mW from 1-V supporting voltage.

The effect of 980 nm and 1480 nm pumping on the performance of newly Hafnium Bismuth Erbium-doped fiber amplifier

An experimental study on the comparison of optical amplifying performance between 980 nm and 1480 nm pumping for the newly Hafnium Bismuth Erbium co-doped fiber (HB-EDF) has been presented. A short length of 1-meter HB-EDF was used as the gain medium of the optical amplifier. 1480 nm pumping is found to provide higher attainable gain and lower noise figure compared to 980 nm pumping. At 1480 nm pumping, the average small signal gain for HB-EDFA in the single pass configuration has improved by 13.4 dB in the C-band region range from 1525 nm to 1565 nm. In the double-pass configuration, a maximum small signal gain of 36.6 dB was achieved at the wavelength of 1560 nm, this is 11.6 dB higher compared to the HB-EDFA with 980 nm pumping. The double pass HB-EDFA with 1480 nm pumping has exhibited a reduction of average noise figure by 23.4% and 29.8% for -30 dBm and -10 dBm of input signal power respectively in the C- and L-band region.

A Comparative Study and Radial Performance Evaluation for Reflective EDFA Configurations with Optimized Intrinsic Parameter Sets

For the improvement of Gain and Reduction in Noise Figure, a range of Erbium Doped Fiber Amplifier (EDFA) based configurations from simple Single Pass (SP) EDFA to Quadruple Pass with Filter (QPF) EDFA have been investigated. Modified Giles model for rate and propagation equations has been proposed and subsequently used for Gain and Noise Figure evaluation for all configurations. The influence of EDFA based configurations on its internal design parameters is investigated to obtain an optimum design parameter set. Among the single stage EDFA configurations, Reflective Double pass with Filter (DPF) with a high optimum Numerical Aperture gives good radial performance with high signal overlap factor of 0.563 and Pump overlap factor of 0.834. For the dual stage configurations, second stage of Reflective QPF EDFA gives best signal overlap of 0.6727 and pump overlap of 0.8827, whereas it has the lowest pump threshold of 0.47 mW, hence highest pumping efficiency. At 1550 nm of input signal wavelength, maximum gain of 27.66 dB and low Noise figure of 5.4 dB was obtained in QPF EDFA at lowest pump power of 20 mW. Thus QPF EDFA is suitable choice for preamplifier applications at 1550 nm.

Cost-Optimized Submarine Cables Using Massive Spatial Parallelism

We study the techno-economics of submarine systems constrained by a fixed electrical power supply. We show significant cost savings for high-capacity submarine systems using massive space-division multiplexing (SDM), even without assuming any savings from SDM-specific subsystem integration. Systems with about 100 parallel optical paths, e.g., $\sim$ 50 fiber pairs are shown to provide minimum cost/bit, operating at reduced spectral efficiencies and deep within the linear regime. While advanced nonlinearity-optimized fibers and digital nonlinearity compensation schemes provide little to no gain in such systems, SDM integration of amplifiers and transponders is shown to be a source for significant additional cost savings. We further examine the permissible cost premium for multicore fibers in such massively parallel systems and revisit various design tradeoffs for optical amplifiers, showing that a reduced noise figure can be traded for better power conversion efficiency. We also evaluate potential gains from increasing the available electrical supply power and discuss reliability aspects of massively parallel submarine systems.

A 79GHz Adaptive Gain Low Noise Amplifier for Radar Receivers

This paper presents an Adaptive Gain 79GHz Low Noise Amplifier (LNA) suitable for Radars applications. The circuit schematic is a two stage LNA consists of Differential cascode configuration followed by a simple common source amplifier with an Adaptive Biasing (ADB) circuit. Adaptive biasing is a three- stage common source amplifier to decrease output voltage as input power increases. The circuit is simulated in 180nm CMOS technology and the simulation results have proved that the circuit operates at the center frequency 79GHz with adaptive biasing for adaptive gain. The gain analysis shows a decrease of 35-30dB with an increase in input power -50 to 0 dB. At 79GHz the circuit has achieved the input reflection coefficient (S11) of -24.7dB, reverse isolation (S12) of -3 dB, forward transmission coefficient (S21) of -2.97dB and output reflection coefficient (S22) of -5.62 dB with the reduced noise figure of 0.9 dB and a power consumption of 236 mW.

Investigation and performance evaluation of filter aided configurations for erbium doped fiber optical amplification system

Various possible configurations of EDFA’s namely Single Pass (SP) EDFA, Double Pass (DP) EDFA, Double Pass with Filter (DPF) EDFA, Triple Pass with Filter (TPF) EDFA and finally Quadruple Pass with Filter (QPF) EDFA are designed. DPF EDFA is an upgraded and enhanced version of DP EDFA configuration designed by using an optical filter in cascade. This filter has been designed with an optimal set of internal parameters namely center wavelength, bandwidth and depth. TPF and QPF EDFA configurations have also been designed. It is observed that in absence of upconversion, maximum Figure Of Merit (FOM) of about 40.35 dB is achieved in QPF EDFA configuration. With upconversion mechanism enabled the FOM of QPF EDFA reduces to only about 37.45 dB thus making QPF EDFA configuration suitable for practical applications. QPF and TPF EDFA had minimum gain ripple thus can be used in WDM applications, where flattened gain spectrum is an important requirement. The configurations offered here are less bulky with only one filter used instead of two as was the case in earlier configurations. QPF EDFA designed in this work has a reduced noise figure of about 4.85 dB at smaller lengths of EDFA of about 4.5 m and lower pump powers of about 90 mW. This configuration has highest sensitivity with the capacity to detect minimum signal power of −41.6 dBm. The QPF EDFA has an improved gain with reduction in noise figure, therefore QPF EDFA can be used as a preamplifier, to improve the sensitivity of receiver.

Quantum dot semiconductor optical amplifier: investigation of amplified spontaneous emission and noise figure in the presence of second excited state

In this paper, amplified spontaneous emission (ASE) in quantum dot semiconductor optical amplifier (QDSOA) is investigated and analyzed theoretically. The presented model is based on a set of rate equations that consider all possible carriers transitions including the second excited state (ES2). This assumption is possible, if the QDSOA’s active region is grown in such a way that the presence of ES2 becomes distinguishable from upper states and wetting layer. Optical gain of QDSOA is calculated using density matrix approach. The coupled rate equations are solved numerically along with propagation equations. It is shown that in the presence of ES2, QDSOA performance can be improved and an ultra-high bit-rate signal amplification without wave distortion is possible. Furthermore, it is illustrated that the obtained ASE spectrum has three peeks which are related to ground, first excited and second excited states. Moreover, noise figure (NF) is calculated numerically using ASE power. It is shown that considering the effect of ES2 in the band diagram of quantum dots (QDs) decreases the NF of amplifier. The effect of increased input power on the reduction of NF is illustrated, too. It is shown that ASE and NF of amplifier can be ignored in the modeling QDSOA at high input powers.

Design and Comparison of Low Power High Gain and Low Noise Figure LNA for ISM Applications

Objectives: This paper represents the design and simulation of LNA (Low Noise Amplifier) for ISM (Industrial, Scientific and Medical) applications operating in the 2.4-2.5 GHz band. Methods/Statistical Analysis: In this paper, a very accurate topology named inductive source degeneration topology has been used to provide low NF (Noise Figure), high S21 (forward gain) and very low Power Consumption (PC). The simulation was made through using Advance Design System (ADS) software. Findings: The proposed work prominence on reduction in Noise Figure with increase in power gain at low power consumption as compared to published previous results at 1.2 V power supply. Improvements: This is done in three steps (three different schematic designs) i.e. start with very basic LNA design to proposed LNA design and presents the comparison of all three designed circuit simulations.

Thulium-Doped Fiber Amplifier at Near 2000 nm with Different Pumping Scheme

We demonstrate two pumping scheme for thulium-doped fiber amplifier (TDFA) by using OptiSys v. 13 that is spanning from 1770 nm to 1970 nm; providing all the results represented in the figures. Higher gain is achieved in the single stage TDFA however high output power is achieved in the distributed pumping TDFA. The reduction of noise figure by almost 2 dB is of the concern during the simulation while the performance of the parameters tested differs with different pumping scheme. This simulation is of the pioneer determination to the real environment experiment.

Noise Figure Optimization Tool for Millimeter-Wave Receivers at Near-&lt;inline-formula&gt; &lt;tex-math notation="LaTeX"&gt;$f_{\max}$&lt;/tex-math&gt; &lt;/inline-formula&gt; Frequencies

This brief presents an evaluation tool of the noise figure reduction that can be achieved by adding a low-noise amplifier in a near- $f_{\max}$ frequency receiver. After choosing a suitable topology and assessing its frequency dependence, an analytical derivation is carried out and preliminary frequency constraints are found. The analytical assessment is followed by a practical example using the CMOS 65-nm technology as a reference for millimeter-wave technologies, where $f_{\max}=234 \text{GHz}$ .

60 GHz Front-End Components for Broadband Wireless Communication in 130 nm CMOS Technology

Abstract The over 5 GHz available spectral space allocated worldwide around the 60 GHz band, is very promising for very high data rate wireless short-range communications. In this article we present two key components for the 60 GHz front-end of a transceiver, in 130 nm RF CMOS technology: a single-balanced mixer with high Conversion Gain (CG), reduced Noise Figure (NF) and low power consumption, and an LC cross-coupled Voltage Controlled Oscillator (VCO) with very good linearity, with respect to Vctrl, and very low Phase Noise (PN). In both circuits, custom designed inductors and a balun structure for the mixer are employed, in order to enhance their performance. The VCO’s inductor achieves an inductance of 198 pH and a quality factor (Q) of 30, at 30 GHz. The balun shows less than 1 o Phase Imbalance (PI) and less than 0.2 dB Amplitude Imbalance (AI), from 57 to 66 GHz. The mixer shows a CG greater than 15 dB and a NF lower than 12 dB. In addition, the VCO achieves a Phase Noise lower than -106 dBc/Hz at 1 MHz offset, and shows great linearity for the entire band. Both circuits are biased with a 1.2 V supply voltage and the total power consumption is about 10.6 mW for the mixer and 10.92 mW for the VCO.