This 2.4 GHz dual patch antenna set by WA5VJB is designed as a direction finding antenna. They operate at the same frequency as 2.4 GHz wifi. One antenna has a center peak, while the other one has a center null. This powerful combination allows for a narrower beamwidth for direction finding. These antennas are roughly 2.5" x 6". The ground plane is the back side of the PCB. You can mount an SMA to the PCB or just solder coax directly to the antenna. See my other listings for 2.4 GHz antennas sold individually, including with coax. The gain  for this 2400 MHz patch antenna is approximately 6 dB.   The price includes free shipping for U.S. customers. International shipping through the eBay global shipping program is available but at extra cost.