UWB microstrip filter design using a time-domain technique

Abstract

propagates, and the OMT for the data channel receives both the horizontal and vertical polarizations. We model the coupler (Fig. 3) by using the FDTD for only one pair of these rectangular guides. The size of the holes is optimized, based on several FDTD runs, in order to achieve proper coupling. NUMERICAL AND MEASUREMENT RESULTSThe simulation results obtained by using the Body of Revolution FDTD code for the corrugated horn are shown in Figures 6 and 7.The symmetric pattern with 10-dB taper in 20 degree is achieved for the E-, H-and 45-deg planes.The phase distribution inside the mode coupler is shown for both the TE 11 and TE 21 modes in Figure 8. The coupling through the holes in the rectangular guides is evident from the figure. It is also evident that two modes generate different radiation patterns. In the TE 21 mode (the right side), the opposite phase led to the field cancellation in the boresight and hence a sharp null.The measurement results for both sum and difference patterns of the monopulse feed are shown in Figure 9. The 40-dB difference in the sum and difference channels in the boresight assures the high sensitivity of the target tracking.

Time domain design for ultra wideband filters

“…For example, in contrast to FCC's single emission mask level over the entire UWB band, in Europe and Japan, the radiation mask for indoor devices has two sub‐bands: a low band ranging from 3.1 to 4.8 GHz and a high band from 6 to 8.5 GHz in Europe; from 3.4 to 4.8 GHz and from 7.25 to 10.25 GHz in Japan. However, some recent works give both design equations and guidelines providing a fast and easy implementation [9–11]. In Ref 9,.…”

“…Whatever the presented technique, the basic principle is always to specify the filter dimensions to satisfy the researched frequency gain response. In Ref 11,. a time domain technique is presented for designing a UWB BPF for the band 2–6 GHz, built on a nonuniform transmission line (NTL).…”