In this paper, a GaAs pHEMT class A balanced power amplifier with a 3-dB bandwidth of 4.5 GHz at the center frequency of 9 GHz is presented. Our amplifier yields to an input/output-matching better than -15 dB over this frequency band. Also, the realization of impedance matching network using microstrip line and lumped component is carried out. At the end, simulation results for the broadband impedance matching network are presented and analyzed تفاصيل المقالة

In this article, we have given the size of the coupling constant, a system of quantum electro-dynamics in weak coupling regime, strong and very strong case our analysis and simulation. Also by choosing the type of quantum system and the electrical field of the electromagnetic wave, the size of Rabi frequency to the extent that we are less than excited states and photons in the cavity decay rate is. In this case, the interaction between the quantum system and electromagnetic field coupling regime is weak. It is one of the properties of quantum light emitting modes of the cavity modes can be in resonance with each other, resulting in a sudden increase in the spontaneous emission rate, causing a sharp peak in the density of the spontaneous emission spectrum. The nature of this regime leads to appropriate in light production applications, such as it is possible to increase efficiency, reduce the threshold lasers emitting light in alignment with the vertical cavity structure light emitting diodes noted. Also property is listed under the regime of entangled photons is used in the production of instant. While this research, the rotating wave approximation is used in this context, survival and annihilation operators of photons Sinusoidal behavior.  تفاصيل المقالة

در این مقاله ما به طراحی و شبیه سازی یک ترانزیستور تونلی جدید پرداخته ایم. ترانزیستورهای فت‌تونلی بدلیل سازوکار جریان تونل‌زنی نوار به نوار، دارای جریان نشتی کم و شیب زیرآستانه کمتر از mV/dec60 هستند و می‌توانند به عنوان جایگزینی مناسب برای ماسفت به منظور استفاده در مدارات کلیدزنی توان پایین باشد. با این حال؛ عیب این ترانزیستورها جریان حالت روشن کمتر آن ها نسبت به ترانزیستورهای ماسفت است. در این مقاله یک ساختار ترانزیستور تونلی دو گیتی – دو ماده‌ای بهینه شده پیشنهاد شده که با اضافه کردن دو ناحیه با آلایش ذاتی به ساختار فت‌تونلی دو گیتی رایج، سعی در افزایش نرخ تونل‌زنی حامل‌ها در مقایسه با ترانزیستورهای تونلی مرسوم شده است. طراحی و شبیه سازی با استفاده از نرم‌افزار سیلواکو - اتلس بصورت دوبعدی صورت گرفته است. نتایج محاسبه شده بصورت زیر است: جریان حالت روشن برابر A/µm6-10×49/5، جریان حالت خاموش برابرA/µm 18-10×2، شیب زیرآستانه برابر mV/dec02/15 و نسبت Ion/Ioff برابر 1012×74/2. نتایج حاصله نشان دهنده بهبود پارامترهای DC افزاره است. تفاصيل المقالة

In the present paper, a nanostructure plasmonic gas sensor based on ring
resonator structure at the wavelength range of 0.6-0.9 μm is presented. The plasmonic
materials/SiO2 with the advantage of high mobility and low loss is utilized as a substrate
for structure to obtain some appropriate characteristics for the sensing Performance
parameters. To evaluate the proposed sensor and calculation of performance parameters
including figure of merit and sensitivity, the effect of the different gas including Carbon
Dioxide (CO2), Acetonitrile (C2H3N), Carbon disulfide, and Sarin are considered. For
this purpose 3D-FDTD method is considered. Our calculations show that by coupling
between the incident waves and the surface plasmons of the structure, a high
transmission ratio of 0.8 and relatively low insertion loss of 6 dB around the wavelength
interval of 0.6-0.9 μm are achievable. Furthermore, the calculated sensitivity and figure
of merit are 28 and 8.75, respectively. This provides a path for development of nanoscale
practical on-chip applications such as plasmonic memory devices. تفاصيل المقالة

In this paper, the numerical design and simulate a biosensor to detect tumors and cancerous tissues by using metamaterial structures in the microwave regime are presented. The presented structure consists of a microstrip transmission line and a split ring resonator (SRR) that form a bandpass filter and has a unique resonance frequency. Given that cancerous tissues have larger volumes of water than healthy tissues. As a result, they have a higher dielectric coefficient and conductivity which use for healthy tissues detection. By placing biological samples on SRR, its dielectric constant changes, therefore, the resonance frequency of the system changes. We can measure the types of biological tissues by measuring these changes. We used the Debye model to simulate the muscles. Also, the benefits of this biosensor are easy to use and operation, but they have lower sensitivity than terahertz biosensors. The minimum resolution for samples under test in this biosensor is 10 MHz. تفاصيل المقالة

Abstract Here, several ring resonator nanostructure for biosensors are proposed. To evaluate the results, finite difference time domain (FDTD) method is applied. Also, several main parameters including transmission spectrum is analyzed to obtain of sensitivity and figure of merit. As the technology goes on, using sensors and biosensors are more attracted by many researchers in various fields such as medicine. Biosensors are devices, in them biological elements and analytes have interacted and the reaction between them is measured then would be expressed as understandably in output. Biosensors have various components such as analyte, bioreceptor, transformer, electronics and display and are in different groups based on their mechanisms. Biosensors could be used to detect and diagnose bacteria, viruses, and early detect of breast cancer. Various methods such as X-ray mammography, ultrasound scan, DBT, ultrasonography of breast, and so on have been provided, but they have some disadvantages. In the biosensors field, various methods are introduced for early detection of breast cancer. In this study some researches and experienced have been investigated. تفاصيل المقالة