Abstract: A mobile transmitting and receiving communications antenna assembly for use on a vehicle, includes a primary radiating element a secondary radiating element having first and second radiating elements, normal to a longitudinal axis of the primary radiating element to form a ground plane therefor. Impedance matching means, comprising a tuned circuit tuned to the nominal resonant frequency of the capacitively loaded antenna and electrically connected to the second electrically conductive coupling member in the immediate proximity thereof to resonate in conjunction with said primary radiating element. The impedance matching means displaying an impedance which varies between a first impedance at the connection to the second electrically conductive coupling member which is substantially equal to the impedance at the base end of the primary radiating element and a second impedance at least several orders of magnitude less than the first impedance.