Stub (electronics)

About: Stub (electronics) is a research topic. Over the lifetime, 8172 publications have been published within this topic receiving 75018 citations.

Fano-type spectral asymmetry and its control for plasmonic metal-insulator-metal stub structures

Abstract: We use coupled mode theory (CMT) to analyze a metal-insulator-metal (MIM) plasmonic stub structure, to reveal the existence of asymmetry in its transmittance spectra. Including the effect of the near field contribution for the stub structure, the observed asymmetry is interpreted as Fano-type interference between the quasi-continuum T-junction-resonator local-modes and discrete stub eigenmodes. Based on the asymmetry factor derived from the CMT analysis, methods to control transmittance asymmetry are also demonstrated.

Uniform theoretical description of plasmon-induced transparency in plasmonic stub waveguide

Abstract: We investigate a classic analog of electromagnetically induced transparency (EIT) in a metal-dielectric-metal (MDM) bus waveguide coupled to two stub resonators. A uniform theoretical model, for both direct and indirect couplings between the two stubs, is established to study spectral features in the plasmonic stub waveguide, and the theoretical results agree well with the finite difference time domain simulations. Adjusting phase difference and coupling strength of the interaction, one can realize the EIT-like phenomena and achieve the required slow light effect. The theoretical results may provide a guideline for the control of light in highly integrated optical circuits.

A $Ka$ -Band High-Gain Circularly Polarized Microstrip Antenna Array

Abstract: In this letter, a four-element high-gain circularly polarized microstrip antenna array operating in the Ka -band is proposed. The sequentially rotated series-parallel stub technique is employed in constructing the feed network to allow symmetrical positioning of microstrip patch elements, resulting in good axial ratio of polarization. In addition, an L-shaped matching branch is used to offer good impedance matching and spatial flexibility for positioning patch elements. Both simulation and measurement results are presented. They agree with each other well and demonstrate much better 3-dB axial-ratio bandwidth and return loss than the single patch antenna.

Wideband Stub-Loaded Slotline Antennas Under Multi-Mode Resonance Operation

Abstract: A novel center-fed wideband slotline antenna is proposed using the multi-mode resonance concept. By symmetrically introducing one or two pairs of slot stubs along the slotline resonator near the nulls of electric field distribution of the second odd-order mode, two modes are excited in a single slotline radiator. With the help of these stubs, the second odd-order mode can be gradually merged with its first counterpart, resulting in a wideband radiation characteristic with two resonances. Prototype antennas are then designed and fabricated to experimentally validate the principle and design approach. It is shown that the operation fractional bandwidth of the proposed slotline antenna could be effectively increased to 31.5% while keeping an inherent narrow slot structure.

Compact Balanced Dual- and Tri-band Bandpass Filters Based on Stub Loaded Resonators

Abstract: A stub loaded resonator (SLR) is presented in this letter, which can achieve dual-band or tri-band differential-mode (DM) bandpass response with a high common-mode (CM) suppression. By changing the length of the center-loaded stub, the resonant frequency of the CM can be varied without affecting that of the DM. This helps in simplifying the design and tuning processes of the balanced filters. In order to validate its practicalbility, two balanced bandpass filters (BPFs) with two and three DM passbands and good CM suppression are designed. Good agreement between simulated and measured results is observed. To our best knowledge, the proposed balanced tri-band BPF is the first ever reported.