High performance MOS integrated circuit using the ion implantation technique

Extensive use has been made of the advantages ion implantation has to offer over standard processing for the fabrication of high performance n-channel MOS circuits. By combining an enhancement driver with a depletion load, the maximum switching speed of FET logic elements has been evaluated for self-aligned structures with various channel lengths and various degrees of substrate decoupling via device-to-substrate capacitances. An 11-stage ring-oscillator circuit is used for performance evaluation. Switching delays as small as 115 ps were obtained for such inverter stages built on 200 /spl Omega//spl times/cm substrate material and having 1-/spl mu/m channel length. Essential fabrication details and circuit behaviors are described.     

A new technique for RF measurements using superconductors

The quantization of magnetic flux in a superconducting circuit can serve for the measurement of electrical quantities in the same way that we use the wavelength of light to measure length. We report a demonstration of this function in the measurement of attenuation ratio at a frequency of 30 MHz.     

ALD中射频阻抗匹配器的设计与研究

阐述原子层沉积系统（ALD）中射频阻抗匹配器的设计方案。利用ADS软件对阻抗匹配网络进行仿真,通过分析ALD真空腔室内等离子体产生前后的负载阻抗变化,结合仿真结果,提出等离子体产生过程中阻抗匹配网络的控制方法。经实验验证,该阻抗匹配器和控制方法可实现阻抗匹配。     

Full software analysis and impedance matching of radio frequencyCMOS integrated circuits

We present a systematic analysis technique of complementary metal-oxide-semiconductor (CMOS) radio-frequency (RF) integrated circuits (ICs). A full simulation program with integrated circuit emphasis (SPICE) simulation of the whole chip including the package and the die, with the parameters extracted from purely software analysis, has been performed. It is shown that the RF impedance matching without S-parameter based techniques is possible and the measured results agree well with our SPICE-only software based technique     

射频电源中的阻抗匹配研究

阻抗匹配是无线电技术中常见的一种工作状态,它反映了输入电路与输出电路之间的功率传输关系。阻抗匹配是功率放大器的核心技术。本文以射频激励CO2 激光器电源为例,根据传输线中高频电磁波的传播理论及一般的阻抗匹配计算方法,推导出1/4传输线阻抗匹配的研究设计方法及计算有关参数的普遍公式。这一结果同样适用于其它射频电源的阻抗匹配研究。     

Novel approach of twin-side thermal interfacing of integrated power modules for reduced thermal impedance

A novel approach of twin-side thermal interfaces of integrated power modules (IPM) is presented. This approach applies and improves commercially off-the-shelf products of IPM without significantly changing the original packaging design and manufacture's fabrication process. This approach can reduce the equivalent thermal impedance of the power module by about 20 %. It, in turn, reduces the p-n junction temperature rise of the power devices inside by 20 % at an equivalent load, thus being able to increase ambient operating temperatures, which is desirable for automotive applications. In addition, the weight and volume associated with conventional cooling mechanism can be reduced.     

Technology developments driving an evolution of cellular phonepower amplifiers to integrated RF front-end modules

Millions of cellular phone power amplifiers (PAs) are produced every day worldwide using a great diversity of technologies. This is true both for the active devices, where various silicon as well as GaAs transistors are used, and for the PA architecture, in which MMIC, module, and discrete solutions compete. This paper gives an overview of the various technological and architectural choices and discusses their influence on the PA performance, notably the power efficiency and linearity. It sketches the future of PA development toward more functional integration, which may be obtained by two paths: integration on chip and added functionality in modules     

A complete small-signal equivalent circuit model of cooled butterfly-type 2.5 Gbps DFB laser modules and its application to improve high frequency characteristics

A small-signal equivalent circuit model of 2.5 Gbps DFB laser modules with butterfly-type dual-in-line packages has been proposed and verified using extracted parameters. Parameters related to the equivalent circuit have been extracted from measured S parameters using the modified two-port black box model. This model includes small-signal equivalent circuits of components used for 2.5 Gbps DFB laser modules such as DFB laser, coplanar waveguides, matching resistor, bonding wires, and thermoelectric cooler (TEC). From this equivalent circuit modeling, we show that calculated frequency characteristics of DFB lasers on submount and complete DFB laser modules are similar to their measured frequency characteristics, respectively. Based on this equivalent circuit model, we propose and demonstrate a method that can improve frequency characteristics of 2.5 Gbps DFB laser modules through both experiments and simulations.     

Design of RF integrated circuits using SiGe bipolar technology

We report on design aspects and the implementation of radio-frequency integrated circuits using TEMIC's SiGe technology. The differences between the device parameters of silicon bipolar junction transistor and silicon germanium heterojunction bipolar transistor technology and their influence on IC design are discussed. Design and measurement results of RFICs, including low noise amplifier, power amplifier, and single-pole, double-throw antenna switch for application in a 1.9 GHz digital enhanced cordless telecommunications RF front end are presented     

DC and RF performance of GaAs MESFET fabricated on silicon substrate using epitaxial lift-off technique

GaAs MESFETs have been fabricated on a silicon substrate using a molecular beam epitaxy grown film detached from its growth substrate and attached on a silicon substrate covered with a dielectric. The device processing is done on the silicon substrate. The MESFETs exhibit I/sub DSS/=130 mA/mm, g/sub m/=135 mS/mm and for 1.3 mu m gate length unity current gain cut-off frequency f/sub T/ of 12 GHz. Excellent device isolation with subpicoampere leakage currents is obtained.<>     

Transmission performance of monolithically integrated Y-branch tunable laser with zero-chirp Mach-Zehnder modulator

A zero-chirp Mach-Zehnder modulator monolithically integrated with a widely tunable modulated grating Y laser and SOA, operating at 10 Gbit/s, is demonstrated. The device is hermetically packaged with a wavelength locker within a 12.7times15.24 mm module. With a fixed receiver threshold and fixed voltage modulation depth, the extinction ratio exceeds 12 dB and the receiver penalty for dispersion in the range plusmn800 ps/nm is below 1.5 dB on all channels     

基于简化实频方法的宽带天线阻抗匹配网络设计

给出了一种便于工程应用的宽带天线阻抗匹配网络设计方法。在简化实频方法的基础上通过遍历不同网络阶数和零频传输零点阶数下的优化过程,避免了简化实频方法中丢失潜在优良解的问题。设计过程引入对网络的匹配性能和物理实现难易程度的权衡考虑,从所有优化结果中选择最终方案,具有较大的工程实用价值。针对一个实际小型短波宽频带天线的阻抗匹配问题,运用该方法设计了匹配网络并进行了测量,结果表明：文中所给出的方法是有效和实用的。     

Input impedance of a circular microstrip disc antenna using mode matching

A model is developed to calculate the input impedance of a coaxially fed circular microstrip disc antenna. A mode-matching approach is used, which makes it possible to include the effects of modes other than the dominant mode. Comparison is made with measured results taken over the frequency range 8 GHz to 11 GHz.     

A new simultaneous noise and input power matching technique formonolithic LNA's using cascode feedback

In this paper, a new simultaneous impedance-matching technique of Γ_opt (optimum noise-match source reflection coefficient) and G_max (maximum available power gain-match (MAPG) source reflection coefficient) using cascode feedback (CF) is proposed. A 1.57-GHz single-stage monolithic-microwave Integrated-circuit (MMIC) low-noise amplifier (LNA) designed with this technique has been fabricated using GaAs MESFET technology in order to verify the feasibility of this scheme. The measured response agrees well with the simulated performance. Extensive computer simulation shows that when silicon npn bipolar junction transistor (BJT) is used, this scheme enables us to make both Γ_opt and G_max points near to 50 Ω, in addition to the simultaneous noise and input power matching. In addition, it has all the advantages of negative feedback such as stability, wider bandwidth, and insensitivity against parameter variation     

High electromagnetic shielding of plastic package for 2.5-Gb/s optical transceiver modules

A lightweight, low-cost plastic package for a 2.5-Gb/s optical transceiver module, that also has good electromagnetic shielding properties, has been fabricated using woven continuous carbon fiber (CCF) epoxy composite. The shielding effectiveness (SE) of the CCF epoxy composite has been modeled theoretically and measured from 500 MHz to 3 GHz using the ASTM D4935 and a near-field test method. Two types of weaving patterns were studied: a balanced twill structure (BTS) and a parallel structure. The BTS was able to achieve an SE of about 80 dB under plane wave conditions and about 50 dB under near-field conditions because of the numerous conductive between crossing fibers. The SE of the proposed package is at least 20 dB greater than the previous package which used a liquid crystal polymer composite. In addition to better shielding performance, the proposed package costs less because it uses less carbon fiber. The proposed package for an optical transceiver is suitable for use in a low-cost lightwave transmission system     

Annual performance enhancement of building integrated photovoltaic modules by applying phase change materials

The performance of photovoltaic (PV) module outdoors suffers from attained high module temperatures due to irradiation as a result of the negative temperature coefficient of their efficiency. Phase change materials (PCMs) are investigated as an option to regulate photovoltaic module temperature and thereby reduce its electrical efficiency decrease. In this study, a simplified heat balance model is used to calculate the extra energy gain; such a PV/PCM system can bring on an annual basis. With present day commercially available PCM materials, a moderate increase of up to 3% of the total energy output can be expected. When taking into account the additional PCM material cost, a PV/PCM module presently is not economically viable. For an acceptable payback period of 10–20 years to be reached, the heat storage capacity of a PCM would require an increase of about one order of magnitude, which is presently not realistic. Nevertheless, a combination with building climate control in which the PCM plays a double role controlling both the PV temperature as well as the inside climate temperature may be feasible. Copyright © 2011 John Wiley & Sons, Ltd.     

Design of a RF matching network based on a new tunable inductor concept

We present in this paper a new technique of matching impedances. It consists in replacing a fixed inductor in a matching network by a variable one, and its value is able to change with the load impedance. In the study, the fixed inductance considered is a CMOS integrated one, while the tunable inductance is based on a new Piezomagnetic MEMS concept. A theoretical model of such a tunable inductor is first presented, and then inserted in a matching network in two different ways: inductance value varies either discretely or continuously. The obtained matching networks are compared with a fixed inductor matching network, and simulation results are presented and discussed to validate the presented method and to evaluate the matching efficiency of each matching network.     

High-frequency modulation of a quantum-cascade laser using a monolithically integrated intracavity modulator

We report a quantum-cascade laser monolithically integrated with an intracavity modulator which could be operated up to 1 GHz. In contrast to earlier approaches, where the radio frequency (RF) modulation signal was supplied to the entire cavity length of the laser structure, we drive only a relatively small 375-/spl mu/m-long section of the cavity. At the same time, a quasi-continuous-wave signal was supplied to the remaining 1125-/spl mu/m-long section. This modulation scheme resulted in smaller parasitic capacitance effects than what we reported previously, and enabled us to work with lower RF voltages and currents.     

Interrogation of an integrated optic modulator over a low-birefringence fiber using polarization tracking

The remote operations of an integrated optic Mach-Zehnder modulator via a low-birefringence fiber link using an input polarization control scheme is demonstrated. The polarization tracking scheme actively maintains the state of polarization arriving at the modulator in the state required for optimum operation of the device. As the feedback signal is determined by the overall optical throughput of the modulator, no modulation is itself required for the modulator to be set for optimum performance.<>     

Microwave I-Q vector modulator using a simple technique forcompensation of FET parasitics

The analysis and design of an improved technique for the realization of vector modulators using analog reflection-type circuits are presented. The analysis focuses on the detrimental effect that the parasitic elements of the FET variable-resistance elements have on the 360° phase and amplitude control. It is shown that a simple circuit technique can be used to compensate for the parasitic effects and achieve a near-ideal constellation. Compared with the balanced structure, the proposed technique leads to a much smaller circuit area and does not require additional complementary control signals. This makes it better suited to commercial wireless applications where low cost is paramount. Simulation and experimental results for an L-band prototype are presented