Journal Description

Microwave

Microwave is an international, peer-reviewed, open access journal on the science and engineering of microwave and its applications, and is published quarterly online by MDPI.

Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
Rapid Publication: first decisions in 19 days; acceptance to publication in 4 days (median values for MDPI journals in the first half of 2025).
Recognition of Reviewers: APC discount vouchers, optional signed peer review, and reviewer names published annually in the journal.
Microwave is a companion journal of Electronics.
Journal Cluster of Electronic Engineering and Hardware Systems: Chips, Electronics, Hardware, Journal of Low Power Electronics and Applications, Microelectronics and Microwave.

Imprint Information Journal Flyer Open Access ISSN: 3042-5697

Latest Articles

14 pages, 1950 KB

Open AccessArticle

Tailoring Microwave Absorption via Ferromagnetic Resonance and Quarter-Wave Effects in Carbonaceous Ternary FeCoCr Alloy/PVDF Polymer Composites

by Rajeev Kumar, Harish Kumar Choudhary, Shital P. Pawar, Manjunatha Mushtagatte and Balaram Sahoo

Microwave 2025, 1(2), 8; https://doi.org/10.3390/microwave1020008 - 25 Aug 2025

Abstract

In this study, we investigate the dominant electromagnetic wave absorption mechanism–ferromagnetic resonance (FMR) loss versus quarter-wave cancellation in a novel PVDF-based polymer composite embedded with carbonaceous nanostructures incorporating FeCoCr ternary alloy. The majority of the nanoparticles are embedded at the terminal ends of the carbon nanotubes, while a small fraction exists as isolated core–shell, carbon-coated spherical particles. Overall, the synthesized material predominantly exhibits a nanotubular carbon morphology. High-resolution transmission electron microscopy (HRTEM) confirms that the encapsulated nanoparticles are quasi-spherical in shape, with an average size ranging from approximately 25 to 40 nm. The polymeric composite was synthesized via solution casting, ensuring homogenous dispersion of filler constituent. Electromagnetic interference (EMI) shielding performance and reflection loss characteristics were evaluated in the X-band frequency range. Experimental results reveal a significant reflection loss exceeding −20 dB at a matching thickness of 2.5 mm, with peak absorption shifting across frequencies with thickness variation. The comparative analysis, supported by quarter-wave theory and FMR resonance conditions, indicates that the absorption mechanism transitions between magnetic resonance and interference-based cancellation depending on the material configuration and thickness. This work provides experimental validation of loss mechanism dominance in magnetic alloy/polymer composites and proposes design principles for tailoring broadband microwave absorbers. Full article

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10 pages, 2156 KB

Open AccessArticle

Highly Linear Loaded-Line Phase Shifter Utilizing Impedance Transformer and PIN Diode

by Farhad Ghorbani, Amir Dayan, Jiafeng Zhou and Yi Huang

Microwave 2025, 1(2), 7; https://doi.org/10.3390/microwave1020007 - 30 Jul 2025

Abstract

This paper presents a highly linear one-bit loaded-line phase shifter that leverages PIN diodes in combination with a coupler-based impedance transformer. The proposed phase shifter adopts a loaded-line topology, where PIN diodes are configured in a parallel-to-ground arrangement to improve linearity performance. To further enhance linearity, a coupler-based impedance transformer is employed to reduce the impedance seen by each PIN diode, thereby minimizing nonlinear behavior. To demonstrate the effectiveness of this design, a one-bit digital phase shifter is developed, simulated, and fabricated to achieve a 45-degree phase shift at 2 GHz. Experimental measurements confirm an input third-order intercept point (IIP3) exceeding 100 dBm under a range of test conditions, validating the proposed architecture’s linearity advantages. Full article

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17 pages, 1570 KB

Open AccessArticle

Overcoming Scaling Challenges in Sol–Gel Synthesis: A Microwave-Assisted Approach for Iron-Based Energy Materials

by Judith González-Lavín, Ana Arenillas and Natalia Rey-Raap

Microwave 2025, 1(2), 6; https://doi.org/10.3390/microwave1020006 - 30 Jun 2025

Abstract

There is currently an effort to scale up sol–gel nanomaterials without compromising quality, and microwave heating can pave the way for this due to its heating efficiency, resulting in a fast and homogeneous process. In this work, the sol–gel synthesis of transition metal aerogels, specifically iron-based aerogels, is studied using a microwave-assisted sol–gel methodology in an open-system multimode device as a potential route to scale-up production. Different approaches were tested to evaluate the best way to increase yield per batch, with different vessel shapes and volumes. It is shown that the shape and size of the vessel can be determinant in the interaction with microwaves and, thus, in the heating process, influencing the sol–gel reactions and the characteristics and homogeneity of the obtained nanomaterials. It has been found that a wide vessel is preferable to a tall and narrow one since the heating process is more homogeneous in the former and the sol–gel and cross-linking reactions take place earlier, which improves the mechanical properties of the final nanomaterial. For mass production of nanomaterials, the interaction of the reagents with the microwave field must be considered, and this depends not only on their nature but also on their volume, shape, and arrangement inside the cavity. Full article

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Graphical abstract

25 pages, 6485 KB

Open AccessFeature PaperReview

Low-Power Rectennas in Microwave Wireless Power Transmission

by Yilin Zhou, Ruinan Fan and Changjun Liu

Microwave 2025, 1(1), 5; https://doi.org/10.3390/microwave1010005 - 18 Jun 2025

Abstract

The advancement of microwave wireless power transfer technology has positioned low-power rectennas as a research hotspot. This paper systematically reviews core technological progress in low-power rectennas, focusing on innovations in rectifier circuit topologies, nonlinear device models, antenna array optimization, and efficiency enhancement strategies. Current technical bottlenecks and future application directions are analyzed, providing theoretical references for space solar power stations, IoTs, and related fields. Full article

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14 pages, 5328 KB

Open AccessArticle

Design of a Novel Ultra-Wideband Antipodal Vivaldi Antenna Based on Klopfenstein Curve

by Yanxing Zhang and Jinling Zhang

Microwave 2025, 1(1), 4; https://doi.org/10.3390/microwave1010004 - 21 May 2025

Abstract

We propose a new ultra-wideband antipodal Vivaldi antenna design based on the Klopfenstein curve, incorporating exponential slots, horns, and apertures to improve the antenna’s return loss and increase its gain in high-frequency bands. The antenna achieves high gain and wide bandwidth characteristics, with [...] Read more.

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Graphical abstract

20 pages, 57469 KB

Open AccessArticle

Experimental and Analytical Studies on Electromagnetic Wave Propagation in DC Circuits

by Mingyu Lu and Charan Litchfield

Microwave 2025, 1(1), 3; https://doi.org/10.3390/microwave1010003 - 7 Apr 2025

Abstract

It is well known that two pieces of electrical conductors behave as a waveguide when they are employed to transmit AC signals. Some experimental and analytical studies are reported in this paper to demonstrate that two pieces of electrical conductors also behave as a waveguide when they are employed to transmit DC signals in practice. Specifically, the speed of wave propagation is measured in the experiments, and the analytical studies are based on the theory of transmission line. Full article

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12 pages, 4905 KB

Open AccessArticle

All-Quartz Integrated Lens Antenna for Surface Wave Loss Reduction

by Haoran Zhao, Qi Wang, Wen Yue and Wei Wang

Microwave 2025, 1(1), 2; https://doi.org/10.3390/microwave1010002 - 13 Feb 2025

Abstract

This work proposes an all-quartz integrated lens antenna for the first time. The antenna feed and lens materials are both made of quartz. The antenna is designed to work at 26 GHz and has the advantages of small size and reduced surface wave loss. Two antennas, a hemispheric lens and an extended hemispheric lens, are demonstrated. The hemispheric lens has an area of 30 × 30 mm² and a height of 16 mm, while the extended hemispheric lens, with the same area, has a height of 26 mm. The measured peak gain of the extended hemispheric integrated lens antenna is 15.49 dBi, and the simulated peak gain is 17.68 dBi. The electric-field distribution was analyzed, and two hemispheric lens and extended hemispheric lens antennas of the same size were designed on PCB substrate for comparative analysis. The measured results validate the impact of the surface wave effect on the gain of the lens antenna proposed in this study. Full article

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2 pages, 311 KB

Open AccessEditorial

Microwave—A New Open Access Journal for Microwave Technologies

by Changjun Liu

Microwave 2025, 1(1), 1; https://doi.org/10.3390/microwave1010001 - 9 Jan 2025

Abstract

Microwave technologies have long been at the forefront of scientific and engineering innovation, driving advancements in wireless communications, radar, satellites, medical applications, wireless power transfer, and more [...] Full article