Electrically-small, low-profile, ultra-wideband antenna

A transmitter comprising:

• a feed network comprising a matching network circuit coupled to receive a signal through a port and to form a matched signal output through a feed element;
• and
• an antenna comprising
• a ground plane substrate;
• a feed conductor comprising a first end and a second end, wherein the first end is configured for electrical coupling to the matching network circuit through the feed element to receive the matched signal, wherein the feed element extends from the ground plane substrate;
• a top hat conductor comprising a generally planar sheet mounted to the second end of the feed conductor in a first plane approximately parallel to a second plane defined by the ground plane substrate;
• a shorting arm comprising a third end and a fourth end, wherein the third end is mounted to the top hat conductor, and the fourth end is mounted to the ground plane substrate;
• and
• a ring slot formed in the ground plane substrate around the feed element and configured to act as a series capacitance;
• wherein the matching network circuit is configured to impedance match the antenna.