Tunable Waveguide Isolator for RF Microwave Signal Isolation
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Solution Overview
Problem
Existing electrosurgical apparatuses face challenges in accurately measuring reflected power due to high insertion losses in microwave and RF channels, which affect the precision of energy delivery and tissue treatment during surgical procedures.
Innovation Solution
A tunable waveguide isolator with adjustable impedance is introduced at the junction between the microwave channel and signal combiner, reducing return losses and improving measurement sensitivity, while a capacitive structure minimizes capacitive coupling to prevent RF energy leakage into the microwave channel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a waveguide isolator is added at the junction between microwave channel and signal combiner, then measurement precision is improved, but device complexity increases
Solution Approach 1:
A waveguide isolator is introduced as an intermediary component at the junction between the microwave channel and signal combiner. This isolator acts as a mediator that allows microwave signals to pass through while blocking reflected power from the RF channel, thereby improving measurement precision without requiring complete system redesign
Solution Approach 2:
The signal pathway is segmented into distinct microwave and RF channels with separate signal pathways. The waveguide isolator is placed specifically at the microwave channel junction, creating modular sections that can be independently optimized and maintained, reducing overall system complexity through functional separation
2Object-affected harmful factors
If capacitive structure is added to minimize capacitive coupling, then harmful factors are reduced, but device complexity increases
Solution Approach 1:
A capacitive structure is introduced as an intermediary element within the feed structure to minimize capacitive coupling between the RF and microwave channels. This capacitive mediator blocks RF energy leakage into the microwave channel while maintaining necessary signal transmission, reducing harmful electromagnetic interference without requiring complete isolation
Solution Approach 2:
The capacitive structure is applied locally at specific coupling points within the feed structure where RF energy leakage is most problematic. Rather than implementing universal isolation throughout the entire system, the capacitive elements are strategically placed only where needed to block harmful coupling, minimizing overall device 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
This solution enhances the accuracy of reflected power measurements, leading to improved energy delivery profiles and therapeutic outcomes in electrosurgical procedures by reducing unwanted energy leakage and increasing the safety and precision of tissue cutting and coagulation.
Implementation Method 1
A tunable waveguide isolator with adjustable impedance is introduced at the junction between the microwave channel and signal combiner, reducing return losses
Implementation Method 2
a capacitive structure minimizes capacitive coupling to prevent RF energy leakage into the microwave channel
Implementation Method 3
as an electric current passes through a tissue matrix (aided by the ionic contents of the cells and the intercellular electrolytes), the impedance to the flow of electrons across the tissue generates heat
Implementation Method 4
When an RF voltage is applied to the tissue matrix, enough heat is generated within the cells to vaporise the water content of the tissue
Implementation Method 5
surgical apparatus capable of generating radiofrequency (RF) energy for cutting tissue. It may be used in as part of a surgical apparatus which also delivers microwave frequency energy for haemostasis (i.e. sealing broken blood vessels by promoting blood coagulation)
Data Source
AI summary
An isolating circuit for electrosurgical generator arranged to produce radiofrequency (RF) energy and microwave energy for treating biological tissue. The generator has an RF channel and a microwave channel which are combined at signal combiner to enable the RF energy and microwave energy to be delivered into tissue along a common feed path. The isolating circuit comprises a tunable waveguide isolator at a junction between the microwave channel and signal combiner, and can include a capacitive structure between a ground conductor of the signal combiner and a conductive input section of the waveguide isolator to inhibit coupling of the RF energy and leakage of the microwave energy. The isolating circuit can combine into a single tunable unit all the necessary components to isolate the microwave and RF channels from one another whilst providing a high withstanding voltage.