Electronically Tunable Active Duplexer Using Varactor Phase Shifters
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Solution Overview
Problem
Current wireless transceiver duplexers suffer from insertion loss, lack of tunability, and inadequate signal amplification, with existing tunable duplexers exhibiting poor repeatable performance across desired frequency bands.
Innovation Solution
An electronically tunable active duplexer utilizing varactors in phase shifting networks between distributed amplifier gain cells, allowing precise electronic tuning of isolation frequency and providing amplification in both transmit and receive modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If passive filters are used in duplexers, then isolation between transmitter and receiver is provided, but insertion loss occurs across the device
Solution Approach 1:
The patent replaces passive mechanical filter systems with an active electronic system using distributed amplifier cells and phase shifting networks. This substitution enables signal amplification while maintaining isolation, eliminating the insertion loss inherent in passive filter-based duplexers.
Solution Approach 2:
The patent introduces electronically controllable parameters through variable phase shifters and amplifier gain control, allowing dynamic adjustment of isolation and signal levels. This enables the system to adaptively optimize performance rather than being fixed at design values.
2Object-affected harmful factors
If fixed capacitor values are used in phase shifting networks, then isolation at a given frequency is achieved, but the duplexer is not tunable
Solution Approach 1:
The patent transforms the static phase shifting networks into dynamic systems by incorporating variable phase shifters and electronically controllable components. This enables real-time tuning of the isolation frequency and level, allowing the duplexer to adapt to different operating conditions and frequency requirements.
3Adaptability or versatility
If mechanically adjustable capacitors are used to enable tuning, then frequency adjustment is possible, but repeatable performance across desired frequency bands is poor
Solution Approach 1:
The patent replaces mechanical adjustment mechanisms with solid-state electronic control systems. This substitution eliminates the mechanical wear, contact resistance, and positioning inaccuracies that degrade repeatable performance, while maintaining full frequency tuning capability through electronic means.
Solution Approach 2:
The patent incorporates control systems that can automatically adjust and maintain optimal performance parameters. The electronically controllable amplifiers and phase shifters can be programmed to achieve precise, repeatable settings across frequency bands without manual intervention.
4Power
If distributed amplifier cells are used, then signal amplification is provided, but device complexity increases
Solution Approach 1:
The patent divides the amplification function into multiple distributed amplifier cells, each handling a portion of the signal. This segmentation allows for modular design and independent optimization of each cell, managing overall complexity while achieving high total gain through cascaded stages.
Solution Approach 2:
The patent designs the distributed amplifier cells and phase shifting networks to serve multiple functions simultaneously. The same structural elements provide both signal amplification and phase control, reducing the need for separate dedicated components and thereby managing complexity.
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 high isolation (>50 dB) and gain (3.9-5.3 dB) across desired frequency ranges, with improved tunability and stability, suitable for both antenna configurations A and B, and suitable for monolithic implementation.
Implementation Method 1
the phase shifting network comprises a varactor (7). The incorporation of varactors, instead of fixed or mechanically adjustable capacitors, in phase shifting networks enables one to electronically tune, with ease and precision, the frequency at which isolation is desired
Data Source
AI summary
This invention provides a novel electronically tunable active duplexer for wireless transceiver applications. It relates to an active duplexer with full-duplex operation, permitting simultaneous transmission and reception of signals at same or different frequencies. It incorporates varactors, instead of fixed or mechanically adjustable capacitors, in phase shifting networks enabling one to electronically tune, with ease and precision, the frequency at which isolation is desired, over a band in both transmit and receive modes of operations. It can be implemented as a Monolithic Microwave Integrated Circuit (MMIC).