The great majority of commercial UHF RFID tags are based on dipole antennas, and it is well-known that the tag performance degrades significantly when placed near a conducting surface. The question we address in this paper is: is it necessarily so? In this paper, we present evidence that suggest that it is not, at least to the degree that it has been observed. We present two antennas: one that ...

In this paper we address methods for characterizing small, low-gain antennas that are intended to be operated autonomously by a passive transponder chip. We present a way to perform accurate 3D gain measurements by means of a small, battery-powered, calibrated signal source and a two axis rotation apparatus. From the measurement results the directional pattern and the antenna efficiency are der...

[1] The design and operation of transionospheric VHF and UHF radars requires knowledge of amplitude and phase scintillation due to ionospheric scattering. Phase coherence is of particular importance where long coherent integration periods and large bandwidths are required. A thin phase screen, parabolic equation based, Trans-Ionospheric Radio Propagation Simulator (TIRPS) is described. Modeled ...

This paper presents effect of delay waves on MIMO over-the-air (OTA) throughput of a handset MIMO array using a spatial fading emulator. The emulator has a number of antenna probes located on a circle around a handset under test to representing a multipath radio environment applicable to the OTA evaluation for a handset MIMO antenna. The MIMO OTA tests with and without delay waves, which have a...

in some mobile systems, intelligent antennas are used to increase efficiency in a wide frequency band and different environmental and electromagnetic conditions. environmental factors, such as position of nearby objects, antenna mobility and even user type, can vary the antenna input impedance appreciably. therefore, it is necessary to incorporate an adaptive impedance matching circuit between ...

This letter discusses the effect of antenna losses due to rain on a 26GHz microwave link and the technique of extracting the losses from the measured rain attenuation. A 2-feet parabolic dish antenna with horizontal polarization has been used in the study. The measurement results have been compared with those obtained from other locations in Malaysia and some other Published Research works. The...

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High-quality wireless devices require an omnidirectional and uniform antenna radiation pattern. This pattern can be verified by measuring the over-the-air (OTA) performance. These measurements, which are an essential part of the certification test, need to be extended to include MIMO operating modes. The Rohde&Schwarz two-channel test method makes these measurements both cost-effective and repr...

─ Development of the RFID tag for paper reel identification in industrial environment is discussed. Paper reel supply chain and history of the development of the presented antenna design is explained. Modeling of the paper reel tag is discussed and a case study of tag antenna − paper reel co-design is presented. Index Terms─ UHF RFID, paper reel identification, tag antenna design.

A performance analysis of an access channel decoder is presented which exploits a diversity gain due to the independent magnitude of received signals energy at each of the antenna elements of a smart-antenna base-station transceiver subsystem (BTS) operating in CDMA2000 1X signal environment. The objective is to enhance the data retrieval at cellsite during the access period, for which the opti...