Difference between broadside and endfire antenna array
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This page compares Broadside array vs End-fire array antenna and mentions difference between Broadside array and End-fire array antenna. It covers types of driven array antennas including collinear antenna.
There are three basic types of driven array antennas viz. collinear, broadside and end-fire. collinear antenna is made up of two or more half wave dipoles mounted end to end. These collinear antennas are used for UHF and VHF bands. The other two types of antennas Broadside and End-fire are explained below.
Broadside Array Antenna
It is a stacked collinear antenna. It is composed of half wave dipoles spaced from one another by one half wavelength. Figure-1 depicts
Broadside array antenna . Two or more elements are usually combined in this type of antenna.
Each is connected to the other antenna and also to the transmission line. The cross over transmission line ensures the correct signal phasing. This antenna produces highly directional radiation pattern. The pattern will be broadside or perpendicular to the plane of the array.
Like collinear antenna type, broadside antenna is bi-directional in radiation. The radiation pattern has a very narrow beam width and also very high gain.
End-Fire Array
Figure-2 (a) depicts End-Fire array antenna type. It uses two half wave dipoles spaced at the distance of one half wavelength. Both the elements are driven by transmission line. The antenna has bi-directional radiation pattern but provide narrower beam-width and gain.
The other method of constructing end-fire array is shown in figure-2(b). As shown there are five driven elements spaced at fraction of wavelength D. By choosing desired number of elements and spacing, high directional antenna can be constructed. This antenna is uni-directional while the one shown in fig-2a is bi-directional. The spacing causes lobe in one direction to be canceled such that it will add to the other lobe. This creates high gain as well as high directivity.