Array Antenna, what is it ?
What is Array Antenna ? The answer lies within the name itself. It is a type of antenna that is made up of an "array of antenna" (not a single antenna). Each single antenna within the array antenna is called 'Antenna Element'. There are various examples of array antenna. Only a few of the examples are shown below.

Why Array Antenna ?
The main motivation of using Array antenna is that it can focus the radiation to a specific direction. Focusing the radiation to a specific beam is called 'Beamforming'.
What is Phased Array Antenna ?
When each of the antenna elements within the array has some way to change the phase of the signal, the array antenna is called 'Phased Array Antenna'. (The phase shift can be done for a specific fixed value by a fixed electric circuit or can be done for arbitray value by variable phase shift or digital signal processing).
Why Phased Array Antenna ?
With Phased Array Antenna, you can change the shape of the radiation pattern (beam) in more diverse way or change the direction of the beam electronically (i.e, without moving the antenna array physically).
What is the relation between Array Antenna and BeamForming ?
The term 'Array Antenna' is focused on the physical structure of the antenna and the term 'BeamForming' is focused on the mechanism by which the radiation pattern from a antenna get focused on a specific direction. Since BeamForming is implemented by Array Antenna in most application, you would see Array antenna and beamforming goes hand in hand in most of technical papers.
I strongly recommend you to study on BeamForming as well when you study on Array Antenna.
Reference :
[1] Algorithms to Antennas: A Blog for 5G, Radar, and EW RF Engineers (Microwave&RF)
[3] Algorithms to Antenna: Achieve System Performance Goals with Less Hardware (Microwave&RF)
[4] Algorithms to Antenna: Designing an Antenna Array (Microwave&RF)
[5] First 5G mmWave Antenna Module for Smartphones
[6] Qualcom QTM052
[7] Qualcomm's First 5G mmWave Chipset: SDX50M and QTM052
[8] Antenna Integrated Radio Unit Description-Ericsson AIR 6488
[9] Advanced Antenna System for 5G (5G America)
YouTube
- Hackaday Supercon - HunterScott : Why Phased Arrays are Cool and How to Build One
- Analog Beamforming—What is it and How Does it Impact Phased-Array Radar and 5G?
- 5G Phased Array Antennas - Simulation Essentials
- Simulation-Enabled 5G Antenna Design
- The art and challenges in designing Printed Antenna Arrays
- Microstrip Antenna Arrays - SixtySec
- Antenna Arrays
- Antenna Arrays Part 2
- Design Example: In-Situ Analysis of Patch-Array Antenna
- ESMA 256 Element Antenna Demonstration
- SatixFy's Antenna Micro Test Range (AMTR) demonstration
- 5G Beam-Steering with EM/Circuit Excitation and Co-simulation in PathWave ADS
- Simulation of Phased Array Radar Systems
- Slot Antenna | Types of Antenna | Antenna and Wave Propagation | AWP |Vaishali Kikan | Lecture 25 |
- RF Elements Webinar – Learn About Beam Efficiency
- RF Elements: AS-5-20 Array Sector Antenna Introduction