ALLPCB
Overview
Radio frequency (RF) uses electromagnetic waves to transmit information between devices. RF refers to electromagnetic frequencies that can radiate into space, typically from 300 kHz to 300 GHz. An RF module is an electronic device used to transmit and receive radio signals between two devices; it is the core module for signal transmission and reception in wireless communication equipment.
Role of the Power Amplifier
Electromagnetic wave transmission distance is proportional to transmit power. A power amplifier (PA) is an amplifying circuit that provides sufficient signal power to the antenna. Its main function is to amplify the relatively low-power RF signal generated by the modulation and oscillator stages and feed it to the antenna for radiation. As a core component of the RF front end, PA performance directly affects communication range, signal quality, and standby power consumption.
In the transmit chain, the primary functions of a PA include:
- Signal gain: increase the input signal power so it has sufficient energy to cover the target transmission area.
- Driving the antenna: the amplified signal must be able to drive the antenna to transmit the signal to the target receiver.
- Compensating for signal attenuation: during transmission the signal weakens due to attenuation and other factors; the PA increases power to compensate for this attenuation and maintain signal quality.
Overall, PA performance directly determines the stability and strength of communication signals.
Applications
PAs are widely used in wireless communication systems such as mobile phones, satellite communications, Wi?Fi, and cellular networks, where they provide sufficient signal strength and coverage. In radar systems, PAs amplify transmitted microwave signals to enable detection of targets over large distances.
According to Yole, the global mobile RF front-end market was $19.2 billion in 2022, with PA modules accounting for 45% of the total. The market is projected to reach $26.9 billion by 2028, representing a CAGR of 5.8%.
PA and LNA in RF Front Ends
Wi?Fi devices, which prioritize low power consumption, require adequate transmit power to maintain coverage and signal quality. A common solution in RF front ends is the front-end module (FEM) that integrates the power amplifier and the low-noise amplifier (LNA). The PA increases transmit power to extend range and throughput, while the LNA improves receive sensitivity.
In the receive chain, a low-noise amplifier (LNA) increases sensitivity while preserving signal integrity. Compared with a PA, an LNA focuses on minimizing noise added by the amplifier itself through internal design and specific techniques, thereby improving receiver sensitivity, increasing effective range, and ensuring output signal accuracy and reliability.
Power amplifiers and low-noise amplifiers are essential components of wireless communication systems. The PA provides sufficient signal power to drive the antenna for long-range transmission, while the LNA minimizes noise during amplification to preserve signal quality. In compact Wi?Fi devices, using a FEM that integrates both PA and LNA can significantly improve signal quality and coverage.
