This work focuses on microstrip patch antennas for the 77 GHz millimeter band. For some combinations of the parameters microstrip width, free wavelength and substrate permittivity, impedance matching via inset fed is found to be non applicable. The current distribution of the desired TM10 mode is partially disturbed. Gap coupled parasitic microstrips are analyzed in order to match the feeding impedance to the feeding microstrip while improving the bandwidth in these particular cases.
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