The Advantages of Phased Array Antenna Designs in Communication Systems

Key Takeaways

• A phased array antenna is a multiple antenna system in which desired field patterns can be achieved through beam steering.

• The fundamental principle of a phased array antenna is the phase-dependent superposition of two or more radiated signals using constructive interference to enhance transmission signals.

• With the different arrangements of antenna elements, desired radiation or reception patterns can be achieved in a phased array antenna, which showcases its spatial filtering characteristics.

The transmitter and receiver systems in wireless communication systems incorporate phased array antennas

A wireless communication system depends on antennas for external data transfer. Transmitter and receiver systems incorporate antennas for the transmission and reception of data or communication signals. Among the different types of antennas, phased array antennas are widely adopted due to advantages such as high gain, reliability, high signal-to-noise ratio, and beam steering capabilities.

A phased array antenna is a collection of several individual antenna elements that are connected together to act as a single unit. Phased array antenna designs are used in various applications such as radar-based sensor technology, satellite communication systems, 5G technology systems, and military aircraft. They possess desirable features such as spatial filtering, gain boosting, and sensitivity improvement. 

Phased Array Antennas

Phased array antenna technology overcomes restricted speed and reliability concerns by employing multiple antennas to work as a group. A phased array antenna is a multiple antenna system in which the desired field patterns can be achieved through beam steering. The number of antennas can range from a few to thousands.

The radiation patterns of phased array antennas can be reinforced in the desired direction and can be suppressed in the undesired direction. The direction of radiation from phased array antennas is electronically controlled and this prevents the need for any mechanical movement. The phase variation between the radiated signals from each antenna in the array is achieved through the electronic steering feature in phased array antennas. 

The Fundamental Principle of Phased Array Antennas

The fundamental principle of a phased array antenna is the phase-dependent superposition of two or more radiated signals using constructive interference to enhance transmission signals. The superposition of signals from individual antennas results in additive amplitude if the signals are in-phase. The counter-phased signals from individual antenna elements cancel each other. It can be concluded that the individual antenna elements in phased array antennas function as radiators. If the signals emitted from two radiators are in the same phase, the signal is amplified in the main direction and attenuated in secondary directions.

Signal radiators or individual antennas in the phased array antenna emit signals of different phase shifts. Distinct signals from each antenna in the array sum up to form a collective signal. The phase shift added to signals received or transmitted by each antenna in the array allows the collective signal to behave as if it is sent from a single antenna.  

The Advantages of Employing Phased Array Antenna Designs in Transmitter and Receiver Systems

Phased array antennas are employed in both transmitter and receiver systems of communication applications. The application of phased array antennas in transmitter and receiver systems helps modify radiation or reception patterns electronically. Employing phased array antenna designs in communication transmitter and receiver systems provides the following advantages:

Spatial filtering: Phased array antennas are incorporated in communication systems due to their spatial filtering feature. Phased array antennas suppress signals moving towards undesired directions. The direction and shape of the radiation pattern of phased array antennas are determined by the product of the single antenna element pattern and array factor. The array factor is the weighted sum of the signals received or transmitted by the antenna elements in an array. The number of antenna elements, spacing between the elements, and geometrical orientation of the elements are some of the factors influencing the array factor. With the different arrangements of antenna elements, desired radiation or reception patterns can be achieved in a phased array antenna, which showcases its spatial filtering characteristics.

Gain boosting: The maximum power transmitted by the transmitting antenna in the direction of the receiver determines the maximum distance of reliable communication from the given system. If the transmitter antennas are phased array antennas, transmit power level can be boosted in the desired direction, keeping the total power transmitted the same. For a given receiver sensitivity, the usage of phased array antennas as transmitters improves the maximum range of communication.

Sensitivity improvement: Receiver sensitivity can be determined from the signal-to-noise ratio of the receiver’s front-end output. The minimum detectable signal at the antenna element can be determined from the lowest signal-to-noise ratio possible. The output signal-to-noise ratio of the phased array antenna is better than single path receiver antennas, thereby improving the sensitivity of the receiver. As the number of individual antenna elements in the array increases, the signal-to-noise ratio also increases.

From the aforementioned advantages, it is clear that phased array antenna design is suitable for transmitter and receiver systems in wireless communication systems. The design of radiators or individual antenna elements and their arrangement in arrays are significant in bringing out the best performance of phased array antennas.

Cadence offers software tools for designing phased-array antennas for multiple-in-multiple-out (MIMO) and beam steering applications. Subscribe to our newsletter for the latest updates. If you’re looking to learn more about how Cadence has the solution for you, talk to our team of experts.