Influence of Passive OTA Measurement on PCB Antenna

Abstract

Mobile internet has grown up to be the most popular industry during the past decade [1,2], more and more kinds of smart mobile devices appeared in the markets, as greatly convenienced people’s life. Meanwhile, more and more kinds of smart antennas were designed to meet the various requirements [3], especially for the wearable devices [4]. Most of these devices worked at the 2.4GHz ISM band (Wi-Fi, Bluetooth, etc), and many researchers were concentrating on improving the performance of the antennas, such as MIMO (Multiple Input and Multiple Output) antennas, PCB antennas, etc. On the other hand, the OTA (Over-the-Air) measurement was an important method to verify the performance of the antenna [5, 6]. There’re two means of OTA measurement, named passive test and active test. Passive test [5] can tell us the parameters such as Pattern, Gain, Efficiency, etc, while active test involves TRP (Total Radiated Power) and TIS (Total Isotropic Sensitivity) [6], they can both check the performance of the design. But for those wireless devices worked at ISM band, active test need more costs, it’s always not easy to verify the TRP or TIS, the passive test was a better choice. In this paper, a passive OTA test was carried out on a meander PCB antenna in several typical configuration, the test results were analyzed.