G-band (140-220 GHz) and W-band (75-110 GHz) InP DHBT medium power amplifiers

We report common-base medium power amplifiers designed for G-band (140-220 GHz) and W-band (75-110 GHz) in InP mesa double HBT technology. The common-base topology is preferred over common-emitter and common-collector topologies due to its superior high-frequency maximum stable gain (MSG). Base feed inductance and collector emitter overlap capacitance, however, reduce the common-base MSG. A single-sided collector contact reduces C_ce and, hence, improves the MSG. A single-stage common-base tuned amplifier exhibited 7-dB small-signal gain at 176 GHz. This amplifier demonstrated 8.7-dBm output power with 5-dB associated power gain at 172 GHz. A two-stage common-base amplifier exhibited 8.1-dBm output power with 6.3-dB associated power gain at 176 GHz and demonstrated 9.1-dBm saturated output power. Another two-stage common-base amplifier exhibited 11.6-dBm output power with an associated power gain of 4.5 dB at 148 GHz. In the W-band, different designs of single-stage common-base power amplifiers demonstrated saturated output power of 15.1 dBm at 84 GHz and 13.7 dBm at 93 GHz     

Electric measurement and modelling of the emitter base junction behaviour of VLSI silicon transistor

A knowledge of the gain of the emitter base junction center is of great interest to evaluate several phenomena which occur in VLSI technology. These effects are mainly: —the edge effects of the emitter base junction, —the heavily doped emitter effects (bandgap narrowing)… We develop in this paper a method to measure the internal gain of the VLSI bipolar transistors using a weak avalanche multiplication in the collector. To verify our results we proposed a model which is convenient to use with our devices and consistent by comparison with some previous works. For the tested devices the ratio of the overall gain with the internal gain is about 0.5. Furthermore, the model allows a knowledge of the average intrinsic concentration of the degenerate emitter.     

Emitter Current Push-Out Effect under Avalanche Multiplication in the Collector p–nJunction

An expression that describes emitter current push-out to the emitter edges with consideration for avalanche multiplication of the current in the collector p–njunction of a bipolar transistor was derived. A strong power dependence of the avalanche multiplication coefficient on the base potential is shown to weaken the push-out effect and to smooth out the current distribution in the system.     

Influence of base thickness on collector breakdown in abruptAlInAs/InGaAs heterostructure bipolar transistors

The avalanche process in the collector of abrupt Al_0.48In_0.52As-In_0.53Ga_0.47 As heterostructure bipolar transistors (HBTs) is reported. It is reported that the collector multiplication constant decreases monotonically with increasing base thickness. When the base thickness is less than the mean-free path for energy relaxation in the base, the avalanche process in the collector is enhanced by high-energy injection from the emitter. On the other hand, no such dependence is observed for long-base transistors with equilibrium base transport. These effects are expected as the emitter injection energy of 0.48 eV is appreciable compared to the impact ionization threshold of 0.83 eV in the InGaAs collector     

Submicron transferred-substrate heterojunction bipolar transistors

We report submicron transferred-substrate AlInAs/GaInAs heterojunction bipolar transistors (HBT's). Devices with 0.4-μm emitter and 0.4-μm collector widths have 17.5 dB unilateral gain at 110 GHz. Extrapolating at -20 dB/decade, the power gain cutoff frequency f_max is 820 GHz. The high f_max, results from the scaling of HBT's junction widths, from elimination of collector series resistance through the use of a Schottky collector contact, and from partial screening of the collector-base capacitance by the collector space charge     

Submicron scaling of HBTs

The variation of heterojunction bipolar transistor (HBT) bandwidth with scaling is reviewed. High bandwidths are obtained by thinning the base and collector layers, increasing emitter current density, decreasing emitter contact resistivity, and reducing the emitter and collector junction widths. In mesa HBTs, minimum dimensions required for the base contact impose a minimum width for the collector junction, frustrating device scaling. Narrow collector junctions can be obtained by using substrate transfer or collector-undercut processes or, if contact resistivity is greatly reduced, by reducing the width of the base ohmic contacts in a mesa structure. HBTs with submicron collector junctions exhibit extremely high f_max and high gains in mm-wave ICs. Transferred-substrate HBTs have obtained 21 dB unilateral power gain at 100 GHz. If extrapolated at -20 dB/decade, the power gain cutoff frequency f_max is 1.1 THz. f_max will be less than 1 THz if unmodeled electron transport physics produce a >20 dB/decade variation in power gain at frequencies above 110 GHz. Transferred-substrate HBTs have obtained 295 GHz f_T. The substrate transfer process provides microstrip interconnects on a low-ϵ_r polymer dielectric with a electroplated gold ground plane. Important wiring parasitics, including wiring capacitance, and ground via inductance are substantially reduced. Demonstrated ICs include lumped and distributed amplifiers with bandwidths to 85 GHz and per-stage gain-bandwidth products over 400 GHz, and master-slave latches operating at 75 GHz     

下一代移动通信LTE中功率放大器芯片设计

基于0.18μm SiGe BiCMOS工艺,设计了一种应用于下一代移动通信3GPP LTE TDD2.6 GHz频段(Band38)的射频功率放大器(PA)芯片。射频功率放大器采用共发射极3级级联的全差分结构,提高了输出电压摆幅,减小了功率晶体管的集电极电流,且降低了寄生的键合线电感。在预放大级和中间放大级、功率级中分别设计了电阻偏置和有源偏置两种偏置电路以提高线性度性能,并通过MOS开关管实现功率控制功能。测试结果表明:在2.57～2.62 GHz工作频段内,正向增益S21大于30.5 dB,输入回波损耗S11和输出回波损耗S22分别均小于-13 dB,功率增益大于31 dB,输出1 dB压缩点功率达28.6 dBm,功率附加效率为18%。     

Highly linear amplification with transistors

Highly linear amplification can be obtained with HF diffused-base transistors in the common base configuration. It is the purpose of this paper to 1) present experimental results to demonstrate this, 2) demonstrate the causes for this high degree of linearity and derive expressions for optimum bias voltages and currents (these results can be extended with certain restrictions to the common emitter and common collector configurations), and 3) present a general method for analytically treating nonlinearity in all transistor configurations. A push-pull amplifier using 2N509- or 2N1195-type transistors provided 13 db of gain, with signal-to-distortion ratios of 70 to 80 db for broad-band white noise signals with +3 dbm of average output power or sine wave signals with +15-dbm peak output power. The stability of this gain and linearity with temperature and interchange of transistors is high. This high degree of linearity is shown to be due to 1) cancellation of current sensitive nonlinearity in the emitter and collector resistances, 2) collector voltage bias adjusted so that the derivative of the collector conductance with respect to collector voltage is zero, and 3) the use of a high alpha cutoff frequency transistor. An expression derived for optimum bias was in good agreement with experiment. The nonlinear distortion in transistors is shown to be different from that found in most devices, in that there are frequency-sensitive and frequency-insensitive nonlinearities. A general analysis carried out including these terms was in good qualitative agreement with experiment.     

低温硅双极晶体管电流增益研究

着重分析了多晶硅发射极对提高电流增益的作用和低温下集电区中性杂质碰撞电离引起的电流倍增效应，导出多晶硅发射极晶体管电流增益的表达式，很好地解释了实验结果。     

A new traveling wave matching structure for enhancing the bandwidth of MMIC broadband amplifiers

Three artificial transmission line sections followed by an input emitter follower buffer are used for constructing a new traveling wave matching structure to enhance the bandwidth of broadband amplifiers. An InGaP HBT MMIC broadband amplifier with 20-mW dc power consumption and a flat gain of 7.5dB over a frequency range from 30kHz to 23GHz is demonstrated.     

9.5-14.5 GHz GaAs HBT 1W MMIC with 55% peak power added efficiency

A fully matched, broadband, high efficiency MMIC power amplifier using AlGaAs/GaAs HBTs has been designed and tested. At 7 V collector bias, this HBT amplifier produced 31 dBm CW peak output power with 9 dB gain and 55% peak power-added efficiency in the 9.5-14.5 GHz band. To the authors' knowledge, this is the highest efficiency ever achieved from a broadband MMIC power amplifier     

低偏置电压工作的自对准InGaP/GaAs功率异质结双极晶体管

介绍L波段、低偏置电压下工作的自对准InGaP/GaAs功率异质结双极晶体管的研制.在晶体管制作过程中采用了发射极-基极金属自对准、空气桥以及减薄等工艺改善其功率特性.功率测试结果显示:当器件工作在AB类,工作频率为2GHz,集电极偏置电压仅为3V时,尺寸为2×(3μm×15μm)×12的功率管获得了最大输出功率为23dBm,最大功率附加效率为45%,线性增益为10dB的良好性能.     

Measurement of avalanche multiplication of injected holds in germanium p-n-p diffused-base transistors

A three-terminal dc measurement is made of avalanche multiplication of holes injected from the emitter into the collector junction of diffused-base germanium p-n-p transistors. The method is applicable to asymmetric thin-base transistors at currents at which dc base current is independent of base width when emitter to base voltage (VEB) is held constant. Injected collector current and VEBare measured at constant emitter current as a function of collector to base voltage (V). VEBis measured to take base narrowing into account. Collector reverse current is balanced out. The advantages of this method over two-terminal measurements are that surface, space-charge recombination and internal field emission currents are balanced out and no a priori assumption of the form of the multiplication factorM(V)is needed. For collector barriers which are nearly stepn^{+}pjunctions with the p-type resistivity in the neighborhood of 1 ohm-cm, the multiplication data, which cover the range1.05 siml M siml 2.0, fit the Miller equationM^{-1} = 1 - (V/V_{B})^{n} n = 3.2 pm 0.2in agreement with Miller's two-terminal measurements using alloy and grown-junction Ge transistors. The parameters VBfrom extrapolation of the present data agree within experimental error of five per cent with the collector diode breakdowns BVCBOmeasured by Miller. However, in the present measurements on diffused-base transistors, appreciable surface current multiplication occurs with the result that BVCBOmeasured at 1 ma is approximately 18 per cent less than VB. The absence of microplasma noise in the multiplied injected hole current indicates that multiplication occurs uniformly in the collector barrier under the emitter at least toM = 2.     

Delta-doped avalanche photodiodes for high bit-rate lightwavereceivers

The authors estimate the GB (grain bandwidth) product limits and the noise performance of a new SAGM-APD (separate avalanche, grating, and multiplication avalanche photodiode) structure: the δ-doped SAGM-APD. It is shown that GB products in excess of 140 GHz for a 0.2-μm-thick multiplication layer and possibly larger GB products for smaller widths can be obtained. While recent calculations have predicted increased GB products for this δ-doped SAGM-APD structure, the authors explicitly prove using conventional theory that this is possible only with a concomitant increase in the multiplication noise. It is further demonstrated that it is essential to optimize the width of the multiplication layer for a given bit-rate to achieve minimum multiplication noise consistent with a GB product high enough to accommodate the requisite frequency response at the optimum gain. It is shown that the δ-doped SAGM-APD structure is a very good candidate for high bit-rate receiver applications     

低电压C类SiGe微波功率异质结双极型晶体管

给出了低电压微波SiGe功率异质结双极型晶体管(HBT)的器件结构和测试结果.器件结构适于低压大电流状态下应用.采用了梳状发射极条的横向版图设计,其工作电压为3-4V.在C类工作状态,1GHz的工作频率下,输出功率可以达到1.65W,具有8dB的增益.3V时可以达到的最高收集极效率为67.8%.     

Gallium arsenide dual Schottky barrier diodes

Gallium arsenide diodes were made which had Schottky-barriers for both contacts. Devices which were too thick for space change reach-through to occur at breakdown showed microwave oscillations, while thin diodes did not oscillate. Additionally, the structures could be distinguished on the basis of the noise accompanying breakdown. The performance was analysed in terms of transistor theory in which there is avalanche multiplication in the collector space charge region. It was concluded that there is a smooth transition between the reachthrough breakdown characteristic of the BARITT and true avalanche breakdown. The nature of the breakdown depends on the base width and the emitter efficiency.     

基于无线功率放大器应用的多指结构SiGe HBT

采用简单的双台面工艺制作了完全平面结构的5个单元、10个发射极指大面积的SiGe HBT.器件表现出了良好的直流和高频特性,最大电流增益β为214.BVCEO为9V,集电极掺杂浓度为1×1017 cm-3,厚度为400nm时,BVCBO为16V.在直流偏置下IC=30mA,VCE=3.0V得到fT和fmax分别为18.0GHz和19.3GHz,1GHz下最大稳定增益为24.5dB,单端功率增益为26.6dB.器件采用了新颖的分单元结构,在大电流下没有明显的增益塌陷现象和热效应出现.     

低电压C类SiGe微波功率异质结双极型晶体管

给出了低电压微波 Si Ge功率异质结双极型晶体管 (HBT)的器件结构和测试结果 .器件结构适于低压大电流状态下应用 .采用了梳状发射极条的横向版图设计 ,其工作电压为 3— 4V.在 C类工作状态 ,1GHz的工作频率下 ,输出功率可以达到 1.6 5 W,具有 8d B的增益 . 3V时可以达到的最高收集极效率为 6 7.8% .     

Separate Absorption-Charge Multiplication Heterojunction Phototransistors With the Bandwidth-Enhancement Effect and Ultrahigh Gain-Bandwidth Product Under Near Avalanche Operation

We demonstrate a high-performance heterojunction phototransistor (HPT): separate absorption-charge multiplication HPT. The incorporation of an $hbox{In}_{0.52}hbox{Al}_{0.48} hbox{As}$-based multiplication layer in the $hbox{In}_{0.53} hbox{Ga}_{0.47}hbox{As}$-based collector layer of our HPT allows for a great shortening of the trapping time ($sim$ns to $ sim$30 ps) of electrons at the base–emitter junction under near avalanche operation, without sacrificing the gain performance. The interaction between the photoconductive gain and avalanche gain means that it is not necessary to use high bias voltages ($≫ hbox{30} hbox{V}$ ) in our device to attain high-gain $(≫ hbox{1} times hbox{10}^{4})$ performance. With this device design, we can achieve an extremely high (90 THz) gain-bandwidth product (1.6 GHz, $hbox{5.5} times hbox{10}^{4}$ ) under a 6-V bias.      

Gain of a heterojunction bipolar phototransistor

Analytical expressions have been derived for the collector current, optical gain, and quantum efficiency for a heterojunction, bi-polar phototransistor (HPT). These expressions can be utilized to optimize the current gain and quantum efficiency for HPT design. The presence of avalanche multiplication in the base-collector junction has been taken into account and shown to be a significant factor in determining the gain of an InGaAs/InP phototransistor. Experimental results of optical gain versus the collector-emitter voltage can only be explained in terms Of avalanche multiplication.