Rotated Patch Research Articles

Enhancing brain tumor detection in MRI with a rotation invariant Vision Transformer.

The Rotation Invariant Vision Transformer (RViT) is a novel deep learning model tailored for brain tumor classification using MRI scans. RViT incorporates rotated patch embeddings to enhance the accuracy of brain tumor identification. Evaluation on the Brain Tumor MRI Dataset from Kaggle demonstrates RViT's superior performance with sensitivity (1.0), specificity (0.975), F1-score (0.984), Matthew's Correlation Coefficient (MCC) (0.972), and an overall accuracy of 0.986. RViT outperforms the standard Vision Transformer model and several existing techniques, highlighting its efficacy in medical imaging. The study confirms that integrating rotational patch embeddings improves the model's capability to handle diverse orientations, a common challenge in tumor imaging. The specialized architecture and rotational invariance approach of RViT have the potential to enhance current methodologies for brain tumor detection and extend to other complex imaging tasks.

Dual-Band Circularly Polarized Rotated Patch Antenna With a Parasitic Circular Patch Loading

A dual-band circularly polarized (CP) rotated patch antenna is proposed in this letter. Dual-band CP operation of the proposed antenna is achieved by adopting a circular patch below the rotated rectangular patch. The extra circular patch not only provides a higher band, but is also employed to tune the operating frequency of the lower band, which is generated by the rotated rectangular patch. The rectangular patch and the circular patch can be arranged on the front and back of a thin substrate and fed by a single slot. The dual CP operating bands can be tuned separately with a small frequency ratio of 1.18. A prototype of the proposed antenna is built to validate the design strategy. The measured 3-dB axial-ratio (AR) bandwidth is 2.1% (2.238-2.285 GHz) for the lower band and 2.0% (2.645-2.695 GHz) for the higher band, with the reflection coefficient being lower than -10 dB. The radiation pattern and gain are also measured and compared to the simulated ones.

A Compact Cross-Shaped Slot Antenna with a Coplanar Waveguide Fed Rotated Patch for UWB Applications

AbstractIn this letter, a compact cross-shaped slot antenna with a coplanar waveguide fed rotated patch is presented and experimentally studied. By properly designing the dimensions of cross-shaped slot and rotated patch, good UWB property can be obtained. In comparison with the previous slot antennas, the proposed antenna has a smaller size as high as

BANDWIDTH ENHANCEMENT DESIGN OF COMPACT UWB STEP-SLOT ANTENNA WITH ROTATED PATCH

In this paper, a novel compact microstrip-fed ultra- wideband (UWB) step-slot antenna with a rotated patch is demonstrated and experimentally studied. With an efiective combination of the step-slot and rotated patch and proper dimensions bandwidth enhancement for UWB operation is obtained. From the simulated and measured results, the enhanced impedance bandwidth is brought up to about 117.5% from 2.88 to 11.08GHz deflned by 10dB return loss. Details of the proposed antenna are described, and experimental results are presented and discussed.

Compact CPW-fed rotated square-shaped patch slot antenna with band-notched function for UWB applications

A novel coplanar waveguide (CPW)-fed slot antenna with bandstop characteristics is presented for ultra-wideband (UWB) applications. The proposed antenna consists of a rotated square-shaped patch and a 50Ω CPW feed line. By embedding an inverted V-shaped slot with folded ends, the band rejection property is achieved. Also, etching two slots on the ground plane leads to an improvement in impedance bandwidth. The proposed antenna covers the frequency range of 3.04–20.22 GHz for VSWR < 2, and rejects 5–6 GHz. The total size of the antenna is 20 × 18 × 1.6mm3, which is smaller than many of the designed slot antennas and covers wider bandwidth. For the fabricated antenna, an omnidirectional pattern is observed over the whole UWB frequency range.

Open L-slot antenna with rotated rectangular patch for bandwidth enhancement

A printed open L-slot antenna with a rotated rectangular patch for bandwidth enhancement is proposed and experimentally studied. Using the rotated patch technique and asymmetrically fed by a microstrip-line, the proposed antenna can achieve an enhanced operating bandwidth of 2.5-14.2 GHz for - 10 dB return loss, which makes it an excellent candidate for the emerging ultra-wideband systems (3.1-10.6 GHz). In particular, the rectangular patch effect on impedance performance is greatly improved, and the rotated patch matches well with the feed at a wider operating frequency range.

Novel Microstrip Antenna With Rotatable Patch Fed by Coaxial Line for Personal Handy-Phone System Units

An enhanced microstrip antenna is proposed that incorporates a patch that rotates around the inner conductor of the coaxial line or dielectric shaft and a novel coaxial line feeding technique that offers constant electromagnetic coupling. This proposal addresses the disadvantages in our previous patch antenna in which the resonant frequency diverges from the center frequency of the personal handy-phone system (PHS) band and the bandwidth decreases as the patch rotates because of the changing electromagnetic coupling between the patch and microstrip line due to the patch rotation. We verify that this enhanced patch antenna achieves the antenna gain of approximately 0 dBd, which is the same as that of the previously proposed antenna, while suffering no significant gain degradation due to unit inclination over inclination angles from plusmn45deg compared to a conventional quarter-wavelength whip antenna, which experiences a degradation of approximately 2.7 dB. We show that the maximum resonant frequency separation from the center frequency of the PHS band is reduced to 15 MHz from 31.4 MHz of the previous antenna using the novel coaxial line feeding technique. The effective bandwidth needed for PHS is achieved over the inclination angles of -20deg to +40deg. Approximately 93% of the total bandwidth needed for PHS is achieved while the previous microstrip line type achieved only 58% coverage; accordingly, an adequate bandwidth for PHS use is obtained.

A novel electromagnetically coupled microstrip antenna with a rotatable patch for personal handy-phone system units

In this paper, we propose a novel electromagnetically coupled microstrip antenna with a rotatable patch to overcome the problems associated with the conventional whip antenna for the personal handy-phone system (PHS). The structure of the newly developed antenna installed in actual PHS units is described. Its fundamental characteristics such as radiation pattern, bandwidth, and gain are shown. The performance of the antenna in actual propagation environments is also clarified. It is shown that this novel antenna is superior to the conventional whip antenna and achieves efficient performance in commercial PHS service.

Simple method of experimentally investigating scanning microstrip antenna arrays without phase-shifting devices

A simple microstrip antenna array which performs beam scanning without the use of electronic phase-shifters or delay lines is described. The array incorporates mechanically rotatable microstrip patch antennas which are designed for circularly polarised (CP) operation. Experimental results obtained from preliminary implementations of the array are provided and discussed.