Passive and semipassive RFID tags do not use a radio transmitter; instead, they use modulation of the reflected power from the tag antenna. Reflection of radio waves from an object has been a subject ...

Figure 4. A snapshot, in time, of two complex numbers whose exponents, and thus their phase angles, change with time. The notion of negative frequency is often troubling to engineers who've spent so ...

It's almost impossible to think about modern IT and networking without bringing radio frequency energy (RF) into the picture. That means it's equally impossible to fully consider IT security without ...