CHAPTER TWO
LITERATURE REVIEW
2.1 BIQUAD
A biquad is a common name applied to antennas usually made from printed circuit board (PCB) cut to a square shape. They use microwave radio frequencies for over-the-air transmissions, and are types of antennas used for 802.11b, ‘b+’, and ‘g’ wireless Ethernet networks (Mike, 2004). They are not the same as the Tin (Cantenna) design and unlike Yagi-style antennas, they do not use a collector rod assembly. The biquad falls to the range of “wideband antennas” and can be used for high-gain, high-directional use for War Driving, Nanny Cam driving, security assessments and any other type application of the 2.4 GHz ISM RF spectrum. They are primarily designed for 802.11b and 802.11g wireless Ethernet networks. They work well in extending the range of your existing WLAN (Wireless LAN), or in sharing network resources or Internet connectivity to other locations (Marshall, 2002).
Furthermore, The Biquad antenna offers good directivity and gain for Point-to-Point communications. It consists of a two squares of the same size of 1⁄4 wavelength as a radiating element and of a metallic plate or grid as reflector. This antenna has a beamwidth of about 70 degrees and a gain in the order of 10-12 dBi. It can be used as stand-alone antenna or as feeder for a Parabolic Dish. The polarization is such that looking at the antenna from the front, if the squares are placed side by side the polarization is vertical.Many people use it to share resources on their network or high-speed Internet connection with others (GET reference). Cantenna gives a better and more focused signal for wireless network. Another reason to use a directional antenna such as this one is security. Using a focused antenna prevents signal from being widely dispersed so that hackers have a harder time finding and getting a useable signal.
Paper clip was one of the first ultimate“homebrew” designs to be popular. This model is commonly called the...