Programmable Multi-Band LC Equalizer for On-Chip Signal Balancing
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Solution Overview
Problem
Existing multi-band filter solutions in wireless communication devices face challenges with high cost, inflexibility, noise issues, and increased power consumption due to off-chip components and fixed frequency bands, leading to noise figure increase and dynamic-range challenges in ADCs.
Innovation Solution
A multi-band equalizer using series-connected LC resonators with programmable capacitors and inductive or capacitive tapping, allowing independent tuning of center frequency and gain, suitable for on-chip integration, reducing noise and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If off-chip multi-band filters and multiple VGAs are used to equalize channel strengths, then signal strength adjustment is achieved, but device complexity and cost increase
Solution Approach 1:
The patent combines multiple resonators with different center frequencies into a single integrated equalizer circuit that processes multiple frequency bands simultaneously. This merging approach replaces the need for separate off-chip filters and multiple VGAs, achieving signal strength adjustment while reducing device complexity and cost.
Solution Approach 2:
The equalizer circuit is designed to handle multiple frequency bands (e.g., 700MHz, 800MHz, 900MHz, 1800MHz, 2100MHz) with a single unified structure. The resonators are configured to provide frequency-selective signal strength adjustment across different bands, eliminating the need for band-specific filter and VGA combinations.
2Reliability
If off-chip multi-band filters with fixed frequency bands are used, then signal filtering is achieved, but adaptability decreases
Solution Approach 1:
The equalizer employs variable gain amplifiers (VGAs) that can dynamically adjust the gain for each frequency band independently. This dynamic control allows the system to adapt to different signal conditions and frequency band requirements, overcoming the fixed frequency band limitation of traditional off-chip filters.
Solution Approach 2:
The resonators are designed with adjustable parameters including center frequency, quality factor (Q), and gain. By changing these parameters, the equalizer can be configured for different frequency bands and signal conditions, providing both effective filtering and high adaptability.
3Reliability
If multiple VGAs are used for different filter channels, then signal gain control is achieved, but noise figure increases
Solution Approach 1:
The patent combines multiple resonators and their associated VGAs into a single integrated equalizer circuit with a unified signal path. This merging reduces the total number of signal combination points, thereby minimizing noise accumulation and reducing the overall noise figure while maintaining signal gain 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 multi-band equalizer provides improved flexibility, cost-effectiveness, and reduced noise performance by enabling independent control of frequency and gain, supporting multiple bands without additional dynamic-range demands on ADCs and minimizing intermodulation distortion.
Implementation Method 1
Each resonator comprises an inductor connected between the first and second terminals and two programmable capacitors connected in series between the first terminal and second terminal
Implementation Method 2
Each resonator comprises an inductor connected between the first and second terminals
Implementation Method 3
two programmable capacitors connected in series between the first terminal and second terminal
Data Source
Figure 1~2
Figure 3
Figure 4a~4b
AI summary
On-chip Multi-band equalizers for adjusting signal strength for a receiver receiving multi-band frequency signals are provided, The multi-band equalizer comprises multiple series connected tapped LC resonators. The tapped LC resonator may be capacitive tapping or inductive tapping, where both frequency and gain of the frequency bands of interest may be programmed by tuning the capacitances of the programmable capacitors and/or selecting the tapped out terminals of the inductors. The multi-band equalizer may be connected to a signal node, for instance between two amplifiers in the receiver.