Eray Yasan

A Method for Improving the Efficiency of Transparent Film Antennas

This letter presents an optically transparent antenna, which is made of conductive AgHT coated film, with an improved efficiency by applying a highly conductive coating or metallization in the form of a very narrow strip to selective antenna areas of high current density. A measurement showed that the proposed method improved the maximum gain of a fabricated transparent antenna using the AgHT film from -5 dBi to 0 dBi at 2.2 GHz while preserving much of the optical transparency. A 3D electromagnetic model using a full-wave method of moments was developed to investigate the effect of width of the highly conductive narrow strip on the efficiency of the transparent antenna.

Single-Feed Dual-Band Stacked Patch Antenna for Orthogonal Circularly Polarized GPS and SDARS Applications

We describe a single-feed stacked patch antenna design that is capable of simultaneously receiving both right hand circularly polarized (RHCP) satellite signals within the GPS LI frequency band and left hand circularly polarized (LHCP) satellite signals within the SDARS frequency band. In addition, the design provides improved SDARS vertical linear polarization (VLP) gain for terrestrial repeater signal reception at low elevation angles as compared to a current state of the art SDARS patch antenna.

Evaluation of vehicle-level MIMO antennas: Capacity, total embedded efficiency, and envelope correlation

The paper describes an approach to estimate 2×2 MIMO channel capacity of a shark-fin radome antenna designed for multiple LTE bands by using channel matrices measured from drive tests in a real driving environment with a commercially available LTE radio network analyzer. The nonproduction shark-fin radome antenna that is mounted on the roof of a sedan is treated as a black box, and the estimated channel capacity is compared with that of a reference MIMO antenna consisting of identical monopoles tuned at 750 MHz. The two element λ/4 monopole array was also measured in a rich isotropic multipath environment at a reverberation chamber so that it can be used as a reference with known channel capacity. Total embedded efficiency and envelope correlation derived from measured s-parameters for the black box and the reference antennas are presented and discussed. The results show that the channel capacity depends on both the embedded efficiency and the correlation, and the approach estimating the MIMO throughput based on the channel matrices measured from the drive tests is shown to be useful to evaluate multiple MIMO antennas in a real driving environment.

A drive test measurement approach to characterize on-vehicle 2×2 LTE-MIMO antennas

This paper presents the use of a commercially available radio scanner for characterizing on-vehicle 2×2 Long-Term Evolution (LTE) radio Multiple-Input Multiple-Output (MIMO) antennas. The scanner measures the LTE eNodeB, i.e. the cell base station, reference signals and each channel and determines the MIMO channel matrices from which the downlink throughput can be determined. For a given LTE radio, this measurement approach can be very useful for efficient comparison between MIMO antennas or among different antenna locations on the vehicle.

A Wideband Stick-On Connector for CPW-Fed On-Glass Antennas

Printed on-glass antennas for automotive applications are less conspicuous than traditional antennas mounted to the vehicle body and are protected from vandalism and other hazards. Efficiently coupling to these antennas at microwave frequencies with low-cost installation is a challenging task due to the small tolerance for position errors. In this letter, an efficient, compact stick-on transition from coaxial cable to coplanar waveguide (CPW) is presented that has less than 0.5 dB insertion loss from 0.9 to 2.4 GHz with a tolerance to location errors of at least 2 mm in any direction. The transition can be paired with any CPW-fed antenna.

New Approach to Predict the Quality of Service of Vehicle-Based GPS System in Mobile Environment

This paper reports a novel approach to simulate on- vehicle GPS system performance which offers a fast estimate of Quality of Service (QoS) in realistic vehicle operation environments. The GPS simulator, which was developed based on the proposed approach, is a dynamic RF link budget calculator that calculates the carrier-to-noise ratio (CNR) at the GPS receiver in a vehicle with each GPS satellite vehicle (SV) in view at a given time. Monte Carlo method was applied to the RF link budget calculation process to account for the random nature of the vehicle dynamics and the broad range of vehicle operation environments. Performance of the GPS simulator was validated against that of the commercial hardware based GPS simulator.