RF Switch-Grounded Amplifier Paths for Port Isolation
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Solution Overview
Problem
Radio frequency (RF) circuits face challenges in isolating unwanted signals from unused input ports, particularly due to parasitic inductance in semiconductor packages, which complicates signal processing and reduces isolation efficiency.
Innovation Solution
The RF circuit incorporates a switch configuration that distributes aggressor signals into RF components with the same phase, allowing these signals to be offset by a mixer stage, thereby isolating unwanted signals without requiring external elements or direct removal of parasitic inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If parasitic inductance is present in the semiconductor package, then the RF circuit can be manufactured with standard packaging, but the impedance increases in higher frequency bands resulting in larger reflected components and reduced isolation performance
Solution Approach 1:
The patent converts the harmful reflected components caused by parasitic inductance into beneficial signals by intentionally routing them through the mixer stage. The switch configuration directs aggressor signals and their reflections to the mixer, where they are processed along with wanted signals, thereby eliminating the harmful effect of parasitic inductance without requiring package modification
Solution Approach 2:
The mixer stage serves as an intermediary that processes both wanted signals and aggressor signals (including reflected components from parasitic inductance) together. By using the mixer to handle all signals uniformly, the patent avoids the need to eliminate parasitic inductance directly, instead managing its effects through signal processing
2Device complexity
If traditional isolation methods are used without internal switches, then the device complexity is reduced, but the isolation performance deteriorates due to inability to effectively separate wanted signals from aggressor signals in multi-band reception
Solution Approach 1:
The patent segments the signal processing path by introducing switches that can independently control the routing of signals from different input ports. Each switch divides the aggressor signals and wanted signals into separate paths, allowing the mixer to process them appropriately. This segmentation enables effective isolation without requiring complex external isolation circuits
Solution Approach 2:
The mixer stage is designed to handle multiple functions: it processes wanted signals for downconversion while simultaneously processing aggressor signals and their reflected components. The switch configuration enables the same mixer to handle different signal types from multiple input ports, achieving multi-functionality without adding separate isolation circuits for each port
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 effectively isolates aggressor signals, ensuring that only the wanted signal is received, thereby improving isolation performance across various frequency bands and overcoming limitations due to parasitic inductance.
Implementation Method 1
a mixer stage connected to the plurality of amplification stages and configured to mix the one RF signal with a local oscillator (LO) signal and offset remaining RF signals
Implementation Method 2
a plurality of switches, each having a first terminal connected to one of the plurality of amplification stages, and a second terminal connected to one of the first ground to the N-th ground
Data Source
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AI summary
An RF circuit (100) including: first and second ports (P1, P2) receiving first and second RF signals (RF1, RF2); a (1-1)-th amplification stage (110) and a (1-2)-th amplification stage (120) connected to the first port (P1) and a first ground (GND1) to amplify the first RF signal (RF1); a (2-1)-th amplification stage (130) and a (2-2)-th amplification stage (140) connected to the second port (P2) and a second ground (GND2) to amplify the second RF signal (RF2); a (1-1)-th switch (SW1-1) connected to the (1-1)-th amplification stage (110) and the second ground (GND2), and a (1-2)-th switch (SW1-2) connected to the (1-2)-th amplification stage (120) and the second ground; (GND2) a (2-1)-th switch (SW2-1) connected to the (2-1)-th amplification stage (130) and the first ground (GND1), and a (2-2)-th switch (SW2-2) connected to the (2-2)-th amplification stage (140) and the first ground (GND1); and a mixer (150) to mix the first RF signal (RF1) or the second RF signal (RF2) with an LO signal, and mix the first RF signal (RF1) or the second RF signal (RF2) with the LO signal.