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ABSTRACT: The relative long wavelength of FM radio signals compared to a typical vehicle length means that a window glass-embedded FM band antenna couples strongly to vehicle structural components. Numerical simulations have been conducted to identify which key structural components in a full-size SUV have an effect on the average antenna gain patterns. In particular, it was found that the rear hatch and the seats of the SUV had a large effect on FM antenna gain patterns and thus required more careful modeling for the electromagnetic simulation. Also, it was found that the sunroof status, opened or closed, had a moderate effect on FM antenna gain patterns. Comparison with experimentally obtained FM antenna gain patterns demonstrated the importance of using the most detailed model possible when simulating patterns in the FM band.
IEEE Transactions on Antennas and Propagation 11/2011; · 2.15 Impact Factor
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ABSTRACT: 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.
Vehicular Technology Conference Fall (VTC 2009-Fall), 2009 IEEE 70th; 10/2009
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ABSTRACT: 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.
Vehicular Technology Conference, 2008. VTC 2008-Fall. IEEE 68th; 10/2008
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ABSTRACT: In this paper, we present a system simulator that can evaluate the performance of direct measurement Tire Pressure Monitoring Systems (TPMS) in various operational scenarios. We also discuss the following capabilities of the simulator: (1) modeling the wireless channel characteristics experienced by the signal between various transmitters and the receiver of a given vehicle, (2) modeling collisions among wireless signals of a given vehicle and those of the nearby vehicles, and (3) quantifying the impact of wireless channel characteristics and collisions among wireless signals on the performance of the TPMS. Using results for hypothetical simulation scenarios, we demonstrate the impact of wireless channel characteristics, receiver sensitivity level, and inter-vehicular interference on the performance of the TPMS.
Vehicular Technology Conference, 2007. VTC-2007 Fall. 2007 IEEE 66th; 11/2007
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ABSTRACT: In this paper, we present a system simulator that can assess the performance of a direct measurement Tire Pressure Monitoring System (TPMS) in various operational scenarios. We also discuss the following capabilities of the simulator: (1) modeling the wireless channel characteristics experienced by the signals between various transmitters and the receiver of a given vehicle, (2) modeling intra-vehicular electromagnetic interference (EMI) as experienced by the wireless signals, and (3) quantifying the impact of wireless channel characteristics and intra-vehicular EMI on the system packet error rate (PER). Using quantitative results for hypothetical simulation scenarios, we demonstrate the impact of different levels of Additive White Gaussian Noise (AWGN) and Amplitude Modulated (AM) Noise on the system PER performance.
Electromagnetic Compatibility, 2007. EMC 2007. IEEE International Symposium on; 08/2007
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ABSTRACT: An electromagnetic (EM) math model of TPMS calculates the data link's RF pathless profile of each four wheels that was later translated into an estimate of packet errors registered by the TPM system using a higher level system simulation tool. A reduced order model (ROM) of a vehicle structure for modeling TPMS performance was developed after investigating four vehicle models having different degree of complexity and identifying effects of various vehicle structures on the pathless profile. Pathless profile of the ROM of a CTS vehicle compared very well with that of the measurement data if variances are minimal in the RF channels between the transmitter and the receiver. The higher-level system model showed the system performance of the ROM converged to that of the measurement data.
Vehicular Technology Conference, 2006. VTC-2006 Fall. 2006 IEEE 64th; 10/2006
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ABSTRACT: A procedure is presented to simulate the complete automobile radio system, from antenna to speaker. The method involves generating reduced order models of all relevant components and interactions, which are then linked together in a time-domain system solver. To illustrate the usefulness of this simulation capability in vehicle-level system design a novel algorithm for automated computer rating of automobile audio tracks is developed. The algorithm uses wavelet and Fourier decompositions for automated computer rating of audio quality. The algorithm developed is validated by comparing its output to a study using human subjects to score recorded audio tracks
Electromagnetic Compatibility, 2005. EMC 2005. 2005 International Symposium on; 09/2005
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ABSTRACT: A MoM-based EM code was applied to model the electromagnetic fields coupled to a vehicle by nearby lightning return strokes. The return stroke model was applied to investigate the effect of the lightning induced electromagnetic fields on an automobile wiring harness; the effect generates high peak current electromagnetic pulse (EMP) and potential EMI/EMC concerns regarding electrical and electronics (E/E) components. The frequency content of the lightning induced current pulse on the wire cable harness was also analyzed by fast Fourier transform (FFT).
Antennas and Propagation Society International Symposium, 2005 IEEE; 08/2005
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ABSTRACT: PCS band and AMPS band antennas were mounted on the dashboard of an automobile. Antenna patterns toward the rear of the vehicle were measured as the antennas were tilted from the horizontal position. Results showed that for the PCS band antenna, the beam pointing angle significantly affected the frequency averaged patterns, while for the AMPS band antenna the frequency averaged patterns were minimally impacted by the antenna tilt.
Antennas and Propagation Society International Symposium, 2005 IEEE; 08/2005
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ABSTRACT: Results of a three-dimensional electromagnetic (3D EM) simulation of a generic automobile is presented. Full wave MoM based 3D EM code was applied to compute the normalized received power between a transmitter and a receiver of a tire pressure monitor system (TPMS) on a simplified model of an automobile. An overview of the procedure used to calculate the TPMS normalized received power using the EM modeling procedure is provided.
Antennas and Propagation Society International Symposium, 2004. IEEE; 07/2004
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ABSTRACT: By covering a metal ground plane with a periodic surface texture, we can alter its electromagnetic properties. The impedance of this metasurface can be modeled as a parallel resonant circuit, with sheet inductance L, and sheet capacitance C. The reflection phase varies with frequency from +π to -π, and crosses through 0 at the LC resonance frequency, where the surface behaves as an artificial magnetic conductor. By incorporating varactor diodes into the texture, we have built a tunable impedance surface, in which an applied bias voltage controls the resonance frequency, and the reflection phase. We can program the surface to create a tunable phase gradient, which can electronically steer a reflected beam over +/- 40° in two dimensions, for both polarizations. We have also found that this type of resonant surface texture can provide greater bandwidth than conventional reflectarray structures. This new electronically steerable reflector offers a low-cost alternative to a conventional phased array.
IEEE Transactions on Antennas and Propagation 11/2003; · 2.15 Impact Factor
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ABSTRACT: Our previous work is presented on diversity antenna experiments in the 2.3 GHz band, specifically for applications in the automotive environment. We describe the case of two-element position diversity, and we study the effects of the antenna positions on the amount of diversity gain. The presentation consists primarily of measurement data on a moving vehicle, with software post-processing to determine the effects of diversity combining. We present several diversity combining schemes, and describe a switched diversity circuit that we have built to address one of these schemes. An in-house developed SPDT MEMS switch, which has desirable insertion loss and isolation characteristics for the diversity switch, is shown. Also, a discussion on using a switch for the switched diversity antenna is included.
Wireless Personal Multimedia Communications, 2002. The 5th International Symposium on; 11/2002
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ABSTRACT: In this paper, we present work on diversity antenna experiments in the 2.3 GHz band, specifically for applications in the automotive environment. We describe the case of. two-element position diversity, and we study the effects of the antenna positions on the amount of diversity gain. The presentation consists primarily of measurement data on a moving vehicle, with software postprocessing to determine the effects of diversity combining. We present several diversity combining schemes, and describe hardware that we have built to address one of these schemes. Finally, we make several conclusions regarding the optimum geometry for antenna diversity in an automotive environment.
Vehicular Technology Conference, 2002. Proceedings. VTC 2002-Fall. 2002 IEEE 56th; 02/2002
