This paper presents a planar multi-circular loop antenna with a wide impedance bandwidth for next generation mm-wave systems. The proposed antenna comprises three circular rings with a partial ground plane with a square slot. The resonating structure is designed on a 0.254 mm thin RO5880 substrate with a relative permittivity of 2.3. The single element of the proposed design showed a resonance response from 26.5 to 41 GHz, with a peak gain of 4 dBi and radiation efficiency of 96%. The proposed multicircular ring antenna element is transformed into a four-element array system. The array size is kept at 18.25 × 12.5 × 0.254 mm³ with a peak gain of 11 dBi. The antenna array is fabricated and measured using the in-house facility. The simulated and measured results are well agreed upon and are found to be suitable for mm-wave communication systems.

In this article, a novel wideband circularly polarized multiple inputs multiple output (MIMO) dielectric resonator antenna (DRA) has been proposed for WiMAX applications. The mutual coupling (MC) between closely placed DRA units at 0.5λ has been significantly reduced by using a new hybrid technique. The exclusive features of the proposed MIMO antenna include wide impedance matching bandwidth (BW), broadband circular polarization (CP) and suppressed MC between the radiating elements. The first step of hybrid technique is the employment of parasitic patch at an optimized distance beside the conformal metal strip of the two identical rectangular DRAs in order to generate CP wave along with a wide impedance matching BW over the same frequency range. In the final step, the mutual coupling is suppressed significantly along with the broadband circular polarization by placing the DRAs diagonally at an optimized position. The proposed MIMO antenna is the hybrid of the parasitic patch and the diagonal position of radiating elements. The CP BW offered by the proposed antenna is ~ 20.82% (3.58–4.40 GHz) in conjunction with an impedance-matching BW of ~ 38.51% (3.50–4.95 GHz). Moreover, MC less than -28 dB, is achieved over the entire band and -26 dB at 3.89 GHz (minimum of the AR) through the hybrid technique. The prototype of the proposed antenna geometry is fabricated and measured. A good agreement has been attained between the simulated and measured results.

This study communicates the theoretical investigations on the cubic double perovskite compounds Cs ₂ XCrCl ₆ (X = K or Na).

This paper presents an S-shape four-port Multiple Input Multiple Output (MIMO) wideband mmWave antenna with bandwidth of 25 GHz to 39 GHz. The antenna is designed on 0.254 mm ultra-thin RO5880 with permittivity of 2.3. The dimensions of proposed S-shape antenna are 10 × 12 mm for single element and 24 × 24 mm for four-port MIMO configuration. A decoupling network is introduced to further compress mutual coupling among MIMO elements. The peak gain achieved is 7.1 dBi and MIMO assembly delivers diversity scheme. The proposed MIMO antenna is fabricated, and simulated results are found to be in excellent agreement with simulations. Through the results obtained, the proposed MIMO antenna system can be considered as a potential candidate for future mmWave devices.

A unique circularly polarized (CP) compact wearable dielectric resonator antenna (DRA) has been proposed for off-body communication in wireless body area network (WBAN) applications. The design is singly fed and a new H-shaped conformal metal strip has been used to excite the DRA. A circular polarization over a bandwidth of ∼9.6% (7.47–8.25 GHz) in conjunction with an impedance matching bandwidth of ∼20.7% (6.95–8.68 GHz) has been offered by the antenna. A prototype has been fabricated and measured. The antenna has been tested both in free space and on-body environment. A robust performance has been offered by the antenna against human body lossy effects. The measured results agree very well with the simulated results.