Stub (electronics)

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

Ultra-Wideband Bandpass Filter With a Notch-Band Using Stub-Loaded Ring Resonator

Abstract: A quadruple-mode ultra-wideband (UWB) bandpass filter with a notch-band and wide upper stopband is presented in this letter. The UWB filter is realized using a ring resonator which is loaded with two sets of stubs, i.e., one is loaded in the center and two little stubs at the symmetrical side locations. The loaded stubs are used to create transmission zeros in upper stopband thus high modes are suppressed greatly. Moreover, two identical via-loaded ring resonators are inserted within the stub-loaded ring resonator, to create a notch-band around 5-6 GHz to avoid WLAN signals. Two reflection poles appear in the notch-band, resulting in a switchable bandwidth of the notch-band. Finally, a UWB filter with a notch-band is simulated and fabricated, and measured results provide an experimental validation of predicted performance of the filter.

A miniaturized dual-mode ring bandpass filter with a new perturbation

Abstract: A miniaturized dual-mode ring bandpass filter at 1.45 GHz with a bandwidth of 6% is demonstrated. The perturbation of the dual modes is realized by a pair of local ground defects. The miniaturization is achieved by loading the peripheral of the ring with the butterfly radial stub structure. A 41% loading factor has been achieved using this method. The simulated and measured results are in good agreement.

Compact Microstrip Dual-Band Bandpass Filter Using a Novel Stub-Loaded Quad-Mode Resonator

Abstract: This letter presents a novel stub-loaded quad-mode resonator Due to the structure geometry, even-odd-mode analysis is applied twice to explain the modal characteristics Each of the four modes equivalent circuits is a quarter-wavelength resonator, so the quad-mode resonator has a compact size The stub-to-stub coupling is introduced to split two identical odd-modes Meanwhile, these two coupling stubs are folded inward, and a new transmission zero is produced, which separates four modes into two parts corresponding to two passbands: the first one is formed by even-modes, and the second one is composed by odd-modes The center frequency and bandwidth of each passband can be controlled by the corresponding physical dimensions For demonstration, a dual-band bandpass filter (BPF) using the proposed quad-mode resonator is designed The simulated and measured results with good agreement are presented

High-Efficiency Harmonic-Peaking Class-EF Power Amplifiers With Enhanced Maximum Operating Frequency

Abstract: The recently introduced Class-EF power amplifier (PA) has a peak switch voltage lower than that of the Class-E PA. However, the value of the transistor output capacitance at high frequencies is typically larger than the required Class-EF optimum shunt capacitance. Consequently, soft-switching operation that minimizes power dissipation during off-to-on transition cannot be achieved at high frequencies. Two new Class-EF PA variants with transmission-line load networks, namely, third-harmonic-peaking (THP) and fifth-harmonic-peaking (FHP) Class-EF PAs are proposed in this paper. These permit operation at higher frequencies at no expense to other PA figures of merit. Analytical expressions are derived in order to obtain circuit component values, which satisfy the required Class-EF impedances at fundamental frequency, all even harmonics, and the first few odd harmonics as well as simultaneously providing impedance matching to a 50- $\Omega$ load. Furthermore, a novel open-circuit and shorted stub arrangement, which has substantial practical benefits, is proposed to replace the normal quarter-wave line connected at the transistor's drain. Using GaN HEMTs, two PA prototypes were built. Measured peak drain efficiency of 91% and output power of 39.5 dBm were obtained at 2.22 GHz for the THP Class-EF PA. The FHP Class-EF PA delivered output power of 41.9 dBm with 85% drain efficiency at 1.52 GHz.

Broad-Band RF Match to a Millimeter-Wave SIS Quasi-Particle Mixer

Abstract: An integrated superconducting microstrip is shown to be a convenient, flexible, and well-characterized matching element for a super-conductor-insulator- superconductor (S1S) quasi-particle heterodyne mixer. The resonant interaction (Fiske modes) between the Josephson oscillations of a voltage-biased junction and the microstrip provides a convenient method for determining the electrical length of the microstrip line. An open-circuited microstrip stub that reflects a parallel inductance across the junction is used to broaden the bandwidth of the RF match of a 36-40-GHz S1S- mixer. Measurements with Pb-alloy junctions in a full-height waveguide mixer with fixed mechanical tuning give an instantaneous bandwidth of '10 to 15 percent with a mixer noise temperature T /sub M/ (DSB) = 10+- 2.5 K.