Relationship Between Noise Figure and Equivalent Input Noise Current Spectral Density for Optical Receiver Design

Based on the equivalent circuit model of a two-port optical receiver front-end,the relationship between the equivalent input noise current spectral density and the noise figure is analyzed. The derived relationship has universal validity for determining the equivalent input noise current spectral density for optical receiver designs, as verified by measuring a 155Mb/s high-impedance optical receiver front.end. Good agreement between calculated and simulated results has been achieved.

Performance Tendency of Gain and Noise Figure at Different EDFA Configurations

A comprehensive behavioral investigation of gain and noise figure （NF） at different erbium doped fiber amplifier （EDFA） configurations is proposed. Configurations such as single pass （SP）, single pass with filter （SPF）, double pass （DP） and double pass with filter （DPF） are designed, investigated and compared. A continuous increasing of gain value is recorded by changing the configuration from SP to SPF to DP then to DPF. The NF value shows different behaviors at different configurations.

Design of a Low Power Low-Noise Amplifier with Improved Gain/Noise Ratio

This work details the development of a broad-spectrum LNA (Low Noise Amplifier) circuit using a 65 nm CMOS technology. The design incorporates an inductive degeneracy circuit, employing a theoretical approach to enhance gain, minimize noise levels, and uphold low power consumption. The progression includes a shift to a cascode structure to further refine LNA parameters. Ultimately, with a 1.8 V bias, the achieved performance showcases a gain-to-noise figure ratio of 16 dB/0.5 dB, an IIP3 linearity at 5.1 dBm, and a power consumption of 3 mW. This architecture is adept at operating across a wide frequency band spanning from 0.5 GHz to 6 GHz, rendering it applicable in diverse RF scenarios.

Gain and Noise Properties of Bidirectional EDFAs

The rate equation model is setup for the signal gain, pump absorption and output noise spectrum of bidirectional EDFA (Bi EDFA) including numbers of signals, pumps of arbitrary direction, amplified spontaneous emission (ASE) and inherent loss. The influence of erbium doped fiber length, input signal power, pump style and pump power on the gain characteristics of Bi EDFA is analyzed. Forward and backward noise figure for different pump style versus bidirectional input signal power is investigated.

Implementation and noise optimization of a 433 MHz low power CMOS LNA

A low power 433 MHz CMOS （complementary metal- oxide-semiconductor transistor） low noise amplifier（LNA）, used for an ISM （ industrial-scientific-medical ） receiver, is implemented in a 0. 18 μm SMIC mixed-signal and RF （ radio frequency） CMOS process. The optimal noise performance of the CMOS LNA is achieved by adjusting the source degeneration inductance and by inserting an appropriate capacitance in parallel with the input transistor of the LNA. The measured results show that at 431 MHz the LNA has a noise figure of 2.4 dB. The S21 is equal to 16 dB, S11 = -11 dB, S22 = -9 dB, and the inverse isolation is 35 dB. The measured input 1-dB compression point （PtdB） and input third-order intermodulation product （IIP3）are - 13 dBm and -3 dBm, respectively. The chip area is 0. 55 mm × 1.2 mm and the DC power consumption is only 4 mW under a 1.8 V voltage supply.

Design and Test of a CMOS Low Noise Amplifier in Bluetooth Transceiver

A RF low noise amplifier,integrated in a single bluetooth transceiver chip and fabricated in 0.35μm digital CMOS technology,is presented.Under the consideration of ESD protection and package,design methodology is discussed from the aspects of noise optimization,impedance match,and forward gain.At 2.05GHz,the measured S 11 is -6.4dB, S 21 is 11dB with 3dB-BW of 300MHz,and NF is about 5.3dB.It indicates that comprehensive consideration of parasitics,package model,and reasonable process is necessary for RF circuit design.

Novel Ka-band low-noise down-converter assembly

An efficient way to design a down-converter assembly for the Ka-band millimeter system is presented, in which dielectric resonators （DR＇s） are adopted in the Schottky barrier diode image recovery mixer and the local oscillator （LO）. DR structures guarantee high frequency stability with an acceptable volume. The configurations of low noise amplifier, mixer and oscillator in the assembly are described and fabricated to estimate the chain performance. According to the verification results, the assembly exhibits the noise figure of less than 5 dB over 1 GHz frequency range, and the single-sideband phase noise （200 kHz offset from carrier frequency） of - 70 dBc/Hz. Utilizing the DR structure, the frequency stability of the local oscillator is less than 60 × 10^-6/℃.

A Wide-Band Low Noise Amplifier for Terrestrial and Cable Receptions

We present the design of a wide-band low-noise amplifier （LNA） implemented in 0.35μm SiGe BiCMOS technology for cable and terrestrial tuner applications. The LNA utilizes current injection to achieve high linearity. Without using inductors, the LNA achieves 0.1 ～ 1GHz wide bandwidth and 18. 8dB gain with less than 1.4dB of gain variation. The noise figure of the wideband LNA is 5dB, and its 1dB compression point is - 2dBm and IIP3 is 8dBm. The LNA dissipates 120mW of power with a 5V supply.

Design and analysis on four stage SiGe HBT low noise amplifier

Focusing on the linearity shortcoming on a bipolar low noise amplifier(LNA),a new 6 ~14GHz four stage SiGe HBT LNA is proposed.This amplifier adopts a method of gain allocation on multiple stages to avoid the limitation on linearity especially with the addition of negative gain on the third stage.To realize gain flatness,extra zero is introduced to compensate the gain roll-off formed by pole,and local shunt-shunt negative feedback is used to widen the bandwidth as well as optimize circuit' s noise.Simulated results have shown that in 6 ~14GHz,this circuit achieves noise figure(NF) less than 3dB,gain of 17.8dB(+0.2dB),input and output reflection parameters of less than- 10 dB,and the K factor is above 1.15.

A NOVEL SIMULTANEOUS NOISE AND INPUT VSWR MATCHING TECHNIQUE FOR BROADBAND LNA

The Simultaneous Noise and Input Voltage Standing Wave Ratio (VSWR) Matching (SNIM) condition for Low Noise Amplifier (LNA), in principle, can only be satisfied at a single fre-quency. In this paper, by analyzing the fundamental limitations of the narrowband SNIM technique for the broadband application, the authors present a broadband SNIM LNA systematic design technique. The designed LNA guided by the proposed methodology achieves 10 dB power gain with a low Noise Figure of 0.53 dB. Meanwhile, it provides wonderful input matching of 27 dB across the fre-quency range of 3～5 GHz. Therefore, broadband SNIM is realized.

Design of 5GHz low noise amplifier with HBM SiGe 0. 13μm BiCMOS process

A fully integrated low noise amplifier( LNA) for WLAN 802. 11 ac is presented in this article.A cascode topology combining BJT and MOS transistor is used for better performance. An inductive source degeneration is chosen to get 50 Ohm impedance matching at the input. The noise contribution of common gate transistor is analyzed for the first time. The designed LNA is verified with IBM silicon-germanium(SiGe ) 0. 13μm BiCMOS process. The measured results show that the designed LNA has the gain of 13 dB and NF of 2. 8 dB at the center frequency of 5. 5 GHz. The input reflection S11 and output reflection S22 are equal to-19 dB and-11 dB respectively. The P-1 dB and IIP3 are-8. 9 dBm and 6. 6 dBm for the linearity performance respectively. The power consumption is only 1. 3 mW under the 1. 2 V supply. LNA achieves high gain,low noise,and high linearity performance,allowing it to be used for the WLAN 802. 11 ac applications.

Optimum Design for a Low Noise Amplifier in S-Band

An optimum design of a low noise amplifier （LNA） in S-band working at 2-4 GHz is described. Choosing FHC40LG high electronic mobility transistor （HEMT）, the noise figure of the designed amplifier simulated by Microwave Office is no more than 1.5 dB, meanwhile the gain is no less than 20 dB in the given bandwidth. The simulated results agree with the performance of the transistor itself well in consideration of its own minimum noise figure （0.3 dB） and associated gain （15.5 dB）. Simultaneously, the stability factor of the designed amplifier is no less than 1 in the given bandwidth.

10Gb/s GaAs PHEMT Current Mode Transimpedance Preamplifier for Optical Receiver

A single power supply common-gate （CG） current mode transimpedance preamplifier （TIA） is developed with a 0.5μm GaAs PHEMT process. The amplifier has a measured - 3dB bandwidth of 7. 5GHz and a transimpedance gain of 45dBΩ. Both the input and output voltage standing wave ratios （VSWR） are less than 2 within the bandwidth. The equivalent input noise current spectral density varies from 14.3 to 22pA/√Hz, with an average value of 17. 2pA/√Hz. Having a timing jitter of 14ps and eye amplitude of about 138mV,the measured output eye diagram for 10Gb/s NRZ pseudorandom binary sequence （PRBS） is clear and satisfactory.

Research on optimizing the noise figure of low noise amplifier method via bias and frequency

In this paper, we present the design of an integrated low noise amplifier （LNA） for wireless local area network （WLAN） applications in the 5.15-5.825 GHz range using a SiGe BiCMOS technology. A novel method that can determine both the optimum bias point and the frequency point for achieving the minimum noise figure is put forward. The method can be used to determine the optimum impedance over a relevant wider operating frequency range. The results show that this kind of optimizing method is more suitable for the WLAN circuits design. The LNA gain is optimized and the noise figure （NF） is reduced. This method can also achieve the noise match and power match simultaneously. This proposal is applied on designing a LNA for IEEE 802.1 la WLAN. The LNA exhibits a power gain large than 16 dB from 5.15 to 5.825 GHz range. The noise figure is lower than 2 dB. The OIP3 is -8 dBm. Also the LNA is matched to 50 Ω input impedance with 6 mA DC current for differential design.

A 0.18μm CMOS GAIN-SWITCHED LNA AND MIXER WITH LARGE DYNAMIC RANGE

A 2.4GHz 0.18μm CMOS gain-switched single-end Low Noise Amplifier （LNA） and a passive mixer with no external balun for near-zero-IF （Intermediate Frequency）/RF （Radio Frequency） applications are described. The LNA, fabricated in the 0.18μm 1P6M CMOS technology, adopts a gain-switched technique to increase the linearity and enlarge the dynamic range. The mixer is an IQ-based passive topology. Measurements of the CMOS chip are performed on the FR-4 PCB and the input is matched to 50Ω. Combining LNA and mixer, the front-end measured performances in high gain state are： -15dB of Sll, 18.5dB of voltage gain, 4.6dB of noise figure, 15dBm of IIP3, 85dBm to -10dBm dynamic range. The full circuit drains 6mA from a 1.8V supply.

Performance Enhancement of Praseodymium Doped Fiber Amplifiers

In this paper,we report a simulation study on the performance enhancement of Praseodymium doped silica fiber amplifiers(PDFAs)in O-band(1270-1350 nm)in terms of small signal gain,power conversion efficiency(PCE),and output optical power by employing bidirectional pumping.The PDFA performance is examined by optimizing the length of Praseodymium doped silica fiber(PDF),its mode-field diameter(MFD)and the concentration of Pr^(3+).A small-signal peak gain of 56.4 dB,power conversion efficiency(PCE)of 47%,and output optical power of around 1.6 W(32 dBm)is observed at optimized parameters for input signal wavelength of 1310 nm.Minimum noise figure(NF)of 4.1 dB is observed at input signal wavelength of 1310 nm.Moreover,the effect of varying the pump wavelength and pump power on output optical power of the amplifier and amplified spontaneous emission(ASE)noise is also investigated,respectively.Finally,the impact of ion-ion interaction(up-conversion effect)on small-signal gain of the amplifier is also studied by considering different values of up-conversion coefficient.

A 6-7 GHz,40 dB receiver RF front-end with 4.5 dB minimum noise figure in 0.13μm CMOS for IR-UWB applications

A wideband receiver RP front-end for IR-UWB applications is implemented in 0.13μm CMOS technology. Thanks to the direct sub-sampling architecture,there is no mixing process.Both LNA and VGA work at RF frequencies.To optimize noise as well as linearity,a differential common-source LNA with capacitive cross- coupling is used,which only consumes current of 1.8 mA from a 1.2 V power supply.Following LNA,a two-stage current-steering VGA is adopted for gain tuning.To extend the overall bandwidth,a three-stage staggered peaking technique is used.Measurement results show that the proposed receiver front-end achieves a gain tuning range from 5 to 40 dB within 6-7 GHz,a minimum noise figure of 4.5 dB and a largest IIP_3 of-11 dBm.The core receiver (without test buffer) consumes 14 mW from a 1.2 V power supply and occupies 0.58 mm^2 area.

Nonlinear performances of dual-pump amplifiers in silicon waveguides

The performances of a dual-pump parametric and Raman amplification process and the wavelength conversion in silicon waveguides are investigated. By setting the Raman contribution fraction f to be 0.043 in our analytical model, the amplification gain of the probe signal can be obtained to be over 10 dB. The pump transfer noise （PTN）, the quantum noise （QN）, and the total noise figure （TNF） are discussed, and the TNF has a constant value of about 4 dB in the gain bandwidth. An idler signal generated during the parametric amplification （PA） process can be used to realize the wavelength conversion in wavelength division multiplexing （WDM） systems. In addition, the pump signal parameters, the generated free carrier lifetime and effective mode area （EMA） of the waveguide are analysed for the optimization of signal gain and noise characteristics.

A WIDE BAND UP-CONVERSION MIXER FOR CABLE TELEVISION TUNER

An up-conversion mixer implemented in a 0.35μm SiGe BiCMOS technology for a double conversion cable TV tuner is described, The mixer converts the 100MHz to 1000MHz band to the Intermediate Frequency of 1GHz above. The mixer meets the linearity and noise figure requirements for a TV tuner. The noise figure （IF） of 19.2-17.5dB, ldB compression of 12.1dBm, and gain of-1-0.7dB in the 900MHz band are achieved at a supply voltage of 5V. The power consumption is 47mW.

A 5.4mW Low-Noise High-Gain CMOS RF Front-End Circuit for Portable GPS Receivers

This paper describes a CMOS low noise amplifier （LNA） plus the quadrature mixers intended for use in the front-end of portable global positioning system （GPS） receivers. The LNA makes use of an inductively degenerated input stage and power-constrained simultaneous noise and input matching techniques. The quadrature mixers are based on a Gil- bert cell type. The circuits are implemented in a TSMC 0.18μm RF CMOS process. Measurement results show that a voltage conversion gain of 35dB is achieved with a cascade noise and an input return loss of - 22.3dB. The fully differential figure of 2.4dB,an input ldB compression point of - 22dBm, circuits only draw 5.4mW from a 1.8V supply.