RF Power Amplifier Termination Circuit for Linear Range Extension
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Solution Overview
Problem
The challenge is to improve the operating efficiency of RF power amplifiers in portable wireless communications devices while meeting stringent linearity and out-of-band emissions requirements, given the constraints of reduced battery size and weight, and increased power consumption.
Innovation Solution
The RF power amplifier circuitry uses source and load termination circuits in an unconventional manner to shape amplitude-based distortion, transitioning between Class AB and Class B operation based on RF output power magnitude, thereby extending the linear operating range and increasing peak efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional Class F RF power amplifier operation is used with termination circuits creating impedance valleys at even harmonics, then saturated efficiency is improved, but linear operating range is limited
Solution Approach 1:
The patent changes the parameters of the termination circuits by creating impedance valleys at frequencies that are not even harmonics of the carrier frequency. This parameter change allows the circuits to shape amplitude-based distortion differently, extending the linear operating range while maintaining improved saturated efficiency through the Class F operation mode.
Solution Approach 2:
The patent employs dynamic biasing circuits that adjust operating parameters in real-time to maintain optimal performance across varying output power levels. This dynamic adjustment enables the amplifier to operate efficiently across a broader linear range while preserving the high efficiency benefits of Class F operation.
2Weight of moving object
If battery size and weight are reduced to meet portable device requirements, then device portability is improved, but battery capacity and operating efficiency deteriorate
Solution Approach 1:
By changing the frequency parameters of the termination circuits to create impedance valleys at non-even-harmonic frequencies, the patent shapes amplitude-based distortion to extend the linear operating range. This allows the amplifier to operate efficiently at lower power levels, improving overall operating efficiency and reducing average current consumption, which extends battery life in portable devices.
Solution Approach 2:
The patent uses feedback mechanisms through the termination circuits to control and shape the amplifier's output characteristics. This feedback enables the system to maintain linearity and efficiency across a broader operating range, optimizing power consumption for portable device applications.
3Adaptability or versatility
If advanced wireless communications protocols are implemented to increase device functionality, then communication capability is improved, but power consumption increases
Solution Approach 1:
The patent changes the operating parameters by creating impedance valleys at frequencies other than even harmonics, which shapes amplitude-based distortion to extend the linear operating range. This enables the RF power amplifier to support advanced wireless communications protocols with stringent linearity requirements while maintaining high efficiency and reducing power consumption across all RF output power levels.
4Loss of energy
If termination circuits are used to create impedance valleys at even harmonics for Class F operation, then saturated efficiency is improved, but amplitude-based distortion is not adequately shaped
Solution Approach 1:
The patent changes the fundamental parameter of where impedance valleys are created in the frequency spectrum. Instead of placing them at even harmonics as in conventional Class F operation, the termination circuits create impedance valleys at frequencies that are not even harmonics of the carrier frequency. This parameter change enables effective shaping of amplitude-based distortion while preserving the saturated efficiency improvements of Class F operation.
Data Source
AI summary
The present disclosure relates to RF power amplifier circuitry that may include a source termination circuit, a load termination circuit, or both used in an unconventional manner to shape amplitude-based amplitude modulation (AM-AM) distortion, amplitude-based phase modulation (AM-PM) distortion, or both to extend a linear operating range of the RF power amplifier circuitry. Conventional RF power amplifier circuitry may operate as a Class F RF power amplifier, which may use termination circuits to create impedance valleys at even harmonics of an RF carrier frequency to improve a saturated efficiency of the RF power amplifier circuitry. However, the termination circuits of the present disclosure may create impedance valleys that are not at even harmonics of an RF carrier frequency to shape amplitude-based distortion, thereby extending a linear operating range of the RF power amplifier circuitry.