Programmable HRM/SHM Mixer Topology for Wideband Harmonic Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radio frequency (RF) mixers, particularly harmonic rejection mixers (HRMs) and subharmonic mixers (SHMs), face limitations due to their upper frequency limits and the complexity of polyphase local oscillator (LO) generation, which restricts their operational range and flexibility.
Innovation Solution
A programmable mixer topology that allows conversion between HRM and SHM modes by bypassing resistors and reconfiguring phase sequences, enabling ultra-wideband operation by reusing clock phases, thus simplifying polyphase LO generation and extending frequency range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a traditional HRM topology is used, then harmonic rejection is achieved at lower frequencies, but the upper frequency limit is restricted and device complexity increases due to polyphase LO generation
Solution Approach 1:
The mixer core is designed to perform multiple functions: it can operate as an HRM for harmonic rejection at lower frequencies and as an SHM for frequency multiplication at higher frequencies. This is achieved through reconfigurable switching elements that can connect different LO ports to different RF/IF paths, allowing the same hardware to adapt to different operational requirements without needing separate dedicated circuits for each function.
Solution Approach 2:
The mixer incorporates dynamic reconfiguration capability through switching elements that can change the LO phase sequences and connection topologies in real-time. This allows the system to transition between HRM and SHM modes based on the operating frequency, optimizing performance across a wide bandwidth while maintaining harmonic rejection where needed.
2Adaptability or versatility
If the mixer is designed for wideband operation, then frequency range is extended, but harmonic rejection performance deteriorates at lower frequencies
Solution Approach 1:
The mixer uses dynamic switching to reconfigure the LO phase sequences based on the operating mode. In HRM mode, specific phase relationships are established to cancel harmonics at lower frequencies. When transitioning to SHM mode for higher frequencies, the switching elements reconfigure the connections to enable frequency multiplication while accepting that harmonic rejection is less critical at these frequencies.
Solution Approach 2:
The system changes operational parameters (LO phase sequences, switching states, connection topologies) depending on the desired operating mode. By adjusting these parameters, the mixer can optimize for harmonic rejection in HRM mode or for frequency range extension in SHM mode, effectively managing the trade-off between these two performance aspects.
3Reliability
If separate HRM and SHM circuits are implemented, then each function performs optimally, but device complexity and component count increase
Solution Approach 1:
The patent merges the HRM and SHM functions into a single reconfigurable mixer core. The same differential mixers, LO ports, and switching elements serve both HRM and SHM operations. By consolidating these functions, the design reduces component count, simplifies the overall circuit architecture, and improves integration efficiency while maintaining the core functionality of both mixer types.
Solution Approach 2:
The mixer core is designed as a universal platform that can perform both HRM and SHM functions. Through reconfigurable switching, the same hardware resources are allocated to different operational modes as needed, eliminating the need for separate dedicated circuits and reducing overall device complexity.
Data Source
AI summary
One embodiment is a reconfigurable mixer topology for selectively implementing one of a harmonic rejection mixer (HRM) and a subharmonic mixer (SHM), the reconfigurable mixer topology comprising a mixer core comprising a plurality of differential mixers each having a first clock input and a second clock input; a clock generator for generating a plurality of clock signals each having a different phase; and a clock distributor for distributing the plurality of clock signals to the first and second clock inputs of the differential mixers in accordance with a designated operation of the reconfigurable mixer as an HRM or an SHM.