Wideband High Gain 3G or 4G Antenna

A flat planar broadband antenna comprising:

• a substrate;
• a first substrate surface having a first planar surface, a portion of said first planar surface of said substrate being covered with a conductive material and a portion of which being uncovered;
• said conductive material forming an antenna element having two half portions, each of said half portions having a substantially equal area of said conductive material, positioned on opposite sides of a cavity therebetween formed by said uncovered portion;
• said cavity having a mouth area adjacent to a first edge of said substrate and extending between respective opposing side edges of both said half portions;
• said cavity having a cross section diminishing in size from a widest point closest to said first side edge, to a narrowest point closest to a second edge of said substrate, opposite said first edge;
• a first linear edge portion of said side edges defining a first flare angle portion of both of said side edges in a first portion of said cavity extending between said mouth and two opposing first points on said side edges;
• a second portion of said cavity defined by opposing curved portions of said side edges extending from said respective first points on said side edges, to said narrowest point of said cavity;
• said second portion of said cavity providing means to improve performance in a midrange or said antenna between a highest frequency determined by said narrowest point and lowest frequency determined by said widest point;
• a curvilineal cavity extending from said narrowest point in a direction substantially parallel to said first edge, toward a side edge of said substrate communicating between said first edge and said second edge;
• and
• a feed line positioned on a second planar surface of said substrate on an opposite side of said substrate from said first planar surface, said feed line being electrically connected to the conductive material of one of said two half portions of said antenna element.