That is 16 turn helical antenna made from nylon. (+18dBm). Usually manufacturing the helical antenna take some time. Now that is easy - needs to print it and add reflection surface from PCB with one sided copper surface. Copper wire (preferable 0.2 mm) added, and antenna ready to use.
Can be used as extension for WiFi. (I used it as Bluetooth antenna - allows 4 km communication, with WiFi can be up to 25-30km direct).
Radiation patter 12 degree from pointed direction. Good to use in noisy environment because helical antennas are polarized.
"Test includes standard Bluetooth transmitter/receiver 1mWt (0 dBm) and second device (LNA with cascade 3x12 =36 dB, transmitter 6dBm 4mWt). "Standard 0dBm" transmitting signal needs to be picked up from 10km. At the same time "standard -- receive" will be picked up from 4 km. Two persons with cell-phones call each other and confirm communication session by looking on a blinking LED. LED blinks only when proper packet was received and processed (including restoration of noisy packets from different BT and WiFi transmitters in urban environment). Noise also has to be suppressed from cell-pones stationary transmitters (on top of SFU hill and QE park at Vancouver).
Design from the beginning was successful but was not able to be proved by range tests, each time max range was 1km. Impedance of wire was measured, adjustments was done, and at rain day pooring rain brought conformation that everything is working, then on march day at clear sky over Vancouver comes conformation of range tests, 2.5km-OK; 4.km-OK;
Even to do test on 10km was not necessary. Signal received by standard BT from 6dBm was picked up on 4km, and according "rainy test" that mean antennas-amplifiers system must to pickup signal over 20km which is more than it was expected."
see more: http://www.adobri.com/ProjectVe.aspx