Antenna unit for a vehicle

A bar-type antenna unit is installed at a normally non-visible point on the lower side of a vehicle body. The unit includes an antenna element, a metal plate, and noise shielding means. The metal plate functions to adjust the reactance of the antenna to obtain a desired sensitivity and protects the antenna from water, mud, or snow splashed from the vehicle's wheels to ensure good insulation between the vehicular body and the antenna element. By selecting capacitance of the metal plate, the length of the antenna can be shortened without reducing sensitivity of the unit. The shielding means shields the antenna from noise generated by for example an engine or electrical equipment which would otherwise interfere with radio broadcasts.