RF Amplifier Bypass Circuit With Switchable Phase Shifter
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Solution Overview
Problem
In mobile radio systems and low power modes of UMTS/3G systems, existing methods fail to effectively reduce current consumption while processing high power dynamics, as they cannot switch off and bypass amplifier stages without increasing instability or requiring additional impedance matching.
Innovation Solution
An amplifier circuit with a switchable phase shifter that has a first impedance for an alternating signal in the 'on' state and a higher second impedance in the 'off' state, allowing the amplifier to be bypassed and reducing current consumption by enabling high-impedance negative feedback when switched off.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If amplifier stages are switched off to reduce current consumption, then power efficiency is improved, but instability increases and additional impedance matching is required
Solution Approach 1:
A bypass circuit is introduced as an intermediary element between the amplifier input and output. This bypass circuit includes a switching element connected in parallel with the amplifier, allowing signal to be routed around the amplifier when it is switched off. The bypass circuit maintains proper impedance matching and signal integrity even when the amplifier is disabled, thereby preventing instability while enabling current consumption reduction.
2Use of energy by moving object
If amplifier stages are switched off to reduce current consumption, then power efficiency is improved, but additional impedance matching is required
Solution Approach 1:
The bypass circuit is merged with the amplifier structure in a integrated manner. The switching element is connected in parallel with the amplifier input and output terminals, creating a unified structure where the bypass path is inherently integrated. This merging eliminates the need for separate, additional impedance matching components that would otherwise be required when switching the amplifier on and off, thereby reducing device complexity while maintaining power efficiency.
Data Source
AI summary
An amplifier circuit includes an amplifier and a phase shifter coupled in parallel to the amplifier and switchable such that the phase shifter has a first impedance for an alternating signal in an on state and has a second impedance for the alternating signal in an off state. The second impedance is higher than the first impedance.