Frequency Synthesizer Using Pulse Trains for Multi-Band LO Generation
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Solution Overview
Problem
Existing frequency synthesis devices for transmitter-receiver systems require numerous local oscillators, leading to high costs, complexity, and large circuit sizes due to the need for multiple frequency transpositions across wide RF frequency bands, which is inefficient and impractical.
Innovation Solution
A frequency synthesis device that generates multiple frequency-stable periodic signals without using as many local oscillators by employing a system with a periodic signal generator, a pulse signal generator, and frequency recovery circuits to produce signals at integer multiples of a base frequency, using band-pass filtering to isolate desired frequencies and reduce circuit complexity and consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple local oscillators are used to generate frequency-stable signals for wide RF frequency bands, then frequency stability and coverage are improved, but device complexity, circuit size, and cost increase
Solution Approach 1:
A single local oscillator is designed to serve multiple frequency bands through frequency multiplication techniques. The oscillator generates a base frequency that is then multiplied by integer factors (2x, 3x, 4x, etc.) to produce multiple output frequencies, allowing one oscillator to replace what would traditionally require multiple oscillators for wide RF coverage
Solution Approach 2:
The frequency output of the oscillator is dynamically changed through parameter modification - specifically by adjusting the multiplication factor applied to the base frequency. This allows the system to generate different frequency multiples (2f0, 3f0, 4f0, etc.) from the same oscillator core, providing frequency adaptability without adding hardware components
2Reliability
If multiple local oscillators are used for frequency transposition, then frequency stability is improved, but electrical consumption increases
Solution Approach 1:
One oscillator circuit is designed to perform the work of multiple oscillators by generating a base frequency and using frequency multiplication to create multiple stable output frequencies. This single oscillator consumes less power than multiple separate oscillators would require, while still providing the same frequency stability and coverage
Solution Approach 2:
Multiple frequency generation functions are merged into a single oscillator system. Instead of having separate oscillator circuits for each frequency band, the invention combines them into one oscillator that produces a base frequency which is then multiplied to generate all required frequency multiples, reducing total power consumption
3Adaptability or versatility
If multiple local oscillators are used across wide RF bands, then frequency coverage is improved, but circuit surface area increases
Solution Approach 1:
A single oscillator circuit is designed to provide frequency coverage across wide RF bands by generating a base frequency and using multiplication circuits to produce integer multiples (2f0, 3f0, 4f0, etc.). This approach requires significantly less circuit area than implementing separate oscillators for each frequency band, as it shares common circuitry and eliminates redundant components
Data Source
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AI summary
The invention relates to a frequency synthesis device (100) comprising: first means (102-112) for generating a periodic signal at a frequency f1; second and third means (114, 116) coupled to the first means and generating, from the f1 frequency signal, a signal SG corresponding to an oscillation train having a frequency equal to N.f1, having a duration shorter than T1 = 1/f1 and repeated periodically at the f1 frequency; fourth means (118) generating, from the SG signal, m periodic signals SLO_CH1 to SLO_CHm having frequency spectra that each comprise a main frequency line fLO_CHi corresponding to an integer multiple of f1, where 1 ≤ i ≤ m, the fourth means being used as a band-pass filter applied to SG and rejecting, from the frequency spectra of each of the periodic signals SLO_CH1 to SLO_CHm, the lines other than the main frequency line fLO_CHi.