Making Radio Amplifiers More Efficient and Clear with Two Tricks

This patent describes a smart way to make radio amplifiers, like those in cell phones, more efficient and produce a clearer signal by adjusting both the power supply and the input signal based on how strong the signal is.

What it covers

This patent describes a method for improving how radio signals are amplified, especially in devices like cell phones. It works by using two main techniques together: first, it 'shapes the envelope signal' for the amplifier's power supply (Claim 1). This means the power supply voltage is adjusted to closely follow the strength of the signal being amplified, but it always stays above a certain minimum voltage (Claim 1). This shaping is specifically designed to improve signal quality in the 'compressed region' of the amplifier, where the signal is very strong (Claim 1). Second, it 'pre-distorts the input signal' before it even reaches the amplifier (Claim 1). This pre-distortion is designed to improve signal quality in the 'linear region' of the amplifier, where the signal is weaker (Claim 1). By combining these two methods, the system ensures the amplified signal is a more accurate copy of the original, reducing distortion and saving power. For example, in a smartphone, this helps the cellular radio transmit a clear signal while using less battery.

What it doesn't cover

• —Does not cover amplification systems that only pre-distort the input signal without also shaping the envelope signal for the power supply.
• —Does not cover systems where the envelope signal shaping is not specifically applied to improve linearity in a compressed power region.
• —Does not cover systems where the pre-distortion function is not specifically applied to improve linearity in a linear power region.
• —Does not cover systems where the power supply voltage tracks the envelope signal even when the envelope signal voltage is below a minimum voltage setting.

The clever bit

The clever part is combining two different signal correction techniques – pre-distortion and envelope shaping – and applying each one specifically to the amplifier's operating region where it's most effective for improving signal quality. This dual approach tackles distortion more comprehensively.

Why it matters

This technology is vital for modern wireless communication, especially in devices like smartphones and cellular base stations. It helps power amplifiers operate more efficiently, which extends battery life in mobile devices and reduces energy consumption in infrastructure. By improving signal linearity, it also ensures clearer, more reliable data transmission, which is critical for high-speed mobile networks like 4G and 5G.

Real-world examples

• 1.Smartphone cellular radios
• 2.5G base station power amplifiers
• 3.Wi-Fi access points
• 4.Satellite communication transceivers