A 2-18 GHz low-noise/high-gain amplifier module

The effectiveness of the two-tier matrix amplifier as a very-low-noise device with very high associated gains across multioctave frequency bands is theoretically and experimentally demonstrated. Experimental modules whose topology is based on a computer-optimized design exhibit an average noise figure of F=3.5 dB with an associated average gain of G=17.8 dB across the 2-18 GHz frequency band. These state-of-the-art results were achieved with GaAs MESFETs whose minimum noise figure is F=2.2 dB at 18 GHz and whose gate dimensions are 0.25×200 μm. The design considerations and the test results are discussed in detail     

基于倒扣技术的190~225 GHz肖特基二极管高效率二倍频器

基于分立式GaAs肖特基势垒二极管,研制出了190～225 GHz高效率二倍频器.50 μm厚石英电路利用倒扣技术,实现二极管的良好散热、可靠的射频信号及直流地.通过数值分析方法,二极管非线性结采用集总端口模拟,提取二极管的嵌入阻抗,以设计阻抗匹配电路.在202 GHz,测得最高倍频效率为9.6％,当输入驱动功率为85.5 mW时,其输出功率为8.25 mW;在190～225 GHz,测得倍频效率典型值为7.5％;该二倍频器工作频带宽、效率响应曲线平坦,性能达到了国外文献报道的水平.     

A 20 mW, 150 GHz InP HEMT MMIC power amplifier module

This paper describes a power amplifier (PA) module containing an InP high electron mobility transistor (HEMT) monolithic millimeter-wave integrated circuit (MMIC) amplifier chip, designed, and packaged at the Jet Propulsion Laboratory, and fabricated at HRL Laboratories. The module features 20 mW of output power at 150 GHz, with more than 10 mW available in the 148-160 GHz frequency range.     

A coplanar X-band AlGaN/GaN power amplifier MMIC on s.i. SiC substrate

This work presents a two-stage high-power amplifier monolithic microwave integrated circuit (MMIC) operating between 9 GHz and 11 GHz based on a fully integrated AlGaN/GaN high electron mobility transistor (HEMT) technology on s.i. SiC substrate and is suitable for radar applications. The MMIC device with a chip size of 4.5/spl times/3 mm/sup 2/ yields a linear gain of 20 dB and a maximum pulsed saturated output power of 13.4 W at 10 GHz equivalent to 3.3 W/mm at V/sub DS/=35V, 10% duty cycle, and a gain compression level of 5 dB. Further, dc reliability data are given for the MMIC HEMT technology.     

5-6.5 GHz LTCC power amplifier module with 0.3 W at 2.4 V in Si-bipolar

A fully integrated 5.5 /spl times/ 8.1 mm/sup 2/ low temperature cofired ceramic (LTCC) power amplifier module for 5-6.5 GHz has been realised in a 40 GHz-f/sub T/-BiCMOS technology. No external components are required. At 1 to 2.4 V supply voltages output powers of 17.5 to 24.8 dBm are achieved at 5.9 GHz. The respective power added efficiency is 28 to 36%. The small-signal gain is 23 dB.     

A broadband Doherty power amplifier with harmonic suppression

In this paper, the design and implementation of the broadband, Doherty power amplifier (DPA) with 2nd and 3rd harmonics suppression, with theoretical analysis is presented. In the proposed structure a novel harmonic suppressed Wilkinson power divider used in DPA, which results in harmonic suppression with high level of attenuation. Moreover the proposed DPA has major advantages in terms of the linearity and works on a wideband frequency range (2.1–2.7 GHz) with minimum 40% drain efficiency (DE). The linearity of the proposed DPA is increased extremely, which significant improvement (7 dBm) is achieved from the main amplifier. In the proposed DPA, the main and the auxiliary amplifiers are implemented using Class-AB and Class-C topology respectively with equal MRF6S27015N MOTOROLA transistors in LDMOS technology.     

Repeaterless transmission with 62.9 dB power budget using a highly efficient erbium-doped fibre amplifier module

A 565 Mbit/s DPSK heterodyne transmission experiment has been demonstrated using a fibre post-amplifier. Over +12 dBm output powers were obtained in a both end pumping configuration for 35 mW total launched pump power, leading to a repeaterless link budget of 62.9 dB.<>     

A novel fully differential biopotential amplifier with dc suppression

Fully differential amplifiers yield large differential gains and also high common mode rejection ratio (CMRR), provided they do not include any unmatched grounded component. In biopotential measurements, however, the admissible gain of amplification stages located before dc suppression is usually limited by electrode offset voltage, which can saturate amplifier outputs. The standard solution is to first convert the differential input voltage to a single-ended voltage and then implement any other required functions, such as dc suppression and dc level restoring. This approach, however, yields a limited CMRR and may result in a relatively large equivalent input noise. This paper describes a novel fully differential biopotential amplifier based on a fully differential dc-suppression circuit that does not rely on any matched passive components, yet provides large CMRR and fast recovery from dc level transients. The proposed solution is particularly convenient for low supply voltage systems. An example implementation, based on standard low-power op amps and a single 5-V power supply, accepts input offset voltages up to +/-500 mV, yields a CMRR of 102 dB at 50 Hz, and provides, in accordance with the AAMI EC38 standard, a reset behavior for recovering from overloads or artifacts.     

Quasi-TEM analysis of coplanar waveguides with an inhomogeneoussemiconductor substrate

In this paper, we study the normalized wavelength and attenuation constant of coplanar waveguides with a finite metal thickness. The substrate is a lossy inhomogeneous insulator-semiconductor, and the conductor is assumed perfect. Electroquasi-static approximation is used to derive a Laplace's equation with a complex permittivity in each inhomogeneous layer, from which the eigenmodes are obtained. Proper boundary conditions between contiguous layers are applied to calculate the charge distribution on the center conductor. The effects of the insulator depth and semiconductor conductivity on the normalized wavelength and attenuation constant are analyzed     

1.8 V–3 GHz CMOS limiting amplifier with efficient frequency compensation

A compact robust CMOS limiting amplifier (LA) for high data traffic optical links is presented in this work. The core considers two different blocks. First, four common-source inverter amplifiers are included, which optimize the gain-bandwidth product of the structure. And second, two additional compensation stages are placed strategically between the gain stages alleviating the pernicious load effect. These stages develop two different compensation techniques simultaneously thus increasing the bandwidth. The proposed design consumes 113 mW with a single 1.8 V supply. It achieves a cut-off frequency up to 3 GHz and provides a gain of 21 dB. The circuit is packaged in a QFN24 and mounted on a commercial FR4 PCB.     

一种带宽为3.8GHz，增益步长为0.1dB的可编程增益放大器

A broadband programmable gain amplifier（PGA） with a small gain step and low gain error has been designed in 0.13 m CMOS technology. The PGA was implemented with open-loop architecture to provide wide bandwidth. A two-stage gain control method, which consists of a resistor ladder attenuator and an active fine gain control stage, provides the small gain step. A look-up table based gain control method is introduced in the fine gain control stage to lower the gain error.The proposedPGAshows a decibel-linear variable gainfrom4 to20 dB with a gain step of 0.1 dB and a gain error less than˙0.05 dB. The 3-dB bandwidth and maximum IIP3 are 3.8 GHz and 17 dBm, respectively.     

6-18 GHz高效率功率MMIC设计与测试

A three-stage monolithic microwave integrated circuit （MMIC） power amplifier from 6-18 GHz, which achieves high output power with excellent efficiency, is designed, fabricated and tested. Measured results show that the saturated output power and the small signal gain are about 32 dBm and 23 dB, respectively. Thus, the power added efficiency of about 28% indicates that it is useful in various communication systems.     

Highly efficient configuration of a Pr3+-doped fluoridefiber amplifier module with an optical circulator

A highly efficient Pr³⁺-doped fluoride fiber amplifier configuration with an optical circulator, in which the input signal light is amplified both forward and backward through a Pr³⁺-doped fluoride fiber, is investigated with a view to decreasing the drive current and improving the reliability of pump laser diodes (LD's). With this double-path configuration, a 25-dB signal gain is achieved at an LD drive current of 110 mA. This LD drive current is about half that needed for a conventional single-path configuration. It is also found that this double-path configuration provides a double-gain coefficient, a slightly low saturation power, and a slightly narrow spectral gain width     

Design of a 94 GHz transition section with cosinusoidal profile

Up to now, many transition sections have been designed and applied successfully. But a transition section with cosinusoidal profile, its operation principle and how to design it have not been found in available literature until now. In this study, a transition section with a cosinusoidal profile and the method to design it are proposed based on the operational principles of mode converters with similar profiles. A 94 GHz transition section used to transmit TE₀₁ mode efficiently is designed using the method. The calculations by our codes and simulations on a high-frequency structure simulator indicate that the section can transmit TE₀₁ mode with transmission efficiency over 0.987 (within a bandwidth of 7.6 GHz) and reflection below ?40 dB. Experimental results show our design is successful. Comparison between the section and the linear one shows that the former is much shorter than the latter when they are used to transmit TE₀₁ mode at the same characteristics above. Such a strong point of shorter length is very helpful for the construction of a compact microwave device.     

Monolithic integration of a 94 GHz AlGaAs/GaAs 2-DEG mixer onquartz substrate by epitaxial lift-off

In this paper, we report the integration of an AlGaAs/GaAs two-dimensional electron gas (2-DEG) bolometric mixer and a quartz-based microstrip circuit using the epitaxial lift-off (ELO) technique. The 1 μm thick high-mobility 2-DEG device transplanted on quartz showed no sign of degradation resulting from the ELO process. The 2-DEG mixer fabrication procedure demonstrated here is advantageous for its simplicity and uncritical choice of substrate. We obtained a minimum intrinsic conversion loss of 17 dB at 94 GHz at liquid nitrogen temperature. The measured IF bandwidth of the mixer was greater than 3 GHz     

应用于5GHz频段带ESD保护的可变增益低噪声放大器

本文给出了应用于5GHz频段的可变增益低噪声放大器。详细分析了输入寄生电容对源极电感负反馈低噪声放大器的影响,给出了一种新的ESD和LNA联合设计的方法,另外,通过在第二级中加入一个简单的反馈回路实现了增益的可变。测试结果表明： 可变增益低噪声放大器增益变化范围达25dB (-3.3dB～21.7dB),最大增益时噪声系数为2.8dB,最小增益时三阶截点为1dBm,在1.8V电源电压下功耗为9.9mW。     

A CMOS variable gain low-noise amplifier with ESD protection for 5 GHz applications

This paper presents a variable gain low-noise amplifier (VG-LNA) for 5 GHz applications.The effect of the input parasitic capacitance on the inductively degenerated common source LNA's input impedance is analyzed in detail.A new ESD and LNA co-design method was proposed to achieve good performance.In addition,by using a simple feedback loop at the second stage of the LNA,continuous gain control is realized.The measurement results of the proposed VG-LNA exhibit 25 dB (-3.3 dB to 21.7 dB) variable gain range,2.8 dB noise figure at the maximum gain and 1 dBm IIP3 at the minimum gain,while the DC power consumption is 9.9 mW under a 1.8 V supply voltage.     

A 6.5 GHz-11.5 GHz source using a grid amplifier with a twistreflector

The authors have constructed and tested an oscillator using a grid amplifier with external feedback from a twist reflector. The twist reflector serves two functions; it changes the output polarization to match the input, and its position sets the feedback phase. This permits a wider tuning range than has been possible with previous grid oscillators. The source could be continuously tuned from 8.2 GHz to 11.0 GHz by moving the twist reflector. By moving the polarizer and mirror in the twist reflector independently, a 1.8-to-1 frequency range from 6.5 GHz to 11.5 GHz was achieved. The peak effective radiated power was 6.3 W at 9.9 GHz     

A novel miniaturized power amplifier with nth harmonic suppression

In this paper, a novel miniaturized power amplifier (PA) matched by two proposed low pass filters (LPFs) with nth harmonics suppression is presented. In the proposed PA, the LPFs are employed as an output and input impedance transformer networks, which transform 50 Ω to the desired impedances. In the proposed PA the conventional output and input matching networks are eliminated, which results in 52% size reduction and 6% power added efficiency (PAE) improvement compared with the conventional PA. Moreover, using the LPFs at the output and input impressively suppress the unwanted harmonics (2nd–6th) with high level of attenuation. The proposed PA works at the 2.6 GHz, which is suitable for long term evolution (LTE) applications. The measured and simulated results are in the good agreement, which confirm the validity of the proposed method.     

Experimental study on the thermo-mechanical effects of underfill and low-CTE substrate in a flip-chip device

Moiré interferometry was used to analyze the thermal deformation of four flip-chip devices mounted on FR-4 substrate and a new multi-layer substrate, with and without underfill. Thermal loading was applied by cooling the devices from 100 °C to room temperature (25 °C). The effects of underfill and the low-CTE (coefficient of thermal expansion) substrate on thermal deformation were investigated. The experimental results showed that the underfill curved in a manner similar to the silicon chip. For the flip-chip devices mounted on the multi-layer substrate, the CTE mismatch between the silicon chip and substrate was reduced, and bending deformation decreased. Of the four flip-chip devices studied, the underfilled flip-chip device mounted on the multi-layer substrate had the least deformed solder balls.