The Blue Antenna: A Comprehensive Guide to its Features and Functionality
Active antennas, also known as phased array antennas, are innovative antenna systems that offer advanced features and functionality for various applications. In this comprehensive guide, we will explore the key aspects of active antennas, their benefits, and how they operate.
Introduction to Active Antennas
Active antennas consist of multiple stationary elements that are fed coherently and utilize variable phase or time delay control to scan a beam to specific angles in space. Unlike traditional antennas with mechanical components, active antennas have electronically-steered beams with no moving parts. The steering of the beam occurs within the integrated circuits (ICs) placed at the radiating elements in the antenna.
Advantages of Active Antennas
Active antennas offer several advantages over traditional antenna systems. One of the key advantages is their ability to steer beams in microseconds, allowing for rapid beamforming and beam tracking. Additionally, active antennas support multiple, simultaneous, independently-steerable beams, enabling enhanced flexibility and adaptability in various scenarios.
Operating Frequencies
Active antennas operate at millimeter-wave (mmWave) frequencies, such as 24 GHz, 26 GHz, 28 GHz, 37 GHz, and 39 GHz. These frequencies allow for the placement of numerous antenna elements in a compact, highly directive aperture. The highly directive beams of active antennas provide spatial diversity, allowing multiple beams to reuse the same frequency spectrum and significantly increasing system capacity.
Directivity and Array Gain
Directivity is a measure of how concentrated the antenna gain is in a given direction relative to an isotropic radiator. In active antennas, directivity follows a 10log(N) relationship, where N is the number of elements in the array. The array gain of an active antenna is equal to 10log(N) plus the embedded element gain (Ge), minus the ohmic and scan losses. This high gain enables long-range communication and improved signal quality.
Beam Squint
Active antennas experience a phenomenon called beam squint. Beam squint occurs because the phase shifters used to steer the beams only work perfectly at the center frequency. At other frequencies, they may understeer or oversteer, resulting in a deviation from the desired beam direction. It is essential to consider beam squint effects when designing and using active antennas to ensure accurate beamforming.
Conclusion
Active antennas, with their advanced beamforming capabilities and electronically-steered beams, offer significant advantages over traditional antenna systems. Their ability to steer beams rapidly, support multiple independent beams, and operate at millimeter-wave frequencies makes them ideal for various applications requiring high capacity and spatial diversity. Understanding the features and functionality of active antennas is crucial for optimizing their performance in different scenarios.
Sources:
- “Welcome To Antennas 101” by Electronic Design (https://www.electronicdesign.com/technologies/components/passives/article/21769333/electronic-design-welcome-to-antennas-101)
- “A Comprehensive Guide To Active Antennas (Or ‘Beamforming 101’)” by RF Globalnet (https://www.rfglobalnet.com/doc/a-comprehensive-guide-to-active-antennas-or-beamforming-0001)
- “The Yagi-Uda Antenna: An Illustrated Primer” by Duo Security (https://duo.com/labs/tech-notes/the-yagi-uda-antenna-an-illustrated-primer)
- “The Best Digital TV Antennas for 2024” by PCMag (https://www.pcmag.com/picks/how-to-find-the-best-digital-tv-antenna)
FAQs
The Blue Antenna: A Comprehensive Guide to its Features and Functionality
What are active antennas and how do they differ from traditional antennas?
Active antennas, also known as phased array antennas, consist of multiple stationary elements that are fed coherently and use variable phase or time delay control to scan a beam to given angles in space. Unlike traditional antennas, active antennas have electronically-steered beams with no moving parts.
What are the advantages of using active antennas?
Active antennas offer several advantages, including rapid beamforming and beam tracking capabilities, support for multiple independently-steerable beams, and operation at millimeter-wave frequencies. They provide spatial diversity, allowing for increased system capacity and enhanced flexibility in different scenarios.
How do active antennas steer beams and what is the benefit of this feature?
Active antennas steer beams by adjusting the phase or time delay of the signals at the radiating elements using integrated circuits (ICs). This allows for precise control over the direction of the beam. The ability to steer beams rapidly enables better signal reception and transmission, improved coverage, and adaptability to changing communication conditions.
What frequencies do active antennas operate at?
Active antennas operate at millimeter-wave (mmWave) frequencies, such as 24 GHz, 26 GHz, 28 GHz, 37 GHz, and 39 GHz. These frequencies enable the placement of numerous antenna elements in a compact, highly directive aperture, resulting in increased gain and system performance.
What is the relationship between directivity and the number of elements in an active antenna array?
Directivity, which measures the concentration of antenna gain in a specific direction, follows a 10*log(N) relationship, where N is the number of elements in the array. Increasing the number of elements in the array enhances directivity, allowing for longer-range communication and improved signal quality.
What is beam squint and how does it affect active antennas?
Beam squint is a phenomenon observed in active antennas where the phase shifters used to steer the beams may not perform optimally at frequencies other than the center frequency. This can result in a deviation from the desired beam direction, impacting the accuracy of beamforming. It is important to consider beam squint effects when designing and using active antennas.
Can active antennas be used for digital TV reception?
Yes, active antennas can be used for digital TV reception. Their ability to steer beams and provide spatial diversity makes them suitable for receiving signals from different directions. However, it is important to select an active antenna specifically designed for TV reception and consider factors such as frequency range, gain, and compatibility with TV tuners.
What are the key factors to consider when choosing an active antenna?
When choosing an active antenna, it is important to consider factors such as operating frequency range, gain, beamwidth, directivity, beamforming capabilities, size, and compatibility with the intended application. Additionally, factors like cost, installation requirements, and environmental conditions should also be taken into account.