This article studies the working principle of a rectenna which is a combination of an antenna and a rectifying circuit. In the simulation, the working properties of the rectifying circuit can be represented by two characteristic curves which are extracted from it, and these two curves are independent of the device which is connected with it. The measured results demonstrate that the data calculated by the two curves can be used to accurately describe the conversion efficiency of the rectifying circuit. Furthermore, the two curves are used to represent the rectifying circuit in the calculation of the rectenna conversion efficiency. In addition, with the characteristic impedance of the antenna, the calculation equation is given. In the experiment of the rectenna, the measured conversion efficiency of the rectenna is in agreement with the data calculated by the proposed equation, which proves the accuracy of this method.

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The transparent antenna can potentially be combined with solar cells to create multifunctional compact systems. In this article, an optically transparent broadside antenna is presented. Based on a meshed patch antenna which has three horizontal lines and three vertical lines, the antenna has four more lines to increase the bandwidth. The antenna is fed by a top fed for simple structure, and the area of the feed line is much smaller than the one of a side fed. The transparency is much better because of the low ratio of metal area, which can be further reduced without destroying the performance of the antenna. The transparent broadside antenna is studied at 2.5 GHz. On the upper surface of the antenna, the ratio of metal area is 3.2%, and the measured −10 dB impedance bandwidth is close to 60 MHz. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:146–149, 2015