Knowledge Centre
Find a document written by the best international scientists in our secure database.
24776 documents found.
Single transistor low phase noise active dielectric resonator oscillator
In this paper, the design theory of an 8 GHz oscillator with a new structure of active dielectric resonator (DR) is presented. The new structure emphasizes on phase noise reduction by using only one active device. The proposed structure uses additional feedback from transistor to resonator in order to increase the quality factor. Measurement results report that phase noise is reduced to ?145.19 dB
A bottom-feed omni-directional circularly polarized antenna array
A bottom-feed omni-directional CP (circularly polarized) antenna array is proposed in this letter. The antenna array is composed of four elements (two printed ZPS (zero-phase-shift) line loops and two half-wavelength dipoles). The four elements are fed with the same phase and amplitude. The ZPS line loops provide the horizontal polarization while the dipoles provide the vertical polarization. Ther
Rectenna panel design optimization for maximum RF power utilization
Now-a-days, far-field wireless power transfer/energy harvesting is underutilized due to the unavailability of proper methodology to design efficient system for maximum radio frequency (RF) power utilization. For efficient utilization of far-field RF energy an array/grid of rectenna, i.e. rectenna panel is required to generate the power from wireless signal. To minimize the engineering design phase
A novel defect ground structure for decoupling closely spaced -plane microstrip antenna array
In this paper, a novel decoupling technique for closely spaced -plane patch antennas using defect ground structure (DGS) is proposed. The electric field coupling between the antennas is suppressed by etching DGS which consists of a pair of rectangular slots and four stubs on the ground plane. Moreover, unlike the other methods, the DGS is not etched in the middle of the antennas but loaded along t
Aperture coupled stacked patch thin film antenna for automotive radar at 77 GHz
A hybrid thin film multilayer antenna for automotive radar is presented in this work. A 2 × 8 aperture coupled stacked patch antenna array is realized on a single layer printed circuit board (PCB) using a novel thin film-based approach. Using a compact 180 phase difference power divider, inter-element spacing in a 2×2 sub-array is reduced. Measurement results show a 19% (67.9?82.5 GHz) impedance b
A polarization and band reconfigurable cross-slot antenna for multiband application
A polarization and band reconfigurable cross-slot antenna for multiband applications is presented in this paper. The antenna consists of four p?i?n diodes embedded in the cross-shaped slot in a ground plane and excited by a microstrip feed line. The p?i?n diodes are placed in such a way that they produce multiple bands, with linearly and circularly polarized (CP) radiation. By switching the states
Selectivity and in-band impedance enhancement of a compact slot antenna with defected ground structures
In this study, a new ultra-wideband (UWB) band-edge selectivity antenna with a modified radiation slot using defected ground structure (DGS) is presented to obtain bandpass filtering reflection coefficient and gain performance. The well-designed DGS is designed on backside metallic of the substrate and can be seen as a low-pass filter that provides a good roll-off at a higher frequency. By connect
Broadband dual linear polarized (DLP) antenna array for energy harvesting system
A broadband linear polarized antenna is designed for radio frequency energy harvesting. The antenna covers the frequency range from 1 up to 6 GHz with relative impedance bandwidth of 126% at ?6 dB reflection coefficient || and extended from 1.1 to 3.3 GHz and from 4.2 to 5.6 GHz at |S| ? ?10 dB. A 2 2 dual linear polarized (DLP) antenna array is designed based on the antenna element by using equa
A miniaturized dual band EBG unit cell for UWB antennas with high selective notching
A high selective dual band and miniaturized electromagnetic band gap (EBG) unit cell is presented in this paper. The analysis and characterization of the new cell are explained. The modified compact EBG unit cell is based on cutting two inverted U-shaped slots inside the typical mushroom-like EBG. The modified EBG has a 70% size reduction. The dual-band functionality of the structure is confirmed
Multi-cut four-port shared radiator with stepped ground and diversity effects for WLAN application
A four-port shared radiator is proposed for 5.2 GHz wireless application using multiple-cut rectangular geometry and partially stepped ground. The difficulty in making the shared radiator structure is almost removed in the presented design, and without the help of any isolating structure, sufficient value of isolation is achieved. The proposed shared geometry produces isolation of >10 dB in the 4.