Electromagnetic interference (EMI) of system-on-package (SOP)

Electromagnetic interference (EMI) issues are expected to be crucial for next-generation system-on-package (SOP) integrated high-performance digital LSIs and for radio frequency (RF) and analog circuits. Ordinarily in SOPs, high-performance digital LSIs are sources of EMI, while RF and analog circuits are affected by EMI (victims). This paper describes the following aspects of EMI in SOPs: 1) die/package-level EMI; 2) substrate-level EMI; 3) electromagnetic modeling and simulation; and 4) near electromagnetic field measurement. First, LSI designs are discussed with regard to radiated emission. The signal-return path loop and switching current in the power/ground line are inherent sources of EMI. The EMI of substrate, which work as coupling paths or unwanted antennas, is described. Maintaining the return current path is an important aspect of substrate design for suppressing EMI and for maintaining signal integrity (SI). In addition, isolating and suppressing the resonance of the DC power bus in a substrate is another important design aspect for EMI and for power integrity (PI). Various electromagnetic simulation methodologies are introduced as indispensable design tools for achieving high-performance SOPs without EMI problems. Measurement techniques for near electric and magnetic fields are explained, as they are necessary to confirm the appropriateness of designs and to investigate the causes of EMI problems. This paper is expected to be useful in the design and development of SOPs that take EMI into consideration.     

Polymer-ceramic nanocomposite capacitors for system-on-package (SOP) applications

This work focuses on optimizing the dispersion of nanosized ceramic particles for achieving higher dielectric constant, thereby higher capacitance density in polymer/ceramic nanocomposites. It has been observed that high solids loading leads to entrapment of porosity in the microstructure which lowers the effective dielectric constant of the films. The amount of solvent in the suspension and the speed at which spin coating was performed were found to impact the dielectric constant of high filler content nanocomposites. The interplay between the rheological properties of the suspension and processing parameters such as solvent content and coating speeds and its impact on the dielectric properties of the film are discussed. Porosity of thin film composites was measured for the first time to study the impact of these processing parameters. Powders of different particle sizes were mixed to obtain bimodal particle size distribution in order to increase the packing density of the composite. Packing density was improved by modifying the dispersion methodology. A nanocomposite with dielectric constant as high as 135 was obtained for the first time in the low-cost printed wiring board compatible epoxy system. A capacitance densities of /spl sim/35 nF/cm/sup 2/ on a nominal 3.5 micrometer films was achieved on PWB substrates with high yield. The manufacturability of these formulated nanocomposites and their applications as decoupling capacitors have been tested using a large area (300 mm /spl times/ 300 mm) system-on-package (SOP) chip-to-chip communication test vehicle.     

Meniscus coating: a low-cost polymer deposition method for system-on-package (SOP) substrates

Meniscus coating is a low-cost deposition method that can be used to apply polymers in solution as thin films to the surface of electronics packaging substrates or flat panel displays. Most Roadmaps in electronics packaging project 6 to 8 /spl mu/m lines and spaces for next generation high density printed wiring board (PWB) substrates in the year 2006, which would require coating thickness of similar magnitudes for manufacturing fine lines with higher yield. Meniscus coating can be an enabling deposition method that can provide finer yet uniform coating on large area substrates which would translate to patterning finer copper traces, thereby increasing the wiring density. This paper reports preliminary results on coating thickness that can be achieved with photoresists, dielectrics, and solder masks which are the integral parts of the sequential build up multi-layer process for the system-on-package substrates.     

Moore's law meets its match (system-on-package)

This paper describes the system-on-package (SOP) approach to miniaturization developed at the Microsystems Packaging Research Center at the Georgia Institute of Technology. Representing a radically different approach to systems, SOP combines IC with micrometer-scale thin film versions of discrete components, and it embeds everything in a new type of package so small that eventually handhelds will become anything from multi- to megafunction devices. It shrinks bulky circuit boards with their many components and makes them nearly disappear. Thus, SOP technology yields far more in system miniaturization than can be expected from Moore's law, which deals only with transistors in ICs.     

Design of an asymmetrical dual-band WLAN filter in liquid crystal polymer (LCP) system-on-package technology

A single-input-single-output (SISO) dual-band filter operating at ISM 2.4-2.5GHz and UNII 5.15-5.85GHz frequency bands, using the novel "dual behavior resonators" technique has been developed. Exploiting the strong second resonant frequency of resonators to realize the filtering response, allows for achieving the asymmetric shape and the good rejection between the two bands. The insertion loss and return loss at the central frequency are -2.4 dB and -15 dB for the 2.4-GHz band, respectively, and -1.8 dB and -10 dB for the 5-GHz band, respectively. The filter has been fabricated using the novel liquid crystal polymer (LCP) based multilayer packaging technology, enabling a low cost SOP implementation.     

Different types of optoelectronic bistabilities inresonant-tunnelling triangular-barrier optoelectronic switch (R-TOPS)

Novel optoelectronic bistabilities in a resonant-tunnelling triangular-barrier optoelectronic switch (R-TOPS) are reported. Optically controlled S-shaped and N-shaped NDRs were observed simultaneously in a single device. Different types of optoelectronic bistabilities originated from S-shaped and N-shaped NDRs were obtained by changing the input light power     

3-D-integrated RF and millimeter-wave functions and modules using liquid crystal polymer (LCP) system-on-package technology

Electronics packaging evolution involves system, technology, and material considerations. In this paper, we present a novel three-dimensional (3-D) integration approach for system-on-package (SOP)-based solutions for wireless communication applications. This concept is proposed for the 3-D integration of RF and millimeter (mm) wave embedded functions in front-end modules by means of stacking substrates using liquid crystal polymer (LCP) multilayer and /spl mu/BGA technologies. Characterization and modeling of high-Q RF inductors using LCP is described. A single-input-single-output (SISO) dual-band filter operating at ISM 2.4-2.5 GHz and UNII 5.15-5.85 GHz frequency bands, two dual-polarization 2/spl times/1 antenna arrays operating at 14 and 35 GHz, and a WLAN IEEE 802.11a-compliant compact module (volume of 75/spl times/35/spl times/0.2 mm/sup 3/) have been fabricated on LCP substrate, showing the great potential of the SOP approach for 3-D-integrated RF and mm wave functions and modules.     

基于单环光电振荡的宽带二倍频信号产生方法

提出了一种基于单环光电振荡器(OEO)的宽带二倍 频信号产生方法。将射频(RF)信号经过第1级马赫-增德尔调制器(MZM)调 制到光信号上,通过控制第1级MZM的偏置电压,使得其工作在最小传输点(MITP)上,产生的 －1阶和+1阶边 带信号通过第2级MZM注入到由单膜光纤(SMF)、光电检测器(PD)和电放大器(amplifier)组成 的光电振荡环腔中,光电检测后产 生二倍频信号,信号的频率稳定度由信号源的稳定度决定,信号的相位噪声由光电振荡环腔 决定。在实验结构简单 的条件下,有效实现了宽带二倍频信号产生。实验结果表明,当本文系统可以实现对C波段 和X波段信号二倍频,输出信号的相位噪声在10kHz偏移处均低于－102dBc/Hz。     

A Schottky-contact triangular-barrier optoelectronic switch (STOS)

A Schottky-contact triangular-barrier optoelectronic switch (STOS), grown by molecular beam epitaxy, has been fabricated. The triangular barrier, formed by inserting an InGaAs delta-doped (/spl delta/-doped) quantum well into an n/sup -/-GaAs layer, provides a potential well for hole accumulation. Due to the hole accumulation in the /spl delta/-doped well and the sequential avalanche multiplications in the reverse-biased p-n and metal-semiconductor junctions, a double S-shaped negative-differential-resistance phenomenon is observed in the current-voltage (I-V) characteristics. The STOS shows a flexible optical function related to the triangular barrier height controllable by incident light. The multistate is switchable by both optical and electrical inputs.     

数字信号光耦合器应用电路设计

较强的输入信号可直接驱动光耦的发光二极管,较弱的则需放大后才能驱动光耦。在光耦光敏三极管的集电极或发射极直接接负载电阻即可满足较小的负载要求;在光耦光敏三极管的发射极加三极管放大驱动,通过两只光电耦合器构成的推挽式电路以及通过增加光敏三极管基极正反馈,既达到较强的负载能力,提高了功率接口的抗干扰能力,克服了光耦的输出功率不足的缺点,又提高光耦的开关速度,克服了由于光耦自身存在的分布电容,对传输速度造成影响。最后给出了光耦合器在数字电路中应用示例。     

Board-level optical interconnection and signal distribution using embedded thin-film optoelectronic devices

Optical interconnection and signal distribution at the backplane, board, and substrate level can be implemented using thin-film active optoelectronic devices embedded in polymer waveguide structures. These active embedded devices eliminate the need for optical beam turning to and from photodetectors and emitters, respectively, for inputs and outputs to the substrate waveguides. In this paper, optical interconnections using fully embedded thin-film metal-semiconductor-metal (MSM) photodetectors in polymer optical waveguides are demonstrated, and the experimental characterization of these thin-film MSMs embedded in polymer waveguides is reported. To illustrate the potential for high-level signal distribution at the backplane, board, and substrate levels, a 1/spl times/4 balanced multimode interference (MMI) coupler has also been demonstrated in a photoimageable polymer for the first time. Finally, a 1/spl times/4 thin-film MSM photodetector array has been embedded in the output arms of the a photoimageable polymer MMI for the first time, and the MSM array photocurrent outputs from the 4 arms show that highly balanced optical signal distribution has been achieved.     

Design and fabrication of integrated Si-based optoelectronic devices

We have designed and fabricated novel Si-based optoelectronic devices. To this aim, different Si-based optical sources have been made and their performances at room temperature compared. Er-doped Si p–n junctions, operating at 1.54 μm and exhibiting an efficiency of 0.05% at room temperature, have been integrated with planar Si rib waveguides using either epitaxial Si or silicon on insulators (SOI) wafers. Optical characterization of these waveguides reveals very low transmission losses (below 1 dB/cm). However, Er-doping of the waveguide core, needed for the realization of the light source, results in a large increase of the losses as a consequence of absorption by the free electrons introduced by the rare earths. These losses can be suppressed when the junction is reverse biased and the whole Er profile is embodied in the depletion layer. Since this also allows efficient pumping of Er ions by hot carriers, the performances of the diodes and of the waveguides can be suitably combined. This optimized structure has also been used to design electrically pumped optical amplifiers and lasers, whose performances have been simulated.     

双向混合信号光纤传输系统的设计与实现

介绍了一种新的多路信号光纤数字化传输方法,基于FPGA设计了混合信号光纤传输系统,并通过实验验证了系统的准确性.该系统不仅能传输模拟信号还能传输数字信号,不仅能传输低速数字信号还能传输高速脉冲信号,此外还能实现双向CAN通信.     

谐波锁模光电振荡器（特邀）

提出了一种主动锁模光电振荡器（OEO）方案,可以实现高阶谐波锁模,从而产生具有高重复频率的微波脉冲信号。在所提方案中,通过在OEO腔内的电光强度调制器直流偏置端口引入一个正弦驱动信号,当该正弦信号的频率为OEO环腔自由光谱范围的整数倍时,实现基频（）或谐波（）锁模,输出重复频率为的微波脉冲信号。实验中分别实现了10阶、50阶和100阶谐波锁模,输出微波脉冲信号的重复频率分别为360 kHz、1.8 MHz和3.6 MHz。该方案为脉冲多普勒雷达等系统应用提供了一种全新的、具备低相噪潜力的微波脉冲信号产生的技术途径。     

光电信息技术的应用及发展前景分析

光电信息技术被应用在轻武器、医学、生物医药、深海探测等领域中,给各个领域都带来了前所未有的发展,光学信息技术的应用情况已成为衡量一个国家综合实力的标志。文章就光电信息技术的发展现状进行分析,研究其应用状况和发展前景。     

基于MSP430单片机的智能阻抗测量仪设计

为了智能小巧高灵敏度地测量电阻、电感和电容,基于MSP430单片机控制、FPGA数字信号处理,设计了一个智能化的LRC（电感、电阻、电容）测量系统,实现了系统使用较少模拟器件,可以实现对电阻、电感、电容元件的自动识别。自动切换档位和测试频率以保证测量精度,具有良好的显示界面,测量范围广,体积小等特点。