Balun-Free Frequency Multiplier for Wideband Differential Output
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Solution Overview
Problem
Existing frequency multipliers for wireless communication systems require baluns or phase shifters to generate differential outputs, which increase losses and limit bandwidth, occupying significant chip area and restricting their performance at microwave and millimeter-wave frequencies.
Innovation Solution
An even-order frequency multiplier design that uses two signal branches with nonlinear components, such as diodes or transistors, configured to produce anti-phase even-order harmonics, eliminating the need for baluns or phase shifters and utilizing high pass or bandpass filters for impedance matching and harmonic extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a balun or phase shifter is used to generate differential outputs, then the frequency multiplier can produce differential signals, but the chip area increases significantly
Solution Approach 1:
The patent combines the frequency multiplication function and differential output generation into a single integrated circuit structure. The push-pull configuration with two nonlinear devices working in parallel achieves both frequency multiplication and differential output simultaneously, eliminating the need for separate balun or phase shifter components.
Solution Approach 2:
The nonlinear devices in the push-pull configuration serve multiple functions: they perform frequency multiplication through their nonlinear characteristics while simultaneously generating differential outputs through their anti-phase operation. This multi-functionality eliminates the need for dedicated balun or phase shifter components.
2Ease of operation
If a balun or phase shifter is used to generate differential outputs, then the frequency multiplier can produce differential signals, but the bandwidth is limited
Solution Approach 1:
The patent combines the frequency multiplication function and differential output generation into a single integrated circuit structure. The push-pull configuration with two nonlinear devices working in parallel achieves both frequency multiplication and differential output simultaneously, eliminating the need for separate balun or phase shifter components.
Solution Approach 2:
The patent employs a push-pull configuration where two nonlinear devices operate in complementary fashion with opposite phase relationships. This dynamic operation allows the circuit to maintain wide bandwidth performance while generating differential outputs, as the push-pull topology naturally accommodates a broader frequency range compared to static balun or phase shifter designs.
3Ease of operation
If a balun or phase shifter is used to generate differential outputs, then the frequency multiplier can produce differential signals, but the losses increase
Solution Approach 1:
The patent combines the frequency multiplication function and differential output generation into a single integrated circuit structure. The push-pull configuration with two nonlinear devices working in parallel achieves both frequency multiplication and differential output simultaneously, eliminating the need for separate balun or phase shifter components.
Solution Approach 2:
The patent converts the inherent nonlinearity of the devices, which traditionally generates unwanted harmonics, into a beneficial mechanism for frequency multiplication. By using two nonlinear devices in push-pull configuration, the circuit generates both the desired frequency multiplication and differential outputs while suppressing unwanted harmonics through phase cancellation.
4Ease of operation
If quarter-wavelength transmission lines are used for balun or phase shifter, then differential outputs can be generated, but the device complexity increases
Solution Approach 1:
The patent combines the frequency multiplication function and differential output generation into a single integrated circuit structure. The push-pull configuration with two nonlinear devices working in parallel achieves both frequency multiplication and differential output simultaneously, eliminating the need for separate balun or phase shifter components.
Solution Approach 2:
The patent extracts and eliminates the separate balun or phase shifter components from the frequency multiplier design. By integrating the differential output generation directly into the frequency multiplication circuit through push-pull configuration, the design removes unnecessary components and simplifies the overall circuit architecture.
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 design achieves compact, low-loss, and wideband operation by generating differential outputs without baluns or phase shifters, enhancing the performance of frequency multipliers in wireless communication systems.
Implementation Method 1
The first and second nonlinear components are configured such that even-order harmonics generated in the first and second nonlinear components are in anti-phase
Implementation Method 2
High pass or bandpass filters are used for extracting the desired harmonic so that the output signals with the frequency of 2nf0, i.e. 2n times the frequency of the input signal are extracted out and other undesired harmonics are filtered out or suppressed
Data Source
AI summary
Frequency multipliers (300) for generating a differential output signal from a single-ended input signal are disclosed. The frequency multiplier comprises a single-ended input (Pin(f0)) to receive the input signal with a frequency of f0 and differential outputs (+/−Pout(2nf0)) to provide the differential output signals. The frequency multiplier further comprises a first signal branch (301) connected to the single-ended input and one of the differential outputs (+Pout(2nf0)). The first signal branch comprises a first low pass or bandpass filter with a center frequency of f0 (L/BPF1), a first nonlinear component (NC1) and a first high pass or bandpass filter with a center frequency of 2nf0 (H/BPF1). The frequency multiplier further comprises a second signal branch connected to the single-end input and another one of the differential outputs (−Pout(2nf0)). The second signal branch comprises a second low pass or bandpass filter with a center frequency of f0 (L/BPF1), a second nonlinear component (NC2) and a second high pass or bandpass filter with a center frequency of 2nf0 (H/BPF2). The first and second nonlinear components are configured such that even-order harmonics generated in the first and second nonlinear components are in anti-phase, thereby the differential output signals with a frequency of 2n times the frequency of the input signal are generated at the differential output, where n is an integer number.