Active Multiband Filter Circuitry With Switchable Impedance Matching
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Solution Overview
Problem
Designing filter and amplifier circuitry for wireless communications in electronic devices is challenging due to the high cost of implementing passive bandpass filters and the complexity of integrating them with low noise amplifiers.
Innovation Solution
The implementation of a circuitry system that includes switchable matching circuits and lowpass-to-bandpass conversion filters, combined with a signal combiner and frequency shifting circuit, allows for efficient handling of multiple frequency bands with a single receive path, reducing costs and simplifying the transceiver design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passive bandpass filters are implemented in wireless communications circuitry, then signal filtering performance is improved, but implementation cost increases
Solution Approach 1:
The patent replaces passive mechanical/acoustic bandpass filters with active electronic filter circuitry that uses switches, resistors, capacitors, and inductors to achieve frequency-selective filtering. This substitution eliminates the need for costly passive filters while maintaining filtering functionality through electronic control mechanisms.
Solution Approach 2:
The patent employs switchable impedance matching circuits that can dynamically change their electrical parameters (impedance values) to optimize performance across multiple frequency bands. By adjusting circuit parameters electronically rather than using fixed passive components, the system achieves versatile filtering and matching capabilities at lower cost.
2Reliability
If passive bandpass filters are integrated with low noise amplifiers, then receiver functionality is improved, but design complexity increases
Solution Approach 1:
The patent combines multiple filter circuits operating at different frequency bands with a single low noise amplifier and signal combiner. By merging the filter outputs and using a shared amplifier, the design reduces the number of separate receiver paths needed, thereby simplifying the overall architecture while maintaining multi-band functionality.
Solution Approach 2:
The patent creates a universal receiver architecture where a single low noise amplifier and signal processing path can handle multiple frequency bands. The switchable matching circuits and filter bank enable one amplifier to serve multiple functions across different bands, reducing design complexity compared to having separate amplifier paths for each band.
3Adaptability or versatility
If multiple frequency bands are handled with separate receive paths, then frequency band coverage is improved, but transceiver design complexity increases
Solution Approach 1:
The patent segments the signal processing into two stages: frequency-selective filtering at the front end using switchable filter circuits, and then combined signal processing through a single amplifier path. This segmentation allows different frequency bands to be handled independently at the filtering stage while converging to a unified processing path later, maintaining band coverage without proportional increase in overall complexity.
Solution Approach 2:
The patent adds the dimension of time-dynamic switching to the frequency domain filtering. By using switchable matching circuits and filter banks that can be configured in real-time, the system handles multiple frequency bands through a single spatial path, effectively adding a temporal control dimension that reduces the need for parallel physical paths.
Data Source
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AI summary
Wireless circuitry can include a first filter circuit configured to output signals in a first frequency range, a second filter circuit configured to output signals in a second frequency range different than the first frequency range, and a signal combiner having a first input coupled to the first filter circuit and having a second input coupled to the second filter circuit. The wireless circuitry can further include a first switchable impedance matching circuit coupled between an antenna and the first filter circuit and a second switchable impedance matching circuit coupled between the antenna and the second filter circuit. The first and second filter circuits can be active filters such as lowpass-to-bandpass conversion filters operable in different frequency bands.