时域差分法分析介质谐振器带通滤波器.pdfVIP

Figure 4 Measured antenna gain of the configuration in the broadside direction the DRA, introducing the vertical current in addition to the ANALYSIS OF A NEW BANDPASS horizontal current on the broadface of the DRA. In contrast, FILTER WITH TWO RING DRs USING there was only a horizontal slot current in the previous configuration. The vertical current in the present configura- THE FDTD METHOD tion helps excite higher order modes of the antenna that 1 1 1 Ho-Tark Hwang, Sang-Ho Lim, Soon-Soo Oh, contribute entirely to the cross-polarized fields. With refer- Jichai Jeong,1 and Young-Sik Kim1 ence to the figure, very good front-to-back radiation ratios of 1 Radio Communication Technology Laboratory more than 20 dB are obtained for both the E - and H -planes. Department of Radio Sciences and Engineering They are at least 5 dB higher than the ratios in the previous Korea University Seoul 136-701, Korea design 7 . The measured antenna gain of the new configuration in the broadside direction Ž 0. is illustrated in Figure 4. At Receied 6 December 2000 resonance, the antenna gain is about 5 dBi, which is very Ž . ABSTRACT: In this paper, a new bandpass filter inserting a microstrip- close to that of the previous configuration 5