Integrated Balanced Duplexer for Ultra-Wideband TX-RX Isolation
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Solution Overview
Problem
Existing duplexers for 5G wireless systems face challenges in achieving high isolation and low insertion loss, particularly at millimeter wave frequencies, due to limitations in integration, bandwidth, and power consumption, which affect signal transmission and reception efficiency.
Innovation Solution
A fully-integrated duplexer module on a silicon substrate, incorporating a transformer and Wilkinson power combiner, provides high isolation and low insertion loss by canceling differential leakage signals and suppressing noise, allowing simultaneous transmission and reception using a power amplifier and low-noise amplifier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If SAW or BAW filters are used for duplexer design, then filtering performance is improved, but integration with semiconductor substrate is difficult and operation above 10 GHz is not achieved
Solution Approach 1:
The patent replaces traditional mechanical/acoustic filter systems (SAW/BAW) with an electrical balanced duplexer implementation using lumped-element LC circuits and transmission line structures that can be fully integrated into standard CMOS semiconductor substrates, enabling operation up to 100 GHz while maintaining filtering performance
Solution Approach 2:
The patent changes the operating parameters and frequency range by designing the EBD with specific LC component values and transmission line dimensions optimized for millimeter-wave frequencies up to 100 GHz, overcoming the 10 GHz limitation of conventional filters
2Ease of operation
If ferrite circulators are used for duplexer design, then signal routing is improved, but device size becomes bulky and integration into integrated circuits is difficult
Solution Approach 1:
The patent replaces bulky ferrite circulator components with planar electrical balanced duplexer circuits implemented using LC lumped elements and transmission lines on semiconductor substrate, achieving the same signal routing function with compact integrated circuit geometry suitable for CMOS fabrication
Solution Approach 2:
The patent merges the circulator's signal routing function with the duplexer's transmit-receive separation function into a single integrated EBD circuit structure, eliminating the need for separate ferrite circulator components and reducing overall device complexity
3Ease of manufacture
If passive components are used for duplexer design, then integration is improved, but bandwidth becomes narrow and chip area occupied is relatively large
Solution Approach 1:
The patent implements a dynamically adjustable EBD structure where the balanced transformer and LC components can be tuned across wide frequency ranges, enabling ultra-wide bandwidth operation from DC to 100 GHz while maintaining compact integration on the chip
Solution Approach 2:
The patent extends the operational bandwidth by utilizing multi-octave frequency coverage through carefully designed LC resonant circuits and transmission line structures that operate effectively across DC to 100 GHz, transforming the narrowband limitation into ultra-wideband capability
4Ease of manufacture
If EBD-based duplexer is used, then integration is improved, but TX-RX isolation degrades at high frequencies above 2.5 GHz
Solution Approach 1:
The patent employs a composite structure combining balanced transformers with LC lumped-element circuits and transmission line structures, creating an integrated EBD design that maintains high TX-RX isolation performance at millimeter-wave frequencies up to 100 GHz through synergistic component interaction
Solution Approach 2:
The patent introduces carefully designed LC matching networks and balanced transformer structures as intermediary elements that maintain signal integrity and isolation performance at high frequencies, acting as mediators between the PA and LNA to prevent degradation of TX-RX isolation above 2.5 GHz
5Reliability
If active devices are used for duplexer design, then linearity is improved, but power consumption increases and receiver noise performance degrades
Solution Approach 1:
The patent replaces active devices requiring power consumption with a fully passive EBD implementation using LC circuits and transmission lines, achieving sufficient linearity for large PA signals without the need for powered components, thereby eliminating the trade-off between linearity and power consumption
Solution Approach 2:
The patent uses simple passive LC components and transmission line structures instead of complex active devices, achieving the desired linearity performance with low-cost, low-power-consuming passive elements that do not degrade receiver noise performance
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 achieves at least 40 dB isolation and less than 10 dB insertion loss across a wide frequency range, enhancing signal integrity and reducing desensitization of the receiver, thus improving overall system performance.
Implementation Method 1
The duplexer includes a transformer and a power combiner. The duplexer is configured to receive differential TX signals, and simultaneously transmit one of the differential TX signals and receive a RX signal
Data Source
AI summary
Architectures of millimeter wave fully-integrated frequency-division duplex (FDD) transmitting-receiving (T/R) front-end (FE) modules include a duplexer (DUX), power amplifier (PA), and low noise amplifier (LNA) on a single semiconductor substrate to facilitate the development of system on a chip (SoC) for millimeter wave 5G wireless and next-generation communications applications. The entire balanced DUX module implements TX signals in differential mode, and RX signals in single-ended mode. LNA input is located at the center of a symmetrical plane of the entire FE module, resulting in an inherent ultra-high isolation between the differential PA output ports and the LNA input port across a ultra-wide bandwidth. The DUX can stand alone as a single unit in a system and is used together with external PA and LNA provided in the system, or it can include its own internal PA and LNA to form a DUX FE module.