采用Ga As衬底增强/耗尽型赝配高电子迁移率晶体管(E/D PHEMT)工艺研制了一款6~10 GHz多功能微波单片集成电路(MMIC)。其集成了4个单刀双掷开关、6 bit数控移相器、6 bit数控衰减器、3个放大器和14 bit并口驱动电路。测试结果表明...采用Ga As衬底增强/耗尽型赝配高电子迁移率晶体管(E/D PHEMT)工艺研制了一款6~10 GHz多功能微波单片集成电路(MMIC)。其集成了4个单刀双掷开关、6 bit数控移相器、6 bit数控衰减器、3个放大器和14 bit并口驱动电路。测试结果表明:接收支路增益大于8 d B,1 d B压缩点输出功率大于3 d Bm;发射支路增益大于1 d B,1 d B压缩点输出功率大于8 d Bm。移相64态均方根误差小于3°,衰减64态均方根误差小于1 d B。在工作频带内接收和发射两种状态下,输入输出驻波比均小于1.5∶1。经过版图优化后,芯片尺寸为3.5 mm×5.1 mm。该多功能MMIC可用于微波收发组件,对传输信号进行幅相控制。展开更多
The production-oriented approach (POA) has been developed over a decade. It is driven by the need to improve English classroom instruction for university students in China (Wen, 2016). It is also motivated by the ...The production-oriented approach (POA) has been developed over a decade. It is driven by the need to improve English classroom instruction for university students in China (Wen, 2016). It is also motivated by the aspiration to enhance the quality of foreign language education in other similar pedagogical contexts outside China. A volume of research has been done by Wen Qiufang and her research team, to formulate the theory of POA and to test its effectiveness in classroom pedagogy (e.g. Wen, 2016, 2015; Yang, 2015; Zhang, 2015). At the moment, the POA is still at an early stage of theory building and almost all empirical research is done in the Chinese context. In order to improve the quality of this theory and to make it intelligible to the international academic community, a one-day symposium was held in Beijing Foreign Studies University on May 15, 2017. The symposium was entitled 'The first international forum on innovative foreign language education in China: Appraisal of the POA'. In the forum, leading experts in applied linguistics were invited to discuss the strengths and weaknesses of the POA and the directions for its future development. The symposium was the first attempt for the POA research team to discuss its latest work with international scholars. This Viewpoint section collects the responses of four experts who participated in the symposium, listed in alphabetical order. The collection of articles covers three topics related to the POA: its pedagogical application, its use for teacher training, and its research. Alister Cumming is Professor Emeritus and the former Head of the Centre for Educational Research on Languages and Literacies, University of Toronto, Canada. His article focuses primarily on POA research as an exemplary case of design-based research. Rod Ellis is Research Professor in the School of Education at Curtin University, Australia. He discusses POA in terms of pedagogy, teacher training and research, with both critiques and constructive suggestions. Paul Kei Matsuda is Professor of English and Director of Second Language Writing at Arizona State University, the writed states. He responds to POA from the perspective of an expert researcher and teacher of L2 writing. Charlene Polio is Professor and Associate Chair in the Department of Linguistics & Germanic, Slavic, Asian & African Languages atMichigan State University, the writed states. She conceptualises POA as a useful method to address some issues in pre-service teacher development. Overall, the articles in this section are insightful and reader-friendly. They are not only useful for the development of POA in particular, but may also be valuable to a broad range of researchers as they touch upon pertaining issues, as well as emerging topics, in the field of applied linguistics. We therefore find it necessary to make them accessible to a wide readership.展开更多
文摘采用Ga As衬底增强/耗尽型赝配高电子迁移率晶体管(E/D PHEMT)工艺研制了一款6~10 GHz多功能微波单片集成电路(MMIC)。其集成了4个单刀双掷开关、6 bit数控移相器、6 bit数控衰减器、3个放大器和14 bit并口驱动电路。测试结果表明:接收支路增益大于8 d B,1 d B压缩点输出功率大于3 d Bm;发射支路增益大于1 d B,1 d B压缩点输出功率大于8 d Bm。移相64态均方根误差小于3°,衰减64态均方根误差小于1 d B。在工作频带内接收和发射两种状态下,输入输出驻波比均小于1.5∶1。经过版图优化后,芯片尺寸为3.5 mm×5.1 mm。该多功能MMIC可用于微波收发组件,对传输信号进行幅相控制。
文摘The production-oriented approach (POA) has been developed over a decade. It is driven by the need to improve English classroom instruction for university students in China (Wen, 2016). It is also motivated by the aspiration to enhance the quality of foreign language education in other similar pedagogical contexts outside China. A volume of research has been done by Wen Qiufang and her research team, to formulate the theory of POA and to test its effectiveness in classroom pedagogy (e.g. Wen, 2016, 2015; Yang, 2015; Zhang, 2015). At the moment, the POA is still at an early stage of theory building and almost all empirical research is done in the Chinese context. In order to improve the quality of this theory and to make it intelligible to the international academic community, a one-day symposium was held in Beijing Foreign Studies University on May 15, 2017. The symposium was entitled 'The first international forum on innovative foreign language education in China: Appraisal of the POA'. In the forum, leading experts in applied linguistics were invited to discuss the strengths and weaknesses of the POA and the directions for its future development. The symposium was the first attempt for the POA research team to discuss its latest work with international scholars. This Viewpoint section collects the responses of four experts who participated in the symposium, listed in alphabetical order. The collection of articles covers three topics related to the POA: its pedagogical application, its use for teacher training, and its research. Alister Cumming is Professor Emeritus and the former Head of the Centre for Educational Research on Languages and Literacies, University of Toronto, Canada. His article focuses primarily on POA research as an exemplary case of design-based research. Rod Ellis is Research Professor in the School of Education at Curtin University, Australia. He discusses POA in terms of pedagogy, teacher training and research, with both critiques and constructive suggestions. Paul Kei Matsuda is Professor of English and Director of Second Language Writing at Arizona State University, the writed states. He responds to POA from the perspective of an expert researcher and teacher of L2 writing. Charlene Polio is Professor and Associate Chair in the Department of Linguistics & Germanic, Slavic, Asian & African Languages atMichigan State University, the writed states. She conceptualises POA as a useful method to address some issues in pre-service teacher development. Overall, the articles in this section are insightful and reader-friendly. They are not only useful for the development of POA in particular, but may also be valuable to a broad range of researchers as they touch upon pertaining issues, as well as emerging topics, in the field of applied linguistics. We therefore find it necessary to make them accessible to a wide readership.