High Frequency Electronic Circuits Research Articles

A Study of Practical Teaching Reform of High Frequency Electronic Circuits Course

A Study of Practical Teaching Reform of High Frequency Electronic Circuits Course

A Facile Strategy for Non-fluorinated Intrinsic Low-k and Low-loss Dielectric Polymers: Valid Exploitation of Secondary Relaxation Behaviors

High-performance low-k and low-loss circuit materials are urgently needed in the field of microelectronics due to the upcoming Fifth-Generation Mobile Communications Technology (5G Technology). Herein, a facile design strategy for non-fluorinated intrinsic low-k and low-loss polyimides is reported by fully considering the secondary relaxation behaviors of the polymer chains. A new amorphous non-fluorinated polymer (TmBPPA) with a k value of 2.23 and a loss tangent lower than 3.94 × 10−3 at 104 Hz has been designed and synthesized, which to the best of our knowledge is the lowest value amongst the non-fluorinated and non-porous polymers reported in literature. Meanwhile, TmBPPA exhibits excellent overall properties, such as excellent thermostability, good mechanical properties, low moisture absorption, and high bonding strength. As high-performance flexible circuit materials, all these characteristics are highly expected to meet the present and future demands for high density, high speed, and high frequency electronic circuit used in 5G wireless networks.

Analogy Teaching Method of High-Frequency Electronic Circuit

High-frequency electronic circuit is an important basic specialized course for the major of electronic information engineering, communication engineering, and electronic science and technology. Combined with a dozen years of classroom teaching experience and started from several aspects like relevancy of front-back courses, teaching framework and theoretical teaching content, this paper will discuss analogy teaching method of related content about signal amplifier, mixing, modulation and demodulation in order to help students to understand chapter structure. In the process of teaching, we should pay more attention to students ' weaknesses of knowledge, then stimulate their interests in learning and improve the teaching effectively quality.

Applications of Simulation and Demo in High Frequency Electronic Circuit

This paper was based on the rich theoretical foundation and practical teaching experience, and focused on current teaching situation of high frequency electronic circuit and the cognition of simulation and demo, then it had the positive analysis on the superiority of simulation and demo in high frequency electronic circuit, and it also got the teaching case analysis on simulation and demo of parallel resonant circuit in the high frequency electronic circuit. Through establishment and verification of teaching effect model of high frequency electronic circuit, it can obtain that the teaching presents the advantage of positive feedback through the simulation and demo, and it also can provide new theoretical basis and path of exploration for the teaching research in this field.

Applying the Multisim Technology to Teach the Course of High Frequency Power Amplifier

As one important professional base course in the electric information specialty, the course of “high frequency electronic circuit” has strong theoretical characteristic and abstract content. To enhance the teaching quality of this course, the computer simulation technology based on Multisim is introduced into the teaching of “high frequency electronic circuit”, which could not only deepen students’ understanding and memory of basic concepts, but also effectively help students to understand and grasp the principle of the high frequency circuit by the circuit design module and the simulation analysis function. The teaching application effect of the high frequency class C power amplifier has also proved that the Multisim software could realize the organic combination of theory and practice, and it is the profitable supplement of the traditional teaching mode.

TUNABLE LOWPASS FILTERS USING FOLDED SLOTS ETCHED IN THE GROUND PLANE

This paper presents a new concept to implement tunable lowpass filters by employing slot resonators etched in the ground plane. The tenability is achieved with the use of switches with varactor diodes attached across the slots on the ground. The concept is demonstrated by considering 10-slots lowpass and 4-slots low pass filters. The Microstrip lines with a folded slot etched in the ground plane structure are modelled in multilayered media. To analyze this type of structure an iterative method based on the concept of waves is developed and adapted to determine features of very high frequency's electronic circuits in a planar wave guide. The analysis takes into account eventual coupling parasites. Ex- perimental measurements are performed to validate the computation. The approach involves the mixed magnetic and electric filed equation technique and the wave concept iterative process which involves S- parameters extraction technique. In this sense, a program in FOR- TRAN has been elaborated to determine different parameters Sij char- acterizing the studied structure.

Heterodyne interferometric technique for displacement control at the nanometric scale

We propose a method of displacement control that addresses the measurement requirements of the nanotechnology community and provide a traceability to the definition of the mèter at the nanometric scale. The method is based on the use of both a heterodyne Michelson’s interferometer and a homemade high frequency electronic circuit. The system so established allows us to control the displacement of a translation stage with a known step of 4.945 nm. Intrinsic relative uncertainty on the step value is 1.6×10−9. Controls of the period of repetition of these steps with a high-stability quartz oscillator permits to impose an uniform speed to the translation stage with the same accuracy. This property will be used for the watt balance project of the Bureau National de Métrologie of France.

ベーシック・サイエンス・シリーズ 第２９回 高周波電子回路の基礎

ベーシック・サイエンス・シリーズ 第２９回 高周波電子回路の基礎

Growth and Characterization of GaAs Single Crystals

From a commercial viewpoint, gallium arsenide (GaAs) is currently the leading member of the III-V compound family. Oriented substrates, cut and polished from single-crystal boules, form the materials foundation for a rapidly maturing technology of high speed and high frequency electronic devices and circuits. The initial thrust of GaAs applications was in high powered lasers and light-emitting diodes (LEDs) fabricated on n-type (Si-doped) GaAs wafers grown by the horizontal Bridgman technique. One of the important benefits of using GaAs is the high electron mobility compared to Si. This property has driven the development of low noise and power field-effect transistors (FETs) for microwave applications. The semi-insulating substrate requirement (>107 Ω-cm) was initially met by chromium doping. Currently, the interest is focused on MMIC (microwave monolithic integrated circuits), MIMIC (millimeter microwave ICs), analog ICs for lightwave transmitters and receivers, and digital ICs. The digital circuits have been realized with ion-implanted FETs, selectively doped heterostructure transistors (SDHTs), and heterostructure bipolar transistors (HBTs). Presently, most of the semi-insulating (SI) material processed by the industry is nominally undoped, and grown by the liquid encapsulated Czochralski (LEC) technique. The SI behavior is attained via a delicate balance of deep EL2 donors and carbon acceptors, avoiding chromium in order to eliminate the anomalous out-diffusion and type-conversion associated with this dopant.GaAs wafers up to 4 inches in diameter, with electrical properties homogenized by whole ingot annealing, are currently available from U.S. domestic and overseas suppliers. However, the overall quality is compromised by the large dislocation densities, varying 104 – 105/cm2.