Programmable Baseband Filter Switching for Stopband Rejection

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Solution Overview

Problem

Current baseband filters in wireless communication devices face challenges in adapting to different frequency channels without increasing the integrated circuit (IC) footprint, leading to inferior stopband rejection and higher noise levels, especially in 5G NR and GSM applications.

Innovation Solution

A programmable baseband filter configuration that includes a pair of filters with switching devices to selectively couple and decouple components, allowing for single-pole or complex-pole configurations, thereby optimizing filter performance across various bandwidths and noise levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a baseband filter is designed with fixed single-pole configuration, then the IC footprint remains compact, but stopband rejection and noise performance deteriorate in certain frequency channels

Engineering Contradiction:

ImproveIC footprintVSAvoidstopband rejection

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The filter design enables dynamic reconfiguration between single-pole and complex-pole configurations using switching devices. This allows the filter to adapt its pole structure based on the required frequency channel, improving stopband rejection when needed while maintaining compact size through shared circuitry.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The filter circuit is designed to perform multiple functions by sharing common components between single-pole and complex-pole configurations. The same filter circuit can be reconfigured to provide different pole structures, eliminating the need for separate dedicated circuits for each configuration and maintaining compact IC footprint.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a baseband filter is designed with fixed complex-pole configuration, then stopband rejection improves, but the IC footprint and circuit complexity increase

Engineering Contradiction:

Improvestopband rejectionVSAvoidIC footprint

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The filter enables dynamic selection between single-pole and complex-pole configurations based on the operating frequency channel. Switching devices allow the circuit to transition between configurations, providing high stopband rejection only when complex-pole mode is activated, rather than maintaining the larger circuit structure continuously.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The design merges the single-pole and complex-pole filter configurations into a single integrated circuit structure. Common components such as amplifiers, resistors, and capacitors are shared between configurations, with switching devices enabling selective activation of complex-pole elements only when needed.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If switching devices are added to enable filter reconfiguration, then adaptability to different frequency channels improves, but device complexity increases

Engineering Contradiction:

Improvefrequency channel adaptationVSAvoidcircuit complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The filter incorporates switching devices that enable dynamic reconfiguration between single-pole and complex-pole configurations. This allows the filter to adapt to different frequency channels and performance requirements while using a unified circuit structure, reducing the need for multiple separate filter circuits.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The filter circuit is designed as a universal structure that can operate in both single-pole and complex-pole modes. Switching devices control the activation of specific circuit elements, allowing the same hardware to provide different filtering characteristics based on the required frequency channel without requiring separate dedicated circuits.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

This approach enhances stopband rejection and reduces noise, particularly in 5G NR and GSM applications, while maintaining a compact IC footprint, thus improving signal-to-noise ratio and cost-effectiveness.

Implementation Method 1

Methodology Applied

Scientific EffectFilter (electronic): Filter (electronic)

Implementation Method 2

The filter includes a first amplifier; first and second resistors coupled in series between a first input of the filter and a first input of the first amplifier

Methodology Applied

Scientific EffectAmplification:

Data Source

PatentUS11863140B2Programmable baseband filter for selecting between single-pole or complex-poles frequency response

Publication Date: 2024.01.02 QUALCOMM INC

AI summary

An aspect includes a filtering method including operating a first filter to filter a first input signal to generate a first output signal; operating a second filter to filter a second input signal to generate a second output signal; and merging at least a portion of the second filter with the first filter to filter a third input signal to generate a third output signal. Another aspect includes a filtering method including operating switching devices to configure a filter with a first set of pole(s); filtering a first input signal to generate a first output signal with the filter configured with the first set of pole(s); operating the switching devices to configure the filter with a second set of poles; and filtering a second input signal to generate a second output signal with the filter configured with the second set of poles.