The Conical Antenna as a Sensor or Probe

The electrically small wide-angled spherically capped conical monopole is shown to have frequency-related properties closely resembling those of the electrically thin cylindrical dipole. It is frequency-independent when used to measure the time derivative of the electric field when it is connected to a matched load and kL = kl( 1 + ¿0) ¿ 1. Here/is the radius of the conical surface and ¿0 is half of the angle subtended by the cone. Graphs are shown for ¿0 470° = 0.82 rad for which the characteristic impedance is 50 ¿.