Phase invariant variable gain amplifier for beamforming applications
The phase-invariant VGA design with cross-coupled cascode paths and capacitors addresses phase variation issues in VGAs, enhancing beamforming performance by maintaining consistent phase and impedance across gain steps.
WO2026136432A1PCT designated stage Publication Date: 2026-06-25SADRABADI MOHAMMAD GHADIRI +2
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Patent Information
- Application Number
- PCT/US2025/059940
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-12-16
- Filing Date
- 2025-12-16
- Publication Date
- 2026-06-25
AI Technical Summary
Technical Problem
Existing variable gain amplifiers (VGAs) in beamforming integrated circuits (BFICs) suffer from phase variation with gain changes, leading to degraded beam accuracy, increased calibration complexity, and reduced side-lobe control.
Method used
A phase-invariant VGA design utilizing differential input stages with cross-coupled cascode paths and capacitors to minimize phase variation, where capacitors are sized based on transistor and load impedance parameters to maintain consistent phase response across gain steps.
Benefits of technology
The solution achieves phase-invariant gain characteristics, reducing calibration overhead and improving beamforming performance by maintaining consistent phase and impedance across different attenuation settings.
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Figure US2025059940_25062026_PF_FP_ABST
Abstract
A variable gain amplifier (VGA) includes a differential input stage, a first cascode path, and a second cascode path that is cross-coupled to the first cascode path. Each cascode path includes a pair of common-gate transistors having capacitors coupled to their gates. Capacitance values of the capacitors are selected or weighted to reduce phase variation of an output signal as overall gain is adjusted by selectively enabling the second cascode path. The second cascode path is cross-coupled relative to the first cascode path to provide a phase-inverted output such that enabling the second cascode path subtracts from the gain of the first cascode path. In one embodiment, additional cascode paths with weighted capacitors may be provided to define multiple gain steps. The VGA may be integrated into a beamforming integrated circuit for wireless communication systems.
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