rectenna composed of the CMSA shown in figure 1. [2,3] Microstrip antennas have several attractive properties, namely they are low in profile, light in weight, compact and conformable in structure, and easy to adapt to the photo-etching technique in fabrication. The eigenvalues of CMSA arc given by the following equation: The radiation characteristics of the CMSA are depicted in figure 2. We can sec that a higher resonance-harmonic frequency is not an integer multiple of the dominant resonance frequency (fy =2.45 GHz). Thus, the CMSA can reduce the re-radiation of higher harmonic microwaves. Furthermore, if we cut slits on CMSA as shown in figure 3, where directions of the slits coincide with the ones of the current flow for the dominant mode (TMuq), we can suppress TMqjq and TMj2o modes. The resonant frequencies of the TMqjo and TM^o modes are 2.08 f$ and 2.9 fg respectively. Then, we can reduce the re-radiation of the 2 and 3 fq more effectively. Figure 4 shows radiation patterns of the CMSA at the frequency of 2.45 GHz. They were calculated assuming that the CMSA is on an infinite ground plane. We can see from figure 4 that the CMSA has a broad beam on both of the E-plane and H-plane. The CMSA has several advantages for the rectenna as shown above. However, if we compose the rectenna from the CMSA, it intercepts the sunshine. This is not preferred for the environment, human activities and industry. Rectenna composed of reflector and CMSA In this section we describe the rectenna which receives microwaves from the SPS and passes sunshine. The rectenna is composed of a reflector with wires and a primary radiator (receiving area) with the CMSAs. Because the wires are used for the reflector, the rectenna is almost transparent. Thus, the SPS system does not affect the environment, industry, and human society. Moreover, since the primary radiator is
RkJQdWJsaXNoZXIy MTU5NjU0Mg==