John C. Batchelor

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A passive UHF RFID tag design is presented in the form of a transfer patch similar to a temporary tattoo that is mountable directly onto the skin surface. The transfer tag is suitable for monitoring of people over time in mission critical and secure environments. The antenna reactance is first calculated to conjugate match the measured RFID chip reactance(More)
Active frequency selective surfaces (FSS) based on slot-form split ring resonators are described. Switching and tuning have been achieved using two different biasing circuit configurations. The first design switches ON and OFF the two concentric rings separately, producing four distinct transmission responses. The second design is able to vary the(More)
Offering good performance in terms of all polarizations affected and good angular stability, the ring element is a popular choice in frequency selective surface (FSS) designs. This paper introduces a topology for two-state switching of a ring based FSS. The two states offered by the surface enable it to be either transparent or reflective at the frequency(More)
A novel design for a beam-switching antenna using active cylindrical slot frequency selective surface (ACSFSS) is presented. The antenna system is composed of an omnidirectional monopole antenna and the ACSFSS, which employs a new technique of switching slot arrays. The ACSFSS is made up of 12 columns with 8 slots each, dividing the cylinder by 30°.(More)
A switchable frequency selective surface (FSS) made of square loop slots and PIN diodes connected to a novel separate biasing circuit is presented. The structure uses a very thin, flexible substrate sandwiched between two physically independent metallic layers to create the active filter. An application is the modification of the EM architecture of(More)
An epidermal passive wireless strain sensor using radio frequency identification (RFID) tags is presented. The tag is intended to detect eyebrow or neck skin stretch where paraplegic patients have the capability to tweak facial muscles. The tag is designed on a barium-titanate-loaded polydimethylsiloxane (PDMS) substrate and is assessed to demonstrate the(More)
In this paper a motion capture system is employed in order to record the position and orientation of body-worn antennas as the body moves. This geometrical data then is used to calculate free space path gain between the antennas. The results are compared to the measured path gain and then the usefulness of this approach to channel characterisation is(More)
Body-worn physiological sensors can facilitate ambulatory patient monitoring, particularly if communication between sensors is wireless; but the communication channel must be robust. This paper presents how a 3D animated human model is created using a 3D scanner and a motion capture system. Then this model is used in XFdtd, electromagnetic simulation(More)
In this paper we introduce a bio-axis passive wireless UHF RFID tilt sensor for applications such as to increase safety in warehouse environment and damage detection in consumer goods and where long term monitoring of the product is essential without the need to supply power to the sensors. Simulation and prototype testing indicate it is possible to detect(More)
In this study, a low-profile slot antenna was designed with the purpose of having the ability to be integrated into the structure of a layered non-metallic polymer battery. Using a set of previous published parameters for the slot antenna, the structure was modified in the CST Microwave Studio package in order to suit the needs of a battery substrate. A(More)