Miniaturized Wideband Bandpass Filter with Wide Stopband using Metamaterial-based Resonator and Defected Ground Structure

This paper presents a miniaturized wideband bandpass filter with wide stopband performance. It is shown that the coupled metamaterial-based resonators (MBRs) incorporating with the defected ground structure (DGS) can significantly increase the coupling value to achieve wideband bandpass filter. This technique has been extended to realize wideband bandpass filter having fractional bandwidth of 63 % and low insertion loss in the passband. To further suppress the spurious harmonics and upper stopband, the combining of the zero-degree feed structure and embedded slot-loaded resonators in both input and output ports is introduced. The proposed filter has not only compact size but also good out-of-band response. The experimental results are demonstrated and discussed

Bandwidth and Gain Enhancement of Microstrip Patch Antennas Using Reflective Metasurface

Bandwidth and gain enhancement of microstrip patch antennas (MPAs) is proposed using reflective metasirface (RMS) as a superstrate. Two different types of the RMS, namely- the double split-ring resonator (DSR) and double closed-ring resonator (DCR) are separately investigated. The two antenna prototypes were manufactured, measured and compared. The experimental results confirm that the RMS loaded MPAs achieve high-gain as well as bandwidth improvement. The desinged antenna using the RMS as a superstrate has a high-gain of over 9.0 dBi and a wide impedance bandwidth of over 13%. The RMS is also utilized to achieve a thin antenna with a cavity height of 6 mm, which is equivalent to γ/21 at the center frequency of 2.45 GHz. At the same time, the cross polarization level and front-to-back ratio of these antennas are also examined.Department of Electronic and Information Engineerin