Power Amplifier Co-Existence Filter for WCDMA-WLAN Interference
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Solution Overview
Problem
Conventional mobile handsets face challenges in multitasking between WCDMA and WLAN modalities due to spurious noise and interference, leading to degraded reception sensitivity and increased current consumption, necessitating external co-existence filters that increase size and cost.
Innovation Solution
Incorporation of an on-die co-existence filter and compensation circuit within the power amplifier architecture to attenuate WLAN transmit signals coinciding with WCDMA reception frequencies, eliminating the need for external filters and improving sensitivity and reducing current consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external co-existence filters are used to minimize WLAN interference with WCDMA reception, then WCDMA reception sensitivity is improved, but device footprint and cost increase
Solution Approach 1:
The co-existence filter is integrated directly into the power amplifier circuitry, merging two previously separate functions (power amplification and interference filtering) into a single unified circuit. This eliminates the need for external filters while maintaining WCDMA reception sensitivity during concurrent WLAN operation.
Solution Approach 2:
The power amplifier is designed to perform multiple functions: it provides power amplification for WLAN transmissions while simultaneously acting as a co-existence filter to protect WCDMA reception. This multi-functionality reduces the overall component count and device footprint.
2Reliability
If external co-existence filters are used to attenuate WLAN transmit signals, then WCDMA reception sensitivity is improved, but current consumption increases
Solution Approach 1:
The filtering function is combined with the power amplifier circuitry, eliminating the need for separate external filter components that would consume additional current. The integrated design uses the same circuit elements for both amplification and filtering, reducing overall power consumption.
3Reliability
If external co-existence filters are used to prevent WLAN interference, then reception sensitivity is improved, but device cost increases
Solution Approach 1:
The co-existence filter functionality is integrated into the power amplifier circuit, eliminating the need for separate external filter components. This reduces the bill of materials cost and simplifies the manufacturing process while maintaining the ability to attenuate WLAN transmit signals that interfere with WCDMA reception.
Solution Approach 2:
The power amplifier performs dual functions as both an amplifier and a co-existence filter, reducing the total component count and associated costs while maintaining reception sensitivity during concurrent WLAN operation.
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 enhances WCDMA and WLAN reception sensitivity while reducing the overall footprint and cost of the front-end system, achieving minimal degradation of less than 0.5 dB in WCDMA reception sensitivity with concurrent WLAN operation.
Implementation Method 1
band-pass co-existence filters are used to minimize the degradation of the WCDMA receive chain sensitivity
Data Source
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AI summary
A power amplifier architecture and front end circuits utilizing the same that connect a transceiver to an antenna are disclosed. The transceiver is configured for a specific operating frequency. An input matching segment is connected to an input port, and an output matching segment is connected to an output port. An amplifier segment includes at least one transistor with a first terminal connected to the input matching segment, a second terminal connected to the output matching segment, and a third terminal connected to a filter with a range of rejection frequencies. The filter is connected in close proximity to a first inductive interconnection tying a junction connected to the third terminal to a ground. A compensator is also connected to the input matching segment and the output matching segment to minimize instability of the filter.