What is the Role of the Arms of a Linear Broadcast Antenna?

The voltage source maintains oscillatory voltage V0 e iωt between its terminals, which are also the ends of the two linear conductors of radius a and total length h. The voltage source can deliver whatever current I0 is required to maintain electric field E0 in the gap of length d, where V0 = E0d. The voltage source, including its terminals, is a small electric dipole oscillator with moment p0 = Q0d = V0C0d, where C0 is the capacitance of the terminals. 1 In the absence of the arms of the antenna, this oscillating dipole emits time-average power P0 into the far zone, where (in Gaussian units; see, for example, sec. 67 of [2])