【文章內(nèi)容簡介】 diation patterns at , , and GHz for the two principal cuts (phi = 0176。and phi = 90176。). For all the three frequencies, the radiation patterns at phi = 0 176。cut have the strongest radiation at 0176。 and 180176。and the weakest radiation at 90176。and 270176。. For all the three frequencies, the radiation patterns at phi = 90176。 cut have nulls at 0176。, 90176。, 180176。, and 270176。. This indicates that the LTCC planar UWB antenna has very similar radiation patterns over the ultrawide bandwidth. Due to the finite ground plane used in the measurements the measured radiation patterns have shallow nulls at both 90176。and 270176。. The measured results demonstrate that the LTCC planar UWB antenna has quasi omnidirectional radiation patterns inthe azimuthal plane. shows the measured antenna gain values at phi=theta=0176。direction. The measured gain is– dBi at GHz, dBi at GHz, and dBi at GHz. shows the measured group delay versus frequency. As shown, the group delay difference is within ns throughout the whole band from 2 to 12 GHz. The small group delay differences ensure the good performance of the antenna against waveform distortion during the transmission.Fig. 3. Measured radiation patterns at GHz: (a) phi = 0 and (b) phi =90 .Fig. 4. Measured radiation patterns at GHz: (a) phi = 0 and (b)phi = 90 . of the Antenna Ground Plane Planar monopole antenna has been proved to yield wideimpedance bandwidth[12]. The removal of the antenna ground plane modifies the planar slot antenna into a planar monopole antenna. The effect of the removal of the antenna ground plane is worth of investigating. The measured return loss plotted versus frequency from to GHz is shown in (b). It also indicates very wide impedance bandwidth over the UWB band. The return loss can be further improved by adjusting the dimension of the radiating element. The measured radiation patterns at , , and GHz without the antenna ground plane are also plotted in –5 for both the phi=0176。and phi=90176。cuts. The shapes of radiation patterns for both cases with and without the antenna ground plane are also very similar. The LTCC planar UWB antenna that shares the same ground plane with the other radio circuitry has been studied for the singlepackage solution of UWB radio. It has been demonstrated that the antenna has achieved an ultrawide bandwidth of GHz from 3 to GHz. It has been also demonstrated that the antenna has relatively omnidirectional radiations over the ultrawide bandwidth in the azimuthal plane. It wasfound that the normalized radiated power spectrum density of the LTCC planar UWB antenna was within the FCCs regulation on emission limit of indoor UWB systems except from to 3 GHz[13]. The measured antenna gain was– dBi at GHz, dBi at GHz,and dBi at GHz. The measured group delay fluctuated within ns from 2 to 12 GHz. Further investigations and developments are being carried out in our laboratory on the effect between the LTCC planar UWB antenna and the other UWB radio circuitry.REFERENCES[1] and ,“The COTA UWB magnetic slot antenna,” in APS .,–107.[2] and ,“The diamond dipole:A Gaussian impulse antenna,”in APS .,–103.[3] and ,“A broadband eccentric annular slot antenna,”in APS .,–97.[4],“Electrically Small Planar UWB Antenna Apparatus and Related System,” 6 590 545,2003.[5][Online].Available:[6][Online].Available:[7][Online].Available:[8],and ,“RF and microwave ponent development in LTCC,”Bob Hunt,CMAC Micro Technologies.[9][Online].Available:[10],“Integration of microstrip patch antenna on ceramic ball grid array package,”.,–208,2002.[11][Online].Available:[12],and ,“Wideband planar monopole antenna,”IEEE Propag.,–295,.[13]“Notice of Inquiry(NOI)Revision of Part 15 of the Commission’s Rules Regarding UltraWideband Transmission Systems 98–208,”Federal Communications Commission,ET Docket 98–153,1998.附件4：外文原文二 BroadBand and Circularly Polarized SpaceFillingBased Slot AntennasHani ,Member,IEEE,and Tarek Abstract—Based on the use of spacefilling curves,broadband and circularly polarized microstripfed slot antennas are proposed. Broadband performance is achieved through merging different downscaled versions of a position of“islandlike”spacefilling slot antennas without increasing the overall antenna size. This technique provides different resonant slot lengths corresponding to a wide range of frequencies. By merging three downscaled versions of a posite seconditeration Moore slot antenna, a broadband slot antenna is developed. The proposed antenna has a bandwidth (VSWR 2)of %around GHz, which is higher by a factor of pared to the square ring slot antenna, and by a factor of 3 pared to the nested square rings slot antenna. The developed slot antenna has a maximum gain of 5 dB and a total area of 3 * 3 cm2. Furthermore, by introducing asymmetry in the proposed slot antenna,which is implemented by replacing all parallel slots on one side of the structure and all inner slots by a ground plane, circular polarization is achieved. The circularly polarized slot antenna version has a 3dB axial ratio bandwidth of 22%with VSWR 2. The design and simulation of the proposed slot antennas have been performed using a momentmethodbased fullwave electromagnetic simulator. Measurements of fabricated antennas are in good agreement with simulation results.Index Terms—Broadband antenna,circularly polarized antenna,fractal antenna,slot antenna,spacefilling curves. Broadband antenna designs represent challenging issues for highfrequency highspeed datarate wireless munication systems. Printed antennas offer ease of integration with monolithic microwave integrated circuits,low cost, and lowprofile efficient solutions. Among different printed antenna topologies, the slot antenna is considered the most appropriate candidate for wideband applications。 impedance bandwidths in the range of 30%–63