Multimode Receiver Blocker Cancellation Circuit
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Solution Overview
Problem
Wireless transceiver systems face challenges in accommodating multiple bands and modes while minimizing component count and cost, as conventional approaches often lead to increased insertion loss and require external amplifiers due to the need for blocker rejection across various band modes like GSM and UMTS.
Innovation Solution
A wireless multimode receiver is designed with on-chip duplex filters and blocker cancellation circuits using feed-forward cancellation, integrating more components onto a single semiconductor die to reject unwanted blocker signals and select between different receiving modes, thereby reducing the need for off-chip amplification and filtering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple duplex filters are used to satisfy blocker rejection requirements for different band modes, then blocker rejection performance is improved, but device complexity and component count increase
Solution Approach 1:
The patent combines multiple duplex filters into a single shared duplex filter that serves multiple band modes (GSM and UMTS). The blocker cancellation circuit is integrated on-chip to provide the additional filtering function that would otherwise require separate off-chip filters. This merging reduces component count while maintaining blocker rejection performance through the combined approach of shared filtering and active cancellation.
Solution Approach 2:
The shared duplex filter is designed to handle multiple frequency bands and modes universally. The blocker cancellation circuit is configured to provide blocker rejection for both GSM-EDGE and UMTS modes simultaneously. This multi-functional design allows a single filter component to replace what would traditionally require multiple dedicated filters for different bands and modes.
2Reliability
If external low-noise amplifiers and interstage filters are used to improve receiver performance, then receiver sensitivity and blocker damping are improved, but cost and device complexity increase
Solution Approach 1:
The patent integrates the blocker cancellation function directly onto the semiconductor chip with the receiver circuitry, eliminating the need for separate off-chip interstage filters. The shared duplex filter handles both GSM and UMTS bands, reducing the need for multiple external filtering components. This integration reduces bill of materials cost and assembly complexity while maintaining performance through the active cancellation mechanism.
Solution Approach 2:
The blocker cancellation circuit acts as an intermediary between the shared duplex filter and the receiver front-end. It provides the additional filtering and damping function that would otherwise require separate external components, mediating between the coarse filtering of the shared duplex filter and the sensitive receiver circuitry to achieve both cost reduction and performance maintenance.
3Adaptability or versatility
If conventional approaches are used to support multiple bands and modes, then band compatibility is improved, but insertion loss increases
Solution Approach 1:
The patent merges multiple band-specific filtering functions into a single shared duplex filter. By using one filter for both GSM and UMTS bands rather than separate filters, the signal path is simplified and insertion loss is reduced. The blocker cancellation circuit compensates for the relaxed filtering requirements, allowing the shared filter to operate with lower loss while maintaining compatibility with multiple bands and modes.
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 solution decreases the size, cost, and component count of receivers by integrating blocker rejection and filtering on-chip, enhancing the ability to support multiple frequency bands and modes while minimizing power consumption and insertion loss.
Implementation Method 1
a blocker cancellation circuit coupled to the duplex filter and configured to reject unwanted blocker signals from the receiver based on a compensation method employing feed-forward cancellation
Implementation Method 2
The method comprises filtering the receive signal comprising first and second receive modes operating within a predetermined frequency band
Data Source
AI summary
Various embodiments of a wireless multimode receiver having an off-chip duplex filter associated with a multimode band, and a blocker cancellation circuit disposed on a semiconductor chip are described in the present disclosure.