Parallel RF Attenuator Circuit for Wide-Range Impedance Matching
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Solution Overview
Problem
Existing wireless chips with multiple transceivers operating in dual frequency bands face challenges in maintaining impedance matching due to the use of RF attenuators, which affect signal levels, linearity, noise, and device reliability.
Innovation Solution
Implementing a controller to manage programmable resistive and capacitive attenuators in parallel with amplifiers to maintain impedance matching across a wide attenuation range, using a configuration that includes a first amplifier, a first resistive attenuator, a second amplifier, and a second attenuator, with independent control of attenuation levels to ensure low reflection coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single RF attenuator is used to scale signal levels, then the attenuation range is limited, but the impedance matching deteriorates
Solution Approach 1:
The patent divides the single attenuator function into multiple parallel attenuators (first attenuator and second attenuator) with different attenuation ranges. The first attenuator provides 0-15 dB range while the second provides 15-30 dB range, allowing the system to achieve both wide overall attenuation range and precise impedance matching by selecting the appropriate attenuator for the required attenuation level.
2Ease of operation
If RF attenuators are used to scale signal levels, then signal power levels can be controlled, but linearity deteriorates
Solution Approach 1:
By segmenting the attenuation function across two parallel paths with different attenuators, the system maintains better linearity. Each attenuator operates within its optimized range, and the parallel amplifier configuration ensures that signal processing remains linear across the full 0-30 dB attenuation range.
3Power
If RF attenuators are used to scale signal levels, then signal power can be reduced, but noise increases
Solution Approach 1:
The segmented attenuator configuration allows the system to apply minimal necessary attenuation through the first attenuator for small adjustments, keeping noise low. For larger attenuations, the second attenuator handles the bulk of the signal reduction, maintaining optimal noise performance across the entire attenuation range.
4Ease of operation
If RF attenuators are used to scale signal levels, then signal power can be controlled, but device reliability deteriorates
Solution Approach 1:
Distributing the attenuation function across two parallel paths with separate attenuators reduces the stress and wear on any single component. This segmentation improves device reliability by preventing any one attenuator from operating at extreme limits, thereby extending overall system lifespan while maintaining full signal control capability.
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 provides a wide attenuation range of at least 20 decibels while maintaining low impedance mismatch, improving linearity and reducing noise and device reliability concerns.
Implementation Method 1
a first amplifier coupled to a first node of a receiver signal processing path, the first amplifier to receive and amplify a radio frequency (RF) signal; a second amplifier coupled in parallel with the first amplifier, the second amplifier to receive and amplify the RF signal
Implementation Method 2
a first resistive attenuator coupled to the first node, the first resistive attenuator programmable to reduce a level of the RF signal; and a second attenuator coupled between the first node and the second amplifier, the second attenuator programmable to reduce the level of the RF signal
Data Source
AI summary
In one aspect, an apparatus includes: a first amplifier coupled to a first node of a receiver signal processing path, the first amplifier to receive and amplify a radio frequency (RF) signal; a first resistive attenuator coupled to the first node, the first resistive attenuator programmable to reduce a level of the RF signal; a second amplifier coupled in parallel with the first amplifier, the second amplifier to receive and amplify the RF signal; and a second attenuator coupled between the first node and the second amplifier, the second attenuator programmable to reduce the level of the RF signal.