Microwave and Optical Technology Letters

ABSTRACT A novel wideband dual cavity backed substrate integrated waveguide antenna is presented in this paper. The properties of dual cavity backed substrate integrated waveguide (SIW), U‐iterative slot design and dumbbell shaped defected ground structure has remarkably improved the bandwidth of the proposed antenna design. The proposed antenna achieves high gain, wide bandwidth, wide beam‐width…

ABSTRACT Although the learning‐based surrogate model could achieve fast prediction, the model uncertainty in data and predictions remains a significant challenge. To alleviate the uncertainty problems for the surrogate model, a learning‐based uncertainty analysis method for improving the stability of the inverse model of RF devices is proposed. The inherent uncertainty in the inverse model is ana…

ABSTRACT To further improve the optimization accuracy, tuning space mapping (TSM) using T‐matrix with fractional exponent is proposed for continuous parameter tuning. By applying logarithmic‐exponential operation, spectral decomposition, Schur decomposition, and singular value decomposition (SVD) algorithm, the T‐parameters of electromagnetic simulated unit circuit (ESUC) can be reconstructed wit…

ABSTRACT In this letter, a spoof surface plasmon polariton (SSPPs)‐based filter, which can be tuned between low‐pass and band‐pass function is proposed. The low‐pass characteristic is generated by the periodic structure of SSPPs. Meanwhile, the band‐pass function is achieved by introducing metal vias in the SSPPs unit cells. PIN diodes and bias circuits are used to control the switching between l…

ABSTRACT This paper proposes a novel switchable Frequency Selective Surface (FSS) design. The designed FSS unit size is only 0.12 λ 0 (where λ 0 represents the wavelength corresponding to the lowest resonant frequency in free space), and its angle stability can reach up to 65°. Meanwhile, it can form stable resonances at the three commonly used frequency bands of 2.4, 3.3, and 5.2 GHz in communic…

ABSTRACT This letter introduces a novel optimization method for suppressing grating lobes (GLs) in the design of aperiodic arrays. An initial element layout is generated using a hybrid approach that combines the Chebyshev distance with a breadth‐first search algorithm. Following the initial placement, a perturbation‐based refinement is applied. The two‐step strategy enhances the optimization's de…

ABSTRACT This paper proposes a probabilistic coupled generative adversarial network (PCGAN) integrating Gaussian process regression (GPR) with adversarial learning for terahertz antenna co‐design under limited datasets. The framework employs SMOTE‐expanded geometric parameters and GPR‐ANN coupled predictions to generate high‐fidelity datasets. A probabilistic discriminator authenticates data whil…

ABSTRACT This article presents a polarization‐insensitive dual‐frequency integrated rectifying metasurface for radio frequency energy harvesting. The metasurface incorporates two uniquely designed circular rings to achieve resonance at 2.45 and 5.8 GHz, respectively. Strategic gaps within the unit cell structure accommodate rectifying diodes and inductive components, facilitating alternating curr…

ABSTRACT In this paper, a Janus metasurface for independent manipulation of reflected wave in different space is investigated. In this reflective metasurface good isolation between the two orthogonally polarized reflection elements is achieved for incident waves from different space. By utilizing this property, we have implemented reflected vortex beam in front of the metasurface and reflected hi…

ABSTRACT A miniaturized ultra‐wideband band‐pass filter with wide out‐of‐band suppression based on low‐temperature cofired ceramic (LTCC) technology is presented, which works from 0.74 GHz to 6.5 GHz, consisting of a highpass filter and a lowpass filter. Because of utilizing advanced LTCC technology, the big multilayer capacitors and helical‐shape inductors can be realized in multiple thin layers…

ABSTRACT The study presents a compact four‐port dual‐band MIMO antenna specific to millimeter‐wave (mm‐Wave) 5 G networks that operate at higher frequency intervals of 26 and 39 GHz. The development process of MIMO antennas that operate at higher frequencies is highly challenging, mainly because of the need to simultaneously achieve wider bandwidth, larger radiation efficiency, and lower mutual c…

ABSTRACT Three monopole antennas, based on both solid and mesh conductors, are designed for a 3–6 GHz operation band. Binary topology optimization is applied to reduce the metal‐covered area by 37.2%, which results in an increase in the antenna's optical transparency by 8% compared to antennas based on uniform mesh. Optical ray tracing is used to render images of the antennas in an automotive env…

ABSTRACT A circularly polarized (CP) helix antenna with conical radiation pattern operating in Global Positioning System L5 (1.176 GHz) and L1 (1.575 GHz) bands is proposed. Adopting helix arm nesting technique, the proposed antenna is equipped with two tapered helix radiation arms, namely, outer tapered helix arm and inner tapered helix arm, which are operated in L5 and L1 bands, respectively. T…

ABSTRACT This study presents a sophisticated sensor based on microwave resonators employing complementary split ring resonators (CSRRs), engineered with uneven coupling and a unique spatial configuration to attain high sensitivity in the detection and characterization of bio‐fluids. The suggested sensor focuses on medical diagnostic applications, such as blood glucose monitoring and evaluation of…

ABSTRACT A filtering metal patch antenna utilizing a pair of folded metal resonators and double‐layer 2 × 2 patches is proposed for expanding bandwidth, enhancing frequency selectivity, and widening the stopband based on characteristic mode analysis (CMA). The folded metal resonator with an L‐shaped stub provides two reflection zeros when the currents on the upper and lower parts are the same. Me…

ABSTRACT To address the severe path loss degradation in the millimeter‐wave band and its consequential significant reduction in received signal‐to‐noise ratio, high‐gain antennas supporting 2‐D beam scanning are critically required. This letter proposes a sliding‐aperture 2‐D beam‐scanning transmitarray (TA) solution. The proposed TA comprises 21 × 41 unit cells, and each unit cell integrates a f…

ABSTRACT A design for dual‐polarized antenna arrays with broadband operation and high isolation is proposed. The radiating element of the array is a flake‐shaped antenna with the dimensions of 10.8 × 0.25 × 6 mm 3 , and it can be mounted directly onto a circuit board of the feed network. Simulated results show that the impedance bandwidth of the radiating element is about 34% with respect to the …

ABSTRACT In this article, a SIW‐SSPP based bi‐directional LWA has been proposed. The presence of a transition structure between SSPPs lines and traditional lines makes it difficult to precisely extract and analyze the dispersion characteristics of LWAs. A general SOC technique is proposed to accurately calculate the propagation constant of SSPPs LWAs using network theory. The antenna's two symmet…

ABSTRACT In this letter, a layered multifunctional tri‐band reflect‐transmit‐array (RTA) with quad‐beam control is reported. The unit adopts a multi‐layer structure and integrates frequency selective surfaces (FSS) to effectively isolate distinct frequency bands. Through a strategic combination of continuous phase (C.P.) and 1‐Bit phase distributions, it achieves precise control over four indepen…

ABSTRACT In this letter, a radiation‐scattering‐integrated antenna designed according to the method of evolution from metasurface to antenna is presented. Firstly, specific metasurface units are arranged according to the cross‐type arrangement, and some of the units are excited as the radiating part of the antenna by adding probes and microstrip lines, and at the same time this part of the units …