Howtosignalprocessing
- What is the advantage of using antenna arrays instead of using a single antenna of same type?
- Is a technique by which an array of antennas can be steered to transmit radio signals in a specific direction?
- What are multi element antenna arrays?
- How is antenna gain array calculated?
What is the advantage of using antenna arrays instead of using a single antenna of same type?
An antenna array can achieve higher gain (directivity), that is a narrower beam of radio waves, than could be achieved by a single element. In general, the larger the number of individual antenna elements used, the higher the gain and the narrower the beam.
Is a technique by which an array of antennas can be steered to transmit radio signals in a specific direction?
Beamforming is the most commonly used method by a new generation of smart antennas. In this method, an array of antennas is used to “steer” or transmit radio signals in a specific direction, rather than simply broadcasting energy/signals in all directions inside the sector.
What are multi element antenna arrays?
Antenna arrays are composed of group of similar antenna elements. The “grouping” of antennas increase the gain compared to a single element antenna. At the same the radiated power is more concentrated to one certain direction. This is due to reduced beam-width compared to the single element antenna.
How is antenna gain array calculated?
Gtot=12π∫2π0|1+ejkdcosθ|2dθ=2(1+J0(2dk)), where J0 is the Bessel function of the first kind. Passive antenna arrays should yield Gtot≤1 , where equality holds for purely lossless systems. However, the expected result is not obtained; for example, using a quarter wavelength antenna separation, the result is Gtot=1.47 .
