射频是那个频段的电磁波啊?电磁波一般分为无线电波、微波、紫外线、可见光、红外线、x射线、γ射线等,那么射频是属于无线电波

线材导体外径大小是按国标,UL标准定的,不是想做多大那多大,大了小了就无法认证.
国标,UL标准如何来的是通过试验确认来的,既然是实验肯定是电阻,电容,衰减,特性阻抗,能满足使用功能.
射频线用单导体是常识了

现今医学上用来做人体检测的核磁共振成像仪磁场的强度是1.5万高斯左右.在这样的磁场中使用的射频是60兆周左右,相当于收音机短波的频率.大量的实验结果表明,这样的磁场强度和射频频率对人体无害.
无创指的是不必切口取样.
核磁共振成像仪使现代医学的诊断和治疗前进了一大步,您千万别因为畏惧使用核磁共振成像仪而耽误了诊断和治疗.
本人是用核磁共振仪做化学分析的.我所使用的仪器的磁场强度是15万高斯,也就是医学核磁共振成像仪的十倍.我从来没有畏惧过,也从来没有因为它而患病.所以请您放心使用医学核磁共振成像仪.
问:但是还有强磁呢!
答:1.5万高斯和15万高斯是强磁了!
问:要是作头部的MRI呢?对智力有影响吗?
答:MRI对人体无害,对智力也无害.
问:另外,头部的能做到喉咙这个部位,看见咽炎、气管炎啥的吗?
答:MRI能看见咽喉和气管喉等.
问:还是害怕 俺看到有说法：3次X辐射就相当于1次和辐射的量
答:X辐射是高能量的射线.收音机短波的频率不是高能量的射线.
问:而且不是说照一次X线在人体存25年
答:尽管X辐射是高能量的射线,此说也不正确!
问:我怕MRI有别的什么,要不你看医生都先把自己藏小屋里.
答:医生把自己藏小屋里是因为他们不想让别干扰,而且他们需要暗房条件.
同时,他们也不想干扰您,在您面前谈一些您无法理解的技术问题,让您瞎猜疑.

生物射频指纹识别技术,射频传感器技术是通过传感器本身发射出微量射频信号,穿透手指的表皮层去控测里层的纹路,来获得最佳的指纹图像.因此对干手指,汉手指,干手指等困难手指通过可高达99.5%,防伪指纹能力强,指纹敏感器的识别原理只对人的真皮皮肤有反应,从根本上杜绝了人造指纹的问题,宽温区：适合特别寒冷或特别酷热的地区.因为射频传感器产生高质量的图像,因此射频技术是最可靠,最有力有解决方案.除此之外,高质量图像还允许减小传感器,无需牺牲认证的可靠性,从而降低成本并使得射频传感器思想的应用到可移动和大小不受拘束的任何领域中.

D

准确来说是频率可以达到最高的信号,音频是人能够听到的范围300Hz-3400Hz.视频最高到HDMI 5GHz,射频是300kHz-30GHz,调幅1MHz-10MHz.所以答案应该是C.

去移动基站里看看,100W,200W的电阻有的是.再大功率的风冷,上千瓦的负载就需要水冷了.功率要大,电压提高就OK.最常见的电炉丝就是个大电阻,1000W的电炉子就是个40多欧的大电阻.

在射频、视频、音频中，音频信号的波长最长，射频信号的波长最短，视频信号的波长介于这两者之间，故A是音频，B是视频，C是射频．
故本题答案为：音频；视频；射频．

解题思路：要解答本题需掌握：音频、视频和射频的频率范围，以及能读懂图象．

【音频】又称声频，是人耳所能听见的频率．通常指15～20000赫（Hz）间的频率．
【射频】无线电发射机通过天线能有效地发射至空间的电磁波的频率，统称为射频．若频率太低，发射的有效性很低，故习惯上所称的射频系指100千赫（KHz）以上的频率．
【视频】电视信号所包含的频率范围自几十赫至几兆赫，视频是这一频率的统称．
所以频率最低的音频的波长最长，频率最高的是 射频．
故本题答案为：音频，射频

点评：
本题考点： 音频、视频和射频信号．

考点点评： 本题主要考查学生对：音频、视频和射频信号的了解和掌握，是一道基础题．

简单的,GALI-5通过电容耦合到F21.4,直接视其为负载,因为GALI-5是集电极开路输出的；
而AD603的输入端并联个1.5KΩ电阻到地就是了；

ar:条
gap：空
指条码符号区域,
可以参考看条码术语国家标准.
是上面这个技术的意思 还是“又有阻拦物,又有沟壑的一片地”要看上下文语境.

大概说：
上图,Q1等构成电容三点式振荡电路,故X1支路等效为一个电感,其中变容二极管用于改变等效电感值,从而改变振荡频率；Q2是起着缓冲与放大作用,避免输出端后级对振荡器频率的影响；
中图,输入输出标注有误,上方运放构成积分电路,输出经二极管整流,运放输出一个直流电平来控制Q8,而Q8集电极没有直流回路?取其极间等效电容?
下图,Q6等构成射频信号电压放大（未见电源）,U9构成功率放大电路,电感部分构成N阶Π型滤波器电路,最后将信号馈至天线；

Radio Frequency Identification as "the wireless radio frequency identify",English brief name RFID).Wireless radio frequency 's identifying a technique is 1 kind that the 90's in 20 centuries starts rise to automatically identify a technique and RFID technique's making use of a wireless radio frequency method's being read an of machine and radio frequency card to carry on doesn't get in touch with a double to deliver to identify by attaining a target the purpose which exchanges with data toward the data.Compared with traditional type code,Ci card and IC card,radio frequency card's have doesn't get in touch with,read speed quick,have never worn away,been free from environment influence,life span long,the characteristics of easy to usage with have to defend conflict function,can handle several cards in the meantime.
The RFID technique is to develop a quickest high-tech technique for 21 centuries,along with with combine of traditional network,the RFID technique emerges a huge market an application a potential,is called "thing allied net" and"the next generation Internet".Currently,the RFID has become study of IT industry a little bit hot,is see as next"gold mine" of IT industry.Each big and soft hardware manufacturer,include IBM,the MicorosoftOracle of the Motorola Philips etc.at inside of each business enterprises all to RFID technique it and the application expressed strong interest,throw a person one after another to in great quantities develop budget and released respectively of software or hardware product and system application solution.
Along with the science technical progress,Be a data to collect an automatically identify of the way's technique to get a fast fierce development,among them applied more and more be subjected to concern in the RFID technique of the logistics and the supply chain realm.The flourishing nation has already applied to the management,safety management...etc.of the management,ancient books of the circulate of library to this technique.Currently American large logistics company,retail store,medicine companies all is continuously trying out this kind of correspondence technique of the short distance wireless to be mainly used for controling the quality,amount of the goods or the merchandise and to the stock more accurate,safe and valid management.The RFID of China is applied main concentration at in low frequency realm(work the frequency be small at the 30 MHzs),such as the identity identify,safe control at gate,electronics ticket-purchasing,transportation etc.realm.If can come to hand the function's integration on board to make it become people,the tool of the shopping balance of accounts so moved an operator to hope to acquire new income from the profession cooperation.Future world,RFID will omnipresent.
Such as the United States of the university library has more than 300 houses to apply RFID technique,Singapore own the first overall applied RFID technique of intelligence library etc..The our country is also usher in this technique,in 2006 Shenzhen library already part of pplied this techniques.This technique brought library boundary huge variety and had very vast foreground.

DPD是指数字预失真处理.由于目前所采用的通信制式的信号的峰均比越来越大,如果采用传统的功率回退的方式来实现功放,会造成很大的功率的浪费,因此目前的功放大多采用Doherty+DPD的架构来实现功放部件的高效率.
DPD技术主要的实现方式是对输入PA部件的信号和PA部件的输出信号进行采样,并进行误差的算法,从而在PA的输入口加入一个与PA的失真反方向的信号,抵消PA部件的失真.
由于一般需要抵消到功放的五阶互调,因此DPD的处理带宽需要是信号带宽的五倍.

射频识别技术 RFID (RadioFrequency Identification)
射频卡 RF Card (RadioFrequency Card)
分类 classification

CCBBADCBA

念紫雪 |同学,
翻译：wireless radio frequency
祝好!

的确是光速!电磁波和光波一样传播速度都是30万公里/秒.

影响距离的因素就是匹配!简单理解,频率f=1/2π√LC,f固定,你改变线圈大小就是改变L和C的值.线圈电感值计算方法自己搜,写公式太麻烦.改变了L,就要补偿C,具体方法自己先研究一下,我不想一下什么都说了.

This paper focuses on the study of the radio frequency identification RFID system data transmission anti-collision protocols as well as the main security technology,completed by ALOHA,ALOHA and CSMA slot anti collision protocol simulation experiment.First of all,the agreement features are analyzed,and on this basis,the application of OPNET tools for this algorithm are simulated,and the simulation results were compared,analysis,verifies the correctness of the model and feasibility.And the radio frequency identification system in which data is transmitted in the main safety technologies are compared and analyzed.
来自【翻译强团】

How does the radio frequency technology is dissolve the fat to lose weight?Answer:The radio frequency dissolves the fat to lose weight is causes the radio frequency wave action using the single-pole radio frequency to the fat spot,causes the partial blood circulation acceleration,the fatty acid to decompose,the fatty cell weakly perishes.The fatty cell decomposes after the metabolite to ship through the organization to the liver metabolism discharges in vitro.2nd,regarding some bodies on ORANGE the organization,the radio frequency technology may treat?Answer:The radio frequency biology is hot may cause the dermis which the textile fiber separates to tighten,after afterwards started the wound inflammation response,including 纤维母 the cell proliferation,the new collagen formation and the reorganization,the biological thermal reaction strengthened the partial blood circulation promotion fat drainage,the fatty cell which the fatty acid decomposition and hotly caused has weakly perished.3rd,does the radio frequency dissolve the fat and,what the laser and the photon tender skin they has to distinguish?Answer:Shoots the frequency wave is the wave band is the 40.67MHZ electromagnetic wave,causes through the different technique to shoot the frequency wave penetration surface layer base first floor the melanophore,depth of penetration 2mm-20mm,resonates the principle through a minute small water-kettle to cause the organization to heat up to the threshold value temperature 65 ℃ -75 ℃,both affects to the collagen organization,and may affect to the fat,achieved dispels wrinkles the skin,dissolves the effect which the fat loses weight,does not have any damage to the epidermis.The laser and the photon are the transmitted light heat,the light demolition effect to the epidermis,but cannot penetrate the epidermis base first floor,only has the function to the epidermis.4th,the radio frequency dissolves the fat the treatment time probably much long time?Answer:Each time treats region 20 minutes,treatment course 3-6,each time is separated 2-4 week (to determine according to spot situation by doctor).5th,the radio frequency dissolves the fat the skin to meet the pain in the course of treatment?Answer:The radio frequency dissolves the fat treatment to use the patent the ultra vigor pulse technology,feels comfortably,merely some point partial or micro burns.6th,which people does the radio frequency dissolve the fat treatment to suit?Answer:In the best treatment crowd is the fat spins the surface water content high patient.After 7th,the radio frequency treatment needs to rest?Answer:Does not need the recovery period,does not affect the normal life and the work.8th,what is the complex wave?Answer:The complex wave is the radio frequency technology in a cosmetology domain significant breakthrough,it through the special emitter electrode,causes the radio frequency electric wave penetration surface layer base first floor,both affects to 真皮层 the collagen organization,and affects to the fat level,achieved dispels wrinkles the skin,dissolves the effect which the fat loses weight,but the traditional radio frequency technology only can solely affect to (electric wave pulls skin),thus is unable to achieve dissolves the fat filament body the effect.9th,which effects does the radio frequency dissolve the fat to have in the filament body aspect?Answer:Improves the skin quality,the reduction "the orange peel organization",the reduced pressure,the promotion blood circulation,the release fat group,the reduced fat piles up and so on the effect.10th,how long does the radio frequency dissolve the fat the effect to be allowed to maintain?Answer:The memoir pointed out that,the satisfying effect at least may maintain above for 2 years to be even long.The maintenance time length,possibly also can because you naturally get older progress speed but different.

射频,稳定度,通俗
麻烦采纳,谢谢!

从物理学角度上看,电磁波从波长最短开始,顺序如下：γ射线、紫外线、可见光、红外线、无线电波（无线电波又分为：微波、短波、中波、长波）.
而电磁波的本质不过是不断变化的电场和磁场.
而楼主所列举的各种名称中,应当都属于电磁波.只是对最近几年在计算机网络中所使用的技术标准,本人不是很擅长,所以不知道蓝牙、wi-fi、802.11n等的波长（或频率）,所以不知道这些电磁波所属的分类.
而其中射频是电磁波的另一种称呼,发射线,这个本人不清楚.

Please notice if all the electric wires,water pipes and radio frequency wires connected to the lid have been pulled out or not.Also please watch out for the safety of all the personnel surrounded.Shout down the power promptly when the crane is not used.

手机、现在的物联网系统、RFID、等离子射频电源60MHZ,13.56MHZ（半导体生产设备）.匹配器.

现在我们看见的情况是星云1.5万年前的样子,1.5万年的前的光走了1.5万年来到地球我们才看到,不是要光从我们这里走1.5万年去星云,所以望远镜看得见.
希望我的答案令你满意.

广播电台 话筒 调制器 收音机 收音机调谐器 收音机内电子电路 扬声器
想看原文,请参见人教版物理八年级下册102页.
加油吧!