Performance of P-type epitaxial silicon millimeter-wave IMPATT diodes

A series of p-type IMPATT diodes (p⁺pn⁺) have been fabricated from epitaxially grown silicon for operation as oscillators at Ka-band frequencies. A maximum CW output power level of 700 mW at 29.6 GHz, a maximum conversion efficiency of 10.9 percent, and a minimum FM noise parameter, M, of 25 dB have been measured on this series of p-type diodes. A diode oscillating in a variable height radial disk cavity was frequency tuned from 27.5 to 40 GHz, covering the entire Ka-band, with a 1.4 dB power variation over the tuning range. The minimum CW output power of this tunable oscillator was 360 mW at 6.5 percent efficiency.     

CMOS IMPATT impedance and design parameters for millimetre-wave applications

This article describes lateral CMOS IMPATT diodes designed, monolithically integrated and fabricated in 0.18?µm CMOS technology. IMPATT diode impedance and avalanche frequency were confirmed in a measurement from 40?MHz to 110?GHz. Avalanche tuning range measured from 24?GHz to 44?GHz with maximum IMPATT negative resistance of 120?Ω at 38?GHz with 28?mA bias current. Furthermore, selection of the process technology and the impact of n-well impurity concentration are discussed. This device showed wide tuning range in the millimetre wave range and with the low cost of the CMOS technology used, these devices appear well suited for use in millimetre-wave applications.     

Proposal of low-noise amplifier utilizing resonant tunnelingtransistors

A low-noise amplifier utilizing the negative input resistance of resonant tunneling transistors (RTT's) is proposed. Expected features of the RTT amplifiers are: 1) negligible effect of noise sources at the output, owing to their large power gain; 2) flat variation of noise figure (NF) versus frequency, due to white spectra of noise sources at the input; and 3) a high maximum oscillation frequency (f_max) (over several 100 GHz), Based on simulated DC characteristics, over 500 GHz f_max and 0.3 dB NF at 100 GHz are predicted for optimized AlGaAs/GaAs/AlGaAs resonant tunneling diodes (RTD's). In an RTT formed by coupling an FET to an optimized RTD, 0.55 dB minimum noise figure and 26 dB associated gain are predicted at 100 GHz. Also, a 1/w² spectrum of the input noise resistance is predicted at low frequencies     

An X‐Band Carbon‐Doped InGaP/GaAs Heterojunction Bipolar Transistor MMIC Oscillator

This paper addresses a fully‐integrated low phase noise X‐band oscillator fabricated using a carbon‐doped InGaP heterojunction bipolar transistor (HBT) GaAs process with a cutoff frequency of 53.2 GHz and maximum oscillation frequency of 70 GHz. The oscillator circuit consists of a negative resistance generating circuit with a base inductor, a resonating emitter circuit with a microstrip line, and a buffering resistive collector circuit with a tuning diode. The oscillator exhibits 4.33 dBm output power and achieves ?127.8 dBc/Hz phase noise at 100 kHz away from a 10.39 GHz oscillating frequency, which benchmarks the lowest reported phase noise achieved for a monolithic X‐band oscillator. The oscillator draws a 36 mA current from a 6.19 V supply with 47.1 MHz of frequency tuning range using a 4 V change. It occupies a 0.8 mm × 0.8 mm die area.     

A 50-GHz silicon IMPATT diode oscillator and amplifier

Recent experimental observations on a silicon impact avalanche transit-time diode oscillator and amplifier CW-operated at 50 GHz are presented. 1) CW oscillation power of 100 mW was obtained at an overall efficiency of 2 percent. The oscillation frequency was continuously tunable over a 1.3-GHz range by a sliding short. 2) Phase-locking has been achieved with a maximum normalized gain-bandwidth product of 0.1. The minimum locking signal power required for a 500-MHz locking bandwidth was 20 dB below the oscillator output. 3) Electronic tuning of the oscillator frequency was demonstrated by placing a millimeter-wave varactor diode in the tuning circuit. The output frequency versus the bias voltage on the varactor diode was linear with maximum frequency deviation of 300 MHz. Frequency modulation of the oscillator by driving the varactor with a sinusoidal source was obtained at a modulation frequency of 50 MHz. 4) Stable amplification with 13-dB gain was obtained, centered at 52.885 GHz with a 3-dB bandwidth of 1 GHz. The maximum output power obtained was 16 mW. Higher gain of about 17 dB was obtained at a reduced bandwidth. The noise figure of the amplifier was 36 dB. Equivalent circuits for the oscillator and the amplifier are derived. The calculated results agree reasonably well with the experimental observations.     

6毫米波段(40～60GHz)砷化镓体效应二极管

通过对体效应二极管在毫米波高端工作特点的分析,详细讨论了6毫米GaAs体效应管的设计原则.着重探讨了器件设计中热参数与微波寄生参数要求间的矛盾,推导得到一组计算公式用以确定器件管芯与封装的设计参数.介绍了采用GaAs/AsCl_3/H_2汽相n~#外延、无氰无铵电镀金热沉、双金带十字引线等措施的器件制备工艺.研制的二极管在V波段的最大输出功率达130mW,最高效率为3.8%;以谐波方式在94GHz下输出大于10mW.本文还重点报道了器件可靠性研究的情况,器件预期的室温平均工作寿命超过1.4×10~8小时.使用该器件的振荡器已成功地用于常温50°K低噪声参放及微波遥感等方面.     

Frequency Modulation of Avalanche Transit Time Oscillators

This paper presents experimental data taken to determine the frequency modulation characteristics of avalanche transit time oscillators. The active element is a diffused mesa diode with a shallow junction in epitaxiad n-n+ silicon; the details of the construction of the diode are presented and its typical characteristics are discussed. The basic oscillator consists of the diode mounted in the capacitive portion of a radial mode cavity machined of copper with the outlines of a DO-5 diode header. The frequency of oscillation is dependent upon the diode junction capacitance and is varied between 5 and 8 GHz for the diodes tested. Microwave power levels up to 100 mW have been observed with an efficiency exceeding 3 percent. The frequency drift over the temperature range from -70 to +100/spl deg/C is 2.5x10/sup -5/ parts/ /spl deg/C. The frequency modulation characteristics of these oscillators indicate their potential applications in miniature solid-state low-power communications systems.     

Fully integrated SiGe VCOs with powerful output buffer for 77-GHz automotive Radar systems and applications around 100 GHz

It is demonstrated that SiGe bipolar technologies are well suited for voltage-controlled oscillators (VCOs) in 77-GHz automotive radar systems. For this, the design of a VCO with powerful output buffer (with good decoupling capability and high output power), comparatively wide tuning range, and reasonably low phase noise is described. To achieve the required high output power, the potential operating range of the output transistors, limited by high-current effects and avalanche breakdown, respectively, had to be exploited using adequate transistor models. The VCOs need a single supply voltage only and have been fully integrated (including resonant circuit and output buffer) on a single small (1 mm/sup 2/) chip, demonstrating their low-cost potential. Experimental results showed, at a center frequency of around 77 GHz, a usable tuning range of 6.7 GHz and a phase noise of -97 dBc/Hz at 1-MHz offset frequency averaged over this range. In addition, the center oscillation frequency can be coarsely adjusted within a wide range by cutting links in the upper metallization layer. The total signal power delivered by both buffer outputs together is as high as 18.5 dBm at a power consumption of 1.2 W. Simulations let us expect a potential doubling of the output power (for two or four outputs) by extension of the output buffer. To get an impression of the maximum frequency achievable with the circuit concept and technology used, a second VCO (again with buffered output) has been developed. To the best of the authors' knowledge, the measured maximum oscillation frequency of about 100 GHz, at 12.4-dBm total output power (14.3 dBm at 99 GHz), is a record value for SiGe VCOs with buffered output operating at their fundamental frequency. The usable tuning range is still 6.2 GHz.     

High-power K-band silicon avalanche-diode oscillators

Large-size silicon avalanche diodes operating at a current density of over 8000 A/cm²have produced pulsed power output of 17 W at 24.0 GHz, and 28 W at 10.5 GHz. A decrease in average voltage up to 25 percent has been observed across the diode during oscillation at its peak power output. This and other experimental results are discussed in terms of a "quenched-plasma" effect in the diode.     

Millimeter-Wave Silicon IMPATT Sources and Combiners for the 110-260-GHz Range

This paper reports recent progress in CVV and pulsed silicon IMPATT sources in the 110-260-GHz frequency range. Pulsed output power levels of 3, 1.3, and 0.7 W, and CW output power levels of 110, 60, and 25 mW have been consistently achieved from single-drift IMPATT diodes at 140, 170, and 217 GHz, respectively. A Read-type IMPATT diode that generated good output power over a wide frequency range was fabricated. A bridged double-quartz standoff package was developed and successfully used for the entire frequency range. Power combiners at center frequencies of 140 and 217 GHz were developed with peak output power of 9.2 and 1 W, respectively.     

Dependency of the highest harmonic oscillation frequency on junction diameter of IMPATT diodes

The effect of series resistance and junction capacitance on the high-frequency limit of IMPATT diode operation is studied with a Read-type small-signal theory, and is confirmed experimentally. Oscillation frequencies from 30 to 400 GHz have been measured with Si p⁺-n-n⁺abrupt junction diodes with a depletion layer width of 0.2 µm. The highest oscillation frequency increases as the junction diameter is decreased, owing to reduced junction capacitance and increased bias-current density. The highest oscillation frequency observed is 423 GHz, which is obtained in the fifth harmonic mode with a diode of 16-µm junction diameter. Fundamental oscillation frequency is found to depend strongly on dc bias-current density, and to be close to the avalanche frequency of the small-signal theory.     

A tunable-frequency Gunn diode fabricated by focused ion-beamimplantation

The fabrication of a planar Gunn diode in which the fundamental transit-time model oscillation frequency can be tuned over the range 6-23 GHz by varying the DC bias across the device is reported. The wide-band tunability is due to a linear doping-concentration gradient between the contacts. This lateral doping is created by implanting the device with a focused beam of silicon ions and smoothly increasing the dose from contact to contact. A Gunn diode with a uniform active region, also fabricated with the focused ion beam, displays a relatively constant oscillation frequency in the same bias range     

0.2 THz二倍频器研究

基于六阳极结反向串联型GaAs平面肖特基二极管,设计并实现了0.2 THz大功率二倍频器。肖特基二极管倒装焊接在50m石英电路上。采用电磁场和电路联合设计仿真获得了二倍频器的倍频效率。当入射功率在100 mW时,输出频率在190~225 GHz带内效率大于5%。在小功率（Pin100 mW）和大功率（Pin300 mW）注入条件下,测试了倍频电路的输出功率和倍频效率。在100 mW驱动功率下采用自偏压测试,最大输出功率为14.5 mW@193 GHz,对应倍频效率为14%;在300 mW驱动功率下采用自偏压测试,在188~195 GHz,输出功率大于10 mW,最大输出功率为35 mW@192.8 GHz,对应倍频效率为11%。     

GaAs TUNNETT Diodes

The tunnel-injection-transit-time (TUNNETT) diode is operated at a high frequency and has a low-noise level compared to the IMPATT diode. The tunnel injection in a thin carrier generating region of the TUNNETT depends strongly on the electric-field intensity over 1000 kV/cm where the ionization of carriers can be neglected, leading to a higher efficiency performance than that of the IMPATT. GaAs TUNNETT diodes with p+-n and p+-n-n+ structures have been fabricated by a new LPE method (the temperature-difference method under controlled vapor pressure). The fundamental oscillation at frequencies from about 100 up to 248 GHz has been obtained from the pulse-driven p+-n-n+ diodes. This paper describes the details of the oscillation characteristics of GaAs TUNNETT diodes.     

Bias-tuned double-drift impatt diodes for wide-bandwidth operation

Double-drift IMPATT diodes with asymmetrical p- and n-type doping concentrations have exhibited output power levels of 3 mW to greater than 100 mW when bias tuned over a 20 GHz bandwidth in a Q band (40?60 GHz) reduced waveguide circuit. Similar output powers were also measured for the same asymmetrical diodes at V band (50?75 GHz) with tunable bandwidths of approximately 18 GHz.     

采用新型可调谐有源电感的频率可调谐高Q低噪声的带通滤波器

对采用双回转结构交叉耦合差分有源电感(DGC-DAI)的可调谐、高品质因子Q和低噪声差分有源带通滤波器(THQLNA-BPF)进行了研究。输入级,采用差分共基-共射结构,以抑制噪声和获得高频特性;输出级,采用差分共集放大器,以获得高的驱动能力和高的隔离度;有源电感滤波网络,利用DAI电感值可宽范围调谐、高Q值和低的噪声,来分别实现BPF的中心频率的宽范围调节、高Q值和良好的噪声特性;进一步地,利用变容二极管网络改善BPF中心频率的可调性和提高Q值,利用有源可调负阻网络提高BPF的Q值和进行Q值独立调节。基于WIN 0.2μm GaAs HBT工艺,利用ADS对THQLNA-BPF进行性能验证。结果表明:中心频率可在1.68 GHz~4.32 GHz范围内调谐,调谐量达2.64 GHz;最大和最小Q分别达到83.6和33.6;噪声范围为6.04 dB~8.83 dB;在中心频率为3.69 GHz时,输入1 dB压缩点为-7.3 dBm,稳定系数μ>1;静态功耗小于18 mW。     

GaAs TUNNETT diodes on diamond heat sinks for 100 GHz and above

Single-drift GaAs TUNNETT diodes were mounted on diamond heat sinks for improved thermal resistance and evaluated around 100 GHz in a radial line full height waveguide cavity. The diodes were fabricated from MBE-grown material originally designed for diodes that operate in CW mode around 100 GHz on integral heat sinks. An RF output power of more than 70 mW with a corresponding DC to RF conversion efficiency of 4.9% was obtained at 105.4 GHz. This is the first successful demonstration of GaAs TUNNETT diodes mounted on diamond heat sinks. To the authors' knowledge, these DC to RF conversion efficiencies and RF power levels are the highest reported to date from TUNNETT diodes and exceed those of any single discrete device made of group III-V materials (GaAs, InP, etc.) at this frequency. Free-running TUNNETT diode oscillators exhibit clean spectra with an excellent phase noise of less than -94 dBc/Hz, measured at a frequency off-carrier of 500 kHz and an RF output power of 40 mW     

IMPATT operation below the avalanche frequency

Very high output powers are obtained with double drift IMPATT diodes at current densities which shift the avalanche frequency above the oscillation frequency: 30-40 W pulsed around 90 GHz. This operation mode cannot be explained in terms of the conventional READ theory. A numerical large signal simulation shows that avalanche multiplication over the whole diode takes place. At high current densities the double drift device behaves like a pin diode without the unfavourable breakdown of the ionisation process in the centre of the diode.<>     

Millimeter-wave diode-grid phase shifters

Monolithic diode grids have been fabricated on 2-cm square gallium-arsenide wafers with 1600 Schottky-barrier varactor diodes. Shorted diodes are detected with a liquid-crystal technique, and the bad diodes are removed with an ultrasonic probe. A small-aperture reflectometer that uses wavefront division interference was developed to measure the reflection coefficient of the grids. A Phase shift of 70° with a 7-dB loss was obtained at 93 GHz when the bias on the diode grid was changed from -3 V to 1 V. A simple transmission-line grid model, together with the measured low-frequency parameters for the diodes, was shown to predict the measured performance over the entire capacitive bias range of the diodes, as well as over the complete reactive tuning range provided by a reflector behind the grid, and over a wide range of frequencies form 33 GHz to 141 GHz. This shows that the transmission-line model and the measured low-frequency diode parameters can be used to design an electronic beam-steering array and to predict its performance. An electronic beam-steering array made of a pair of grids using state-of-the-art diodes with 5-Ω series resistances would have a loss of 1.4 dB at 90 GHz     

C.W. oscillation with p+-p-n+ silicon IMPATT diodes in 200 GHz and 300 GHz bands

Submillimetre-wave silicon single-drift-region IMPATT diodes with a p+?p?n+ structure have been fabricated by ion implantation. C.W. output powers of 7.5 mW at 285 GHz and 78 mW at 185 GHz were obtained. The maximum c.w. oscillation frequency observed was 394 GHz.