Baseband Phase Shifter Using 90°/45° Steps for Low-Power Control
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Solution Overview
Problem
High-frequency wireless communication systems face power consumption issues due to the use of phase shifters with significant loss, leading to increased circuit size and power consumption, especially when controlling antenna radiation patterns in high-frequency bands.
Innovation Solution
A phase shifter that adds phase information to baseband signals using a 90° step phase shifter and a 45° phase shifter, performing signal replacement and polarity inversion to control the phase of output signals, thereby reducing power consumption by eliminating the need for a Gilbert cell mixer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a phase shifter for high-frequency band is used to control the phase of transmitted signals, then the radiation pattern can be controlled to establish communication, but the phase shifter has great loss which requires a new amplifier, causing an increase in circuit size and power consumption
Solution Approach 1:
The patent replaces the high-frequency phase shifter (electromagnetic system) with a baseband phase shifter operating at lower frequencies. By shifting the phase modulation to baseband signals before upconversion, the system avoids the high losses inherent in high-frequency phase shifters, eliminating the need for additional amplifiers and reducing overall power consumption while maintaining communication reliability
2Ease of operation
If a Gilbert cell mixer is used to add phase information to baseband signals, then phase control can be achieved, but the current drive type mixer consumes considerable power, especially when the number of antennas increases
Solution Approach 1:
The patent extracts the phase control function from the Gilbert cell mixer and implements it separately through baseband phase shifters. By removing the mixing operation from the high-power current drive path and performing phase modulation at baseband, the system achieves the same phase control capability without the excessive power consumption of the Gilbert cell mixer, especially beneficial when scaling to multiple antennas
Data Source
AI summary
Disclosed are a phase shifter, a wireless communication apparatus, and a phase control method in which power consumption is reduced. A phase shifter includes a 90° step phase shifter (17) and a 45° phase shifter (18) and adds phase information to two baseband signals to be output to an orthogonal modulator. The 90° step phase shifter (17) contributes to adding any one of phases 0°, 90°, 180°, and 270° to the baseband signals according to a first control signal. The 45° phase shifter (18) contributes to adding one of phases 0° and 45° to the baseband signals according to a second control signal. A phase shifter (8) performs replacement of component signals of one of the baseband signals with component signals of the other of the baseband signals and inversion of polarities of the component signals.