Interference Considerations
The RF spectrum is crowded and the potential for conflict with other
unwanted sources of RF is very real. While all RF products are at risk
from interference, its effects can be minimized by better understanding its
characteristics.
Interference may come from internal or external sources. The first step is to
eliminate interference from noise sources on the board. This means paying
careful attention to layout, grounding, filtering, and bypassing in order to
eliminate all radiated and conducted interference paths. For many
products, this is straightforward; however, products containing
components such as switching power supplies, motors, crystals, and other
potential sources of noise must be approached with care. Comparing your
own design with a Linx evaluation board can help to determine if and at
what level design-specific interference is present.
External interference can manifest itself in a variety of ways. Low-level
interference will produce noise and hashing on the output and reduce the
link’s overall range.
High-level interference is caused by nearby products sharing the same
frequency or from near-band high-power devices. It can even come from
your own products if more than one transmitter is active in the same area. It
is important to remember that only one transmitter at a time can occupy a
frequency, regardless of the coding of the transmitted signal. This type of
interference is less common than those mentioned previously, but in severe
cases it can prevent all useful function of the affected device.
Although technically it is not interference, multipath is also a factor to be
understood. Multipath is a term used to refer to the signal cancellation
effects that occur when RF waves arrive at the receiver in different phase
relationships. This effect is a particularly significant factor in interior
environments where objects provide many different signal reflection paths.
Multipath cancellation results in lowered signal levels at the receiver and,
thus, shorter useful distances for the link.
– 13 –
相关PDF资料
RXM-418-LR_ RECEIVER 418MHZ LR SERIES
RXM-869-ES_ RECEIVER RF 869MHZ 16PIN SMD
RXM-GPS-SG-T GPS MODULE SMD SIRF
RXM-GPS-SR-T GPS MODULE SMD SIRF W/ANT
RZE002P02TL MOSFET P-CH 20V 200MA EMT3
RZF020P01TL MOSFET P-CH 12V 2A TUMT3
RZF030P01TL MOSFET P-CH 12V 3A TUMT3
RZM002P02T2L MOSFET P-CH 20V 0.2A UMT6
相关代理商/技术参数
RXM-418-LR 功能描述:射频模块 RF Receiver 418MHz RoHS:否 制造商:Linx Technologies 产品:Transceiver Modules 频带:902 MHz to 928 MHz 输出功率:- 15.5 dBm to + 12.5 dBm 接口类型:UART 工作电源电压:- 0.3 VDC to + 5.5 VDC 传输供电电流:38.1 mA 接收供电电流:22.7 mA 天线连接器类型:U.FL 最大工作温度:+ 85 C 尺寸:1.15 mm x 0.63 mm x 0.131 mm
RXM-418-LR_ 功能描述:RECEIVER 418MHZ LR SERIES RoHS:是 类别:RF/IF 和 RFID >> RF 接收器 系列:LR 产品培训模块:Lead (SnPb) Finish for COTS 产品变化通告:Product Discontinuation 09/Jan/2012 标准包装:50 系列:* 频率:850MHz ~ 2.175GHz 灵敏度:- 数据传输率 - 最大:- 调制或协议:- 应用:* 电流 - 接收:* 数据接口:PCB,表面贴装 存储容量:- 天线连接器:PCB,表面贴装 特点:- 电源电压:4.75 V ~ 5.25 V 工作温度:0°C ~ 85°C 封装/外壳:40-WFQFN 裸露焊盘 供应商设备封装:40-TQFN-EP(6x6) 包装:托盘
RXM-418-RM 功能描述:RECEIVER RF 418MHZ RoHS:否 类别:RF/IF 和 RFID >> RF 接收器 系列:RM 产品培训模块:Lead (SnPb) Finish for COTS 产品变化通告:Product Discontinuation 09/Jan/2012 标准包装:50 系列:* 频率:850MHz ~ 2.175GHz 灵敏度:- 数据传输率 - 最大:- 调制或协议:- 应用:* 电流 - 接收:* 数据接口:PCB,表面贴装 存储容量:- 天线连接器:PCB,表面贴装 特点:- 电源电压:4.75 V ~ 5.25 V 工作温度:0°C ~ 85°C 封装/外壳:40-WFQFN 裸露焊盘 供应商设备封装:40-TQFN-EP(6x6) 包装:托盘
RXM430-408 制造商:未知厂家 制造商全称:未知厂家 功能描述:Analog IC
RXM-433-LC 制造商:未知厂家 制造商全称:未知厂家 功能描述:LC SERIES TRANSMITTER MODULE
RXM-433-LC-P 制造商:未知厂家 制造商全称:未知厂家 功能描述:LC SERIES RECEIVER MODULE DATA
RXM-433-LC-S 功能描述:RECEIVER RF 433MHZ SMT RoHS:否 类别:RF/IF 和 RFID >> RF 接收器 系列:LC 产品培训模块:Lead (SnPb) Finish for COTS 产品变化通告:Product Discontinuation 09/Jan/2012 标准包装:50 系列:* 频率:850MHz ~ 2.175GHz 灵敏度:- 数据传输率 - 最大:- 调制或协议:- 应用:* 电流 - 接收:* 数据接口:PCB,表面贴装 存储容量:- 天线连接器:PCB,表面贴装 特点:- 电源电压:4.75 V ~ 5.25 V 工作温度:0°C ~ 85°C 封装/外壳:40-WFQFN 裸露焊盘 供应商设备封装:40-TQFN-EP(6x6) 包装:托盘
RXM-433-LR 功能描述:射频模块 RF Receiver 433MHz RoHS:否 制造商:Linx Technologies 产品:Transceiver Modules 频带:902 MHz to 928 MHz 输出功率:- 15.5 dBm to + 12.5 dBm 接口类型:UART 工作电源电压:- 0.3 VDC to + 5.5 VDC 传输供电电流:38.1 mA 接收供电电流:22.7 mA 天线连接器类型:U.FL 最大工作温度:+ 85 C 尺寸:1.15 mm x 0.63 mm x 0.131 mm