Design of Dual Band MIMO Antenna for 5G Smartphone Application
上传时间： 2022-02-26
上传用户：xsr1983
Abstract: Many industrial/scientific/medical (ISM) band radio frequency (RF) products use crystal oscillators to generate areference for the phase-locked loop (PLL)-based local oscillator (LO). This tutorial provides a basic description of theISM-RF Crystal Calculator, which can be used to calculate various impacts on crystal frequency accuracy and startupmargin for such an LO.
上传时间： 2013-11-15
上传用户：JasonC
The MAX2691 low-noise amplifier (LNA) is designed forGPS L2 applications. Designed in Maxim’s advancedSiGe process, the device achieves high gain andlow noise figure while maximizing the input-referred 1dBcompression point and the 3rd-order intercept point. TheMAX2691 provides a high gain of 17.5dB and sub 1dBnoise figure.
标签： Amplifier Low-Noise 2691 Band
上传时间： 2014-12-04
上传用户：zaocan888
This application note describes a Linear Technology "Half-Flash" A/D converter, the LTC1099, being connected to a 256 element line scan photodiode array. This technology adapts itself to handheld (i.e., low power) bar code readers, as well as high resolution automated machine inspection applications..
上传时间： 2013-11-21
上传用户：lchjng
The equal-area theorem●This is sinusoidal PWM (SPWM)●The equal-area theorem can be appliedto realize any shape of waveforms ●Natural sampling●Calculation based on equal-area criterion●Selected harmonic elimination●Regular sampling●Hysteresis-band control●Triangular wave comparison withfeedback control
上传时间： 2013-11-22
上传用户：linyao
今天，电视机与视讯转换盒应用中的大多数调谐器采用的都是传统单变换MOPLL概念。这种调谐器既能处理模拟电视讯号也能处理数字电视讯号，或是同时处理这两种电视讯号(即所谓的混合调谐器)。在设计这种调谐器时需考虑的关键因素包括低成本、低功耗、小尺寸以及对外部组件的选择。本文将介绍如何用英飞凌的MOPLL调谐芯片TUA6039-2或其影像版TUA6037实现超低成本调谐器参考设计。这种单芯片ULC调谐器整合了射频和中频电路，可工作在5V或3.3V，功耗可降低34%。设计采用一块单层PCB，进一步降低了系统成本，同时能处理DVB-T/PAL/SECAM、ISDB-T/NTSC和ATSC/NTSC等混合讯号，可支持几乎全球所有地区标准。图1为采用TUA6039-2/TUA6037设计单变换调谐器架构图。该调谐器实际上不仅是一个射频调谐器，也是一个half NIM，因为它包括了中频模块。射频输入讯号透过一个简单的高通滤波器加上中频与民间频段(CB)陷波器的组合电路进行分离。该设计没有采用PIN二极管进行频段切换，而是采用一个非常简单的三工电路进行频段切换。天线阻抗透过高感抗耦合电路变换至已调谐的输入电路。然后透过英飞凌的高增益半偏置MOSFET BF5030W对预选讯号进行放大。BG5120K双MOSFET可以用于两个VHF频段。在接下来的调谐后带通滤波器电路中，则进行信道选择和邻道与影像频率等多余讯号的抑制。前级追踪陷波器和带通滤波器的容性影像频率补偿电路就是专门用来抑制影像频率。
上传时间： 2013-11-19
上传用户：ryb
An essential component of a noise-free audio device isa clean power supply, but few switching regulators canoperate at high efficiency while keeping the switchingfrequency out of the audio band. The LTC®3620 fills thisvoid. It is a high efficiency 15mA buck regulator with aprogrammable minimum switching frequency, making itpossible to virtually eliminate audible switching noise. Theinternal synchronous switches and low quiescent currentof this buck regulator provide the ability to maintain highefficiency, while its small footprint makes it ideal for tiny,low power audio applications.
上传时间： 2013-10-21
上传用户：非衣2016
锁定放大是微弱信号检测的重要手段。基于相关检测理论，利用开关电容的开关实现锁定放大器中乘法器的功能，提出开关电容和积分器相结合以实现相关检测的方法，并设计出一种锁定放大器。该锁定放大器将微弱信号转化为与之相关的方波，通过后续电路得到正比于被测信号的直流电平，为后续采集处理提供方便。测量数据表明锁定放大器前级可将10-6 A的电流转换为10-1 V的电压，后级通过带通滤波器级联可将信号放大1×105倍。该方法在降低噪声的同时，可对微弱信号进行放大，线性度较高、稳定性较好。 Abstract: Lock-in Amplifying（LIA）is one of important means for weak signal detection. Based on cross-correlation detection theory， switch in the swithched capacitor was used as multiplier of LIA， and a new method of correlation detection was proposed combining swithched capacitor with integrator. A kind of LIA was designed which can convert the weak signal to square-wave， then DC proportional to measured signal was obtained through follow-up conditioning circuit， providing convenience for signal acquisition and processing. The measured data shows that the electric current（10-6 A） can be changed into voltage（10-1 V） by LIA， and the signal is magnified 1×105 times by cascade band-pass filter. The noise is suppressed and the weak signal is amplified. It has the advantages of good linearity and stability.
上传时间： 2013-11-29
上传用户：黑漆漆
介绍一种简单射频识别系统设计。该设计包括阅读器、应答器和线圈3部分。由单片机控制阅读器向应答器发射无线信号，并接收应答器回送的信号，再通过分析回送信号识别物品。阅读器和应答器之间以半双工通信方式通信。 Abstract: A simple design of radio frequency identification system is given in this paper.The design includes reader,responder and winding.Through MCU，signals are sent to responder from reader，then corresponding signals are sent back. According to the analysis of the signals sent back，the objects can be identified.Half-duplex communication is adopted? between? reader? and? responder.
上传时间： 2013-10-11
上传用户：plsee
基于幅移键控技术ASK（Amplitude-Shift Keying），以C8051F340单片机作为监测终端控制器，C8051F330D单片机作为探测节点控制器，采用半双工的通信方式，通过监控终端和探测节点的无线收发电路，实现数据的双向无线传输。收发电路采用直径为0.8 mm的漆包线自行绕制成圆形空心线圈天线，天线直径为（3.4±0.3）cm。试验表明，探测节点与监测终端的通信距离为24 cm，通过桥接方式，节点收发功率为102 mW时，节点间的通信距离可达20 cm。与传统无线收发模块相比，该无线收发电路在受体积、功耗、成本限制的场合有广阔的应用前景。 Abstract: Based on ASK technology and with the C8051F340 and C8051F330D MCU as the controller， using half-duplex communication mode， this paper achieves bi-directional data transfer. Transceiver circuit constituted by enameled wire which diameter is 0.8mm and wound into a diameter （3.4±0.3） cm circular hollow coil antenna. Tests show that the communication distance between detection and monitoring of the terminal is 24cm，the distance is up to 20cm between two nodes when using the manner of bridging and the node transceiver power is 102mW. Compared with the conventional wireless transceiver modules， the circuit has wide application prospect in small size， low cost and low power consumption and other characteristics.
上传时间： 2013-10-19
上传用户：xz85592677
