Injection-Locked Oscillator Phase Sensing for TDD Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In time division duplexing (TDD) applications, injection locking oscillators face phase uncertainty due to oscillating signals aligning to either the rising or falling edges of a locking signal, which is undesirable for phase synchronicity requirements.
Innovation Solution
The synchronized injection locking oscillator (SILO) circuit includes a sense circuit and phase control circuit to ensure the oscillating signal aligns consistently to a specific edge of the locking signal, using amplifiers, inductors, capacitors, and voltage sources to control phase symmetry and provide a stable phase output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If injection locking oscillator is used in TDD applications, then frequency locking is achieved, but phase uncertainty occurs due to alignment to either rising or falling edges
Solution Approach 1:
The patent implements a feedback mechanism using a sense circuit that detects the phase relationship between the oscillator output and locking signal, then feeds this information to a correction circuit. The correction circuit adjusts the oscillator phase based on the detected phase error, creating a closed-loop system that eliminates phase uncertainty while maintaining frequency locking.
Solution Approach 2:
The patent introduces a phase sense circuit and correction circuit as intermediary components between the injection locking oscillator and the locking signal source. These intermediary circuits measure the phase relationship and provide corrective adjustment, acting as mediators that resolve the phase alignment issue without disrupting the frequency locking function.
2Measurement precision
If phase alignment is corrected to ensure consistent edge alignment, then phase synchronicity is improved, but circuit complexity increases due to additional sense and correction circuits
Solution Approach 1:
The patent combines the phase sensing and correction functions into an integrated phase control circuit that works seamlessly with the injection locking oscillator. By merging these functions into a unified control mechanism, the patent reduces the overall circuit complexity compared to having separate sense and correction circuits, while still achieving precise phase alignment.
Solution Approach 2:
The correction circuit automatically adjusts the oscillator phase based on feedback from the sense circuit, enabling the system to self-correct phase alignment issues without external intervention. This self-service mechanism eliminates the need for complex external phase control circuitry, reducing overall system complexity while maintaining precise phase synchronicity.
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 SILO circuit ensures consistent phase alignment across power cycles, reducing phase noise and jitter, and facilitates efficient power management in TDD systems by maintaining phase synchronicity for transmitter and receiver operations.
Implementation Method 1
an injection locking oscillator (ILO) circuit, having an input configured to receive a locking signal, and an output. The ILO circuit is configured to provide, at the output, an ILO output clock having a frequency based on a frequency of a locking signal
Implementation Method 2
The sense circuit is coupled to the ILO circuit. The sense circuit is configured to sense a phase of the ILO output clock relative to the locking signal, and provide a phase signal representing the phase
Data Source
AI summary
A circuit includes an injection locking oscillator circuit and a sense circuit. The injection locking oscillator circuit has an input and an output. The sense circuit includes a sampling circuit and a comparator. The sampling circuit has a first input coupled to the input of the injection locking oscillator circuit, a second input coupled to output of the injection locking oscillator circuit, and an output. The comparator has an input coupled to the output of the sampling circuit, and an output.