Average Noise Figure Research Articles

Development of Integrated Broad-Band CMOS Low-Noise Amplifiers

This paper presents a systematic design methodology for broad-band CMOS low-noise amplifiers (LNAs). The feedback technique is proposed to attain a better design tradeoff between gain and noise. The network synthesis is adopted for the implementation of broad-band matching networks. The sloped interstage matching is used for gain compensation. A fully integrated ultra-wide-band 0.18-mum CMOS LNA is developed following the design methodology. The measured noise figure is lower than 3.8 dB from 3 to 7.5 GHz, resulting in the excellent average noise figure of 3.48 dB. Operated on a 1.8-V supply, the LNA delivers 19.1-dB power gain and dissipates 32 mW of power. The gain-bandwidth product of the UWB LNA reaches 358 GHz, the record number for the 0.18-m CMOS broad-band amplifiers. The total chip size of the CMOS UWB LNA is 1.37 times 1.19 mm2.

220 GHz low‐noise amplifier MMICs and modules based on a high performance 50 nm metamorphic HEMT technology

A metamorphic composite-channel InAlAs/InGaAs based high electron mobility transistor (MHEMT) technology has been developed for active and passive high-resolution imaging applications. The technology features 50 nm gate length in combination with an In content of 80% in the main channel and 53% in the second channel. An extrinsic transit frequency ft of 400 GHz and an extrinsic maximum transconductance gm,max of 1800 mS/mm were measured at a drain voltage of 1 V. Based on this advanced MHEMT technology, coplanar G-band low-noise amplifier (LNA) MMICs were realized, achieving a small-signal gain of more than 15 dB between 192 and 230 GHz together with an average noise figure of 8 dB. Furthermore, mounting and packaging of the monolithic amplifier chips into G-band waveguide modules was accomplished with only minor reduction in circuit performance. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

A 0.6-V Low Power UWB CMOS LNA

This paper presents the design of a low-power ultra-wideband low noise amplifier in 0.18-mum CMOS technology. The inductive degeneration is applied to the conventional distributed amplifier design to reduce the broadband noise figure under low power operation condition. A common-source amplifier is cascaded to the distributed amplifier to improve the gain at high frequency and extend the bandwidth. Operated at 0.6V, the integrated UWB CMOS LNA consumes 7mW. The measured gain of the LNA is 10dB with the bandwidth from 2.7 to 9.1GHz. The input and output return loss is more than 10dB. The noise figure of the LNA varies from 3.8 to 6.9dB, with the average noise figure of 4.65dB. The low power consumption of this work leads to the excellent figure of gain-bandwidth product (GBP) per milliwatt

Wideband and low noise CMOS amplifier for UWB receivers

AbstractAn ultra‐wideband (UWB) low noise amplifier (LNA) that consists of two common‐source and shunt‐feedback stages is presented. Measurement results show the maximum gain (S21) of 13.5 dB with the 3‐dB band from 1.85 to 10.2 GHz and return losses (S11, S22) of less than −10 dB from 3 to 11 GHz. In addition, the fabricated LNA achieves the average noise figure (NF) of 4.5 dB from 1.85 to 10.2 GHz. To our knowledge, these are the best measured data up to date for the CMOS LNA. The input‐referred third‐order intercept point (IIP3) and the input‐referred 1‐dB compression point (P1dB) are obtained as −1 dBm and −9 dBm, respectively, while consuming 13 mW in 0.18 μm RF CMOS process. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 749–752, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22282

Modeling and experiments of packaged Er 3+–Yb 3+ co-doped glass waveguide amplifiers

A full characterization of packaged Er 3+–Yb 3+ co-doped waveguide amplifiers (EYDWAs) fabricated using ion-exchange and field-assisted annealing was reported. The amplifier was modeled using an extended overlapping factors method, and two overlapping factors at the pump and signal wavelengths were introduced to simplify the overlapping integrals between levels’ population densities and mode intensity profiles. The rate equations and the propagation equations depend on one variable: the longitudinal parameter z, and the overlapping integrals have to be carried out once only. The gain and noise characteristics of the EYDWAs were investigated, and there is good agreement between the theoretical and experimental results. With a single 975 nm diode pump of 200 mW power, this packaged ∼4.0 cm long waveguide device delivers a total net gain of ∼12.0 dB peak value at 1.534 μm, and a net gain of ∼8.0 dB and an average noise figure of ∼5.1 dB in the 1530–1560 nm band. The polarization dependent gain of <0.2 dB is also estimated for the device. Comparing to commercially available Er-doped fiber amplifiers, these low cost, high gain pigtailed glass waveguide amplifiers have a great potential to be used in optical access networks.

Optimizing the incoherent pump spectrum of low-gain-ripple distributed fiber Raman amplifier for a given main pump wavelength

The method for designing the incoherent pump spectrum for the distributed fiber Raman amplifiers (DFRAs) of low gain ripple is studied, in which the wavelength of the maximum power spectral density can be assigned. The assigned wavelength is called the main pump wavelength. Incoherent pump spectrum is described with the power spectral density function (PSDF) that comprises a set of piece-wise continuous functions. PSDF is optimized for the minimum gain ripple with the least-square minimization method. An extremum pump wavelength condition is applied to PSDF. A proper initial trial PSDF is given so that the optimized PSDF converges to the desired result and the power spectral density at the extremum pump wavelength is the maximum. With this design method, we show the optimized PSDFs for the DFRAs using backward pumping and bidirectional pumping. The gain ripples of considered DFRAs are less than 0.1 dB for 20-dB ON-OFF Raman gain over 70-nm bandwidth. The reduction of average effective noise figure with shorter main pump wavelength is shown and investigated.

High efficiency and low noise figure double-pass fibre Raman amplifier

A new S-band double-pass (DP) fibre Raman amplifier (FRA) with the characteristics of improved gain and noise figure (NF) is demonstrated. By employing a high birefringence fibre loop mirror (HiBi-FLM) with a comb-like reflection spectrum as a signal reflector, the ASE noise of this DP-FRA greatly decreases compared with that of the conventional DP-FRA with the FLM. A maximum NF improvement of 6.2 dB and an average NF improvement of 4.9 dB over 40 nm (1480–1520 nm) bandwidth are realized. By using the FLM as a residual pump reflector to improve the gain of the amplifier, a maximum gain of 24 dB and an average NF of 4.3 dB are obtained in the same bandwidth.

A novel CMOS low-noise amplifier design for 3.1- to 10.6-GHz ultra-wide-band wireless receivers

An ultra-wideband (UWB) 3.1- to 10.6-GHz low-noise amplifier (LNA) employing a common-gate stage for wideband input matching is presented in this paper. Designed in a commercial 0.18-mum 1.8-V standard RFCMOS technology, the proposed UWB LNA achieves fully on-chip circuit implementation, contributing to the realization of a single-chip CMOS UWB receiver. The proposed UWB LNA achieves 16.7plusmn0.8 dB power gain with a good input match (S11<-9 dB) over the 7500-MHz bandwidth (from 3.1 GHz to 10.6 GHz), and an average noise figure of 4.0 dB, while drawing 18.4-mA dc biasing current from the 1.8-V power supply. A gain control mechanism is also introduced for the first time in the proposed design by varying the biasing current of the gain stage without influencing the other figures of merit of the circuit so as to accommodate the UWB LNA in various UWB wireless transmission systems with different link budgets

Impact of dispersion fluctuations on the noise properties of fiber optic parametric amplifiers

The effects of zero-dispersion wavelength (ZDWL) fluctuations on the noise characteristics of fiber optical parametric amplifiers (FOPAs) are investigated. The numerical derivation of the noise figure (NF) in terms of the amplifier operating conditions and the magnitude of ZDWL fluctuations is achieved by utilizing a simulation method based on the three-coupled propagation equations. The numerical analysis shows that the average NF of FOPAs is increased compared with the case of uniform dispersion, especially at high-gain operation. Apart from the NF, the gain-to-NF ratio is also evaluated to assess the amplifier performance for a variety of amplifier operating conditions and dispersion profiles.

Ultra‐wideband low noise amplifier using a cascode feedback topology

AbstractAn ultra‐wideband (UWB) low‐noise amplifier (LNA) that consists of two cascode and shunt feedback stages is presented. The measurement results show the maximum gain (S21) of 11.9 dB with the 3‐dB band from 2 to 6.5 GHz and return losses (S11, S22) of less than −7.8 dB from 2 to 11 GHz. In addition, the fabricated LNA achieves the average noise figure (NF) of 4.5 dB from 2 to 10 GHz, which value is much lower than previously reported state‐of‐the‐art UWB amplifiers. The input‐referred 3rd‐order intercept point (IIP3) and the input‐referred 1‐dB compression point (P1dB) of the LNA are achieved as 4 and −5 dBm, respectively, while consuming 27 mW in the 0.18‐μm RF CMOS process. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1102–1104, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21611

Performance enhancement of C + L band EDFA by recycling the residual pump lasers

By recycling the residual pump power, performance improvements of parallel type C + L band erbium-doped fiber amplifier are demonstrated. For C-band branch, the average gain and noise figure are enhanced by 2.0 dB and decreased by 1.1 dB, respectively. Whereas for L-band branch, the average gain is raised by 0.5 dB and noise figure is lower by 0.3 dB. Bit error rate performance is verified with negligible power penalty of 0.3 dB for the proposed C + L band EDFA. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1953–1955, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21833

High Efficiency and Low Noise 980 nm Dual Stage Dual Band EDFA with over 72 nm Bandwidth

We report a 980 nm dual stage EDFA operating in both the C-band (1530 nm to 1560 nm) as well as the L-band (1570 nm to 1605 nm) region. This 980 nm co-pumped design delivered an average noise figure (NF) of 5.3 dB throughout the 75 nm wide region. With the use of high-doped EDF an average power of 12.9 dBm over a 3 dB bandwidth of 72 nm was obtained. A maximum output power was 13.7 dBm was achieved in this design with power conversion efficiency (PCE), high of 25.5%.

A wideband low noise amplifiers design incorporating the CMRC circuitry

An impedance bandwidth enhancement technique for tuning a low noise amplifier (LNA) is presented. With the use of the compact microstrip resonant cell (CMRC) at the emitter pins of a bipolar junction transistor (BJT), the impedance bandwidth achieved is about 95%, for a simple single stage amplifier design. The LNA attains a gain of about 15 dB; also a low noise figure of 1.16 dB at 2.1GHz and an average noise figure of about 1.5 dB across the operation bands have been achieved.

GaAs-based high-gain direct-coupled distributed preamplifier using active feedback topology

A single-chip ultra-high gain distributed amplifier (DA) was developed using commercial GaAs PHEMT foundry for 40-Gb/s base band applications. Two seven-section DAs are directly coupled using a lumped dc level-shift circuit. The dc bias level of the second-stage DA can be tuned using the level-shift circuit for optimum gain. The gain of each DA stage has been optimized using a novel active feedback cascode topology, which allows the gain bandwidth product to be maximized while avoiding instability problems. The fabricated single-chip DA with a size of 2.1 mm /spl times/ 2.3 mm showed a high gain of 28 dB, and an average noise figure of 4.6 dB with a 41 GHz bandwidth. The corresponding transimpedance gain was 62 dB/spl Omega/ and the input noise current density was 14.5 pA//spl radic/Hz. The gain bandwidth product (GBWP) is 1030 GHz, which corresponds to the highest performance using GaAs technology for 40 Gb/s applications.

GaAs pHEMT broadband low‐noise amplifier for millimeter‐wave radiometer

AbstractThis paper describes a GaAs pHEMT low‐noise amplifier (LNA) in the 38–48 GHz frequency band, which has been developed for the radiometers of the ESA Planck mission. It demonstrates a stable LNA design using a potentially unstable device. The three‐stage amplifier with 0.15‐μm AlGaAs/InGaAs pHEMTs, exhibits more than 16‐dB gain and 1.8‐dB average noise figure over the entire frequency band. The minimum measured noise figure was 1.6 dB with an associated gain of 17.5 dB at 43 GHz. These results show the best noise performance demonstrated among all those reported for a broadband GaAs‐based LNA at these frequencies. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 475–479, 2003

Millimeter Wave MMIC Low Noise Amplifiers Using a 0.15 um Commercial pHEMT Process

This paper presents millimeter wave monolithic microwave integrated circuit (MMIC) low noise amplifiers using a 0.15 µm commercial pHEMT process. After carefully investigating design considerations for millimeter-wave applications, with emphasis on the active device model and electomagnetic (EM) simulation, we designed two singleended low noise amplifiers, one for Q-band and one for V-band. The Q-band two stage amplifier showed an average noise figure of 2.2 dB with an 18.3 dB average gain at 44 GHz. The V-band two stage amplifier showed an average noise figure of 2.9 dB with a 14.7 dB average gain at 65 GHz. Our design technique and model demonstrates good agreement between measured and predicted results. Compared with the published data, this work also presents state-of-the-art performance in terms of the gain and noise figure.

Low-noise-figure optical parametric amplifier with a continuous-wave frequency-modulated pump

We present what are to our knowledge the first gain and noise-figure measurements of a fiber optical parametric amplifier pumped by a simple frequency-modulated source. The maximum gain was 27.2 dB and the average noise figure was 4.2 dB. We achieved the low noise figure by filtering the pump to remove the broadband amplified spontaneous-emission pedestal on the pump spectrum.

1.58 [micro sign]m band Er3+-doped fibre amplifier pumped in the 0.98 and 1.48 [micro sign]m bands

The amplification characteristics of 1.58 /spl mu/m band Er/sup 3+/-doped fibre amplifiers pumped in the 0.98 and 1.48 /spl mu/m bands were investigated. The noise characteristics were improved by adopting 0.98 /spl mu/m band pumping. There was >0.3 dB improvement in both the average noise figure and the flatness of the noise figure.

A 60-GHz-band monolithic HJFET LNA incorporating a diode-regulated self-bias circuit

This paper presents a 60-GHz-band GaAs heterojunction FET (HJFET) low-noise amplifier (LNA) operating with a single bias supply. A diode-regulated self-bias circuit was incorporated for suppressing the FET drain-current variations due to threshold voltage nonuniformities. The effect of the bias circuit on the drain-current distribution is carefully discussed based on the FET dc characteristics. A developed three-stage monolithic microwave integrated circuit (MMIC) LNA exhibited an average noise figure of 3.3 dB with 18-dB gain from 58 to 62 GHz. The LNA could operate over 2-5 V with a constant noise figure. The LNA chip size is 1.85 mm/spl times/1.07 mm.

High-performance Ka-band monolithic low-noise amplifiers using 0.2-μm dry-recessed GaAs PHEMTs

Ka-band ultra-low-noise amplifiers fabricated with a manufacturable dry-recess process are presented. Low-damage selective dry etching was used for gate recess to achieve uniform threshold voltage (Vth) and saturation current (I/sub dss/). Threefold improvement in Vth uniformity was achieved in comparison with the wet recess process. Fabricated PHEMT low-noise amplifiers (LNAs) employing 0.2-μm mushroom gates showed an average noise figure of 2.2 dB from 31-36 GHz with an associated gain of 22.5 dB. At the design frequency of 35 GHz, the noise figure was less than 2 dB. This is among the best results ever reported for Ka-band LNA's.