Brijesh Iyer

Dual-Input Dual-Output RF Sensor for Indoor Human Occupancy and Position Monitoring

This paper reports a concurrent dualband occupancy sensor, based on Doppler principle, for monitoring of human presence in a room. The proposed sensor operates simultaneously at 2.44 and 5.25-GHz frequency bands. The sensor prototype has been realized using own customized concurrent dualband subsystems. A measurement setup has been developed using off-the-shelf laboratory equipment and the sensor prototype. The human presence in a room has been predicted from the analysis of correlation spectrum of the signals received at individual frequency bands and from the estimation of the direction of arrival of received signals. The main advantage of the proposed sensor lies in the reduction of the false alarms, power consumption, and size.

Concurrent Dualband Diplexer for Nanoscale Wireless Links

This letter reports the design and full wave analysis of a compact and low-loss filter-based concurrent dualband diplexer for high-density multiband photonic integrated circuits. The proposed diplexer consists of a chamfered T-junction in nanoplasmonic metal-insulator-metal waveguide and two bandpass filters (BPF) inserted in the two output arms. Plasmonic BPF have been designed using stepped width resonator. These filters are concurrently operating at 1427-/1665-nm and 1355-/1595-nm wavelength. The optimized chamfered T-junction has return loss >8 dB, whereas insertion loss of each dualband BPF is <;5 dB.

Concurrent dualband patch antenna array for non-invasive human vital sign detection application

This article reports design and fabrication of a 1 × 2 planner rectangular dualband patch antenna array using circular CSRR in the ground plane. The proposed antenna operates simultaneously at 2.44 and 5.25 GHz band. It has measured gain of 7.21 and 8.12 dBi, 10 dB bandwidth of 120 MHz and return loss of -14dB at desired bands. The proposed antenna is specially designed to cater the needs of a portable human non-invasive vital sign detection (NIVSD) system for medical and defense applications. Low cost, high directivity and light weight are desired for antenna used in these applications. The concurrent dualband operation and fair agreement between simulated and measured characteristics such as return loss and radiation pattern confirms the efficacy of this antenna in NIVSD systems.

Reconfigurable multiband concurrent RF system for non-invasive human vital sign detection

The non-invasive vital sign detection (NIVSD) system works on the principle of change in phase of electromagnetic waves due to partial reflection from separation of two mediums and invasion all the way through the medium. Radio frequency (RF) system based non-invasive measurement methods neither confines nor cause distress as conventional vital sign measurement methods to the human being. This aspect of non-invasive detection becomes predominantly significantfor long-term continuous monitoring of vital signs of human being. The paper reports a reconfigurable multiband NIVSD RF system for effective use of available frequency bands without increasing the size, cost and power consumption level of the system. The proposed system simultaneously operates in entire WLAN band. Experimentally, it has been observed that 2.48-/5.15-GHz frequency band is found better in terms of low radiation power; while 2.48-/5.35-GHz band is better in terms of receivingpower at the antenna.

Metal-silica-metal plasmonic waveguide based concurrent dualband directional coupler

This paper reports design and full wave analysis of a concurrent dualband directional coupler using metal-silica-metal plasmonic waveguide for nanoscale wireless links. Two edge coupled asymmetric plasmonic slot waveguides have been analyzed to obtain characteristics such as propagation constant, propagation length and characteristic impedance of even and odd modes. Concurrent dualband response of the edge coupled parallel coupler has been obtained by replacing coupled line section with a stepped width coupled line. The designed coupler can be used simultaneously in O and L bands.

Plasmonic metal-insulator-metal-waveguide based concurrent dual band antenna for nanoscale wireless links

Plasmonic antennas are one of the key components in the realization of future nanoscale wireless links. This paper reports design and analysis of a CPW fed dual band antenna designed using a plasmonic metal-insulator-metal waveguide operating simultaneously in O- and L-bands. The full wave simulation results obtained using CST Microwave studio shows a return loss of -18dB (VSWR of 1.11) at the desired band. The antenna has a gain of 8.88 dBi and 8.50 dBi at wavelengths 1309-nm and 1604-nm respectively. The simulated radiation pattern at desired wavelengths shows an Omni-directional pattern which is desired for wireless applications.

Design and simulation of plasmonic MIM slot waveguide based dualband bandpass filter

This paper reports simulation of nano plasmonic MIM stepped width resonator (SWR) based BPF having two resonators and a dual band impedance inverter. Simulation results confirms the presence of pass bands at 1350-nm and 1650-nm.