10-04-2017, 08:54 PM
1 Defining Low Power
The obvious: a solution where the RF transceivers use a minimum of energy to communicate with each other, and where periods without communication are characterized by a minimal amount of energy spent idling. To quantify this statement for 2009, a low power RF technology worth its salt has no problem operating at an average current draw under 0.1 mA and a max current draw under 50 mA. Some technologies achieve far lower figures; for example, a well-conceived ISO 18000-7 solution can easily average under 0.05 mA and max under 20 mA when using a low-leakage lithium battery.
2.1.2 Defining RF
RF stands for Radio Frequency, and it is used to mean just that. The nuance here has more to do with the application than the method of communication. Low Power RF products need:
RF silicon parts, ideally with as much integration as
possible (i.e. a single chip is better than two chips).
Power supplies, which are usually batteries. Recently, no
Shortage of attention has been paid to so-called energy
harvesting, where the idea is for the low power RF device
to absorb energy from its environment.
A microcontroller, which contains a small CPU and
memory. Again, integration is important. For 2009
and beyond, designers should expect RF silicon and the
microcontroller to be in one package.
Some kind of antenna for conveying the RF energy.
Optionally sensors, which are typically silicon parts
themselves and hence also benefit from integration.