SAW Filtered Multi-Band Amplification With Noise-Terminating Network
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Solution Overview
Problem
RF electronics face challenges in amplifying aggregated carrier component signals due to significant noise and gain differences among different frequency bands, which affect overall signal quality.
Innovation Solution
A device comprising a filter that separates aggregate signals into sub-signals of different frequency bands, followed by low noise amplifiers and a switchable passive network that terminates unwanted frequency components, ensuring consistent gain and reduced noise across all bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple bandpass filters are used to receive aggregated component carriers in different frequency bands, then the device can simultaneously receive multiple frequency bands, but significant noise and gain differences are introduced among the different received frequency bands
Solution Approach 1:
The aggregate signal is separated into multiple sub-signals corresponding to different frequency bands using bandpass filters. Each sub-signal is then processed independently through dedicated amplifiers, allowing individual gain control for each frequency band to compensate for the noise and gain differences introduced by the filtering process.
Solution Approach 2:
Different gain control mechanisms are applied to different frequency bands. Each amplifier associated with a specific frequency band has its own gain control circuitry, allowing the gain to be locally adjusted for each band to achieve uniform overall gain across all aggregated bands despite the varying characteristics introduced by each bandpass filter.
2Productivity
If signals are amplified and combined onto a single path after filtering, then the aggregated signal can be processed further, but noise and gain differences among the different received frequency bands affect overall signal quality
Solution Approach 1:
The system incorporates feedback mechanisms where the output signals from each frequency band are monitored and used to adjust the gain of corresponding amplifiers. This feedback loop ensures that variations in noise and gain characteristics introduced by the bandpass filters are compensated, maintaining consistent signal quality across all frequency bands while enabling continued processing of the aggregated signal.
3Adaptability or versatility
If independent bandpass filters are used for each frequency band, then each band can be received separately, but the device complexity increases
Solution Approach 1:
The bandpass filters are designed and configured to handle multiple frequency bands within a unified architecture. Rather than requiring completely separate filter systems for each band, the same filter structure and processing pipeline are used across all frequency bands, with only the filter tuning parameters varying. This universal approach maintains frequency band separation capability while reducing overall device complexity.
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 solution effectively reduces noise and improves gain consistency across multiple frequency bands, enhancing the overall signal quality in RF electronics by selectively terminating unwanted frequencies and matching impedance for optimal amplification.
Implementation Method 1
the filter includes a surface acoustic wave (SAW) filter
Implementation Method 2
at least one filter that receives an aggregate signal having a plurality of signal components of different frequency bands and separates the aggregate signal into a plurality of sub-signals of different frequency bands
Implementation Method 3
a plurality of amplifiers that receive the plurality of sub-signals from the plurality of different outputs and amplify the plurality of sub-signals; the plurality of amplifiers include low noise amplifiers formed of field effect transistors or bipolar junction transistors
Implementation Method 4
the passive network includes a resistor in parallel with an inductor
Implementation Method 5
the network includes components selected to terminate at least a portion of the signals on the plurality of outputs that have a frequency outside of the frequency band corresponding to the output
Data Source
AI summary
A surface acoustic wave (SAW) filter that receives an aggregate circuit and outputs two or more sub-signals on outputs each of a different frequency band. The sub-signals are amplified by low noise amplifiers and, in one implementation, the amplified sub-signals can be summed. The outputs are connected via a switched passive network so that portions of the sub-signals on the outputs that are not in the selected frequency band are at least partially terminated.