| The research in this paper is supported by grants from The National Basic Research Program of China(No.2003CB314901),The National High Technology Research and Development Program of China (No.2003AA31g050,No.2006AA03Z416,No.2007AA03Z418),The National Natural Science Foundation of China(No.60576018,No. 90601002)and Program of Key International Science and Technology Cooperation Projects(2006DFB11110)Today,With the rapid development of communication technology, increasing requirement of bandwidth and number of terminal clients, fiber-optic communication undergoes evolution to the new generation with intelligence,integration,low cost and high reliability. Optoelectronic integrated circuits(OEICs)have advantages over discrete optoelectronic devices in smaller dimension,lower parasitics,lower cost, better performance and higher reliability,these merits make it suitable for the development of fiber-optic communication.OEICs have already become extremely attractive domain as the research subject in the area of optical communications and optoelectronics.InP-based heterojunction bipolar transistor(HBT)is the essential element in long wavelength OEICs,furthermore,and it has extensive application prospect in the field of microwave communication,and so on. Thus,deep researches on InP-based HBT modeling method and its application have extremely important meaning.Supervised by Prof.Xiaomin Ren,and through participating in the projects relative to OEICs,the author focused researches on the modeling method of InP-based HBT and its application in monolithic integrated photoreceiver front-end fabrication.Research results achieved are listed below.1.Starting from physical characteristics of materials,the physical structure and performance parameters of HBT have been analyzed. The expression of each parameter has been derived,the effects of different conditions on physical parameters of InP-based HBT have been studied.The optimization design for InP-based HBT has been presented based on above analysis.2.The InP-based HBT has been fabricated successfully,and the setup for device test has been constructed.The DC and AC characteristics of HBT have been tested using this setup.The testing results of 2μm size style of InP-based HBT are listed as follow:turn-on voltage is 0.35V,DC current gain is 80,and characteristic frequency f_T is about 40GHz.3.Paremeter extraction method for HBT small-signal model was studied, and a new joint parameter extraction method was presented.The extraction procedure is shown below:based on the fact that parasistic parameters have no concern with bised condiction,parasistic paramenters have been extracted using linear regression analysis and S-parameters measured in strong reverse biased and strong reverse biased condictions;the S-parameters of HBT intrinsic part was obtained using deembeding method,then intrinsic parameters were extracted by means of circuit topology transformation and linear regression analysis;taken extracted parameters as initial values,more accurate model parameters were determined based on adaptive optimization algorithm,this optimization step can decrease fitting error of linear regression analysis.By comparision,S-parameters simulated with the extracted model have a good accordance with measured S-parameters.4.Parameter extraction method for HBT large-signal model was studied deeply,based on different physical properties,the 30 commonly used parameters of large-signal model were divided into several types,that is C-V parameters,resistor parameters,early voltage parameters,DC parameters,input impedance parameters and transmission delay parameters.The extraction method for parameters of each type was researched and testing platform was constructed.By comparision,the extracted large-signal model shows a good agreement with measured DC and AC characteristics.5.Several types of preamplifier were designed based on the constructed HBT model.The DC and AC characteristics of preamplifiers were obtained using the circuit simulation software.Next,optimization and selection could be done among different preamplifiers according to simulated results.Then,the final circuit with excellence performance and easy to be fabricated was determined for the design of monolithic integrated photoreceiver front-end.6.The monolithic integrated PIN+HBT photoreceiver front-end has been fabricated successfully.The incidence area of PIN was 22×22μm~2,InP-based HBT was 3μm size style,and transimpedance negative feedback one stage common-emitter amplifier was adopted. When the detector was inversely based at 2.5V and the circuit was based at 2V,the front-end 3dB bandwidth over 3GHz was observed.
|
PDF Full Text Request