Modal Analysis of Directional Coupler and Its Equivalent Circuit

Mohammadi, Morteza

doi:10.7716/aem.v8i4.1252

Cited by 3 publications

(3 citation statements)

References 9 publications

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“…A hybrid optimization algorithm based on the combination of the genetic algorithm and conjugate gradients method is used to obtain low-noise fgure, gain fatness, stability, and loss factor correlated with each reactive element and matching network accomplishment included together. An 8∼16 GHz broadband microwave amplifer is designed to verify its application [92]. In order to solve the matching problem of the directional coupler, a very good method for mode matching of directional coupler in mode analysis is proposed and verifed on directional coupler of X-band rectangular waveguide ports.…”

Section: Efect Of Element Feed Errormentioning

confidence: 99%

Structural-Electromagnetic-Thermal Coupling Technology for Active Phased Array Antenna

Wang

et al. 2023

International Journal of Antennas and Propagation

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Active phased array antenna (APAA) is a representative of complex electronic equipment, and it plays significant roles in scenarios such as battlefield situation perception, aviation guidance, and communication. It has become the core equipment in land, navigation, and aeronautical applications. With the continuous improvement of technical changes and military requirements, the working frequency band, pointing accuracy, gain, and low sidelobe level of APAA increase, and the multi-disciplinary design contradiction between antenna electrical performance and structure and temperature becomes increasingly prominent. As a result, the electrical performance of APAA in service is prone to be affected by the external complex environments. The structural-electromagnetic-thermal (SET) coupling problem has become a key problem restricting the development of APAA. This paper has summarized the structural features and environmental loads of advanced APAA on different platforms and provided design basis and principle for antenna designer. And then the SET coupling theory of APAA has been introduced, which can be applied in both the design and manufacturing stage, as well as the performance control technology in service environment of APAA. This theory helps to analyze the impact of environmental factors, such as antenna structure deformation, radome high-temperature ablation, and feed errors, on the antenna's performance. For 128 × 768 spaceborne array antenna, in the range of 25∼85°C, the gain of antenna decreases with the increase of operating temperature and decreases by 0.015 dB with each increase of 1°C. The key design parameters in the fields of antenna manufacturing accuracy, efficient heat dissipation, and lightweight design are also analysed; for 32 × 32 rectangular planar phased array antenna, the gain of antenna decreases by 2.715 dB when the random error of installation position in x, y, and z direction reaches 1/10 of the wavelength. In addition, condition monitoring, displacement field reconstruction, and electrical performance compensation of APAA have also been touched to help engineers maintain and guarantee the antenna performance throughout its life cycle. Finally, the future research direction of SET technology of APAA has been discussed, and SET technology is extended to more fields such as antenna parameter uncertainty, high-frequency circuit electronics manufacturing, and electronic equipment performance guarantee.

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Section: Efect Of Element Feed Errormentioning

confidence: 99%

Structural-Electromagnetic-Thermal Coupling Technology for Active Phased Array Antenna

Wang

et al. 2023

International Journal of Antennas and Propagation

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“…The equivalent circuit model for gas pipelines is established in [17,18]. In [19], the equivalent circuit model of the directional coupler with lumped elements is proposed. In [20], an equivalent circuit of the proposed low-noise broadband microwave amplifier is shown, aiding in the selection of optimal component parameters.…”

Section: Introductionmentioning

confidence: 99%

Lumped‐element equivalent circuit modelling of district heating pipe in electromagnetic transients program

Jiang,

Xia,

Lan

et al. 2024

The Journal of Engineering

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Electromagnetic transients program (EMTP) is widely used to analyze transients in power systems. With the increased interest in integrated energy systems (IESs), it would be beneficial to extend the application of EMTP to multi‐physics transients in integrated electrical and heating networks. In this paper, an accurate and efficient lumped‐element circuit model of the heating district pipe is developed in EMTP. The pipe is split into segments using spatial discretization. The application of the numerical discretization to the energy conservation equation gives the discretized pipe equation which is expressed in the form of a companion model of EMTP. In order to reduce the computational effort, the time‐varying terms in the admittance matrix of the companion model of pipe are eliminated. The modification of the admittance matrix is avoided. Furthermore, the internal nodes resulting from spatial discretization are eliminated, resulting in a lumped‐element circuit model with only two external nodes. Case studies are carried out to validate the proposed model in terms of accuracy and efficiency. The 2‐norm error of the proposed model is 0.0153%. With a pipe length of 100 m, the computational speed of the proposed model is increased by a factor of 2.94 compared with the existing distributed‐element circuit model. The implementation of the proposed pipe model in the EMTP‐type simulator enables the analysis of multi‐physics transients in a multi‐carrier energy system.

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“…Constrained by the output power capability of monolithic microwave circuit (MMIC) [1][2][3][4][5][6][7][8][9][10][11][12][13], several methods of power combiner technique, such as magic T, radial-line etc., have been developed for SSPA operating in the W-band [14][15][16][17][18][19][20]. Galliumnitride high-electron-mobility-transistor (GaN HEMT) MMICs used as the PA's last stage of is mainly addressed in the recent literatures [21][22][23].…”

Section: Introductionmentioning

confidence: 99%

W band solid‐state power amplifier for aerospace usage

Yang

Zhang

et al. 2021

The Journal of Engineering

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Concentrating on the high frequency aerospace demand of solid-state power amplifier (SSPA), this paper presents the methodology and key technique of a W-band 3-W SSPA that achieves high efficiency while maintaining excellent reliability capability. An improved Magic-T power combiner is utilized to achieve high output power, and eliminate the influence of the parallel end-stage gallium-nitride high-electron-mobility-transistor (GaN HEMT) PAs by its good isolation performance. The SSPA's millimetre-wave circuit is implemented by three stages of amplifier, to realized more than 30-dB power gain. The power-supply circuit based on the two-transistor forward topology is proposed for voltage converting and output serious sequence controlling. The SSPA is fabricated and measured, achieving 33-dBm to 34.1-dBm output power within the frequency range of 92-96 GHz, with the power gain of 31-32 dB, and peak efficiency of 7.1%, respectively. The proposed SSPA shows competitive performance for space application.

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Modal Analysis of Directional Coupler and Its Equivalent Circuit

Cited by 3 publications

References 9 publications

Structural-Electromagnetic-Thermal Coupling Technology for Active Phased Array Antenna

Structural-Electromagnetic-Thermal Coupling Technology for Active Phased Array Antenna

Lumped‐element equivalent circuit modelling of district heating pipe in electromagnetic transients program

W band solid‐state power amplifier for aerospace usage

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