This communication presents a bandwidth-enhanced, compact, monopole antenna with modified ground plane for modern automotive ultra wide-band (UWB) applications. The proposed antenna has hybrid geometry and is constructed using half circular ring and half square ring. The ground plane of the fundamental radiator is curved and defected to improve the VSWR bandwidth. An extended ground stub is added to further enhance the bandwidth to suit the modern automotive requirements. The designed antenna covers 3.1-10.9 GHz frequency spectrum with VSWR ≤ 2. This antenna can be conveniently placed inside the shark fin housing or it can be printed along with the existing print circuit board (PCB) electronics nullifying the need for dedicated location for in-car communications. Furthermore, a simple two-port multiple input multiple output (MIMO) antenna is constructed and its diversity performance is estimated. The prototype is fabricated and tested for impedance and radiation characteristics.

A novel optically transparent multiple-input multiple-output (MIMO) antenna for automotive applications is presented in this article. The MIMO antenna consists of a two-semicircular slot-loaded monopole with a staircase ground structure. It is developed on a glass substrate with dimension 29×50 mm ² . The fluorine-doped tin oxide and indium-doped tin oxide (ITO) are used as the conductive layers on the bottom and top of the substrate with sheet resistance 4 Ω/sq and 10 Ω/sq, respectively. The fabricated antenna has an optical transmittance greater than 72%; hence, it can be placed on the glass surface of the automotive. The measured results show that the proposed antenna exhibits a good impedance matching over a frequency of 2.4-11 GHz with isolation greater than 20 dB and a peak realized gain of 2 dBi, which is suitable for ultrawideband (UWB) automotive applications.

This letter presents the design of a novel patch antenna with frequency and pattern reconfiguration with polarization switching. The proposed antenna consists of a rhombus-shaped radiator with three excitation lines oriented at different angles. All the excitation lines are connected to a common feedline. The reconfiguration is achieved by changing the bias states of three pairs of p-i-n diodes. The dynamic nature of the antenna offers two operating bands, viz., 5.2/5.8 GHz, and provides linear/circular/±45° slant polarization. Furthermore, the pattern can be tilted 30° in right- and left-hand directions. The proposed antenna exhibits cross-polarization discrimination greater than 20 dB in all the operating modes. The prototype antenna is fabricated, and the simulation results are verified using measurements.

A compact, low profile UWB directional antenna for wireless body area network (WBAN) is reported in this paper. The directional an-tenna is designed using a monopole backed with Electromagnetic Band Gap (EBG) structure which acts as a reflector. The beveled y shaped monopole antenna covers the ultra-wide bandwidth from 3.1 GHz to 10.6 GHz. The monopole antenna backed with fork slotted EBG is designed with a size of 8 × 8 mm2. The 2 × 1 EBG array is printed on the same plane above the partial ground. This integrated structure provides band-stop characteristics from 3.1 - 10.6 GHz with a directional radiation pattern intended for wearable applications. It also acts as a protective shield against the electromagnetic radiation emerging from the monopole antenna towards the body tissue. The proposed directional antenna provides a peak gain of 6.25 dBi with high radiation and total efficiency. The calculated SAR value is 0.695 W/Kg which is well below the desired 1.6 W/kg.

This communication presents the design of a dual-band circular implantable antenna for biomedical applications. The proposed antenna operates at the Medical Implant Communication Services (MICS) band (402-405 MHz) and Industrial Scientific and Medical (ISM) band (2400-2483.5 MHz). The antenna occupies an area of ${\rm{\pi \times 10^{2} \times 2.54\ mm^{3} (797.96\ mm^{3})}}$ . The dual-band is realized in a circular patch by deploying via holes, open-ended slots in the ground plane and a superstrate. The prototype antenna is fabricated and measured using tissue-equivalent liquid model and pork meat to verify the suitability design. The proposed antenna has a peak gain of -33.1 and -14.55 dBi at 400 MHz and 2.45 GHz respectively. The specific absorption rate is 241.5 W/Kg for 1g of Tissue with a maximum input power of 6.625mW. Furthermore, the proposed antenna's salient features are compared with the state-of-the-art implantable antennas.

A novel multiband terahertz (THz) refractive index-based carcinoma sensor is designed and investigated in this paper. The proposed THz sensor is constructed using meandered sectoral stubs enclosed in a square loop. The proposed sensor has a footprint of 1.019 λeff× 1.019 λeff and operates at three distinct frequencies, viz. 1.095 THz, 2.865 THz, and 4.065 THz. The absorption characteristics of the sensor are analyzed to estimate the performance of the proposed sensor. The free space absorptivity is estimated as 99.6%, 99.1% and 99.2% at the said three resonant frequencies. The peak Q factor of 22.58 is realized at 4.065 THz under free space unloaded condition. Further, a study on different design parameters on absorption peaks and polarization independency is conducted and the results are presented. Followed by these, the sensitivity performance of the proposed carcinoma THz sensor is analyzed for healthy and cancerous cells of blood, skin and breast based on their unique refractive index profile. The peak sensitivity of 514.28 GHz/RIU at 2.865 THz, 476.35 GHz/RIU at 4.065 THz, and 476.91 GHz/RIU at 4.065 THz is theoretically observed for blood, skin and breast cancer cells respectively. Similarly, the high Q factor of 21.85, 18.06, 19.21 at 4.065 THz with FoM of 2.8, 2.38 and 2.384 are also observed for blood, skin and breast cancer respectively. Furthermore, the influence of the sample thickness on the THz sensor performance is analyzed. Thus, the proposed THz sensor is a promising entity for the detection and early diagnosis of cancer cells using THz radiation.