Design Of Impedance Matching Network Research Articles

Dual-Frequency Impedance Matching Network Design Using Genetic Algorithm for Power Ultrasound Transducer.

Dual-frequency ultrasounds have demonstrated significant potential in augmenting thermal ablation efficiency for tumor treatment. Ensuring proper impedance matching between the dual-frequency transducer and the power amplifier system is imperative for equipment safety. This paper introduces a novel dual-frequency impedance matching network utilizing L-shaped topology and employing a genetic algorithm to compute component values. Implementation involved an adjustable capacitor and inductor network to achieve dual-frequency matching. Subsequently, the acoustic parameters of the dual-frequency HIFU transducer were evaluated before and after matching, and the effects of ultrasound thermal ablation with and without matching were compared. The proposed dual-frequency impedance matching system effectively reduced the standing wave ratio at the two resonance points while enhancing transmission efficiency. Thermal ablation experiments with matching circuits showed improved temperature rise efficiencies at both frequencies, resulting in an expanded ablation zone. The dual-frequency impedance matching method significantly enhances the transmission efficiency of the dual-frequency ultrasound system at two operational frequencies, thereby ensuring equipment safety. It holds promising prospects for application in dual-frequency ultrasound treatment.

A multi‐variable double impedance matching network design algorithm with design example of a low noise amplifier

In this article, we propose a matching network design algorithm based on the segmentation of the real and imaginary part of optimum source impedance curve with respect to space variable x $$ x $$ and frequency ω $$ \omega $$ , respectively. The impedance curve (comprising of real and imaginary parts) is approximated as a collection of n $$ n $$ linear segments, represented by the weighted sum of n $$ n $$ semi-infinite linear functions. Using the numerical method, optimum weight vectors that maximize transducer power gain are obtained to model the real and imaginary parts of the source impedance curve. We get the values of optimum weight vectors and the rational input impedance function for the matching network, which are then synthesized in the desired topology by a continued partial fraction. Experimentally, we validate the novelty of the proposed method by designing matching networks of a wideband custom monolithic microwave integrated circuit (MMIC) low noise amplifier (LNA) in 1.3–2.3 GHz frequency band. The measured results of the designed LNA are significantly close to the simulated results. We bias our LNA at (5 V, 150 mA) and achieve a maximum noise figure of 1.25 dB, OP1dB of 26 dBm, and an average TOI of 38 dBm. Moreover, our design of custom LNA MMIC has an integrated ESD structure while occupying only 0.32 mm2 of chip area.

Design of impedance matching network based on optimized real frequency algorithm

In the recent couple of decades, some multifunctional spaceborne active radars had been launched. Those radars used to be broadband radars using dipole transmitting antennas. The odd-order resonant frequency of the antenna does not completely cover the operating frequency of the entire radar, so this may cause the antenna's radiation efficiency to deteriorate. The typical method to solve this problem was to design an impedance matching network system for broadband antennas to achieve a good voltage standing wave ratio and transmit power gain. In this paper, a new optimized real-frequency method was designed, and a 0.4-meter dipole antenna was tested before and after impedance matching. The measured results showed that the impedance matching network obtained by the optimized real-frequency method proposed in this paper can improve the antenna radiation efficiency, and can effectively reduce the standing wave ratio to avoid damage to the transmitter caused by high echo power.

Theory and Design of Impedance Matching Network Utilizing a Lossy On-Chip Transformer

In this paper, we present a study on a transformer-based impedance matching network. We use a simplified transformer model comprising two magnetically coupled coils, which are driven by a source and terminated by a load. The formulae of the load and the source impedance for conjugate matching of both sides of the transformer are presented, and a figure of merit is proposed for the evaluation of the power transfer efficiency of the transformer under conjugate matching conditions. Analytical expressions are provided for constructing the widely used transformer network consisting of a resistive load and a parallel tuning capacitor. To verify the proposed work, we examined various on-chip transformers implemented in 0.18 μm CMOS technology. Simulation and measurement results for a matching network synthesized using the aforementioned analytical expressions corresponded well with the result of analysis for operating frequencies up to 72% of the self-resonant frequency of the transformer. The presented results confirm that the proposed analytical formulae based on the simplified transformer model are useful for the design and optimization of transformer-based impedance matching networks in the microwave and millimeter-wave regimes.

Design of Impedance Matching Networks for RF Applications

This technical paper presents a design and study of impedance matching for RF (radio frequency) circuit application of common-source amplifier topology. Input and output matching networks of the amplifier were designed and computed ensuring unconditional stability. Inductors and capacitors are key passive components that are crucial for impedance matching, and are specifically designed such that they would satisfy the gain requirements at a specific frequency of operation. Impedance matching is necessary in RF circuit design to provide maximum possible power transfer between the source or the generator and the load. Complex tradeoffs among technology specifications and design parameters exist and should be carefully handled when designing the impedance matching networks, to optimize the performance of the amplifier.Â

Equivalent circuit model of a rectangular RF driven hydrogen ion source for impedance matching network design

KAERI is presently developing a rectangular RF driven deuterium ion source for both neutron source and fusion applications. For a model-based design of a reliable impedance matching network for the ion source, we extend an equivalent circuit model of the ion source system by allowing effects of an isolation transformer and a Faraday shield on the system to be reflected in our previous model (Huh et al., 2017 Fusion Eng. Des.121 337). In this paper we use the model to investigate the trends in external electrical characteristics of the ion source system (e.g., voltage and current across and through an RF antenna coil and the impedance matching network circuit components) with RF power of up to 50 kW. The model results provide criteria for the impedance matching network design and data for an assessment of the ion source performance.

Variability Analysis of T Network Impedance Matching

Harmonic rejection ability and reflection coefficient are the most important factors in the design of impedance matching network. However, stability of impedance matching should be taken into account in applications existing load impedance variation and component deviation due to tolerance and process variation. This paper investigates variability of T network impedance matching analytically. The formulas for calculating the resulting reflection coefficient caused by parameter variations are derived from quality factor-based design method. The analysis results can provide reference for design process and an opportunity for a better understanding of the dynamic behavior of the narrowband impedance-matching networks.

Variability Analysis of Pi Network Impedance Matching

Harmonic rejection ability and reflection coefficient are the most important factors in the design of impedance matching network. However, stability of impedance matching should be taken into account in applications existing load impedance variation and component deviation due to tolerance and process variation. This paper investigates variability of Pi network impedance matching analytically. The relationships between resulting reflection coefficient with component deviation and load impedance variation are theoretically derived on the basis of Q-based design method. The deviation from perfect match due to component deviation is proportional to quality factor. Higher quality factor probably means poorer quality in terms of variability. The resulting reflection coefficient caused by load impedance variation increases rapidly when the load reflection coefficient is larger than 0.66. A small variation in the load impedance will cause a large deviation from perfect match when the impedance difference between load and source is quite large.