Push-Pull Power Amplifier With Switchable Capacitance for Multi-Band RF
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing RF communication systems face challenges in efficiently supporting multiple frequency bands and bandwidths, particularly in 5G NR, due to the complexity and inefficiency of managing multiple active power amplifiers, which leads to increased board space and costs in devices like smartphones and base stations.
Innovation Solution
A reconfigurable push-pull power amplifier is introduced, which includes controllable input and output capacitors and ballasting networks, controlled by a band control signal, to manage impedance and amplify RF signals efficiently across different frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple active power amplifiers are used to support multiple frequency bands, then frequency band coverage is improved, but device complexity and board space increase
Solution Approach 1:
The power amplifier uses dynamically switchable capacitors that can change capacitance values based on the operating frequency band. This dynamic reconfiguration allows a single power amplifier to adapt to different frequency bands (e.g., 5G NR n77 and n79 bands) by adjusting its input and output capacitance, eliminating the need for multiple fixed amplifiers for different bands
Solution Approach 2:
The invention changes the electrical parameters (capacitance values) of the power amplifier circuit to optimize performance across different frequency bands. By switching capacitor values in the input matching network and output network, the same amplifier can be tuned for different bands, reducing the total number of amplifiers needed while maintaining broad frequency coverage
2Adaptability or versatility
If multiple active power amplifiers are used to support multiple frequency bands, then frequency band coverage is improved, but board space increases
Solution Approach 1:
The power amplifier is designed as a universal multi-functional device that can operate across multiple frequency bands through reconfigurable capacitance. The same amplifier hardware serves multiple bands (e.g., both 5G n77 and n79) by changing its electrical characteristics via capacitor switching, making the amplifier universally applicable to different frequency requirements without needing separate dedicated amplifiers for each band
Solution Approach 2:
The dynamic switching of capacitor values allows the amplifier to adapt its characteristics in real-time based on the required frequency band, enabling a single compact amplifier to replace what would traditionally require multiple larger amplifiers, thus reducing overall board space while maintaining multi-band capability
3Adaptability or versatility
If controllable capacitors are used to reconfigure impedance, then adaptability across frequency bands is improved, but device complexity increases
Solution Approach 1:
The invention changes the capacitance parameter of selected capacitors in the input and output networks to achieve proper impedance matching across different frequency bands. By switching between predetermined capacitance values, the amplifier can be optimally matched to different bands (e.g., 5G n77 and n79) without requiring complex real-time impedance tuning circuits, thus achieving high adaptability with relatively simple control
Data Source
AI summary
Apparatus and methods for reconfigurable power amplifiers are disclosed. In certain embodiments, a mobile device includes a transceiver configured to generate a first radio frequency signal of a first frequency band and a second radio frequency signal of a second frequency band, and a front-end system including a push-pull power amplifier configured to selectively amplify one of the first radio frequency signal or the second radio frequency signal based on a band control signal. The push-pull power amplifier includes an input balun, an output balun, and a pair of amplifiers coupled between the input balun and the output balun. The band control signal is operable to control an output capacitance of the pair of amplifiers.