A compact microstrip multi-stub loaded bandpass filter (BPF) with ultra-wide stopband is introduced and investigated. Lumped-equivalent circuit (LEC) method is adopted to analyze the characteristics of the in-band response based upon the low frequency LEC and even-odd mode analytical method. Besides, equivalent transmission line circuit method with even-odd mode analytical method are adopted to di

In this paper, significance of studying the nonlinear performance of amplifying reflectarray antenna is clarified by showing nonlinear behavior of the unit cell. Furthermore, the procedure for nonlinear analysis of amplifying reflectarray antenna is described and nonlinear analysis is verified by ADS software simulation. Moreover, a typical amplifying reflectarray antenna is designed considering t

This paper compares the noise performance of two different types of time-domain microwave detection systems: a pulsed system and a pseudo-random noise sequence system. System-level simulations and laboratory-based measurements are carried out in the study. Results show that the effect of timing jitter is more significant on the measurement accuracy of the pseudo-random noise sequence system than t

A super-wideband (SWB) omnidirectional antenna is reported in Lau et al. in 2005 and 2008, but the antenna structure was complex and the radiation properties were unsatisfactory. In this paper, a SWB omnidirectional antenna with simple structure and improved radiation properties is presented. The antenna just consists of a two-stage inverted cone and two shorting pins. The proposed two-stage cone

In this paper, a microstrip lowpass filter with wide stopband and sharp roll-off is presented. The proposed filter consists of a modified radial stub resonator which is cascaded by four suppressing cells. To reduce the overall size, the transmission lines are folded. The cut-off frequency of the proposed filter is 1.19 GHz. The transition band is approximately 0.2 GHz from 1.19 to 1.39 GHz with co

Design and realisation of a compact power divider based on half mode substrate integrated waveguide (HMSIW) with an arbitrary power dividing ratio is presented. This design consists of a substrate integrated waveguide (SIW) transition, two bisected HMSIW transitions by a gap, an SIW-to-microstrip transition, and two microstrip feed lines. In addition, a resistor is attached between two HMSIW trans

This paper presents a new broad band circularly polarized slot antenna array based on substrate-integrated waveguide (SIW) and aperture feeding techniques. The antenna element's impedance and 3 dB axial-ratio (AR) bandwidths are from 8.8 to 10.4 GHz (16.67%) and 9.5?10.7 GHz (12%), respectively. Employing aperture-coupled feed and combining this method with sequentially rotated network, a 2 × 2 an

Novel impedance transforming directional couplers are proposed in which the achievable impedance transformation ratio is increased above the previously reported limit related to coupling of the coupled-line sections. The proposed couplers consist of two coupled-line sections between which uncoupled sections of left-handed lines are connected. The presented concept has been verified by circuit simu

This paper presents a high gain, wideband circularly polarized (CP) antenna. High gain of the antenna is achieved by employing a frequency selective surface (FSS) as a reflector. The antenna is a coplanar waveguide-fed structure with a modified L-shaped radiating patch. The unit element of the FSS is formed by connecting two modified dipoles at an angle of 90°. The antenna with reflector has a mea

We report in this paper a novel miniaturized (12 × 18 × 1.6 mm) microstrip fed UWB antenna with tunable notched band characteristics. The proposed antenna covers the tunable notched band for IEEE 802.11a wireless local area network operating in the frequency band of 5.15?5.825 GHz. The design of proposed antenna includes annular ring radiating patch with two T-shaped strips present inside it. The