Direct calorimetric measurement of small antenna radiation efficiency

A novel radiation efficiency measurement method for small antennas and portable wireless devices is presented. Instead of measuring radiated power, it is based on direct measurement of the power dissipation in the antenna under test. Due to the calorimetric principle which is used, the method qualifies equally well as an accurate reference method, a low-cost substitute for 3D pattern integration and a replacement of the Wheeler cap method. The main features of the calorimetric measurement setup are described. First validation measurements and application examples are presented which illustrate its accuracy and versatility.