time-domain transmission from one to another is measured in door with the Advantest R3770 Network Analyzer, which has the time-domain function. The relative orientations of them are set as the following five kinds: (a) face to face; (b) face to back; (c) back to back; (d) in the same plane, and (e) perpendicular, as drawn in Figure 12. The input signal of the radiating antenna is a modulated gauss pulse with the width of 0.3 ns and the normalized amplitude of 1, as shown in Figure 13. The measured and simulated received signals are listed in Figure 12. The measured waveforms are consistent with the simulated results basically, validating the calculations in part 3. The durations of the waveforms may come from the reflection by the cable connectors or the walls near the antenna in the measurement. Moreover, the main parts of the received signals in the five orientations maintain consistency to the input pulse of the radiating antenna except in case (a), indicating the nice pulse fidelity of the proposed antenna. CONCLUSIONSThe traditional antenna parameters such as the return loss and the antenna gain are not good descriptors for the antenna used in the pulse radio UWB systems. The group delay in S 11 cannot point out how good are the time-domain characteristics directly. The correlation coefficient can depict the fidelity of the radiated pulse but ignore the energy. For describing the comprehensive time-domain performance of the UWB antenna used in the correlation detection UWB systems, the CEG is a good descriptor. By using the MCEG as the criterion, a planar goblet-like UWB antenna is proposed and optimized successfully. The simulated and measured results show that the new designed antenna has good time-domain waveform fidelity while keeping good match performance and radiating ability. ACKNOWLEDGMENTSAuthors would like to express their sincere thanks to Nation Nature Funding U0635004 for its financial support. ABSTRACT: This work proposes a highly reliable, hybrid star-ring-bus architecture (SRBA) for broadband wavelength-division multiplexed (WDM) regional access networks. A delta-star network on the top level acts as high-capacity trunk infrastructure, whose weakness in reliability is overcome by the self-healing function of the concatenated ring network on the lower level. The ring network is divided into several delta regions, where the traffic load inside each region is unified to minimize the backup resources required in the network. On the bottom level, considerable bus subnets are constructed to serve end users. The idea of k-bands is introduced to efficiently manage wavelength carriers used in the network. Moreover, by means of the automatic protection switching (APS) systems in all the optical network units (ONUs), a minimum-hop rerouting protection scheme against fiber failure(s) is designed. Specifically, we carry out an experimental network to demonstrate the feasibility and survivability of the proposed architecture.

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