Active antenna systems (AAS) in 5G are complex arrays with individual RF components, enabling dynamic beamforming, massive MIMO, and high performance, making them suitable for high-capacity scenarios but costly. In contrast, passive antenna systems are simpler and lack individual RF components, offering fixed radiation patterns and lower costs, making them suitable for straightforward coverage needs in less demanding areas or legacy networks. The choice depends on the deployment’s specific requirements.
What is the difference between active and passive antenna system in 5G?
In 5G and wireless communication in general, there are active and passive antenna systems, each serving different purposes and with distinct characteristics.
Here’s a detailed explanation of the differences between active and passive antenna systems in 5G:
Active Antenna System (AAS):
Components:
- Active antenna systems, also known as Active Antenna Arrays (AAAs), consist of multiple antenna elements with individual radio frequency (RF) components.
- Each antenna element has its transmitter and receiver, along with digital signal processing (DSP) capabilities.
Beamforming and MIMO:
- AAS enables advanced beamforming and Multiple Input Multiple Output (MIMO) techniques.
- Beamforming in AAS allows dynamic steering of beams in real-time, focusing signal energy in specific directions for improved coverage and capacity.
- MIMO with AAS can create multiple spatial streams, enhancing data rates and capacity.
Massive MIMO:
- Active antenna systems often employ Massive MIMO technology, which uses a large number of antenna elements (hundreds or more) to serve multiple users simultaneously.
- Massive MIMO can significantly increase network capacity and spectral efficiency.
Signal Processing:
- AAS relies on extensive signal processing to manage and optimize the signals from each antenna element.
- Digital beamforming algorithms are used to adjust phase and amplitude to create directed beams.
Complexity and Cost:
- Active antenna systems are more complex and expensive due to the need for multiple RF components, signal processing, and advanced algorithms.
- They are typically used in high-capacity and high-performance scenarios.
Passive Antenna System:
Components:
- Passive antenna systems consist of a set of antenna elements but lack individual RF components and signal processing capabilities.
- These systems are essentially arrays of passive radiating elements.
Fixed Radiation Patterns:
- Passive antennas have fixed radiation patterns and cannot dynamically steer beams like active systems.
- They have a specific coverage pattern, often with a wide beamwidth, which limits their adaptability.
Simplicity and Cost:
- Passive antenna systems are simpler and more cost-effective than active systems since they lack the complex RF components and DSP capabilities.
- They are suitable for less demanding scenarios where advanced beamforming and massive MIMO are not required.
Applications:
- Passive antenna systems are often used in scenarios with straightforward coverage requirements, such as rural areas or less densely populated regions.
- They are also commonly used in legacy 2G, 3G, and 4G networks.
In summary, the main difference between active and passive antenna systems in 5G lies in their capabilities and complexity. Active antenna systems (AAS) are advanced, expensive, and capable of dynamic beamforming and massive MIMO, making them suitable for high-capacity and high-performance networks. Passive antenna systems, on the other hand, are simpler, cost-effective, and have fixed radiation patterns, making them suitable for scenarios with less demanding coverage and capacity requirements. The choice between the two depends on the specific needs of the 5G deployment.