IPWV estimation and data quality analysis from different GNSS antenna

Global Navigation Satellite System (GNSS) is widely used now days in variety of applications. The observation file for the near realtime estimation of Integrated Precipitable Water Vapour (IPWV) received at the ground-based receiver is mixed with ambiguities. Multi-path effects affect the positional accuracy as well as range from satellite to ground based receiver of the system. The designing of the antenna suppress the effect of multi-path, cycle slips, number of observations, and signal strength and data gaps within the data streams. This paper presents the preliminary data quality control findings of the Patch antenna (LeicaX1202), 3D Choke ring antenna (LeicaAR25 GNSS) and Trimble Zephyr antenna (TRM 39105.00). The results shows that choke ring antenna have least gaps in the data, cycle slips and multi-path effects along with improvement in IPWV. The signal strength and the number of observations are more in case of 3D choke ring antenna.

Frequency Reconfigurable Multiband MIMO Antenna Base on Gradient Arcs for IoT Devices

A frequency reconfigurable multi-band MIMO antenna is presented in this study. The single antenna consists of only one PIN diode that can change antenna operating frequencies from different quad-band to another one. Their bands not only cover the popular NB-IoT bands such as 900MHz, 1.8GHz, 2.4GHz for Z-Wave, ZigBee, RFID, GSM communication but also contain 5G IoT bands which are 2.4GHz, 2.6 GHz and 5GHz for LTE-A, 802.11n, ac, and 5G below 10GHz. Basing on the complex structure of ring and new moon shape, the single antenna achieves a compact size of 30 mm x 30 mm x 1.6 mm which is about 76% reduction compared to a conventional ring antenna at 900MHz. Besides, a structure of gradient arcs is proposed to decrease mutual coupling among closed-spaced elements of MIMO antenna for the distance of 0.033l at the lower band from edge to edge. The proposed antennas are analyzed by CST software, VNA measurement, and IEEE 802.11 USB Adapter that the simulated, measured as well as experimental results are agreed well.

Wideband split-ring antenna arrays based on substrate integrated waveguide for Ka-band applications

This paper presents wideband split-ring antenna arrays based on substrate integrated waveguide (SIW) for Ka-band (26.5–40 GHz) applications. The antenna array is fed by a 2.92 mm coaxial connector (K-connector) and the power is equally distributed to each split-ring resonator. The designed coplanar waveguide (CPW), SIW, CPW-to-SIW transition, coaxial-to-CPW transition, and two-stage SIW power divider are described in detail. By using a thin Rogers 6002 substrate with silver epoxy-filled vias, a transition prototype is designed, fabricated, and tested in a back-to-back configuration. A wideband split-ring resonator is developed as a single element and four possible arrangements of antenna arrays are introduced. By combining the designed components and routing paths, two full layouts of the antenna arrays with four split-ring resonators are addressed. As a demonstrator, a 2×2 antenna array prototype in a compact format is designed, fabricated, and tested. The fabricated antenna array achieves a measured directivity of 15.0 dBi with a fractional bandwidth of 23.0% centered at 30.5 GHz.