Topic
Stub (electronics)
About: Stub (electronics) is a research topic. Over the lifetime, 8172 publications have been published within this topic receiving 75018 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, a Fourier transform spectrometer with an Hg-arc lamp source was used as an RF sweeper to measure the frequency response of a planar lithographed quasioptical mixers.
Abstract: Planar lithographed quasioptical mixers can profit from the use of integrated tuning elements to improve the coupling between the antenna and the SIS mixer junctions. We have used a Fourier transform spectrometer with an Hg-arc lamp source as an RF sweeper to measure the frequency response of such integrated tuning elements. The SIS junction connected to the tuning element served as the direct detector for the spectrometer. This relatively quick, easy experiment can give enough information over a broad range of millimeter and submillimeter wavelengths to test both design concepts and success in fabrication. One type of tuning element, an inductive wire connected in parallel with a series array of 5 SIS junctions across the terminals of a bow-tie antenna, shows a resonant response peak at 100 GHz with a 30% bandwidth. This result is in excellent agreement with theoretical calculations based on a simple L-C circuit. It also agrees very well with the RF frequency dependence of the mixer gain measured using the same structure. The other type of tuning element, an open-circuited stub connected in parallel with a single SIS junction across the terminals of a bow-tie antenna, exhibits multiple resonances at 110, 220, and 336 GHz, with bandwidths of 9–15 GHz. This result is in good agreement with theoretical calculations based on an open-circuited stub with small loss and small dispersion. The position and the bandwidth of the resonance at 110 GHz also agrees with the RF frequency dependence of the mixer gain measured using similar structures.
23 citations
23 citations
TL;DR: In this article, an improved uniplanar antenna for handheld RFID reader applications covering free ISM bands of 2.45 and 5.8 GHz is presented, which is composed of a microstrip feeding line, two unsymmetrical ground planes, and a folded strip with a small top branch.
Abstract: Radio frequency identification (RFID) excelled in automatic identification and data collection industry through its speed, agility, and endurance. In this letter, an improved uniplanar antenna for handheld RFID reader applications covering free ISM bands of 2.45 and 5.8 GHz is presented. The antenna is composed of a microstrip feeding line, two unsymmetrical ground planes, and a folded strip with a small top branch. The folded strips generate radiations in resonances and the ground, which act as reflectors, force the radiation in the endfire direction. The impedance matching and bandwidth of the antenna is improved by inserting optimized triangular periodic open-end stub (POES) cells on the top edge of the coplanar ground. A good impedance bandwidth of 320 MHz is achieved in measurement (from 2.35 to 2.67 GHz for the lower band), while the upper band covers 310 MHz (from 5.60 to 5.91 GHz). Also, good polarization purity, front-to-back ratio, and gain are found, which makes the antenna a strong candidate for compact handheld RFID reader applications.
23 citations
TL;DR: This paper presents branch line couplers with compact size and harmonic suppression based on non-periodic reactively loaded artificial lines based on step impedance shunt stubs, which exhibit a slow wave effect of interest for device miniaturization.
Abstract: This paper presents branch line couplers with compact size and harmonic suppression based on non-periodic reactively loaded artificial lines. The reactive loading elements of the lines are step impedance shunt stubs (SISSs). Such elements provide transmission zeros, which are useful to efficiently suppressing the harmonic content of the device. Moreover, by virtue of reactive loading, the reported artificial lines exhibit a slow wave effect of interest for device miniaturization. The combination of size, harmonic suppression efficiency, and design simplicity (with a clear design methodology) is of interest within the framework of artificial transmission lines and their application to the optimization of microwave passive components.
23 citations
Patent•
15 May 1998
TL;DR: In this paper, a reconfigurable filter system designed using micro-elecro-mechanical (MEM) switches is described. But the authors did not specify the characteristics of the filter system and only the length of filter stubs attached to the transmission line.
Abstract: A reconfigurable filter system designed using micro-elecro-mechanical (MEM) switches is disclosed. The filter comprises a transmission line with one or more filter stubs coupled to the transmission line by MEM switches. The impedance of the filter system is altered by selectively opening and closing the MEM switches, which alters the filter characteristics of the filter system. Alternatively, the characteristics of the filter system are altered by using the MEM switches to selectively alter the length of filter stubs attached to the transmission line.
23 citations