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Recently, automated identification techniques that utilize radio frequency (RF) systems have experienced growth both in the industry and in research worldwide. The current state-of-art of this identification realm is the radio frequency identification (RFID) system, which utilizes a transponder with a unique identifier. RFID systems can be classified into active systems (with built-in power supply),...
Due to the development of micro-mechanical systems (MEMS), RF MEMS switches are being widely investigated. Although RF MEMS switches have been intensively studied, limited work was done on switches that are suitable for integration in large switching networks such as switch matrices and multi-bit phase shifters. These switching networks require very small switches each with independent controls. Their...
This paper introduces an efficient method to calculate the total isotropic sensitivity (TIS) of a mobile phone. The method is implemented by using the EM simulation, the digital signal modeling and the RF link budget simulation. By considering digital harmonic noise, the accuracy of the TIS calculation can be increased. Simulation results for the phone structure show the availability of this proposed...
Based on the structure of CRLH-TL, a novel phase shifter with high power capacity is proposed. In this structure, switches are mounted on the fingers of CRLH-TL, thus the current through a single switch is only a fraction of that through the whole phase shifter, which greatly improves the power capacity. Moreover, the present phase shifter possesses other advantages such as low cost, small size and...
This paper discusses harmonic scattering from passive UHF RFID tags. We describe the problem and the basic theory; explain our measurement setup, and present experimental results for three different commercial Gen2 tags.
The advancement in new numerical technique is the key to success of newer generation RF MEMS devices. In this paper, a novel time-domain modeling technique that has the capability to accurately simulate the transient effect of RF MEMS variable capacitors with accelerated motion controlled by the coupling of the electrostatic and mechanical forces is presented. The relation between the sinusoidal modulations...
In this paper, we present an analytical view of the maximum far-field tag gain of a typical commercially available passive UHF RFID tag design operating at 915 MHz, which is the center frequency of the Industrial, Science, and Medical (ISM) band. The far field gain is calculated using FEKO 5.3 designed by EMSS, which is a computational electromagnetic (CEM) tool, and the method used here includes...
A new highly sensitive radio frequency pressure transducer has been designed to operate in the millimeter wave frequency range that can be seamlessly integrated with other RF circuits in the LTCC multilayer packaging technology. The resonator consists of a stacked-patch based on LTCC multilayer packaging technology, having an air cavity embedded by a silicon (Si) diaphragm that deflects due to pressure...
We have presented the design and full-wave analyses of a frequency reconfigurable antenna in response to public safety communities' mobile wireless communications applications. The antenna, MRA patch, can be tuned to operate at 0.8 GHz, 2.4 GHz and 4.9 GHz frequrencies. The MRA patch exhibits very similar gain and well behaved radiation patterns at each frequency band. The design and microfabrication...
This work demonstrates a useful application of the ferroelectric thin film varactor technology in the design of reconfigurable microstrip patch antennas. Results show that the resonant frequency of the microstrip patch antenna can be tuned by varying the applied DC voltages on the ferroelectric varactor. A resonance frequency shift from 12.4 GHz to 13.8 GHz was observed for a small dc bias voltage...
It is shown in this paper that properly designed R-Card fences can be installed in indoor measurement facility to reduce the multipath signals in the chamber. The design is especially more effective when the transmit antenna is closer to the absorber wall. The traditional foam absorber works well when the angle of incidence is less than 50 degrees if the thickness is about 2 wavelengths. The R- Card...
This paper describes the development of a dual frequency, circular polarized feed which operates over the S/X frequency bands. The feed is incorporated into a 12 meter Cassagrain reflector system for use in radio astronomy applications. The selected design consists of two separate feeds assembled in a coaxial configuration. The inner circular waveguide is used for X-band and the outer coaxial circular...
This paper proposes a PCE that uses available space in the phone housing effectively and adds additional bands to existing PIFA. The PCE can be used advantageously to add a GPS band to a cellular band PIFA but other uses. The PE can be manufactured cost effectively and can be added to an existing phone without re-tooling the plastic housing.
In this paper, the passive UHF RFID tag is characterized on a metal slab for varying distances. The bent dipole tag designed by UPM Raflatac Corporation and the Squiggle tag designed by Alien Corporation is tested for electromagnetic strength of the reply signal. These tags are also simulated in FEKO 5.3 designed by EMSS to depict their performances on the metal slab for varying distances, and is...
We presented a novel process for constructing high conductivity CNT surfaces. This is done by growing high density CNTs on light-weight and highly flexible polymer substrates. The proposed vertically aligned CNT printing technology can also be adapted for constructing flexible RF circuits integrated on a variety of commercial and defense related applications. Given the desirable RF and mechanical...
We presented a channel capacity evaluation of body-worn radio systems using a decomposition of the channel environment. Specifically, the human body interactions were treated separately from the propagation channel. Via this decomposition, we proceeded to evaluate body-worn antenna diversity. Full wave simulations of the environment were compared with the decomposition approach for validation. A systematic...
For the first time the use of RCS of multi-band scatterers is proposed for the remote identification of micro-sensors in a wireless sensors network. The next step will consist of connecting a specific multi-band scatterer to each micro-sensor and, to achieve simultaneously the remote measurement of a physical quantity (via the electromagnetic transduction principle) and the sensor identification (via...
Experimental results have showed that beam patterns can achieve their theoretically expected performances only if the non-ideal array behavior is appropriately compensated. We have developed an automatic calibration system for smart antenna array. It is time saving, easy to operate and accurate. The test results show that the calibrated array has a much improved beam pattern comparing with the one...
The analysis of path loss in scattering zone by using UTD is presented. The results of the total field results from the UTD solution agree very well with that from NEC-BSC. Around the vicinity of the source, the UTD results agree with experimental results but not in the further region. This is due to the fact that the line-of-sight and reflected field components are very strong in this region. For...
This paper presents a design concept to aid in the detection and tracking of objects in a cluttered environment. The goal is to uniquely identify large, relatively cylindrical metallic objects in a warehouse setting. In addition to the challenge of determining the object's precise location, it is also desirable to uniquely identify each cylinder. The application is similar to RFID but differs in that...
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