Transconductance Boosting Circuit for Low-Phase-Noise VCOs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for reducing phase noise in voltage-controlled oscillators (VCOs) either require increasing the Q value of inductors, which necessitates a larger area, or increasing output power, which consumes more power, both of which are inefficient.
Innovation Solution
A transconductance controlling circuit comprising a resonance circuit, a negative-resistance unit-circuit, and a transconductance boosting circuit, where the transconductance boosting circuit boosts the transconductance of transistors in the negative-resistance unit-circuit, thereby increasing the Q value of the inductors and reducing phase noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the Q value of the inductor is increased to reduce phase noise, then the phase noise is reduced, but the area required for the inductor increases
Solution Approach 1:
The patent changes the electrical parameters of the circuit by introducing a transconductance boosting circuit that modifies the transconductance of transistors in the negative-resistance unit-circuit. This parameter change effectively increases the Q value of the inductor without physically enlarging it, thereby reducing phase noise while maintaining the same inductor area.
Solution Approach 2:
The patent introduces a transconductance boosting circuit as an intermediary component between the voltage-controlled oscillator and the output. This intermediary circuit boosts the transconductance of the transistors, which indirectly increases the inductor's Q value and reduces phase noise without requiring a larger inductor.
2Object-affected harmful factors
If the output power is increased to reduce phase noise, then the phase noise is reduced, but the power consumption increases
Solution Approach 1:
The patent changes the transconductance parameter of the transistors in the negative-resistance unit-circuit through the transconductance boosting circuit. This parameter modification reduces phase noise by effectively increasing the inductor's Q value without requiring an increase in output power, thus avoiding additional power consumption.
3Object-affected harmful factors
If the Q value of the inductor is increased to reduce phase noise, then the phase noise is reduced, but the circuit complexity increases
Solution Approach 1:
The transconductance boosting circuit is designed to perform multiple functions: it boosts the transconductance of the transistors, effectively increases the inductor's Q value, and reduces phase noise. By consolidating these functions into a single circuit module, the patent minimizes the overall circuit complexity while achieving the desired phase noise reduction.
Data Source
AI summary
A transconductance controlling circuit is provided. The transconductance controlling circuit includes a resonance circuit, a negative-resistance unit-circuit and a transconductance boosting circuit. The resonance circuit generates an oscillation signal. The negative-resistance unit-circuit is coupled to a resonance circuit and includes a first transistor and a second transistor. The transconductance boosting circuit is coupled to the negative-resistance unit-circuit and includes a third transistor and a fourth transistor. A first drain of the first transistor is coupled to a third drain of the third transistor, a first gate of the first transistor is coupled to a third gate of the third transistor, the first gate of the first transistor is coupled to a second drain of the second transistor, and a first base of the first transistor is coupled to a fourth base of the fourth transistor and to a fourth source of the fourth transistor.