نتایج جستجو برای: pcs band
تعداد نتایج: 142965 فیلتر نتایج به سال:
حلقه های قفل شده فاز تمام دیجیتال یکی از مباحث مهم در دنیای امروز الکترونیک هستند. حلقه قفل فازهای (pll ) که به وسیله روشهای آنالوگ طراحی می شدند نسبت به تغییرات دما و ولتاژ و پروسس حساس بودند. این امر موجب سختی طراحی و نیازمندی به طراحی مجدد در تکنولوژی های جدید می شود. این در حالی است که با استفاده از حلقه های قفل فاز تمام دیجیتال این مشکلات برطرف میشوند. حلقه های قفل فاز تمام دیجیتال (adpll...
زمینه وهدف: حاملگی خارج رحم در محل اسکار سزارین قبلی(PCS) یک در 2000 مورد از حاملگیها و 6 درصد موارد حاملگی خارج رحمی در زنانی که سابقة PCS داشتهاند، دیده میشود. هدف از این مطالعه، بررسی مادران بارداری بود که با تشخیص حاملگی نابجا در محل PCS در مرکز ما بستری شده بودند. روش بررسی: طی یک مطالعة گذشتهنگر پروندة موارد حاملگی نابجا در محل برش س...
Tunable photonic crystals PCs have attracted much attention in the past decade because of their various applications, such as ultrafast optical filters and optical waveguides with add–drop functionalities. One way of achieving tunability is to make use of ferroelectric materials since the refractive index of ferroelectric materials can be electrically tuned through the electro-optic effect. In ...
The prevention of environmental vibration pollution induced by train operation is one the inevitable problems in construction urban rail transit. With advantage flexible adjustment, phononic crystals (PCs) have a broad application prospect suppressing elastic wave propagation In this paper, damped with two-dimensional honeycomb PCs was proposed, and its band structure analysed FEM. Then, parame...
in this thesis, structural, electronical, and optical properties of inverse pervskite(ca3pbo) in cubic phase have been investigated.the calculation have been done based on density functional theory and according to generalized gradiant approximate (gga) as correlating potential. in order to calculate the configurations, implementing in the wien2k code have been used from 2013 version. first of ...
Introduction: Unwanted exposure of ionizing radiation may result in carcinogenesis, cell mutations, and organ failure. High-atomic number elements such as lead, tungsten, bismuth have been traditionally used for radiation protection. Theoretical and practical studies have shown that a variety of shielding materials e.g. polymer composites (PCs) can be used for attenuation of th...
The development of compact antennas plays an important role in the rapidly growing mobile communication market. This paper presents a novel design technique of the quad-band small internal antenna covering GSM-900/DCS-1800/PCS-1900/IMT-2000 bands. The innovative quad-band built-in handset antenna is developed within the limit of a 44×25×4mm3 volume. The following document describes a new idea o...
Manuscript Received 4-June-2012 and revised 18-September-2012 ISSN: 2322-3936 Accepted on 1December-2012 Abstract—This paper presents a new approach for the design of a multiband uniplanar CPW-fed monopole antenna. The antenna consists of a fork like monopole strip to which is added an inverted U-shaped strip. The three branch fork like strip can create three resonant bands within the WLAN rang...
In this paper we present a novel miniaturized dual-band patch antenna based on the metamaterial concept. Complementary split ring resonators, which are excellent structures for miniaturization; along with spiral resonators are used in the proposed design for obtaining a compact dual-band patch antenna. The original patch which is designed to resonate at 2.86 GHz is found to resonate at 1.92 GHz...
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