Showing 4 results for Dual Band
Y. Zehforoosh, M. Sefidi,
Volume 13, Issue 2 (6-2017)
Abstract
In this article, we present a new design of a coplanar waveguide fed (CPW-fed) ultra-wideband (UWB) antenna with dual band-notched characteristics. Two notched frequency bands are achieved by using two inverted U-shaped stepped impedance resonators. The proposed antenna can operate from 2.82 to 11 GHz (118%), defined by VSWR< 2, except two notched bands around 3.5 GHz (WiMAX) and 5.5 GHz (WLAN). The size of the antenna is 20×20×1.6 mm3. The experimental and simulated results of the prototyped antenna, including voltage standing wave ratio (VSWR), radiation pattern, and gain characteristics are presented and discussed. In addition, Analytical Hierarchy Process (AHP) method used for comparison the proposed antenna with previous designed structures.
H. Rajabalipanah, M. Fallah, A. Abdolali,
Volume 15, Issue 2 (6-2019)
Abstract
An intelligent design method of double screen frequency selective surfaces (FSSs) is addressed in this paper. The employed unit cell is composed of two metallic screens, which are printed on both sides of a substrate. The presented non-trial-and-error approach is investigated based on the separate design of each screen. With the help of some physical intuition and an equivalent circuit model, it is shown that the conventional use of complement geometries restricts the final desired filtering response. Therefore, unlike the previous studies, the metallic screens are not geometrically complementary in this paper. An excellent agreement between the full-wave simulations and corresponding equivalent circuit models has been observed. Using standard lumped elements, a highly selective miniaturized FSS (0.06λ0 ~ 0.08λ0) with two closely-spaced pass bands is designed, for GSM and WLAN frequencies. Simulation results show a dual-polarized characteristic with a good angular stability performance for the proposed structure.
H. Ghonoodi, M. Hadjmohammadi,
Volume 17, Issue 4 (12-2021)
Abstract
In this paper a novel design is presented for a dual-band LC oscillator, using an analytical approach. The core of the proposed circuit contains a cross-coupled CMOS LC oscillator with two serried LC tanks so that the inductors of these tanks have mutual inductance. There are some switches in the circuit that directly changes mutual inductance to produce two different frequencies. This technique increases the oscillation amplitude in the same power consumption that leads to the decrement of phase noise. In other words, using two serried LC tank compensates the injected phase noise from switches. The symmetrical structure is another advantage of the presented design that makes it possible to be used in multiphase oscillator. To assess the quality of the proposed circuit, a dual-band quadrature LC oscillator has been designed to oscillate at 3.6 GHz and 6.4 GHz with 1.5 V supply and 1 mA current consumption, with TSMC 0.18 CMOS practical model. Lastly, simulation results confirm the correctness of analytical results and high proficiency of the proposed design.
F. Bahmanzadeh, F. Mohajeri,
Volume 18, Issue 1 (3-2022)
Abstract
In this article, a very small flexible antenna with dual-band rejection specifications is proposed for operating in both wearable and ultra-wideband (UWB) applications. The overall size of this antenna is about 18×18×0.508 mm3 and by etching out two rectangular slot type single split-ring resonators (SRRs) of different dimensions from the radiating patch, dual band-notched specifications are obtained in WiMAX (3.3 GHz to 3.7 GHz) and WLAN (5.15 GHz to 5.825 GHz) wireless communication bands. The designed antenna operates over a wide impedance bandwidth (|S11| < –10 dB) from 2.1 GHz to 12 GHz which can cover the whole UWB band from 3.1 GHz to 10.6 GHz and reject the two mentioned bands. An asymmetrical partial ground plane and a beveled radiating patch are utilized to achieve 140% fractional bandwidth. Also, due to the good wearable radiation characteristics, this antenna can operate in industrial scientific medical (ISM) band from 2.4 GHz to 2.5 GHz. Meanwhile, the specific absorption ratio (SAR) value of the proposed antenna is less than the standard limit of 1.6 W/kg.
