I = 0 mm, 1 = 7.5 mm, and 1 = 12.5 mm). For a patch without slots, the current flows primarily in a straight line from one side to the other. From Figures 5(b) and 5k), it is clear that the presence of the slots forces the current to travel through a much longer path. This explains the decrease in the resonance frequency of the meander patch antenna. Also, it is evident from the figures that the patch length of the current flow increases with increasing slot length. This confirms the experimental observation of the reduction in the resonant frequency with an increase of the slot length. From the figures it is also clear that an increase in the slot width does not significantly increase the path length to the flow of the current. This validates the earlier results that the change in the slot width does not bring any significant change in the resonance frequency.
CONCLUSIONThe design of a compact meander patch antenna has been presented. The length of the antenna is 70% less than that of a half-wave microstrip patch antenna. It is anticipated that this design will find application in hand-held communication systems where light weight and compactness are the most desirable criteria. Mbit/ s and h = 1.53 p m is analyzed, and is shown to offer a sensiticQ benefit of 9.2 dB oc,er an equiralent OOK system. Fiber chromatic dispersion is taken into account and is used to estimate the receiced pulse shape. Pulse dispersion can potentially induce a significant performance penalty in PPM system because of the temporal nature of the PPM format. Thr results show that for a transmitted pulse of duration 80 ps, the receiced pulses have full widths at half maximum (FWHM) of 160 and 320ps forfiber lengths equaling 120 and 240 km, respectiL,ely. The system sensitivity degradation due to dispersion is explicitly eilaluated. It is shown that a sensitivivpenal(y of up to 5 dB can be incurred over the transmission spans considered. 0
ABSTRACT
An optically preamplified pulse position modulation (PPM) system operating at 622