How an RF Amplifier Boosts Signal Power Efficiently

This patent describes an RF power amplifier design that uses a main amplifier and several auxiliary amplifiers to efficiently boost radio signals over a wide power range, especially useful in wireless communication basestations.

What it covers

This amplifier design boosts radio frequency (RF) signals efficiently across a wide range of power levels. It uses a main amplifier (Claim 1a) to handle lower power signals. When the main amplifier approaches its maximum power output, or 'saturation,' a series of auxiliary amplifiers (Claim 1b) are biased to sequentially turn on, one after another, to continue boosting the signal. An input signal splitter (Claim 1c) directs the signal to both the main and auxiliary amplifiers, with a quarter-wave transformer connected to the main amplifier's input. The amplified signals are then combined at an output, where the auxiliary amplifiers connect through quarter-wave transformers to a specific resistive load (Claim 1d, Claim 5d). For example, a cell tower could use this to amplify a weak incoming signal to a strong, broadcast-ready signal without wasting much energy, even as the required output power changes.

What it doesn't cover

• —Amplifiers where auxiliary amplifiers do not turn on *sequentially* after the main amplifier approaches saturation (Claim 1b).
• —Amplifiers that do not use lateral DMOS transistors for both the main and auxiliary amplifier components (Claim 1a, 1b).
• —Amplifiers that lack a signal splitter that includes a quarter-wave transformer connected to the input of the main amplifier (Claim 1c).
• —Amplifiers where the output does not combine signals from main and auxiliary amplifiers, with auxiliary outputs connected through quarter-wave transformers (Claim 1d).
• —Amplifiers that do not operate over a 'broad range of power' or where the main amplifier's saturation level is not below the maximum of that broad range (Claim 1a).

The clever bit

The novelty lies in the sequential activation of multiple auxiliary amplifiers, each precisely biased to engage only after the main amplifier nears its power limit. This, combined with the strategic use of quarter-wave transformers at both the input and output stages, allows for highly efficient power combining and extended operation over a very wide power range, significantly reducing wasted energy.

Why it matters

Efficient RF power amplifiers are crucial for modern wireless communication systems. This design helps reduce energy consumption and heat generation in devices like cell tower basestations, which are always on and handling varying signal loads. By improving efficiency, it helps maintain signal quality and extend the reach of wireless networks while lowering operational costs for telecommunication providers.

Real-world examples

• 1.Cellular basestations
• 2.Radio transmitters
• 3.Satellite communication systems
• 4.Wireless network infrastructure
• 5.High-power radar systems