RF Signal Transmission Apparatus for LO Leakage Suppression
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Solution Overview
Problem
In phased-array RF systems, local oscillator (LO) leakage signals sum together, making it difficult to satisfy spectrum mask requirements due to increased spurious signal levels, which existing technologies struggle to suppress effectively.
Innovation Solution
A radio frequency (RF) signal transmission apparatus and method that includes a signal detector to measure LO leakage, an LO leakage suppression chain with a variable gain amplifier and phase shifter to generate an LO leakage suppression signal, and a processor to adjust the signal's magnitude and phase, ensuring the suppression signal is transmitted via an antenna to attenuate the LO leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If beamforming is used in a phased-array system with multiple RF chains, then signal transmission capability is improved, but LO leakage signals sum together causing spurious signal levels to increase
Solution Approach 1:
The patent converts the harmful LO leakage signals into a useful suppression mechanism by measuring the leakage signals and generating cancellation signals. The LO leakage signals that would normally sum constructively and increase spurious levels are instead measured and used to generate suppression signals that cancel them out, transforming the harmful effect into a beneficial suppression mechanism.
Solution Approach 2:
The patent implements feedback by measuring the actual LO leakage signals in the phased-array system and using these measurements to generate suppression signals. The signal detector measures the leakage signals, and the suppression signal generator creates cancellation signals based on these measurements, creating a closed-loop feedback system that continuously suppresses LO leakage.
2Productivity
If multiple RF chains are used in a phased-array system, then transmission performance is improved, but spectrum mask requirements become difficult to satisfy due to summed spurious signals
Solution Approach 1:
The patent converts the harmful summed LO leakage signals into a useful suppression mechanism. By measuring the actual leakage signals and generating cancellation signals, the system transforms the problem of satisfied spectrum mask requirements into a solvable challenge, enabling phased-array systems to meet spectral regulations.
Solution Approach 2:
The patent introduces intermediary components including a signal detector to measure LO leakage signals and a suppression signal generator to create cancellation signals. These intermediary elements mediate between the multiple RF chains and the spectrum mask requirements, enabling the system to maintain transmission performance while satisfying regulatory constraints.
3Manufacturing precision
If LO leakage suppression is implemented in phased-array systems, then spectrum mask requirements are satisfied, but system complexity increases
Solution Approach 1:
The patent implements multi-functionality by using the existing RF chain infrastructure for both signal transmission and LO leakage suppression. The same antennas and signal processing paths are utilized for both purposes, reducing the need for separate dedicated suppression hardware and thereby limiting the increase in system complexity while achieving spectrum mask compliance.
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
The solution effectively suppresses LO leakage signals, ensuring compliance with spectrum mask requirements by generating a suppression signal that matches the magnitude and is 180 degrees out of phase with the LO leakage, thereby reducing the summed signal to negligible levels, thus improving the system's performance in phased-array systems.
Implementation Method 1
a variable gain amplifier configured to adjust magnitude of the LO leakage suppression signal
Implementation Method 2
a phase shifter configured to adjust a phase of the LO leakage suppression signal
Implementation Method 3
an antenna configured to transmit the LO leakage suppression signal
Data Source
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AI summary
Provided are a radio frequency (RF) signal transmission apparatus and a control method of the RF signal transmission apparatus, in which a local oscillator (LO) leakage signal may be suppressed. The RF signal transmission apparatus may perform beamforming to form a beam based on a plurality of RF signals generated in a plurality of transmission chains, measure magnitude of an LO leakage signal of the beam formed by performing beamforming, and generate an LO leakage suppression signal based on the magnitude of the LO leakage signal.