A Compact Bandpass Microstrip Filter for Wireless Communication Applications

A design of Compact Bandpass Microstrip Filter is proposed for wireless communication applications like Bluetooth, Wi-Fi, and 5G. Filter is constructed using parallel-coupled Microstrip lines to form 5th order filter of an inverted C structure. Ground slotted technique is used to enhance the bandwidth with dielectric constant of 9.9. The designed filter is simulated at a center frequency of 5.87GHz and bandwidth of 1.9GHz with an insertion loss of -0.5dB, return loss of greater than 12dB. The proposed filter has a compact size, good increased bandwidth and cost-effective. These results are verified with the theoretically designed values and good agreements are recorded. Hence the proposed compact filter will provide a platform for designing and development of compact filters for the microwave regime.

Design of optical cavity for air sanification through ultraviolet germicidal irradiation

The transmission of airborne pathogens represents a major issue to worldwide public health. Ultraviolet light irradiation can contribute to the sanification of air to reduce the pathogen transmission. This study concerns the design of a compact filter for airborne pathogen inactivation by means of UV-C LED sources, whose effective irradiance is enhanced thanks to high reflective surfaces. Ray-tracing and computational fluid dynamic simulations are both used to model the device and to maximize the performance inside the filter volume. Simulations foresee the inhibition of SARS-Cov 2 also in the case of high air fluxes. This study demonstrates that current available LED technology is effective for air sanification purposes.

Dual Band Filter-Antenna with Fixed Low Band and Frequency-Agile High Band for Wireless Communications

This work proposes a design of compact filter-antenna with fixed and frequency-agile bands for wireless communications and cognitive radio (CR) systems. The filter-antenna is realized by attaching a bandpass filter with an independent fixed band and a tunable band to a UWB antenna. The dual bandpass filter consists of a folded open loop resonator loaded with single varactor diode at a suitable location to achieve reconfigurability operations for the high band while the low band remains fixed at 4.5 GHz. A reconfigurable broadband frequency range of 3.2 GHz from 7.8 to 4.6 GHz is achieved for the high band by changing the capacitance of the varactor from 0.16 to 2.25 pF, respectively. A prototype of the filter-antenna is fabricated and measured at a selected capacitance of 0.6 pF to verify the simulation results. Good agreements between simulated and measured results are obtained.