Broadband Frequency Generation Using Mixed PLL-Controlled Oscillators
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Solution Overview
Problem
Existing oscillators have limited bandwidth, making it difficult to generate broadband signals, and the high variation in loop gain of phase-locked loops (PLLs) used in these devices can limit the frequency range for stabilizing oscillators, leading to fluctuations and increased complexity.
Innovation Solution
A device comprising two controlled oscillators with separate phase-locked loops is used, where the output signals of these oscillators are mixed to generate a broadband frequency signal, utilizing a common phase-locked loop for stabilization and feedback, reducing switching complexity and phase noise, and allowing for increased bandwidth through differential tune voltages and interference suppression techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a single oscillator with high frequency is used to generate broadband signals, then the frequency range can be extended, but the bandwidth remains limited and the relative bandwidth decreases
Solution Approach 1:
The patent divides the broadband signal generation into two separate controlled oscillators (VCO1 and VCO2), each operating in different frequency ranges with their own PLLs. By segmenting the frequency generation task across multiple oscillators and combining their outputs via mixing, the system achieves extended bandwidth while maintaining stability in each segment.
2Speed
If the frequency range of the oscillator is extended to generate broadband signals, then higher frequencies can be achieved, but the loop gain of the PLL varies significantly, limiting the stabilizable frequency range
Solution Approach 1:
By dividing the broadband frequency range into two separate frequency ranges, each handled by its own PLL-controlled oscillator, the system maintains loop gain stability within each segment while achieving extended overall bandwidth through mixing of the two oscillators' outputs.
3Speed
If broadband signal generation is implemented using existing oscillators, then frequency coverage can be increased, but the circuit complexity and power consumption increase
Solution Approach 1:
The patent combines two PLL-controlled oscillators with a mixer to generate broadband signals. By merging the outputs of two stabilized oscillators through mixing, the system achieves extended frequency coverage while maintaining relatively simple and efficient circuitry compared to using a single complex broadband oscillator.
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 enables the generation of broadband signals with significantly increased bandwidth, reduced phase noise, and lower in-loop phase noise, while minimizing circuit complexity and power loss, suitable for applications like FMCW radar systems and mobile communications.
Implementation Method 1
a mixer (18) configured to generate the broadband frequency signal (11) by mixing the output signal (15, 17) of the first controlled oscillator (12) and the output signal of the second controlled oscillator (13)
Data Source
AI summary
An example of a device for generating a broadband frequency signal comprises a first controlled oscillator, a second controlled oscillator, a phase-locked loop for feeding back an output signal of a controlled oscillator to the corresponding controlled oscillator, and a mixer. The mixer is configured to generate the broadband frequency signal by mixing an output signal of the first controlled oscillator and an output signal of the second controlled oscillator. The device may, for example, be realized by means of a single phase-locked loop. A further example relates to a device for generating a frequency signal with a controlled oscillator and a phase-locked loop with a further controlled oscillator and a mixer in the feedback path of the phase-locked loop. Examples further relate to a high-frequency device for emitting a high-frequency signal and a method for generating a broadband frequency signal.