Novel Shorted Meander‐Line USB Dongle Antenna with a Compact Ground Plane

This letter presents the design of a novel multiband USB dongle antenna with a compact ground plane. The radiating patch is composed of a modified meander‐line monopole and a shorted loop to generate a dual‐broadband resonance. The proposed antenna supports WiBro, Bluetooth, WLAN, WiMAX, and S‐DMB services. The total dimensions of the fabricated antenna are 10 mm × 45 mm × 1 mm, the most compact size among multiband USB dongle antennas reported to date. The measured 10 dB reflection loss bandwidths are 20.8% (2.24 GHz to 2.76 GHz) and 20.2% (4.86 GHz to 5.95 GHz). The measured peak gain is 2.97 dBi, and efficiency is higher than 58%. In addition, the radiation pattern approximates an omnidirectional pattern.     

Compact Folded Monopole Antenna Excited by a Conductor‐Backed Coplanar Waveguide with Vias

A compact monopole antenna excited by a conductor‐backed coplanar waveguide (CBCPW) is developed for wireless USB dongle applications. The proposed antenna has a compact dimension of 14 mm × 47.4 mm × 3.5 mm, which is suitable for a USB dongle housing. A slotted elliptical patch and a CBCPW with vertical vias are employed to achieve a further size reduction and an improved impedance bandwidth. The measurement result demonstrates that the fabricated antenna resonates from 2.25 GHz to 10.9 GHz, which covers all of the important wireless communication bands, including WiBro (2.3 GHz to 2.4 GHz), Bluetooth (2.4 GHz to 2.484 GHz), WiMAX (2.5 GHz to 2.7 GHz and 3.4 GHz to 3.6 GHz), satellite DMB (2.605 GHz to 2.655 GHz), 802.11b/g/a WLAN (2.4 GHz to 2.485 GHz and 5.15 GHz to 5.825 GHz), and ultra‐wideband (3.1 GHz to 10.6 GHz) services. The radiation characteristics of the proposed antenna when attached to a laptop are tested to investigate the influence of the keypad and the LCD panel of the laptop.     

Compact Triple‐Band Monopole Antenna for WLAN/WiMAX‐Band USB Dongle Applications

A miniaturized triple‐band antenna suitable for wireless USB dongle applications is proposed and investigated in this paper. The presented antenna, simply consisting of a circular‐arc‐shaped stub, an L‐shaped stub, a microstrip feed line, and a rectangular ground plane has a compact size of and is capable of generating three separate resonant modes with very good impedance matching. The measurement results show that the antenna has several impedance bandwidths for of 260 MHz (2.24 GHz to 2.5 GHz), 320 MHz (3.4 GHz to 3.72 GHz), and 990 MHz (5.1 GHz to 6.09 GHz), which can be applied to both 2.4/5.2/5.8 GHz WLAN bands and 3.5/5.5 GHz WiMAX bands. Moreover, nearly‐omni‐directional radiation patterns and stable gain across the operating bands can be obtained.     

蓝牙V2.0+EDR标准的SCO/eSCO语音测试系统开发

现有的蓝牙语音专用测试系统价格昂贵、系统复杂、完全依赖进口.针对研究机构和生产厂商对保证蓝牙语音测试效率和性能基础上最小化测试成本的均衡考虑,本文开发了成本较低的蓝牙V2.0 EDR标准语音测试系统,该系统可以完成必要的蓝牙SCO/eSCO语音链路测试,而不依赖于进口测试设备.     

射频通信设备的FCC电磁照射评估要求

为应对各种复杂的射频通信设备的电磁照射评估要求,在通用评估要求和认证政策的基础上,FCC制定了完备的电磁照射评估体系,内容包括便携照射条件下无需进行同时发射模式评估的条件和评估程序、便携照射条件下支持同时发射的发射机和模块的评估要求、一些典型的主机平台和照射条件下的SAR测试要求、一键通设备的评估要求、移动设备的单发射机工作模式和同时发射模式的评估要求,以及如何简化测试、限值和照射条件的使用要求等。     

工控软件USB加密狗的设计

主要介绍了加密狗的基本原理与框架以及相关技术优势，根据这些特点，在工业测控系统上实现了自定义加密算法的设计，最后给出了该算法的关键技术说明。