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Power Vacuum Tube Applications
Published in Jerry C. Whitaker, Power Vacuum Tubes, 2017
Generally speaking, the fields of RF and microwave engineering together encompass the design and implementation of electronic systems utilizing frequencies in the electromagnetic spectrum from approximately 300 kHz to over 100 GHz [1]. The term “RF engineering” is typically used to refer to circuits and systems utilizing frequencies in a range from approximately 300 kHz at the low end to between 300 MHz and 1 GHz at the high end. The term “microwave engineering” meanwhile is used rather loosely to refer to design and implementation of electronic systems with operating frequencies in a range from 300 MHz to 1 GHz on the low end to upwards of 100 GHz at the high end. The boundary between RF and microwave design is both somewhat indistinct and one that is continually shifting as device technologies and design methodologies advance.
Compact Microstrip Diplexer Based on CRLH Metamaterial Concept
Published in IETE Journal of Research, 2020
On the other hand, there has been a great increasing attention in the field of DNG (double negative) or CRLH structures [13–15]. DNGs are artificial materials with negative permittivity and permeability, simultaneously. DNGs make a great interest in the microwave engineering based on their unusual properties [13–15]. DNG structures are frequency-selective structures and the electrical size of them is significantly small. Therefore, this approach can be more appropriate to miniaturize the physical size of microwave components [16–21]. Consequently, DNG structures are widely used to improve the performance of the planar miniaturized microwave devices such as filters, diplexers, couplers, and power dividers [16–21]. Among various implementations for DNG structure, the resonant-type approach has been used more for the design of microwave filters and diplexers [13]. The key resonant elements for implementations of the resonant-type approach are the split ring resonators (SRRs), complementary split ring resonators (CSRRs), and complementary spiral resonators (CSRs) [13–18]. The SRRs provide a negative effective permeability while the CSRRs exhibit an effective negative permittivity in a narrow band at the resonate frequencies [13–18]. Therefore, by using these particles, the physical size of the microwave components is miniaturized [13–18].
Design and fabrication of a fabric for electromagnetic filtering application (experimental and modeling analysis)
Published in The Journal of The Textile Institute, 2018
Mir Saeid Hesarian, Saeed Shaikhzadeh Najar, Reza Sarraf Shirazi
FSS is considered as a promising technique for preparing a medium, as an artificial surface, that has two-dimensional regular planar structure of conductive material (Tanaka, 2004). Artificial media have several applications in microwave engineering including new generation wireless communication systems, radar systems, and high directivity antennae (Kildal, Kishk, & Maci, 2005). Modern wearable communication systems have growing applications in industry (Acti et al., 2011; Salonen & Hurme, 2003; Seager, Chauraya, Vardaxoglou, & de Maagt, 2008). The periodic metallic structures are the base of an FSS layer. This surface, as an artificially engineered structure, has the characteristics of the selective EM wave transmission or reflection.
A multi-coupled line based microstrip diplexer with high figure-of-merit
Published in Electromagnetics, 2019
Baidenger Agyekum Twumasi, Jia-Lin Li, Lei Xia
The microwave diplexer is a basic component in microwave engineering. It separates the transmitting and receiving signals located after the antenna in a frequency division communication system. In general, it consists of a T-junction network and two channel selection filters (Chen et al. 2014; Fernandez-Prieto et al. 2018; Guan et al. 2014; Manchec et al. 2005; Tsai et al. 2002; Zhou, Deng, and Zhao 2014). Basic requirements of such a device include high isolation between the channel selection filters and low insertion losses. The T-junction based structures are generally bulky in size, therefore, techniques to reduce the circuit size while maintaining good electric performance are of significance and paid great attentions in recent years.