Wideband antenna efficiency measurements

Over the past 10 years or so, many broadband and ultra-wideband antennas have been developed for broadband high data rate mobile communications. It is realized how to make efficient and accurate measurements for such antennas could be a challenging issue. In this paper, we examine the antenna efficiency measurement techniques which have been used up to now, and identify their advantages and disadvantages for broadband measurements. It is shown that the classic Wheeler cap method, which is the best for electrically small antennas, has a lot of attractive features even for broadband antenna measurements in terms of the cost and efficiency although the newly proposed reverberation chamber method may become a good alternative method. A ¿source stirred¿ method is proposed as a new approach for the broadband antenna efficiency measurement and its major advantages are cheap, convenient, and efficient. Both the experimental and numerical results are provided. It is shown that the loss due to the imperfection of the cavity can cause a serious problem for obtaining an accurate result. How to eliminate the effects of the cavity loss and improve the measurement accuracy for this method is an issue to be resolved.