Compact Inter-Stage Network for RF Amplifier Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Doherty amplifiers require large space due to complex inter-stage networks with many components, leading to efficiency losses, especially at frequencies above 2 GHz, as they implement separate power amplifiers in separate packages with independent input matching and biasing networks.
Innovation Solution
A compact inter-stage network is introduced, connecting a single driver amplifier to multiple power transistors, reducing the number of components and allowing for tunable amplitude and phase control, implemented within a single semiconductor die, using a capacitor and inductor configuration that includes a variable resistor for fine signal adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate power amplifiers with independent inter-stage networks are used in conventional Doherty amplifiers, then each amplifier path can be independently configured, but the overall device size increases significantly
Solution Approach 1:
The patent combines multiple amplifier paths into a single integrated circuit package, merging previously separate driver amplifiers, power transistors, and inter-stage networks into one unified device. This integration maintains the functional independence of each amplifier path while dramatically reducing the overall device footprint compared to separate packaged amplifiers.
Solution Approach 2:
The inter-stage network is designed as a shared component that serves multiple amplifier paths simultaneously. Instead of having separate inter-stage networks for each power amplifier path, a single inter-stage network performs impedance matching and signal distribution for multiple paths, reducing redundant components and device size.
2Ease of operation
If complex inter-stage networks with many components are used in conventional power RFIC amplifiers, then input matching and biasing can be optimized for each path, but efficiency losses increase, especially at frequencies above 2 GHz
Solution Approach 1:
The patent extracts and eliminates unnecessary components from the inter-stage network while retaining the essential functions of impedance matching and signal distribution. By removing redundant elements, the network becomes simpler with fewer loss mechanisms, particularly reducing efficiency losses at high frequencies above 2 GHz while maintaining optimization capability for each amplifier path.
3Ease of operation
If separate RFIC packages are used for each power amplifier, then independent input matching networks can be implemented, but the number of components and overall complexity increase
Solution Approach 1:
The patent merges multiple input matching networks into a unified structure within the inter-stage network that serves all amplifier paths. This integrated approach maintains the ability to independently optimize matching for each path while reducing the total component count compared to having separate matching networks in each packaged amplifier.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution reduces the size of RFIC die and packaged power amplifier modules by up to three times, improving efficiency and reducing RF losses at high frequencies, enabling a single integrated circuit to handle multiple amplifier stages with reduced complexity.
Implementation Method 1
a first capacitor having a first terminal and a second terminal, the first terminal of the first capacitor being connected directly to the driver output terminal and the second terminal of the first capacitor being connected directly to the main input terminal
Implementation Method 2
an inductor having a first terminal and a second terminal, the first terminal of the inductor being connected directly to the first terminal of the first capacitor, and a second capacitor having a first terminal and a second terminal, the first terminal of the second capacitor being connected directly to the second terminal of the inductor
Data Source
AI summary
A device includes a substrate and a package input terminal. The device includes a driver amplifier mounted to the substrate and configured to receive a radio frequency input signal. A first amplifier is mounted to the substrate. The first amplifier includes a first amplifier input terminal. A second amplifier is mounted to the substrate. The second amplifier includes a second amplifier input terminal. An inter-stage network is connected between the driver amplifier and the first amplifier and between the driver amplifier and the second amplifier. The inter-stage network includes a first capacitor connected between the driver amplifier and the first amplifier input terminal, and an inductor having a first terminal and a second terminal. The first terminal of the inductor is connected to the first capacitor. The inter-stage network includes a second capacitor connected between the second terminal of the inductor and the second amplifier input terminal.