The Millimeter Wave Radiation of a Dielectric Leaky-Wave Antenna Coupled with a Diffraction Grating: Broad-Face Interaction

Abstract

The millimeter wave radiation of a dielectric leaky-wave antenna (DLWA) coupled with a metallic diffraction grating with a sinusoidal height profile is experimentally investigated. The interaction between dielectric and grating is contactless and it is from the broad-face of the dielectric line. The measured field patterns are compared with the simulated HFSS patterns. Antenna parameters such as polarization, HPBW, crosspolarization and side lobe levels are measured. The effects of the geometrical parameters of the grating to the radiation are also investigated. Some results are compared with a DLWA which has another diffraction grating profile shape (rectangular). The investigated antenna can be used as a frequency scanning antenna in mm-wave radars because it has low cross and side lobe levels and narrow beam width.

The Millimeter Wave Radiation of a Dielectric Leaky-Wave Antenna Coupled with a Diffraction Grating for the Broadside Radiation: Narrow-Face Interaction

“…11 One can see that the cross-polarization level is around −30 dB at the beam maximum, 12 which is quite low level value. 11 It was polarized in longitidunal direction (z-axis) for DLWA for broad-face interaction [16]. 12 The cross polarization level of DLWA for the broad-face interaction [16] was 5 dB worse than the DLWA coupled with sinusoidal grating for the narrow-face interaction, which is investigated in this study.…”

“…11 It was polarized in longitidunal direction (z-axis) for DLWA for broad-face interaction [16]. 12 The cross polarization level of DLWA for the broad-face interaction [16] was 5 dB worse than the DLWA coupled with sinusoidal grating for the narrow-face interaction, which is investigated in this study. The measured half power beam width (HPBW) and SWR of the same antenna (DLWA coupled with DPS1) is given in Fig.…”

“…9 The side lobe level of the antenna is about −15 dB for the low frequencies and it decreases to −20 dB level for the higher frequencies. 10 9 The broadside radiation was approximately the same for the DLWA with broad-face interaction [16] because both antennas are coupled with the same sinusoidal grating (the grating period is the same for both measurement). 10 The side lobe level of DLWA for the broad-face interaction [16] was 5 dB worse than the DLWA for the narrow-face interaction, which is investigated in this study.…”

“…Surface wave is coupled to the dielectric, which is made of Teflon (" r ¼ 2:1), by a standard Ka-band horn antenna. The dimension of the dielectric line is very close to the inner dimensions of the metallic 6 A similar parametric investigation was also performed for the DLWA coupled with sinusoidal grating for the broad-face interaction in [16]. 7 The same setup and grating sets were also used for the DLWA coupled with sinusoidal grating for the broad-face interaction, which was investigated in [16].…”

“…The DLWA coupled with a metallic diffraction grating for broad-face interaction was investigated before [16] and in this type of interaction, the suppression due to the open stop-band behavior was observed. By proposing the narrow-face interaction to the same antenna, the attenuation at broadside angles is tried to reduce or completely remove to be able to use the antenna as a broadside radiator as well as the frequency scanning purposes.…”