Push-Push Microwave Oscillator Circuit for Higher Output Power
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Solution Overview
Problem
Existing voltage-controlled oscillators (VCOs) do not optimize output power at the working frequency f0 while maintaining the same power consumption, and prior art fails to improve the signal/noise ratio without increasing phase noise.
Innovation Solution
A microwave oscillator design with a push-push structure and a central node circuit that includes a second connection to ground in parallel, using MMIC technology, which maintains low impedance at frequency f0/2 and high impedance at frequency f0, preventing signal dissipation and enhancing output power without increasing phase noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the circuit is optimized to the frequency of the two half-circuits resonating at frequency f0/2, then the oscillation is supported at the required output frequency f0, but the output power at the working frequency f0 is not optimized
Solution Approach 1:
The circuit is divided into two separate resonant circuits, each resonating at frequency f0/2. This segmentation allows each circuit to be optimized for its specific frequency while collectively supporting the overall oscillation at frequency f0, thereby improving output power without requiring complete redesign of the entire circuit structure.
Solution Approach 2:
Each resonant circuit is locally optimized for resonance at frequency f0/2 with specific component values (inductors L1, L2 and capacitors C1, C2), while the overall circuit architecture maintains the capability to generate oscillation at frequency f0. This local optimization enables improved output power at the working frequency without compromising the oscillation support function.
2Power
If the output power is increased, then the signal/noise ratio is improved, but the phase noise of the oscillator increases
Solution Approach 1:
The two resonant circuits operate in phase opposition at frequency f0/2, creating a periodic alternating pattern that reinforces the oscillation at frequency f0. This periodic action between the two circuits increases the output signal power while the balanced nature of the arrangement helps maintain phase noise performance by distributing the noise contributions.
Solution Approach 2:
The resonant circuits are configured with specific asymmetric component values (L1≠L2, C1≠C2 in general) that are optimized for their respective positions in the circuit. This asymmetric configuration allows each circuit to contribute optimally to the overall output power at frequency f0 while maintaining balanced noise characteristics through the phase opposition arrangement.
3Power
If a voltage-controlled oscillator is designed with push-push structure, then the oscillation at frequency f0 is supported, but the output power at working frequency f0 is not optimized
Solution Approach 1:
The push-push oscillator structure is segmented into two independent resonant circuits, each with its own inductor and capacitor. This segmentation allows standard manufacturing techniques to be applied to each circuit module independently while the combined structure optimizes the output power at frequency f0 through the phase opposition resonance mechanism.
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 design achieves a 6dB gain in output power with improved phase noise performance, maintaining the same power consumption and using standard production techniques, while maintaining low production costs.
Implementation Method 1
two LC resonant circuits, which each contain at least one variable capacitance depending on the tuning voltage and which are connected to the active component and oscillate in phase opposition at the frequency f0/2
Implementation Method 2
to the real ground earth by means of a further LC circuit connected to ground which, resonating at the frequency f0/2, produces a short-circuit to ground at the said frequency
Implementation Method 3
two circuits 120 resonating at a frequency f0/2, consisting of a respective microstrip line 121 which forms the inductive part of the circuit and the opposite ends 121a,121b of which are respectively connected to the respective node 112 of the active component 110 and to a respective varactor diode 122 which forms the variable capacitive part and which allows tuning of the two circuits 120 and therefore of the oscillator 100 within the desired band
Data Source
Figure 1~3
Figure 4~8b
AI summary
Voltage-controlled microwave oscillator (100) comprising: an active component (110) designed with a push-push structure and arranged between two nodes (112), with a central output (111) at a frequency f0 and having a negative differential resistance at the said nodes (112) able to support an oscillation at a frequency f/2; two lines (120), the opposite ends (121a,121b) of which are respectively connected to the associated node (112) of the active component (110) and to a varactor diode (122); a central node circuit (130) comprising a central node (131) to which are connected: the said varactor diodes (122), a decoupling inductor (140), and a first LC circuit (150) comprising a first inductor (151) and a first capacitor (152) connecting the central node (131) to the real earth of the oscillator and resonating at the frequency f0/2 so as to produce a short-circuit to earth at said frequency, said oscillator comprising a second LC circuit (160) for connecting the central node (131) to earth, arranged in parallel with the first circuit (150), comprising a second capacitor (162) and a second inductor (161) arranged in series, said first LC circuit (150) and second LC circuit (160) being able to produce a short-circuit at the frequency f0/2 and an open circuit at the output frequency f0 of the oscillator, between the central node (131) and earth.