Analog Baseband Filter Blocks With Shared Capacitors for Multi-Mode RF
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-mode and multi-band wireless transceivers face challenges in efficiently filtering analog baseband signals due to the large variation in bandwidths, leading to increased circuit area and noise, as the cut-off frequency of analog baseband filters is difficult to accurately set and correct, especially when transitioning between 2G and 3G/4G modes.
Innovation Solution
A variable-gain amplifier and variable-frequency filter architecture that allows sharing of capacitors and optimization of resistor paths across multiple filter blocks, enabling efficient processing of diverse signal bands by connecting RF units to filter blocks based on selected communication modes, thereby reducing circuit area and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a capacitor for processing low band (2G) is used, then the cut-off frequency can be adjusted for low band signals, but the circuit area increases significantly
Solution Approach 1:
The filter circuit is divided into multiple filter blocks (first filter block, second filter block, third filter block) with each block having its own capacitor (first capacitor, second capacitor, third capacitor). This segmentation allows different capacitors to be selectively connected based on the operating mode (2G or 3G/4G), enabling the circuit to achieve low-band cut-off frequencies without permanently occupying the large area required for low-band capacitors in all operating conditions.
Solution Approach 2:
The circuit employs dynamic switching mechanisms where switches connect different capacitors to different filter blocks based on the selected communication mode. When 2G mode is selected, the first capacitor is connected to the first filter block; when 3G/4G mode is selected, the second and third capacitors are connected to the second and third filter blocks respectively. This dynamic reconfiguration allows the circuit area to be optimized for the current operating mode while maintaining adaptability for future mode changes.
2Area of stationary object
If the circuit area is reduced by not including all necessary capacitors, then power consumption and processing cost decrease, but the filter cannot process signals across all required frequency bands
Solution Approach 1:
Each filter block is designed to be multi-functional by having the capability to work with different capacitors depending on the operating mode. The first filter block can work with the first capacitor for 2G mode, while the second and third filter blocks can work with the second and third capacitors for 3G/4G modes. This universal design allows the same filter block structure to serve multiple frequency band requirements without dedicating separate hardware for each mode.
Solution Approach 2:
Switches act as intermediary elements that dynamically connect appropriate capacitors to appropriate filter blocks based on the selected communication mode. These switches enable the circuit to transition between different configurations (2G mode with first capacitor, 3G/4G mode with second and third capacitors) without requiring all capacitors to be permanently connected, thus reducing circuit area while maintaining full frequency band coverage capability.
3Manufacturing precision
If the circuit area increases to support low band processing, then the cut-off frequency can be accurately set for 2G mode, but the signal path length increases causing more noise and error
Solution Approach 1:
The filter circuit is divided into multiple filter blocks (first filter block, second filter block, third filter block) with each block having its own capacitor (first capacitor, second capacitor, third capacitor). This segmentation allows different capacitors to be selectively connected based on the operating mode (2G or 3G/4G), enabling the circuit to achieve low-band cut-off frequencies without permanently occupying the large area required for low-band capacitors in all operating conditions.
Solution Approach 2:
The circuit employs dynamic switching mechanisms where switches connect different capacitors to different filter blocks based on the selected communication mode. When 2G mode is selected, the first capacitor is connected to the first filter block; when 3G/4G mode is selected, the second and third capacitors are connected to the second and third filter blocks respectively. This dynamic reconfiguration allows the circuit area to be optimized for the current operating mode while maintaining adaptability for future mode changes.
4Manufacturing precision
If digital correction is applied to adjust the cut-off frequency, then the accuracy can be improved, but the complexity of the control system increases
Solution Approach 1:
The patent incorporates a feedback mechanism where the controller receives information about the selected communication mode and automatically adjusts the capacitor connections accordingly. This feedback-based control simplifies the system by using mode selection as the primary control input, eliminating the need for complex digital correction algorithms while still achieving accurate cut-off frequency settings through appropriate capacitor selection.
Data Source
AI summary
An analog baseband filter apparatus for a multi-mode and multi-band wireless transceiver and a method for controlling the analog baseband filter apparatus are provided. The analog baseband filter apparatus includes a plurality of Radio Frequency (RF) units, each of the plurality of RF units being for receiving RF signals of one of a plurality of frequency bands and outputting baseband signals, a plurality of filter blocks for filtering and amplifying the baseband signals, and a switching unit for connecting at least two of the plurality of RF units to at least one of the plurality of filter blocks according to a selected communication mode, wherein the at least one of the plurality of filter blocks is configured to be connected to a capacitor region of an adjacent filter block from among the plurality of filter blocks.