8 December 1995 Whip antenna design for portable rf systems
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Proceedings Volume 2601, Wireless Data Transmission; (1995); doi: 10.1117/12.228157
Event: Photonics East '95, 1995, Philadelphia, PA, United States
Abstract
Whip type antennas are probably the most commonly used antennas in portable rf systems, such as cordless and cellular phones, rf enabled laptop computers, personal digital assistants (PDAs), and handheld computers. Whip antennas are almost always mounted on the chassis which contains the radio and other electronics. The chassis is usually a molded plastic which is coated with a conducting paint for EMI purposes. The chassis which appears as a lossy conductor to the antenna, has several effects -- detuning, altering the gain of the antenna, and shadowing its radiation pattern. Extensive modeling and measurements must be performed in order to fully characterize the affects of the chassis on the whip antenna, and to optimize antenna type, orientation and position. In many instances, modeling plays a more important role in prediction of the performance of whip antennas, since measurements become difficult due to the presence of common mode current on feed cables. In this paper models and measurements are used to discuss the optimum choice of whip antennas and the impact of the chassis on radiation characteristics. A modeling tool which has been previously described and has been successfully used to predict radiated field patterns is used for simulations, and measured and modeled results are shown.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Saila Ponnapalli, Frank J. Canora, "Whip antenna design for portable rf systems", Proc. SPIE 2601, Wireless Data Transmission, (8 December 1995); doi: 10.1117/12.228157; http://dx.doi.org/10.1117/12.228157
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KEYWORDS
Antennas

Polarization

Computing systems

Electronics

Environmental sensing

Ions

Personal digital assistants

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