Segmented Low-Pass Filter for Cellular Receiving Circuit
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Solution Overview
Problem
Current cellular phone receiving circuits face challenges in reducing size and power consumption while maintaining sensitivity, particularly due to the need to suppress Narrow Band Blocking interference across different frequency bands, which requires optimal filter configurations that vary by band, leading to sensitivity degradation and increased current consumption.
Innovation Solution
A receiving circuit with a low-pass filter composed of multiple filters with different circuit configurations and pole positions, allowing for switching between filter configurations to optimize blocker removal and reduce sensitivity degradation, while cutting power to unused filter portions to minimize power consumption and area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a low-pass filter with cutoff frequency near 1.92 MHz is used to suppress Narrow Band Blockings in bands II to V, then blocker removal is improved, but sensitivity degradation occurs and current consumption increases
Solution Approach 1:
The filter system is segmented into multiple independent filter circuits, each optimized for specific frequency bands. A first filter circuit handles bands I and VI with higher cutoff frequency to maintain sensitivity, while a second filter circuit handles bands II to V with lower cutoff frequency to suppress Narrow Band Blockings. This segmentation allows each filter to be optimized for its specific function without compromising overall system performance.
Solution Approach 2:
The filter configuration is made dynamic through switching mechanisms that selectively activate different filter circuits based on the received signal band. The switching element dynamically reconfigures the filter path to match the active band, ensuring optimal filter characteristics are always applied. This dynamic adaptation resolves the contradiction by providing band-specific filter optimization rather than a fixed compromise configuration.
2Object-affected harmful factors
If a low-pass filter with cutoff frequency near 1.92 MHz is used to suppress Narrow Band Blockings in bands II to V, then blocker removal is improved, but power consumption increases
Solution Approach 1:
The filter system is divided into separate filter circuits that can be independently powered. The first filter circuit (for bands I and VI) and second filter circuit (for bands II to V) are segmented such that only the required circuit is activated based on the operating band. This segmentation enables selective power consumption, avoiding the need to power all filter circuits simultaneously.
Solution Approach 2:
The filter system employs periodic switching between different filter configurations based on band selection. The switching element periodically activates the appropriate filter circuit corresponding to the current operating band, ensuring that filter resources are used only when needed for specific bands requiring Narrow Band Blocking suppression, thereby reducing overall power consumption.
3Object-affected harmful factors
If multiple filter configurations are used to optimize blocker removal for different bands, then filtering performance is improved, but device area increases
Solution Approach 1:
The filter system is segmented into specialized filter circuits for different band requirements. Instead of using a single large filter that handles all bands with compromise performance, the system segments filtering functions into a first filter circuit for bands I and VI, and a second filter circuit for bands II to V. This segmentation achieves optimal blocker removal for each band while minimizing total area by only activating required filter circuits.
Solution Approach 2:
The filter system achieves multi-functionality through a unified switching architecture that can selectively activate different filter circuits based on band requirements. The switching element and control logic serve universal purposes across all bands, while the filter circuits themselves are specialized. This multi-functional approach allows one system to provide band-specific optimization without requiring separate complete filter systems for each band, thereby reducing overall device area.
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 enables a compact, low-power cellular phone receiving circuit that effectively suppresses Narrow Band Blockings across various bands, maintaining reference sensitivity and reducing power consumption by using a combination of filters with complementary characteristics.
Implementation Method 1
a low-pass filter for removing blockers unnecessary for reception
Data Source
AI summary
The present invention is a receiving circuit used for a cellular phone that is reduced in size and can realize low power consumption. In a signal reception circuit that is used in a cellular phone that perform transmission and reception of a plurality of band wireless signals and includes a low-pass filter for removing blockers unnecessary for signal reception, the low-pass filter 104 is composed of a plurality of filters composed of a plurality of different circuit configurations and having a plurality of different pole positions, switching between a filter for blocker removal and a filter configuration with reduced sensitivity degradation is performed by combining a plurality of filters for each signal reception band, and by performing power-off of an unnecessary filter portion in the filter configuration, power consumption is reduced. By constituting a plurality of different filters using filters mutually complementing their characteristics, a redundant filter configuration can be avoided, so that the area thereof can be suppressed to necessity minimum, and cost can be reduced.