Noise Figure Variation Research Articles

A K-Band Hybrid-Packaged Temperature-Compensated Phased-Array Receiver and Integrated Antenna Array

This article presents an eight-channel 1.9-dB noise figure (NF) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula> -band phased-array receiver (RX) for satellite communication (SATCOM). It employs the hybrid-packaged 65-nm CMOS beamformer and 0.1- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> GaAs low-noise amplifiers (LNAs) based on the fan-out wafer-level chip-scale packaging (WLCSP) technology. For the power-efficient RX implementation, the power consumption of gain and phase tuning blocks is discussed, and the fully passive phase shifter (PS) and attenuator (ATT) are employed in this work. A global biasing scheme is proposed to ensure performance uniformity across temperature variations. Across the SATCOM band of 17.7–20.2 GHz, the proposed hybrid-packaged phased-array RX IC only consumes 30.2-mW dc power per channel and achieves < 1.2-dB gain variation and < 0.9-dB NF variation from −40° to 85 °C. Based on the RX IC, a dual-polarized 1024-element RX antenna array is further introduced. The measured gain-to-noise temperature ratios (G/Ts) are 6.22 and 6.51 dB/K at 19.7 GHz for left- and right-hand circular polarizations, respectively.

Ku‐band GaAs mHEMT MMIC and RF front‐end module for space applications

AbstractThis article presents a Ku‐band Low Noise Amplifier (LNA) Monolithic Microwave Integrated Circuit (MMIC) and RF front‐end module for space applications. LNA MMIC was developed with utilizing 0.07 μm GaAs m‐HEMT process. Noise Figure (NF) and gain results of LNA module were measured as 1.3 and 43 dB, respectively and OIP3 was measured as +20 dBm at the ambient temperature. The LNA module was tested in the temperature range between −25°C and 75°C and small signal gain and NF variation were less than 3 and 0.8 dB, respectively. This article describes the MMIC LNA design, mechanical chassis design, WR75 waveguide‐to‐microstrip design, and measurement results of the LNA front‐end module.

PVT ‐compensated low‐voltage and low‐power CMOS LNA for IoT applications

In this paper, a low‐noise amplifier (LNA) with process, voltage, and temperature (PVT) compensation for low power dissipation applications is designed. When supply voltage and LNA bias are close to the subthreshold, voltage has significant impact on power reduction. At this voltage level, the gain is reduced and various circuit parameters become highly sensitive to PVT variations. In the proposed LNA circuit, in order to enhance efficiency at low supply voltage, the cascade technique with gm boosting is used. To improve circuit performance when in the subthreshold area, the forward body bias technique is used. Also, a new PVT compensator is suggested to reduce sensitivity of different circuit's parameters to PVT changes. The suggested PVT compensator employs a current reference circuit with constant output regarding temperature and voltage variations. This circuit produces a constant current by subtracting two proportional to absolute temperature currents. At a supply voltage of 0.35 V, the total power consumption is 585 μW. In different process corners, in the proposed LNA with PVT compensator, gain and noise figure (NF) variations are reduced 10.3 and 4.6 times, respectively, compared to a conventional LNA with constant bias. With a 20% deviation in the supply voltage, the gain and noise NF variations decrease 6.5 and 34 times, respectively.

A 4-mW Temperature-Stable 28 GHz LNA with Resistive Bias Circuit for 5G Applications

This paper presents a low power two-stage single-end (SE) 28 GHz low-noise amplifier (LNA) in 90 nm silicon-on-insulator (SOI) CMOS technology for 5G applications. In this design, the influence of bias circuit is discussed. The 1200 Ω resistor which was adopted in bias circuit can feed DC voltage as well as keep whole circuit unconditionally stable. The gate bias points are set to 0.55 V to make the circuit low-power and temperature-stable. Measurement results illustrated that the LNA achieved a maximum small signal gain of 18.1 dB and an average 3.1 dB noise figure (NF) in operating frequency band. Measured S11 was below −10 dB between 25 GHz and 29 GHz and reverse isolation S12 was below −25 dB throughout the band. It consumed only 4 mW by proper selection of bias point with core area of 0.16 mm2 without pads. The fabricated LNA has demonstrated a gain variation of 3 dB and a NF variation of 1.9 dB from −40 °C to 125 °C with power variation of 0.8 mW. It suggests that the proposed SOI CMOS LNA can be a promising candidate for 5G applications.

Hybrid Optical Amplifier for Flat Gain in Super Dense Wavelength Division Multiplexed (SDWDM) System

Abstract Large capacity optical networks require flattened gain spectrum and large gain bandwidth of the optical networks. In order to achieve this large number of hybrid optical amplifiers are designed. Here we proposed a competent flat gain hybrid optical amplifier with an optimum combination of Erbium Doped Fiber Amplifier (EDFA) and Raman amplifier. Attempts are made to design a hybrid optical amplifier for 100 channels, 10 Gbps Super Dense Wavelength Division Multiplexed (SDWDM) systems at different channel spacing of 0.1, 0.2, 0.4 and 0.8 nm. Work capacity of the network was compared on the basis of various parameters viz., gain and noise figure that determined the performance of the system. The gain spectrum of the hybrid optical amplifier depends upon the parameters viz., pump wavelength, pump power and laser input power of the amplifier. Various efforts were conceded out to optimize these parameters. It was found that for wavelength range 1,570.5–1,580.75 nm, a flat gain of 5.36 dB is achieved for input power of −15 dB with noise figure variation of 0.57 dB without using any gain flattering scheme. Being simple and cost effective, this hybrid optical amplifier could be recommended for gain flatness characteristics and acceptable noise figure for super dense wavelength division multiplexed system.

Performance Evaluation of Hybrid Optical Amplifier for Ultra Dense Wavelength Division Multiplexed Optical Network at Narrow Channel Spacing

Abstract In this paper, a competent flat gain hybrid optical amplifier is proposed with an optimum arrangement of erbium doped fiber amplifier (EDFA) and Raman amplifier. Attempts are made to design a hybrid optical amplifier for100 channels, 10 Gbps super dense wavelength division multiplexed (SDWDM) systems at channel spacing of 0.1 nm. Work capacity of the system was compared on the basis of various parameters, viz., noise figure and gain that determined the performance of the system. The gain spectrum of the hybrid optical amplifier depends upon the parameters viz., laser input power, pump power and pump wavelength of the amplifier. It was found that for wavelength range 1,560.38–1,579.59 nm, a flat gain of 4.34 dB is achieved for input power of −10 dB with noise figure variation of 0.818 dB without using any gain flattering scheme. Being simple and cost effective, this hybrid optical amplifier could be recommended for gain flatness characteristics and acceptable noise figure for dense wavelength multiplexed systems.

Optical Fiber Amplifiers: Optimization and PerformanceEvaluation

This work demonstrates the simulation of two different types of optical fiber amplifiers (OFA) utilizing OptiSystem–10, namely, 3 m length of erbium doped fiber amplifier (EDFA) and 7 km length of Raman fiber amplifier (RFA). The counter-pumped architecture is adopted for both proposed optical amplifiers. The optimum pump power (OPP) for each amplifier determines in which the longest 3–dB flat gain bandwidth (3–dB BW), reasonable average gain level (Gav), proper average noise figure (NFav) and lower gain variation (Gvar) were achieved. The EDFA shows best performance at conventional band (C–band) within the pump power of 30 mW.While the better performance is observed at long band (L–band) within the pump power of 600 mW for the RFA.

Noise in phase-(in)sensitive dual-core fiber parametric amplification.

Flat and wide-bandwidth gain spectrum, along with phase-sensitive gain with no need to generate amplifier input idlers, can be achieved with a coupled dual-core fiber optical parametric amplifier. In this paper, we analyze the noise properties of such an amplifier. We achieve a 3 dB noise figure in the phase-insensitive case and a minimum of -6 dB noise figure in the phase-sensitive configuration. An alternative phase-sensitive configuration is also studied, that avoids the use of idlers at the input of the amplifier, leading to a 3 dB flat spectrum combined noise figure for the output signals. Pump transfer noise in phase-insensitive and phase-sensitive configurations is also studied along with the noise figure variation against the length of the amplifier.

Performance optimization of hybrid optical amplifier for dense wavelength division multiplexed system

Today’s high capacity dense wavelength division multiplexed (DWDM) systems required the flattened gain spectra with large gain bandwidth. This required properly broadening the gain bandwidth of the optical amplifiers with proper amplification of the signals. In order to achieve this, a competent flat gain hybrid optical amplifier is demonstrated that comprised of a erbium doped fiber amplifier (EDFA) and Raman amplifier with multi-wavelength backward pumping scheme. Attempts were done in order to design a (E-R) hybrid optical amplifier (HOA) for 16 channels, 20 Gbps DWDM systems at reduced channel spacing of 0.2 nm and also compared with conventional amplifiers. The performance of the system is evaluated on the behalf of different parameters viz. gain, noise figure, output power, Optical Signal to Noise Ratio (OSNR). Numerous parameters of EDFA and Raman amplifiers are optimize to find the gain spectrum of E-R HOA. It is found that E-R HOA provides better gain uniformity with noise figure less than 5 dB. It is also found that for wavelength range 1553.13–1556.15 nm, a uniform gain of 38.85 dB is achieved for input power of “0” dB with noise figure variation of 0.29 dB without using any gain flattering scheme. The output power and OSNR of all the channels is measured at 0 dBm input power and found maximum power and SNR at 1556.15 nm channel frequency is 26.44 dBm and 40.71 dB respectively.

A 50 MHz ~ 10 GHz, 3.3 dB NF, +6 dBm IIP3 resistive feedback common source amplifier for cognitive radio application

Cognitive radio is a smart ultra-wideband wireless communication system that is capable of optimizing the usage of the available frequency spectrum. In this work, an ultra-wideband low noise amplifier with an operating bandwidth from 50MHz to 10GHz with integrated resistive feedback and π-matching network is presented. The amplifier is designed to self-bias via the feedback path to optimize the chip area consumption. The input signal is sourced to two common-source amplifiers to achieve the input matching configuration and subsequently cascaded to another common source amplifier with resistive termination in achieving the output matching. On-chip inductors were adapted to improve the high frequency response and to extend the bandwidth up to 10GHz. Measured results show that the input and output matching are better than −10dB with a gain variation of 10.32–13.28dB, noise figure variation of 3.29–6dB, and a third order intercept point ranging from −3.2 to +6dBm in a frequency span of 50–10GHz on a CMOS 0.13µm platform. The physical layout occupies 0.77mm2 chip area with the bondpads intact and consumes 31.2mW of DC power from 1.2V DC supply headroom.

Frequency-resolved noise figure measurements of phase (in)sensitive fiber optical parametric amplifiers.

We measure the frequency-resolved noise figure of fiber optical parametric amplifiers both in phase-insensitive and phase-sensitive modes in the frequency range from 0.03 to 3 GHz. We also measure the variation in noise figure due to the degradation in pump optical signal to noise ratio and also as a function of the input signal powers. Noise figure degradation due to stimulated Brillouin scattering is observed.

On noise figures in transistor audio amplifiers

The noise figures of two general purpose transistors of Philips and Hitachi (Japanese) make have been determined under identical experimental conditions with a view to see whether they differ in their noise properties. The variation of noise figure of Philips as well as Hitachi transistors with (i) frequency (ii) collector voltage (iii) collector current (iv) emitter current (v) input impedance have been investigated. It was concluded that Philips and Hitachi transistors do not differ much in their noise properties, when operated under identical conditions. For both the transistors the noise figure increase with collector voltage, collector current and emitter current. Increasing input impedance of either of the transistors increases the noise figure when the input impedance exceeds two thousand ohms. For both transistors the noise figure decrease with frequency, then remains constant over a small frequency band and finally increases slowly with frequency.

56.6 dB high gain L-band EDFA utilizing short-length highly-doped erbium rare-earth material

In this paper, we experimentally investigate the performance of an efficient high gain L-band erbium-doped fiber (EDF) amplifier structure utilizing short-length highly-doped erbium rare-earth material with a single pump source. The amplifier gain and noise figure variation for different amplifier structures have been investigated. A filter is used to reduce the self-saturation effect and suppress the C-band amplified spontaneous emission (ASE) noise. The amplifier achieves a signal gain of 56.6 dB with a low noise figure of 4.8 dB at −50 dBm input signal power using only 8 m of EDF length. The amplifier gain shows significant improvement of 6 dB with C/L band coupler and 13 dB with tunable-band pass filter compared to amplifier structure without ASE suppression.

Investigation of Constant Transconductance Circuit for Low Power Low-Noise Amplifier

In this paper, the design of wide-swing constant transconductance (gm) bias circuit that generates bias voltage for lownoise amplifier (LNA) circuit design by using an off-chip resistor is demonstrated. The overall transconductance (Gm) generated by the constant gm bias circuit is important to maintain the overall gain and noise figure of the LNA circuit. Therefore, investigation is performed to study the variation in Gm with process, temperature and supply voltage (PVT). Temperature and supply voltage are swept from -10 °C to 85°C and 1.425 V to 1.575 V respectively, while the process conditions are also varied to the extreme and the gm variation is eventually concluded at between -3% to 7%. With the slight variation in the gm value, through simulation, at worst condition of state SS, we are able to attain a conversion gain (S21) variation of -3.10% and a noise figure (NF) variation of 18.71 %. The whole constant gm circuit draws approximately 100μA from a 1.5V supply and is designed based on 0.13μm CMOS process. Keywords—Transconductance, LNA, temperature, process.

Wide-Range Variable Gain Fiber Amplifier With Erbium-Doped Fiber Switching

A variable gain erbium-doped fiber amplifier (EDFA) with a wide gain range and a small noise figure (NF) variation is analyzed numerically and demonstrated experimentally. The EDFA can change the total erbium-doped fiber length by selecting six combinations of three EDFs with optical switches (SWs). The numerical calculation of the NF and the pump power using the analytical model of an EDFA indicates that such a variable gain EDFA has an advantage over a conventional multi-stage EDFA in terms of NF variation and required pump power. These characteristics are demonstrated by constructing a variable gain EDFA that employs SWs and variable optical attenuators (VOAs) integrated on a silica-based planar lightwave circuit (PLC). The variable gain EDFA exhibits a smaller NF variation of 1.2 dB for the 24-dB variable gain range than conventional two- and four-stage EDFAs, which have NF variations of 12.6 and 2.0 dB, respectively, for the same variable gain range. The power consumption of these EDFAs is also discussed by comparing the operating electric power of the SWs and VOAs with that of the pump laser.

Behavioral Variations of Gain and NF Owing to Configurations and Pumping Powers

Six configurations are proposed in this paper to explore the gain and noise figure (NF) variations under the pumping power effect. I propose a new investigation of gain and NF at different EDFA configurations. Configurations such as SPSS, DPSS, DPSSF, TPDS, TPDSF, and QPDSF are designed, investigated and compared. A continuous progress of gain values is observed from SPSS to QPDSF, and a change of NF values related to configurations is recorded. The NF variations show different behaviors at different configurations. High gain of 59.49 dB and low NF value of 4.22 dB are recorded for the QPDSF configuration and low gain and low NF are recorded for the SPSS configuration.

Model of Temperature Dependence Shape of Ytterbium -doped Fiber Amplifier Operating at 915 nm Pumping Configuration

We numerically analyze the temperature dependence of an ytterbium-doped fiber amplifier (YDFA) operating at 915 nm, investigating its gain and Noise Figure properties variation with temperature. The temperature-dependent gain and noise figure variation with YDFA length are numerically obtained for the temperature range of +20 0C to +70 0C. The results show that good intrinsic output stability against temperature change can be achieved in ytterbium doped fiber amplifiers even when operating at high gain regime with small signal input. This result demonstrates the great potential for stable high power laser communication systems based on ytterbium system.

Gain and Noise figure performance of erbium doped fiber amplifiers (EDFAs) and Compact EDFAs

In this paper, we compare the Gain and Noise figure characteristics of physical EDFAs and Compact EDFAs in an optical system consisting of cascade of both the amplifiers. We demonstrate the gain, noise figure variations of a forward pumped EDFA and Compact EDFAs as functions of Er 3+ fiber length, injected pump power and up-conversion co-efficient. It is observed that the gain becomes constant when the length of both the amplifiers reaches above 20 m. The comparison shows that the higher gain with flatter output is obtained in case of Compact EDFAs than Physical EDFAs in a system consisting of chain of both the amplifiers. It is further investigated that the agreement between the Compact and Physical EDFA models is good up to 10 m with the no up-conversion co-efficient. Also, the noise figure obtained in case of Physical EDFA is higher than Compact EDFAs when same amplifier length is more than 20 m and then becomes constant for both the amplifiers.

Temperature Effect on $Ku$-Band Current-Reused Common-Gate LNA in 0.13-$\mu{\hbox{m}}$ CMOS Technology

This paper presents the temperature effect on a Ku-band NMOS common-gate low-noise amplifier (CG-LNA). The temperature characteristics of an NMOS transistor and spiral inductors are obtained over the temperature range from 253 to 393 K. These results show that the optimal bias condition minimizes the transconductance and drain current temperature variations. Based on these results, a current-reused CG-LNA with good temperature performance is designed. At ambient temperatures, the CG-LNA has a measured power gain of 10.3 dB and a noise figure (NF) of 4.3 dB at 15.2 GHz, while consuming 4.5 mA from a 1.3-V power supply. When the temperature varies from 253 to 393 K, the CG-LNA has a power gain variation of 3 dB, NF variation of 2 dB , and dc power consumption variation of 11.9%. This paper is the first to report the temperature effect on Ku-band CG-LNAs.

WAVELENGTH SELECTIVE AUXILIARY C-BAND ASE PUMPING FOR L-BAND EDFA

The variation of Gain and Noise Figure (NF) at 1580 nm with length of Erbium doped fiber (EDF) for two auxiliary pumping schemes employing narrowband Amplified Spontaneous Emission (ASE) and ASE filtered up to a particular wavelength in C-band, by considering a serially cascaded two stage wideband amplifier model are investigated. It is shown that indeed, there exists a wavelength range of ASE for achieving maximum gain. The gain can be increased by 14 dB if wavelength bandwidth of 1480–1554 nm is selected instead of pumping with the broadband ASE (1480–1700 nm). By auxiliary pump using ASE sliced in the 1533 nm window, gain as high as 28 dB and NF as low as 5.5 dB can be achieved for shorter fiber length. To achieve gain of 25–30 dB for the L-band signal only a EDF length of 30 m is required in the case of tuned ASE launching at 1533 nm as compared to 40 m and 65 m by optimized ASE bandwidth and broadband. The values of noise figure do not show significant variation in any of the three configurations. It is apparent that using single wavelength ASE pumping at 1533 nm reduces the fiber length by 10 m (compared to optimized ASE bandwidth pumping) and by 32 m (compared to broadband ASE bandwidth pumping), when L-band EDFA is designed for 25–30 dB signal gain and NF less than 6 dB. These results will be important in designing cascaded wideband EDFA for Optical Fiber Communication (OFC) systems.