A novel compact Ultra-Wideband Multiple Input Multiple Output (UWB-MIMO) antenna with enhanced bandwidth is proposed. The bandwidth of the designed antenna ranges from 1 to 30 GHz which covers L, S, C, X, Ku, K bands and some part of Ka-band. A square slot & inverse L-shaped strip is used to improve the isolation amid antenna elements. The suggested antenna achieves Mutual Coupling and Envelope Correlation Coefficient below −17 dB and 0.15, respectively. MIMO performance parameters like Mean Effective Gain is around 0 dB, and Total Active Reflection Coefficient is less than −10 dB. The Channel Capacity Loss and Effective Diversity Gain are less than 0.3 bits/s/Hz and 9.2 dB, respectively. The radiation efficiency of the designed antenna is around 80% over the complete frequency range. The overall dimensions of designed antenna are 27 × 17 × 1.6 mm 3 .

This article presents a bandstop Frequency Selective Surface (FSS) prototype based on square split ring resonators (SSRRs) and a square loop (SL) structure for Ultra Wide Band (UWB) frequency range. Triple band notches are obtained at WiMAX (3.3-3.6 GHz), WLAN (5-6 GHz), and Satellite communication X-band (7.2-8.4 GHz). To make this proposed design work as a band-stop filter, two SSRRs are positioned at the top layer of the substrate to resonate at WiMAX and WLAN frequency band, respectively. A single SL is located at the bottom of the substrate that resonates at satellite communication X-band. Attenuation more than 20 dB is observed at all notched frequencies. An angular stability from 0 • to 40 • is obtained. Compact size, simple structure, low cost material, single layer, easy fabrication, and wide coverage are some of the feathers of this proposed FSS. The dimension of proposed unit cell of FSS is 10 × 10 mm 2 .

This article presents a dual-band 12-element antenna system based on slot antennas for fifthgeneration (5G) of mobile communication. The basic structure of each antenna element is composed of a T-shaped slot. The antenna array is designed to operate at LTE 42 and LTE 43 bands ranging from 3400-3600 MHz and 3600-3800 MHz, respectively. The impact on the antenna parameters due to the user's hand is also explored. The isolation between antenna elements is better than 14.8 dB with a total efficiency of more than 74%. A small envelope correlation coefficient less than 0.05 and the channel capacity of 61.9 bps/Hz make the proposed array a viable solution for 5G smartphones.

obtained. The far-field results demonstrate that vertical signal reception is achieved at 650 elevation angles. Thus, the proposed vehicle antenna can effectively receive a WiBro vertical polarized signal. In addition, it is shown that the proposed antenna is omnidirectionally radiating in the azimuth plane. FIELD TESTDuring the outdoor field test, the omnidirectional radiation patterns of the proposed antenna in the azimuth plane were measured at 2.3 GHz. As shown in Figure 5(a), the antenna was installed on the roof of a mid-sized car, and the test was repeated three times at positions A, B, and C. An RF cable was inserted through the car's sun roof and was connected to a spectrum analyzer to measure the received power. A printed dipole antenna operating at 2.3 GHz was used to transmit the vertical polarized signal. The far-field distances were 12, 12.63, and 13.27 m at positions A, B, and C, respectively. However, in our measurement environments, we verified that the result at position A was similar to the simulated result. Moreover, in the field test, we demonstrated that the large conductive plate modeling method in the simulation environment produced reasonable results. CONCLUSIONSA low-profile planar roof-mounted vehicle antenna for monopole vertical polarization reception was proposed. The proposed antenna has a very low height of 0.062k 0 with an 18.2% wide bandwidth. The height of 8.2 mm is very small compared with one of the commercially used pole antenna (k 0 /4 ¼ 32.6 mm at 2.3 GHz). By modeling a large conductive plate instead of the large car body, our simulation time was greatly reduced. The omnidirectional radiation performance of the packaged antenna was demonstrated using an outdoor field test.

This paper addresses the design of a compact passive tag antenna for Ultra High Frequency (UHF) radio frequency identification (RFID) applications involving living beings or metallic goods as the objects to be tagged or bio-monitored. A triangular shaped patch tag antenna which is shorted to the ground plane and coupled by a meander microstrip line is presented, making the tag performance suitable to be mounted on metallic goods or on the body of living beings. The shorting pins connected to the ground plane reduce the antenna size and the overall dimension is 50*50*1.6 mm 3 only. Such a design can find use in highly metallic environment with appreciable efficiency.