Injection-Locked Polar Receiver for Wideband Phase Detection
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Solution Overview
Problem
Existing polar receiver architectures and signal processing methods suffer from poor performance and high bit error rates due to deficiencies in extracting modulation phase components without carrier recovery circuitry.
Innovation Solution
A polar receiver architecture utilizing an injection-locked oscillator with multiple injection points corresponding to different harmonics, combined with band-specific amplifiers and phase detection circuitry, selects the appropriate harmonic and amplifier based on the input signal frequency to generate an oscillator output signal for phase and amplitude detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a polar receiver architecture without carrier recovery circuitry is used, then device complexity is reduced, but measurement precision of phase components deteriorates
Solution Approach 1:
An injection-locked oscillator is introduced as an intermediary component that receives the input signal and generates an oscillator output signal with a known phase relationship. This mediator enables phase measurement without requiring complex carrier recovery circuitry, as the oscillator's output phase can be directly correlated to the input signal phase through the locking mechanism.
Solution Approach 2:
The system changes the operating parameters of the injection-locked oscillator, specifically tuning its free-running frequency to be substantially equal to the input signal frequency divided by N. This parameter adjustment optimizes the locking range and ensures accurate phase tracking across different input frequencies, maintaining measurement precision while avoiding carrier recovery complexity.
2Device complexity
If a fixed-frequency oscillator is used, then device complexity is reduced, but adaptability to different input signal frequencies deteriorates
Solution Approach 1:
The injection-locked oscillator is designed with multiple injection points corresponding to different harmonics (Nth harmonic injection). This universal design allows the same oscillator circuit to lock onto input signals across a wide frequency range by selecting different harmonic injection points, making the receiver adaptable to various frequencies without requiring multiple fixed-frequency oscillators.
Solution Approach 2:
The system dynamically adjusts which harmonic injection point is used based on the input signal frequency. The controller selects the appropriate Nth harmonic injection point to ensure the oscillator locks correctly, enabling the fixed-frequency oscillator to adaptively handle a broad range of input frequencies through dynamic injection point selection.
3Adaptability or versatility
If multiple harmonic injection points are added to the oscillator, then adaptability to different frequencies is improved, but device complexity increases
Solution Approach 1:
The oscillator is segmented into multiple distinct injection points, each corresponding to a specific harmonic (fundamental, second harmonic, third harmonic, etc.). This segmentation allows independent control and selection of injection points based on the input signal frequency, enabling wide frequency adaptability while maintaining a modular and manageable structure that doesn't excessively increase complexity.
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
This approach improves the locking range and accuracy of phase detection, reducing bit error rates and enhancing the overall performance of polar receiver systems by aligning the input signal frequency with the oscillator's harmonic range.
Implementation Method 1
an injection-locked oscillator. The injection-locked oscillator is operated to generate an oscillator output signal while the input signal is injected at the selected set of injection points
Implementation Method 2
A phase of the oscillator output signal is measured to determine the phase of the modulated input signal
Data Source
AI summary
Wideband polar receivers and method of operation are described. A phase-modulated input signal is received at a polar receiver that includes an injection-locked oscillator. The injection-locked oscillator includes a plurality of injection points. Based on the frequency of the input signal, a particular Nth harmonic is selected, and the input signal is injected at the set of injection points corresponding to the selected Nth harmonic. The injection-locked oscillator generates an oscillator output signal, and the phase of the input signal is determined from the phase of the oscillator output signal. In some embodiments, the oscillator output signal is frequency-multiplied by N, mixed with the input signal, and filtered for use in amplitude detection. The input signal is decoded based on the phase and amplitude information.