Important

It has been found out that there is lot of delay from the time it is posted in the blog to the time when the content is delivered to my sms channel EMfactoid. Hence it has been decided to update the channel directly instead of working through this blog. Kindly click here to redirect to channel for electromagnetics trivia.

An antenna pattern can be controlled by the amplitude and phase of the current excitations.

With broadband antennas, one can track a large number of frequencies thus enabling us to track several devices with a single design.

A tiny GPS chip embedded onto a cell phone can help you to trace it. This is how mobile tracker works.

All cab services in most of the cities like radio cab, city cab,etc.. use a GPS receiver on top of each vehicle that gives its location to the master controller who manages cab assignment.

Cable TV wire is called co-axial cable. It has one inner conductor(wire) and one outer conductor(meshed sleeve) separated by a dielectric. Fields propogate through dielectric.

An antenna converts electromagnetic fields into electron oscillations(currents) or vice versa.

Dishes on roof tops are called parabolic reflectors that collect electromagnetic energy and focus on to the receiver more than ordinary dipole antenna

Doppler Radar is the arrangement that determines velocity and direction of an aircraft.

Remote controls of TV, AC and other home appliances transmit energy in infrared spectrum.

Electromagnetic pulse (EMP) is the electromagnetics version of a nuclear bomb with similar mass destruction capabilities.

IEEE 802.11(wireless LAN) and microwave oven operate the same frequency of 2.45GHz.Interference issue commented in 2mrw's post.

A mobile ad hoc network (MANET) is a sef-configuring network of mobile devices connected by wireless links.More on this in 2mrw's post.

In India, GSM is operated in 2 bands namely GSM 900(operating at 900MHz) and GSM 1800(operating at 1800MHz).

Frequency and size of antenna are inversely related. Hence cell phone antennas are compact in size due to their high frequency operation(order of MHz).

Shortwave(SW1 & SW2) stations on ur old radio set tune the receiver to receive radio waves reflected by ionosphere. This is called skywave propogation.

Uplink freq is the freq band over wich u send the signal and downlink freq is the freq band over wich u receive. Think y they can't be kept the same.

Direct To Home(DTH) television broadcasting via satellite falls under Ku band of microwave region. 11.7-12.7GHz(uplink), 14-14.5GHz(downlink)

GSM stands for Groupe special Mobile. CDMA stands for Code Division Multiple Access.

Wireless cellular signal booster is an antenna setup which can b used to enhance the signal reception of a cell phone.

For a phone to pass Federal Communications Commision(FCC) certification and be sold commercially, the SAR rating should be 1.6 to 2.0W/kg or less.

Specific Absorption Rate(SAR) is a measure of rate at which RF energy is absorbed by body. It is expressed in Watt/kg. All cell phns hv SAR rating.

Electromagnetic waves cannot exist inside the bulk of conductors. And hence u cannot stay connected on ur mobile phone when in an elevator.

Microwave oven in ur kitchen has a magnetron that generates microwaves of frequency 2.45Ghz. It falls under ISM band.

Five bars in signal strength indicator of cell phone represent the levels of reception at that point in space. It corresponds to a range of -51dB(best) to -141dB(poor).

Bluetooth version 1.2 gives a data rate of 1Mbps. Version 2.0 gives a data rate of 3Mbps and version 3.0 gives a datarate of 24Mbps.

Bluetooth operates in the frequency range 2402MHz to 2480MHz dividing the channel bandwidth into 79 bands of 1MHz each.

The collapsible antenna on ur car is a quarter wave monopole. By varying it's length, its resonant frequency is changed and hence u are able to tune to any freq(though in a limited band) with a single antenna.

Omnidirectional pattern isn't d 1 dat radiates equally in all planes. It is directional in atleast one plane and non-directional in another.

maxwell's equations

What we c 2day as Maxwell's eqns aren't proposed in that form by Maxwell. His highness didn't have the knowledge of vector calculus-for it hadn't been proposed by then.