Prediction of Wide-Band Power Performance of MESFET Distributed Amplifiers Using the Volterra Series Representation

The power performance of a four-section MESFET distributed amplifier is predicted over the frequency range 2-8 GHz. The nonlinear model of the MESFET used has three nonlinear elements: g/sub d/, and C/sub gs/, which are represented by power series up to the third order. The analysis employs the Volterra series representation up to the third order. Experimental verification is first made on a 0.5x400-µm medium-power MESFET device to confirm the validity of the nonlinear model used in the analysis. The agreement between predicted and measured output power at 1-dB gain compression is within +-0.5 dBm across the 2-16 GHz band. A four-section distributed amplifier was then built with four 0.5x400-µm MESFET's. The agreement between predicted and measured output power at 1-dB gain compression of this amplifier is within +-0.7 dBm across the 2-8-GHz band. The measured output power at 1-dB gain compression is (22+-1) dBm across the 2-8-GHz band.     

44-GHz monolithic GaAs FET amplifier

Millimeter-wave monolithic GaAs FET amplifiers have been developed. These amplifiers were fabricated using FET's with MBE-grown active layers and electron-beam defined sub-half-micrometer gates. Source groundings are provided through very low inductance via holes. The single-stage amplifier has achieved over a 10-dB gain at 44 GHz. A 300-µm gate-width amplifier has achieved an output power of 60 mW with a power density of 0.2 W per millimeter of gate width.     

An all solid-state modulator for the ARSR-3 transmitter

This paper describes an all solid-state, high-power pulse modulator used in the ARSR-3 system (an FAA air route surveillance radar system). The modulator, the culmination of a number of years of both device and circuit development, uses fast switching Reverse Blocking Diode Thyristors (RBDT's) to directly switch 14-MW, 3-µs video pulses at high current without the use of magnetic switching aids. The modulator consists of five identical PFN modules, a trigger amplifier, and a pulse transformer which matches the modulator output to the beam characteristics of a klystron. Each module contains its own PFN, discharge RBDT switch assembly, and associated circuitry. This modulator is the first production equipment to use the new Westinghouse T62R RBDT devices. The devices switch 2200-A pulses with a turn-on rate of rise of up to 3000 A/µs.     

The Declining Drain Line Lengths Circuit--A Computer Derived Design Concept Applied to a 2 26.5-GHz Distributed Amplifier

The principle of the "declining drain line lengths" has emerged as a successful concept in the pursuit of improved gain flatness and bandwidth. The optimized performance parameters of an "identical links" gain module are compared to those of a "declining drain line lengths" gain module, and the advantages of one design principle over the other are discussed. In addition, the paper studies the RF voltages and currents of the circuits' GaAs MESFETs and draws some qualitative conclusions as to the causes of gain limiting when approaching nonlinear operation. Finally, experimental results of a power module based on the "declining drain line lengths" principle are reported. The hybrid amplifier which incorporates five active devices with 0.25-µm gates achieves a small signal gain of G = 6.1+-0.6 dB from 2-27 GHz. Measurements of its output power, reflection coefficients and noise figure are afso discussed.     

High-efficiency millimeter-wave GaAs/GaAlAs power HEMT's

The power, gain, and efficiency of 0.5-µm gate-length, 75- and 50-µm gate-width multiple heterojunction high electron mobility transistors (HEMT's) have been evaluated from 10 to 60 GHz. At 10 GHz, with a source-to-drain voltage as low as 2.4 V, the device delivers a power density of 0.37 W/mm with 13.4-dB gain and 60.8-percent efficiency. At 60 GHz, a 50-µm device gave 0.4 W/mm with 3.6-dB gain and 14-percent efficiency. The power density and efficiency of these 0.5- µm gate-length HEMT's above 40 GHz are the best reported for a three-terminal device. Fundamental frequency oscillations up to 104 GHz were observed when a device was bonded as a free-running oscillator.     

Planar fully ion implanted InP power junction FET's

This letter reports on the fabrication and performance of planar all ion-implanted 1.0-µm gate length InP power junction field effect transistors (JFET's). The devices were fabricated utilizing n+ implantation, a AuZn/TiW/Au gate metallization, and an n+ drain ledge. At 4.5 GHz, the 300-µm gate width JFET's exhibited maximum insertion gains of up to 13 dB and scaled output powers as high as 1 W/mm with 3-dB gain.     

The influence of diffusion on the stability of the supercritical transferred electron amplifier

The influence of the diffusion coefficient-electric field characteristic on the stability of the supercritical n-GaAs transferred electron amplifier (TEA) with ohmic contacts is investigated in computer simulations. Typical effects of doping profile, bias voltage, and temperature are considered. For a 10-µm 5-Ω TEA, a negative input conductance in the 7-31- GHz range is computed along with a corresponding 37-GHz voltage gain 3-dB bandwidth product in a 50-Ω circuit.     

A 0.13 μm CMOS UWB RF Transmitter with an On‐Chip T/R Switch

This paper presents a fully integrated 0.13 μm CMOS MB‐OFDM UWB transmitter chain (mode 1). The proposed transmitter consists of a low‐pass filter, a variable gain amplifier, a voltage‐to‐current converter, an I/Q up‐mixer, a differential‐to‐single‐ended converter, a driver amplifier, and a transmit/receive (T/R) switch. The proposed T/R switch shows an insertion loss of less than 1.5 dB and a Tx/Rx port isolation of more than 27 dB over a 3 GHz to 5 GHz frequency range. All RF/analog circuits have been designed to achieve high linearity and wide bandwidth. The proposed transmitter is implemented using IBM 0.13 μm CMOS technology. The fabricated transmitter shows a ?3 dB bandwidth of 550 MHz at each sub‐band center frequency with gain flatness less than 1.5 dB. It also shows a power gain of 0.5 dB, a maximum output power level of 0 dBm, and output IP3 of +9.3 dBm. It consumes a total of 54 mA from a 1.5 V supply.     

敏感头T/R组件

敏感头T／R组件利用一套发射机和四套接收机（简称1×4结构）在靶标上作面阵配置，通过对运动物体产生的多普勒频率测试处理，可及时获得运动物体相对靶标系统的空中轨迹。从而得到脱靶参数（距离和方向）即脱靶量的矢量位置。已研制成功的这套T／R组件是矢量脱靶参数测试系统中的核心部件──遥测敏感头。组件采用调频连续波多普勒雷达体制。工作在L波段的调频发射机输出1W功率。接收机采用相干接收、选颁中放、同步检波、有源滤波等电路，灵敏度为-120dBm。全套组件（1×4结构）重量3kg，功耗12W，探测距离50m，模拟试验已获成功。     

A 3.1 to 5 GHz CMOS Transceiver for DS‐UWB Systems

This paper presents a direct‐conversion CMOS transceiver for fully digital DS‐UWB systems. The transceiver includes all of the radio building blocks, such as a T/R switch, a low noise amplifier, an I/Q demodulator, a low pass filter, a variable gain amplifier as a receiver, the same receiver blocks as a transmitter including a phase‐locked loop (PLL), and a voltage controlled oscillator (VCO). A single‐ended‐to‐differential converter is implemented in the down‐conversion mixer and a differential‐to‐single‐ended converter is implemented in the driver amplifier stage. The chip is fabricated on a 9.0 mm² die using standard 0.18 µm CMOS technology and a 64‐pin MicroLead Frame package. Experimental results show the total current consumption is 143 mA including the PLL and VCO. The chip has a 3.5 dB receiver gain flatness at the 660 MHz bandwidth. These results indicate that the architecture and circuits are adaptable to the implementation of a wideband, low‐power, and high‐speed wireless personal area network.     

Low-Noise, Low Power Dissipation GaAs Monolithic Broad-Band Amplifiers

Low-noise, low dc power dissipation GaAs monolithic amplifiers have been developed for use in VHF-UHF mobile radio systems. The developed amplifiers have two-stage constuction, where gate width for the first stage is 1000 µm, and for the second stage is 500 pm. Using this circuit configuration, both noise figure and bandwidth have been improved. To maintain the uniformity for the ion-implanted active layers and to reduce gate-source resistance R/sub S/ and gate-drain resistance R/sub D/, the "closely spaced electrode FET" was adopted. The FET enables low drain voltage operation, resulting in low dc power dissipation. The developed amplifier for the FET threshold voltage VT= --0.6 V provides a 3-dB noise figure, less than 170-mW dc power dissipation, 9-MHz-3.9-GHz bandwidth with 16-dB gain. It can operate under a unipolar power source. When external choke inductors were introduced for the amplifier, 120-mW dc power dissipation has been achieved. It has also been demonstrated that the amplifier for V/sub T/= --0.6V, which is inferior to the amplifier for VT= -2.7V regarding gain-bandwidth product and power efficiency under the same dc power dissipation, however, has an acceptable performance for use in the mobile radio systems.     

Microwave performance of InAlAs/InGaAs/InP MODFET's

Modulation-doped InAlAs/InGaAs/InP structures were grown by molecular beam epitaxy (MBE) and fabricated into FET's with excellent RF gain performance. The intrinsic transconductance was about 400 mS/mm at 300 K. Current gain cutoff frequencies of up to 26.5 GHz were obtained in 1-µm gate devices. Extremely small S12and large S21led to a very largef_{max}of 62 GHz. These results represent the best reported figures for 1-µm devices in this material system and slightly better than those obtained in recently developed pseudomorphic modulation-doped field effect transistors (MODFET's).     

A low-noise GaAs MESFET made with graded-channel doping profiles

We have demonstrated that devices fabricated from epitaxially grown material with a graded-channel doping profile are capable of improved microwave performance. For operation at 12 GHz, graded-channel doping profile devices have an associated gain that is always 1 dB higher at the minimum noise-figure point compared to ion-implanted Gaussian-channel doping profile devices. A noise figure of 1.60 dB with 11-dB associated gain has been obtained at 12 GHz for 0.5-µm × 300-µm gate devices. A tranconductance of 200 mS/mm for this device has been achieved.     

基于GaN HEMT的13～17 GHz收发多功能芯片

基于GaN高电子迁移率晶体管(HEMT)工艺设计制作了一款收发(T/R)多功能芯片(MFC),主要用于射频前端收发系统.该芯片集成了单刀双掷(SPDT)开关用于选择接收通道或发射通道工作,芯片具有低噪声性能、高饱和输出功率和高功率附加效率等特点.芯片接收通道的LNA采用四级放大、单电源供电、电流复用结构,发射通道的功率放大器采用三级放大、末级四胞功率合成结构,选通SPDT开关采用两个并联器件完成.采用微波在片测试系统完成该芯片测试,测试结果表明,在13～ 17 GHz频段内,发射通道功率增益大于17.5 dB,输出功率大于12W,功率附加效率大于27％.接收通道小信号增益大于24 dB,噪声系数小于2.7 dB,1 dB压缩点输出功率大于9 dBm,输入/输出电压驻波比小于1.8∶1,芯片尺寸为3.70 mm×3.55 mm.     

A DC-coupled wide dynamic range AGC amplifier IC for 560-Mbit/s optical transmission

A wide-band high-gain AGC amplifier stabilizing the output dc level against a broad gain variation is proposed and monolithically integrated using high-speed 1-μm Si-bipolar IC technology. The fabricated IC exhibits a maximum gain of 39 dB, gain dynamic range of 44 dB, bandwidth of 800 MHz, and output dc-level fluctuation of 8 mV, and realizes wide dynamic range and direct dc-coupling of the multistage AGC amplifier. Also, in order to examine the feasibility of the fabricated IC, a 1.5-μm-wavelength optical transmission experiment was carried out using DFB-LD and InGaAs-APD. Measured minimum received optical power for an error rate of 10^-9is -40 dBm at 560 Mbit/s and -38 dBm at 1.12 Gbit/s. Optical dynamic range of 30 dB is also achieved by using the fabricated IC and APD.     

Ga0.4In0.6As/Al0.55In0.45As pseudomorphic modulation-doped field-effect transistors

High-performance pseudomorphic Ga0.4In0.6As/ Al0.55In0.45As modulation-doped field-effect transistors (MODFET's) grown by MBE on InP have been fabricated and characterized. DC transconductances as high as 271, 227, and 197 mS/mm were obtained at 300K for 1.6-µm and 2.9-µm gate-length enhancement-mode and 2-µm depletion-mode devices, respectively. An average electron velocity as high as 2.36 × 10⁷cm/s has been inferred for the 1.6-µm devices, which is higher than previously reported values for 1-µm gate-length Ga0.47In0.53As/Al0.48In0.52As MODFET's. The higher bandgap Al0.55In0.45As pseudomorphic barrier also offers the advantages of a larger conduction-band discontinuity and a higher Schottky barrier height.     

Fabrication and thermal performance of a novel TRAPATT diode structure

The development of TRAPATT diodes for long-pulse operation (10 to 100 µs), high duty cycle (1 to 15 percent), and wide bandwidth (12 percent), for phase array systems atFband requires new device fabrication and new heat-sinking technology. A novel TRAPATT diode in the form of interconnected long strips having high periphery-to-area ratio (cruciform) has been designed and fabricated. In this paper we described the thermal properties of the cruciform structure diode, which sustains 50-µs pulse width at 5.5-percent duty cycle while delivering 68-W RF power at 5-dB gain and 9-percent added efficiency, in addition to 100-µs pulse width at 4.2-percent duty cycle while delivering 50-W RF power output ast 3.6-dB and 5.5-percent added efficiency, both as narrow-band amplifier.     

A comparison of Nd:YAG fundamental and second-harmonic Q-switched laser-beam lifetime doping in single-crystal silicon

Silicon devices including bipolar transistors, junction diodes, and MOS capacitors were scanned by aQ-switched Nd:YAG (1.06 µm) and frequency-doubled Nd:YAG (0.53 µm) radiations under various conditions. The electrical characteristics of these devices were measured before and after scanning and again after thermal annealing. The data includes transistor gain versus laser power; junction diode leakage current versus junction depth; MOSC-Vlifetime versus laser power and the effects of subsequent thermal anneals on all of these. The results are that bulk minority-carrier lifetime decreases of several orders of magnitude will be produced by either of these radiations at peak power levels below those which will produce any visible surface damage. The changes in minority-carrier lifetime are stable for post scanning thermal anneals up to 400°C and are almost completely removed from an 800°C anneal. The depths within which minority-carrier lifetime changes significantly are 0.7 and 1.8 µm for 0.53- and 1.06-µm wavelength laser radiations, respectively. The results indicate that the recombination centers produced by the scanning are point defects and their density decreases exponentially with the distance into the silicon. The average power thresholds for point defect production (for both 0.53- and 1.06-µm wavelengths) were determined and are observed to increase with increased laser wavelength and pulse width. Potential applications in silicon devices and integrated circuits such as selective lifetime doping, β trimming, and selective-link making without passivation damage are possible.     

12-GHz-Band Low-Noise GaAs Monolithic Amplifiers

One- and two-stage 12-GHz-band low-noise GaAs monolithic amplifiers have been developed for use in direct broadcasting satellite (DBS) receivers. The one-stage amplifier provides a less than 2.5-dB noise figure with more than 9.5-dB associated gain in the 11.7-12.7-GHz band. In the same frequency band, the two-stage amplifier has a less tlhan 2.8-dB noise figure with more than 16-dB associated gain. A 0.5-µm gate closely spaced electrode FET with an ion-implanted active layer is employed in the amplifier in order to achieve a low-noise figure without reducing reproducibility. The chip size is 1 mm x 0.9 mm for the one-stage amplifier, and 1.5 mm x 0.9 mm for the two-stage amplifier.     

GaInAsP semiconductor laser amplifiers for single-mode fiber communications

Gain, polarization sensitivity, saturation power, and noise characteristics of quaternary semiconductor laser amplifiers of the Fabry-Perot (FP) and traveling-wave (TW) types are reviewed. The status of antireflection coatings for TW amplifiers is presented. New results concerning the polarization sensitivity and output saturation power of a 1.5-μm buried-heterostructure (BH) amplifier are reported. A theoretical model is presented concerning the influence of the waveguide structure on the maximum internal gain of a CW-operating 1.5- μm BH amplifier, including thermal effects, and a comparison of this model with recent experimental results is reported. The influence of nonresonant losses on the noise factor of 1.5-μm amplifiers is discussed.