Data Interface - Virtual Instrumentation, Device Networking.

Saturday, July 09, 2016

Facts of EMI and RFI from the Inside

Electromagnetic interference (or EMI, also called radio-frequency interference or RFI when in radio frequency) is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source.
 
Electromagnetic interference Wiki

Vertical polarized VHF- UHF biconical antenna

Vertical polarized VHF- UHF biconical antenna
170 – 1100 MHz with omni directional H-plane pattern

Who would know better about Radio Frequency Interference and ElectroMagnetic Interference more than the Hams or Amateur Radio Community.

If they have to communicate effectively using limited resources, they have to deal with EMI/RFI effectively, While they build their equipment or combat Noise from other Machines and Installations nearby.

EMI RFI Mains Filters

This problem needs more practical involvement and experimentation to learn, compared to learning something like Digital Electronics.

Equipment and Electricals like SMPS, AC/DC Drives, Motors, Solenoids and CFL Lamps are to be built/reinforced for low EMI/RFI emission/radiation.

Sensitive Medical Equipment like ECG or even a Aircraft can be seriously affected by Noise.

Radio Frequency Interference (RFI)

Friday, July 08, 2016

Reference Charts RF µWave Communications - Anritsu

These charts provide Band Designation, RF Measurements Conversion Tables, RF Spectrum Bands, RF Connector Comparison Tables, S-Paramaters, the Electromagnetic Spectrum, Waveguide Designation, Power to Voltage Conversion,

Others are Spectrum Analyzer Conversion Factors, SWR ñ Reflection Coefficient ñ Return Loss, Power Measurements, Amplitude Modulation, Pulse Modulation, Frequency Modulation, and Bessel Functions. From - Anritsu

Reference Charts RF µWave Communications - Anritsu

Reference Charts for RF & µWave Communications - Anritsu

"Conversion tables for return loss, reflection coefficicient, and SWR with values for interaction of a small phasor (utility reference) expressed in dB related to the reference.

In microwave circuit design S-parameters are very useful for the full characterisation of any 2 port network. In contrast to z,y and h-parameters, which require broadband short circuited and open circuited connections at the TEST ITEM for the measurement,

S-parameters are determined with input and output terminated with the resistive characteristic impedance of test systems (generally 50 ohms in a coaxial line system). Parasitic oscillations in active devices are minimised when these devices are terminated in resistive loads."

Tuesday, July 05, 2016

Data, Media and Telecommunications Standards

Wireless Communications now have voice, data, media. It has capability of the Internet, making a portable device part of the World Wide Web. There are companies and institutions that are making this utopia of a connected world possible with the systematic approach.

The Communications Network

Now with IoT, WSN and M2M a complexity arises. Robots, Drones, Automobiles and Machines have wireless connectivity with an IP address or a Phone Number. All this is possible when we think of technologies more like Wi-Fi and WiMax merging with mobile-cellular systems. We have to abandon the Towers and go for Modular Daisy Chain of Repeaters on Street Poles and Fiber Optic Nodes. Maybe like these folks say LightRadio Antenna Module

ETSI - European Telecommunications Standards - ETSI produces globally-applicable standards for Information and Communications Technologies (ICT). Includes - Fixed, mobile, radio, converged, broadcast and internet technologies.

ITU-T - Infocommunications Standards - "ITU-T Recommendations are defining elements in information and communication technology (ICT) infrastructure. Whether we exchange voice, data or video messages, communications cannot take place without standards linking the sender and the receiver. See " Telecommunication Standardization Bureau" TSB

CDG - 3G Wireless CDMA Development - "The CDMA Development Group (CDG), founded in December 1993, is an international consortium of companies who have joined together to lead the adoption and evolution of 3G CDMA wireless systems around the world." See also CDMA Technology

3GPP - Mobile Broadband Standard - "The original scope of 3GPP was to produce Technical Specifications and Technical Reports for a 3G Mobile System based on evolved GSM core networks …" Global System for Mobile communication (GSM), GPRS and EDGE.

IEEE - Broadband Wireless Access Standards - "The IEEE 802.16 Working Group on Broadband Wireless Access is creating the IEEE 802.16 family of WirelessMAN Standards for Wireless Metropolitan Area Networks."