wireless charging technology-EPC,PMA,A4WP

Due to emergence, availability and consumption of wireless electronic devices; various standards and technologies have been developed for wireless charging need. They are Qi, EPC, PMA, WPC etc.

wireless charging standards

Following table summarizes all these wireless charging technologies. The table mentions major difference between these standards comparing various factors such as frequency of operation, coupling factor, cost, metal, form factor, efficiency etc.

Specifications EPC PMA A4WP
Frequency of operation 100 to 205 KHz 250 to 400 KHz 6.78MHz
coupling range 0.4 to 0.7 0.6 yo 0.8 0.1 to 0.5
Quality factor 6 to 10 6 to 10 40 to 100
cost Medium High Small
Thickness 0.3 to 1.0 mm 0.8 to 1.3 mm 0.2 to 0.5 mm
Heating of metal Medium Medium Low
Form factor flexibility Medium Low Medium to High
Efficiency Higher than 70% Higher than 70% Approx. 50%

Qi Wireless charging basics and how it works

For basics of Qi wireless charging and mentions how does Qi wireless charging work. Refer Qi Wireless charging➤


Qi Wireless Charging
wireless system overview
What is RF
What is Wireless
Zigbee based Security system

RF and Wireless Terminologies