单片集成的增强型和耗尽型pHEMT技术

随着射频/微波器件的快速发展及其应用领域的日益扩大,基于半导体单片集成技术的多种器件集成工艺不断发展。研究了一种采用AlGaAs-InGaAs的砷化镓化合物衬底。琥珀酸湿法蚀刻工艺对器件电性能影响较小。将耗尽型和增强型赝配高电子迁移率晶体管(pseudomorphic High-Electron-Mobility Transistor, pHEMT)器件集成于同一芯片半导体工艺技术。结果表明,增强型晶体管Y型栅极的线宽为0.25 m,开启电压为0.3 V;耗尽型晶体管栅极的线宽为0.5 m,开启电压为-0.8 V,实现了在同一芯片上集成从负到正的栅极电压分布,为设计者提供了更为宽广的设计平台。这种集成技术可以应用于低噪声放大器、线性天线开关、滤波器以及功率控制装置等领域。     

The study of δ-doped InGaP/InGaAs/GaAs pseudomorphic high electron mobility transistor

An enhancement-mode pseudomorphic high electron mobility transistor (E-mode pHEMT) with In_0.49Ga_0.51P/In_0.25Ga_0.75As/GaAs structure is studied in this paper. The two-dimensional device simulator, MEDICI, is used to solve the Poisson's equation and the electron/hole current continuity equations. An optimized δ-doped InGaP/InGaAs pHEMT structure is found to be superior to the conventional AlGaAs/InGaAs pHEMT. It reveals that the maximum drain-source current (I_DS) goes up to 1600 mA/mm and transconductance (G_m) is 2120 mS/mm.     

Ka波段单片压控振荡器的设计

基于0.25μm GaAs pHEMT工艺设计了Ka波段单片压控振荡器,该压控振荡器采用源极正反馈结构,变容管采用源极和漏极接地的pHEMT管。通过优化输出匹配网络和谐振网络以改善输出功率和相位噪声性能,使用蒙特卡洛成品率分析对本设计的成品率进行分析和改进。版图仿真结果显示:芯片输出频率为24.6²6.3 GHz,输出功率为(10±1)dBm,谐波抑制大于19 dB,芯片尺寸为1.5 mm×1 mm。     

Changes of electrical properties by Al content of AlxGa1−xAs in pHEMT structures as observed using HRXRD

Characterizations on the pseudomorphic High Electron Mobility Transistor structure under High-Resolution X-ray Diffraction (HRXRD) have been carried out at room temperature. Variation of Al contents in Al_xGa_1−xAs alloys has been found to show a shift of diffraction peaks. This variation is also found to show the change of lattice constant of crystal and also sheet carrier concentration as obtained from a Hall effect measurement. The latter phenomenon is considerably interesting to study in the early stage of the electrical properties of device based on the crystal structure.     

Current-voltage behavior of AlGaAs/InGaAs pHEMT structures and the effect of optical illumination

Various pseudomorphic High Electron Mobility Transistor (pHEMT) structures of AlGaAs/InGaAs alloys have been observed their current-voltage behavior. The tungsten probes were used for a measurement the structures by ramping the voltage from −5 to 5 V and measure the electrical current. Measurement was carried out at room temperature and also under optical illumination. From the measurement, the electrical current was found to increase as the increase of Al content in the AlGaAs alloys layer in the pHEMT structure. This phenomenon was supported by the decrease of sheet resistance as obtained from Hall effect measurement. Under visible light illumination, the current-voltage behavior of pHEMT structure was observed to vary as the light power density was varied for 0, 25 and 55 μW/cm.     

Performance optimizing on multi-function MMIC design

Integration of GaAs BiFET (bipolar-FET) devices to obtain the optimum performance for multiple functions of MMIC design has been achieved. In this study, heterojunction bipolar transistors (HBTs), enhancement mode pseudomorphic HEMTs (E-pHEMTs), and depletion mode pHEMTs are developed for potential applications, including the integration of HBT power amplifier circuitry with pHEMT-based bias control, logic, RF switch, and low-noise amplifier circuitries. Critical processes including gate photolithography and gate recess control are presented and discussed in detail. The enhancement-depletion modes of pHEMT, HBT electrical performance, and uniformity are investigated comprehensively. In addition, power amplifiers and high power switches based on BiFET technology are investigated.     

Design of a 24-40 GHz balanced low noise amplifier using Lange couplers

A wide band(24-40 GHz)fully integrated balanced low noise amplifier(LNA)using Lange couplers was designed and fabricated with a 0.15/zm pseudomorphic HEMT(pHEMT)technology.A new method to design a low-loss and high-coupling Lange coupler for wide band application in microwave frequency was also presented.This Lange coupler has a minimum loss of 0.09 dB and a maximum loss of 0.2 dB over the bandwidth from 20 to 45 GHz.The measured results show that the realized four-stage balanced LNA using this Lange coupler exhibites a noise figure(NF)of less than 2.7 dB and the maximum gain of 30 dB;moreover,a noticeably improved reflection performance is achieved.The input VSWR and the output VSWR are respectively less than 1.45 and 1.35 dB across the 24-40 GHz frequency range.     

Millimeter wave band ultra wideband transmitter MMIC

This paper presents a new millimeter-wave (MMW) ultra wideband (UWB) transmitter MMIC which has been developed in an OMMIC 0.1 μm GaAs PHEMT foundry process (f_t = 100 GHz) for 22-29 GHz vehicular radar systems. The transmitter is composed of an MMW negative resistance oscillator (NRO), a power amplifier (PA), and two UWB pulse generators (PGs). In order to convert the UWB pulse signal to MMW frequency and reduce the total power consumption, the MMW NRO is driven by one of the UWB pulse generators and the power amplifier is triggered by another UWB pulse generator. The main advantages of this transmitter are: new design, simple architecture, high-precision distance measurements, infinite ON/OFF switch ratio, and low power consumption. The total power consumption of the transmitter MMIC is 218 mW with a peak output power of 5.5 dBm at 27 GHz.     

带有小型化Balun的C波段单片GaAs pHEMT单平衡电阻性混频器

 本文介绍了一种带有小型化无源Balun的C波段单片GaAs pHEMT单平衡电阻性混频器.Balun 采用集总—分布式结构,使其长度与常用λ/4耦合线Balun相比缩小了11倍,大大降低了将无源Balun应用于C波段单片集成电路中所需的芯片尺寸.混频器采用单平衡电阻性结构,在零功耗的情况下实现了良好的线性和口间隔离性能.测试结果显示,在固定中频160MHz,本振输入功率0dBm条件下,在3.5~5GHz RF频带内,最小变频损耗为8.3dB,1dB压缩点功率为8.0dBm,LO至IF之间的隔离度为38dB.     

A high-speed power detector MMIC for E-band communication

An E-band high speed power detector MMIC using 0.1 μm pHEMT technology has been designed, manufactured and experimentally characterized. By employing a 4-way quadrature structure for phase cancellation, the first, second and third harmonics can be suppressed and the ripple at the output is minimized. Compared to conventional topology with a low pass filter, a short response time and high speed performance of demodulation can be reached. Simulated results indicate that the detector is capable of demodulating an on-off keying signal at a data rate up to 5 Gbps. The fabricated chip occupies 1×1.5 mm²and the on-wafer measurement shows a return loss of less than -15 dB, responsivity better than 700 mV/mW and dynamic range of more than 25 dB over 70 to 90 GHz.