Abstract: With industrial/scientific/medical (ISM) band radio frequency (RF) products, often times users are new to the structure of Maxim's low pin-count transmitters andfully integrated superheterodyne receivers. This tutorial provides simple steps that can be taken to get the best performance out of these transmitters and receivers whileproviding techniques to measure the overall capability of the design.
上傳時間: 2013-11-02
上傳用戶:yph853211
Abstract: While many questions still surround the creation and deployment of the smart grid, the need for a reliablecommunications infrastructure is indisputable. Developers of the IEEE 1901.2 standard identified difficult channel conditionscharacteristic of low-frequency powerline communications and implemented an orthogonal frequency division multiplexing (OFDM)architecture using advanced modulation and channel-coding techniques. This strategy helped to ensure a robust communicationsnetwork for the smart grid.
上傳時間: 2013-10-18
上傳用戶:myworkpost
Radio frequency (RF) can be a complex subject to navigate, but it does not have to be. If you are just getting started with radios or maybe you cannot find that old reference book about antenna aperture, this guide can help. It is intended to provide a basic understanding of RF technology, as well act as a quick reference for those who “know their stuff” but may be looking to brush up on that one niche term that they never quite understood. This document is also a useful reference for Maxim’s products and data sheets, an index to deeper analysis found in our application notes, and a general reference for all things RF.
上傳時間: 2013-10-23
上傳用戶:685
Radio frequency (RF) can be a complex subject to navigate, but it does not have to be. If you are just getting started with radios or maybe you cannot find that old reference book about antenna aperture, this guide can help. It is intended to provide a basic understanding of RF technology, as well act as a quick reference for those who “know their stuff” but may be looking to brush up on that one niche term that they never quite understood. This document is also a useful reference for Maxim’s products and data sheets, an index to deeper analysis found in our application notes, and a general reference for all things RF.
標簽: 無線技術
上傳時間: 2013-10-08
上傳用戶:kinochen
Abstract: This application note illustrates the flexibility of the MAX7060 ASK/FSK transmitter. While the currently available evaluationkit (EV kit) has been optimized for the device's use in a specific frequency band (i.e., 288MHz to 390MHz), this document addresseshow the EV kit circuitry can be modified for improved operation at 433.92MHz, a frequency commonly used in Europe. Twoalternative match and filter configurations are presented: one for optimizing drain efficiency, the other for achieving higher transmitpower. Features and capabilities of earlier Maxim industrial, scientific, and medical radio-frequency (ISM-RF) transmitters areprovided, allowing comparison of the MAX7060 to its predecessors. Several design guidelines and cautions for using the MAX7060are discussed.
上傳時間: 2013-11-14
上傳用戶:swaylong
提出了一種基于PIC16F877A微控制器和CC2500射頻收發器芯片的低功耗、低成本RFID(Radio Frequency Identification, 無線射頻識別)局域定位系統設計方法,介紹了系統的定位工作原理、主要硬件電路模塊及定位算法的設計和實現。采用基于序列號對時隙數運算的排序算法有效解決了多標簽識別碰撞的問題,基于射頻輻射強度(Received Signal Strength Indication, RSSI)和圓周定位算法實現了基于RFID多標簽系統的平面定位。實驗測試表明,這種射頻定位方法能夠實現一定精度下的無線局域定位的功能。
上傳時間: 2013-11-06
上傳用戶:weareno2
正交頻分復用 (Orthogonal Frequency Division Multiplexing,OFDM)是一種多載波調制技術,由于具有良好的抗多徑干擾性能,適用于高速數據傳輸,OFDM成為近年來人們研究的熱點。但是其峰均比較高,應用受到了限制,因此有必要研究降低PAPR的方法。本文首先介紹了OFDM的基本原理和PAPR的基本概念,然后討論了目前常用的降低PAPR的方法,最后對SLM和PTS方法進行了MATLAB仿真。
上傳時間: 2013-11-19
上傳用戶:moshushi0009
Radio Frequency Identifi cation (RFID) technology usesradiated and refl ected RF power to identify and track avariety of objects. A typical RFID system consists of areader and a transponder (or tag). An RFID reader containsan RF transmitter, one or more antennas and an RFreceiver. An RFID tag is simply an uniquely identifi ed ICwith an antenna.
上傳時間: 2013-10-17
上傳用戶:lepoke
Abstract: Engineers often wish that radio susceptibility (RS) or radio immunity could be cured with an antibiotic, a vaccine, or someform of cure-all. Unfortunately, solving the RS problem is not that easy. Indeed, the laws of physics apply. In this article we discusssources of RS. We also offer tips and hints to protect systems, power supplies, printed circuit boards (PCBs), and electroniccomponents from radio frequency interference.
標簽: Susceptibility Radio 無線電干擾
上傳時間: 2014-12-30
上傳用戶:旗魚旗魚
在研究傳統家用燃氣報警器的基礎上,以ZigBee協議為平臺,構建mesh網狀網絡實現網絡化的智能語音報警系統。由于傳感器本身的溫度和實際環境溫度的影響,傳感器標定后采用軟件補償方法。為了減少系統費用,前端節點采用半功能節點設備,路由器和協調器采用全功能節點設備,構建mesh網絡所形成的家庭內部報警系統,通過通用的電話接口連接到外部的公用電話網絡,啟動語音模塊進行報警。實驗結果表明,在2.4 GHz頻率下傳輸,有墻等障礙物的情況下,節點的傳輸距離大約為35 m,能夠滿足家庭需要,且系統工作穩定,但在功耗方面仍需進一步改善。 Abstract: On the basis of studying traditional household gas alarm system, this paper proposed the platform for the ZigBee protocol,and constructed mesh network to achieve network-based intelligent voice alarm system. Because of the sensor temperature and the actual environment temperature, this system design used software compensation after calibrating sensor. In order to reduce system cost, semi-functional node devices were used as front-end node, however, full-function devices were used as routers and coordinator,constructed alarm system within the family by building mesh network,connected to the external public telephone network through the common telephone interface, started the voice alarm module. The results indicate that nodes transmit about 35m in the distance in case of walls and other obstacles by 2.4GHz frequency transmission, this is able to meet family needs and work steadily, but still needs further improvement in power consumption.
上傳時間: 2013-10-30
上傳用戶:swaylong