Monolithically Integrated 100 GHz DFB-TWEAM

A monolithically integrated distributed feedback (DFB) laser and traveling-wave electro-absorption modulator (TWEAM) with ${geq} 100$ GHz ${-}3$ dBe bandwidth suitable for Non-return-to-zero (NRZ) operation with on-off keying (OOK) is presented. The steady-state, small-signal modulation response, microwave reflection, chirp characteristic, and both data operation and transmission were investigated. The DFB-TWEAM was found to be an attractive candidate for future short distance communication in high bitrates systems.      

11 dBm photonic millimetre-wave generation at 100 GHz usinguni-travelling-carrier photodiodes

The design and characterisation of a millimetre-wave uni-travelling-carrier photodiode with a monolithically integrated matching (impedance transform) circuit utilising a coplanar-waveguide short-stub are presented. The device with the matching circuit shows ~50% higher efficiency than one with a 50 Ω load design. The maximum saturation output power obtained is 13.6 mW at 100 GHz     

Integrated antennas on Si with over 100 GHz performance, fabricated using an optimized proton implantation process

We have improved the performance of integrated antennas on Si for possible application in wireless communications and wireless interconnects. For practical VLSI integration, we have reduced the antenna size and optimized the proton implantation to a low energy of /spl sim/4 MeV with a depth of /spl sim/175 /spl mu/m. To avoid any possible contamination, the ion implantation is applied after device fabrication. Excellent performance such as very low RF power loss up to 50 GHz, record high 103 GHz antenna resonance, and sharp 5 GHz bandwidth have been achieved.     

跨越100GHz壁垒的取样器及其应用

在时域和视域测量仪器中,取样技术一直起着重要的信号捕获和变换作用,例如数字示波器的实时带宽远远不如取样示波器的等效带宽.     

An Integrated Sideband-Separating SIS Mixer Based on Waveguide Split Block for 100 GHz Band with 4.0–8.0 GHz IF

We have developed an integrated sideband-separating SIS mixer for the 100 GHz band based on the waveguide split block. The measured receiver noise temperatures with 4.0–8.0 GHz IF are less than 60 K in the LO frequency range of 90–110 GHz, and a minimum value of around 45 K is achieved at 100 GHz. The image rejection ratios are more than 10 dB in the frequency range of 90–110 GHz. We have installed the sideband-separating SIS mixer into an atmospheric ozone-measuring system at Osaka Prefecture University and successfully observed an ozone spectrum at 110 GHz in SSB mode. This experimental result indicates that the sideband-separating SIS mixer is very useful for astronomical observation as well as atmospheric observation.     

The 100 GHz light switch

Escalating transmission rates in telecoms networks are the spur behind an international research effort in optical processing. The author reports on the work of the BT researchers who are laying the foundations for a new era of photon-based switching systems. The work is based on an interferometric switch known as the TOAD. The TOAD is a variant of a Mach-Zehnder interferometer. Light enters the interferometer, then passes through a 50:50 coupler which divides the input equally between the upper and lower arms. In general, the upper and lower light streams will experience different phase shifts, and these shifts will determine the way the original input is allocated between the two output ports. In particular, if the interferometer is suitably biased then all the light will appear at one or other of the outputs. Now, if a phase shift is introduced into one of the arms the output will switch between ports. This is the principle; its practical exploitation depends on the availability of a device that can effect a π phase shift at a rate of at least tens of GHz. In the TOAD this function is assigned to a semiconductor optical amplifier     

High-speed VCSEL of modulation bandwidth over 7.0 GHz and itsapplication to 100 m PCF datalink

High-speed vertical cavity surface emitting laser (VCSEL) with 6×6 μm active area is fabricated by reducing its pad area in order to reduce its parasitic capacitance. The fabricated VCSEL shows the 3 dB bandwidth of over 7 GHz and average threshold current of 0.7 mA. This is the highest 3 dB modulation bandwidth ever reported for the plan type bottom emitted laser with pad. The maximum intrinsic bandwidth as estimated from k-factor is found to be over 20 GHz, which is less than three times than the observed bandwidth. The thermal characteristics are also found to be almost unchanged due to the reducing of its pad size. It also showed open eye pattern for 3 GHz nonreturn to zero (NRZ) pseudorandom signal after transmission through 100 m large core plastic clad fiber (PCF), which could be used in short and medium distance optical links     

Microstrip IMPATT-diode oscillator for 100 GHz

The design and performance of a rugged duroid-microstrip IMPATT-diode oscillator is described. The oscillator's frequency was set by a simple, easily replaceable metal resonant cap, with fine tuning of about 30 MHz/mA being achieved by means of the diode current.     

Leakage currents over the Surface of CdHgTe-based photodiodes

The leakage current I _p over the surface of Cd_xHg_1−x Te-based photodiodes that have a cutoff wavelength of the photosensitivity spectrum of λ=9.8–11.6 μm and are fabricated by implanting Zn⁺⁺ ions into the p-type solid solution is investigated. The surface character of the I _p current is indicated by a coordinate shift of the peak in the sensitivity profile of n ⁺-p junctions, which is measured in a scanning mode by the beam of a CO₂ laser with a wavelength of 10.6 μm, with an increase in voltage U across the photodiode and the shift of spectral characteristics to shorter wavelengths with increasing U. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 38, No. 7, 2004, pp. 890–895. Original Russian Text Copyright ? 2004 by Biryulin, Turinov, Yakimov.     

Double-drift IMPATT diodes near 100 GHz

This paper reports the highestxpower (frequency)²IMPATTS produced to date. A CW output power of 380 mW has been achieved at 92 GHz with an efficiency of 12.5 percent. An all-implanted double-drift n⁺-n-p-p⁺silicon structure was fabricated, using a lightly doped epitaxial layer as the starting material. The newly made structure uses a more shallow n⁺contact than previous diodes, and therefore has more equal drift spaces. Small-signal admittance calculations show lower susceptance per unit area in the newly made structure. The shallow contact has allowed the study of unequal dopings in the n- and p-drift spaces. Unequal dopings up to 50 percent can be tolerated with less than 20 percent variation in measured efficiency and output power. Both admittance and breakdown voltage calculations based upon experimentally determined doping profiles and independently measured ionization coefficients were found to be in good agreement with experiment. The doping profiles on both sides of the depletion region were determined byC(V)analysis. The testing of both the old and new structures has been carried out in a microwave circuit having improved mechanical tuning accuracy due to the introduction of a newly designed tuning plunger.     

Groove-guide connection losses at 100 GHz

Sections of groove guide can be simply connected together with a loss of less than 0.2 dB even at 100 GHz. A gap of up to 1 mm between the sections introduced an additional loss of only about 0.1 dB and alignment tolerances needed to be no better than ±0.5 mm.     

Integrated 460 GHz photonic transmitter module

A photonic sub-millimetre (sub-mm) wave transmitter module has been developed and fabricated. The module consists of a 1.55 μm waveguide InP photodetector monolithically integrated with a planar full wave slot antenna and passive lowpass filter for DC bias supply. For the first time, optical heterodyne 460 GHz sub-mm signal generation is demonstrated It is further shown that the module can effectively replace the classical solid-state oscillator of an astronomical superconductor-insulator-superconductor heterodyne receiver The module generates sufficient sub-mm wave power to operate the receiver under optimum conditions     

Monolithic millimetre wave ICs for 100 GHz

The primary research field of Fraunhofer-Institut Angewandte Festkörperphysik (IAF)(Applied Solid-State Physics) in Freiburg, Germany, is III–V electronics, with a focus on high-speed/high-frequency devices and integrated circuits for various applications in commercial and military systems. William Haydl, head of the MMIC group, reports on IAF's latest developments.     

A Low Noise 100 GHz Sideband-Separating Receiver

We have built a 100 GHz sideband-separating receiver. The receiver, a breadboard for the band 3 cartridges for ALMA, achieves a SSB noise temperature of 6hf/k with a 4–8 GHz IF. We show that it is possible to meet the ALMA specifications. The design of the receiver is reviewed and the relationships between the receiver noise temperature and properties of the components used in the receiver are discussed.     

100 GHz MMIC Power Source Development Study

This paper comprises a tutorial in the development of MMIC based high frequency multiplier chains, suitable for use in high frequency power sources. The development of suitable single function building blocks is discussed. The arrangement of suitable combinations of these building blocks in more complex cascaded chains is also presented. A strategy to aid in the identification of an optimum solution for the nominal requirement is provided. Using this approach, it is shown that a 25 to 100GHz multiplier capable of delivering more than 100mW at 100GHz is feasible using existing GaAs technology. In fact it is shown that there is potential to deliver this power level for an incident level of about 10mW at 25GHz.     

Groove-guide microwave detector for 100 GHz operation

A detector has been designed and constructed, using a beam-lead diode, directly in a groove guide. A triangular dipole, produced by photolithography on RT/Duroid 5880, is placed transversely across the guide. A GEC beam-lead Schottky diode, bonded across the dipole, acts as the rectifying element. When used with a cylindrical back short-circuit and an appropriate bias current, a voltage sensitivity of about 400 VW?1 and a tangential sensitivity of about ?42 dBm was obtained at a frequency of 100 GHz.     

100GHz高增益InP基MMIC共源-共栅放大器

本文介绍了一种高增益InP MMIC共源-共栅放大器,当偏置在最大带宽时,该器件在75～100GHz下的平均增益为8.0dB;当偏置在最高增益时,80GHz下的增益高于12dB。这是目前报道的W波段(75～100GHz)增益最高的放大器。所用的有源器件是栅长为0.1μm晶格匹配的InGaAs-InAlAs高电子迁移率晶体管(HEMT)。该放大器以共面波导(CPW)作为传输线,芯片总面积为600μm×500μm。     

Characteristics of double-groove guide for 100 GHz operation

There are two types of possible transmission modes in double-groove guides. They are:

1. modes with a concentration of energy in the groove regions (region A), and
2. modes with a concentration of energy in the region between the two grooves (region S).

Attention had been concentrated on the first type of modes[1]. This paper gives the theoretical and experimental work on the second type of modes.     

6GHz~100GHz频段传播特性及覆盖能力分析

为了分析6GHz~100GHz应用于移动通信的覆盖能力,文中首先分析了大气和雨水分别对该频段无线电波传播的影响。基于自由空间传播模型,叠加气衰和雨衰,构建出不同路损因子下的传播模型。最后依据链路预算理论,仿真实现不同频率在不同路损因子下的可达传播距离与传播速率的映射关系。理论仿真结果显示,在一定条件下,6GHz以上频段在覆盖范围从几十到几百米范围内达到了可接受的传播速率。     

Wideband Circulators for Use at Frequencies Above 100 GHz to Beyond 350 GHz

High-performance circulators operating at frequencies in the range from 100 to 350 GHz have been developed for application in major measurement systems. These circulators have open quasi-optical structures. The magnetized plates in these devices are of nonmetallic magnetic materials which have both well-developed millimeter-wave gyrotropic properties and the magnetostatic properties of an excellent permanent magnet material. Very few commercially available magnetic materials have been found that meet both the magnetostatic and the magnetooptical selection criteria. Those few have, however, made possible the design, manufacture, and successful operation of high-performance circulators/isolators at these high operating frequencies. Several circulators/isolators of this type have been installed in major measurement systems.