Stub (electronics)

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

High-Performance Multiple-Input Multiple-Output Antenna System For 5G Mobile Terminals

Abstract: In this paper, the systematic design of a multiple antenna system for 5G smartphone operating at 3.5 GHz for multiple-input multiple-output (MIMO) operation in smartphones is proposed. The smartphone is preferred to be lightweight, thin, and attractive, and as a result metal casings have become popular. Using conventional antennas, such as a patch antenna, Inverted-F antennas, or monopole, in proximity to metal casing leads to decreasing its total efficiency and bandwidth. Therefore, a slot antenna embedded in the metal casing can be helpful, with good performance regarding bandwidth and total efficiency. The proposed multiple antenna system adopted the unit open-end slot antenna fed by Inverted-L microstrip with tuning stub. The measured S-parameters results agree fairly with the numerical results. It attains 200 MHz bandwidth at 3.5 GHz with ports isolation of (≤−13 dB) for any two antennas of the system. The influence of the customer’s hand for the proposed multiple antenna system is also considered, and the MIMO channel capacity is computed. The maximum achievable MIMO channel capacity based on the measured result is 31.25 bps/Hz and is about 2.7 times of 2 × 2 MIMO operation.

Back fire helical antenna

Abstract: A first radiation member 165 includes radiation conductors 166 and 167, an arm 168 and a lower connection piece 169 all integrally formed by blanking. A stub 170 is likewise integrally formed on radiation conductor 166. A second radiation member 171 includes radiation conductors 172 and 173, an arm 174 and a lower connection piece 175 all integrally formed by blanking. A stub 176 is likewise integrally formed on radiation conductor 173. A first loop comprised of radiation conductors 167 and 172, arms 168 and 174 and lower connection pieces 169 and 175 exhibits capacitive impedance at a wavelength for use. The overall length of a second loop comprised of radiation conductors 166 and 173, arms 168 and 174 and lower connection pieces 169 and 175 is set equal to that of the first loop. The second loop, however, exhibits inductive impedance at the wavelength for use by adjustment of the length of stubs 170 and 176. Adjusting stubs 170 and 176 enable control of a phase of a current flowing through the second loop.

Folded dipole antenna

Abstract: A folded dipole antenna for transmitting and receiving electromagnetic signals is provided. The antenna includes a ground plane and a conductor extending adjacent the ground plane and spaced therefrom by a first dielectric. The conductor includes an open-ended transmission line stub, a radiator input section, at least one radiating section integrally formed with the radiator input section, and a feed section. The radiating section includes first and second ends, a fed dipole and a passive dipole. The fed dipole is connected to the radiator input section. The passive dipole is disposed in spaced relation to the fed dipole to form a gap. The passive dipole is shorted to the fed dipole at the first and second ends.

A New Defected Ground Structure and its Application for Miniaturized Switchable Antenna

Abstract: A new defected ground structure (DGS) is flrstly proposed in this paper, which has better slow-wave efiect than that of cross or dumbbell one. Using the model of transmission line, its equivalent parameters are extracted. With good omni-directional properties, the proposed DGS is then used in the design of a proximity coupled antenna for its miniaturization. The size of the developed antenna is about 68% smaller than that of the conventional one. Further, two artiflcial cells are added on the feed line to reduce the protrudent stub length from 26.9mm to 18.94mm. With the utility of the DGS and artiflcial cells, the size of proximity coupled antenna is reduced signiflcantly. By introducing a PIN diode at the end of feed line, the antenna is switchable in both x- and y-direction linear polarizations. Such miniaturization in antenna size has little negative efiect on its cross polarization, with both simulated and experimental results presented for comparison.

Multi-Stub-Loaded Differential-Mode Planar Multiband Bandpass Filters

Abstract: A new type of RF $/$ microwave differential-mode planar multiband bandpass filters (BPFs) are presented. Each symmetrical half of the proposed balanced filtering architecture is composed of the in-series cascade of $K$ $N$ -stub-loaded cells through $K-1$ inter-connection transmission-line segments to synthesize a differential-mode transfer function with $N$ $K$ th-order passbands. Additional features of this balanced multiband BPF topology are as follows: 1) generation of transmission zeros at both sides of all differential-mode passbands; 2) high common-mode power-rejection levels within the differential-mode passband ranges; 3) scalability to any number of arbitrary-order differential-mode transmission bands; and 4) lack of electromagnetic couplings in its physical structure. The theoretical foundations of the engineered balanced filter approach, along with guidelines to design the differential-mode transfer function and to attain optimum in-band common-mode power-attenuation characteristics, are expounded. Furthermore, for experimental-demonstration purposes, a third-order triple-band microstrip prototype with differential-mode passbands that are located within the range 1.4–3 GHz is manufactured and characterized.