Ultra-wideband square-slot antenna

Abstract

The intrinsic characteristics of LDMOS transistor amplifier can be extracted by removing the simulated characteristics of the input side and output side of test fixtures from the overall measured characteristics. In addition, impedance-matching networks are designed with these extracted S-parameters of the LDMOS transistor amplifier. The transistor used in this work is an MRF21030 LD-MOS 30W transistor provided by Freescale Semiconductor, Inc., and biased such that I DS_DQ is equal to 200 mA. Figures 4(a) and 4(b) show the measured and simulated S-parameters of the impedance matched transistor amplifier in the frequency range from 2.0 to 2.3 GHz. The maximum deviations of the measured ͉S 11 ͉, ͉S 21 ͉, and ͉S 22 ͉ from the simulated ͉S 11 ͉, ͉S 21 ͉, and ͉S 22 ͉ are 0.66, 0.17, and 0.13 dB, respectively. The simulated characteristics of impedance matching blocks can accurately predict the measured ones, as shown in Figures 4(a) and 4(b). CONCLUSIONIn this paper, we have presented a method of extracting 3D field simulation parameters of RF-band transistor amplifier test fixtures and demonstrated that a circuit model of the test fixtures can be constructed via pure 3D field simulation using the extracted material constants. The developed circuit model predicts measurement results within 0.5 dB.ABSTRACT: A simple square-slot antenna capable of providing a very wide impedance bandwidth of larger than 9 GHz is presented. The ultra-wideband operation for the proposed antenna is realized by using a novel feeding mechanism of loading an offset rectangular stub at the end of the microstrip feed line. With the proper offset distance of rectangular stub chosen, the proposed antenna can operate in the 2.78 -12.02-GHz frequency range and covers the UWB operating bandwidth of 3.1-10.6 GHz. The antenna radiation patterns at 3, 5.3, 7.9, and 10 GHz are also presented.ABSTRACT: An H-plane hybrid ring 3-dB power divider constructed with substrate integrated rectangular waveguide (SIRW) is proposed. Theoretical simulations are carried out at the X-and Ka-bands. The results show that the isolation between two output ports is high up to 35 dB and good 3-dB power division within the band of interest is observed also, that is, less than 0.3-dB derivation in the band of interest. In addition, the simulation results at the X-band shows a bandwidth of 10% at Ϫ15 dB. A prototype in the Ka-band is fabricated and the measured data at the Ka-band shows a bandwidth of 7% at Ϫ15 dB, in good agreement with simulation.

Compact Open-Ended L-Shaped Slot Antenna With Asymmetrical Rectangular Patch for Uwb Applications

“…For a wider bandwidth, Antenna Type B with a rectangular patch (l = 10 mm, w = 9 mm, d = 0 mm, g = 0 mm) symmetrically fed by the 50 Ω micro-strip line can excite an enhanced operation range from 3 to 7.05 GHz, which is still unable to fulfill the UWB 7.5 GHz bandwidth requirement. Interestingly, the complete UWB band can be realized when the rectangular patch of the proposed antenna is asymmetrically fed by the 50 Ω micro-strip line like some reported asymmetrical structures [3,5]. By carefully tuning the parameters (d = 2.25 mm, g = 0.35 mm), an approximate 112% impedance bandwidth from 3 to 10.66 GHz can be obtained, and is also much wider than those that have been reported for broadband open slot antennas [8][9][10][11].…”

“…Various wide slot antennas have been reported in [1][2][3][4][5][6][7]. With a variety of wide slots such as an additional quarter-wavelength line slot resonator [1], two different feed-slot combinations [2], square-slot [3], square-ring slot fed by a fork stub [4], asymmetrical CPW slot [5], a circular slot [6], and a fractal-shaped slot [7], these wide slot antennas can achieve a good ultra-wideband characteristic. Unfortunately, these inchoate investigations on the ultra-wideband operation bandwidth and size reduction are not solved well because that the limited bandwidths in [1,2,5,7] are not enough for ultra-wideband requirement and the sizes in [1-4, 6, 7] are too large for the portable systems.…”

Comparison between Fenton oxidation process and electrochemical oxidation for PAH removal from an amphoteric surfactant solution

“…They reported that electrooxidation around pH 7.0 was more effective in removing phenol, compared to pH 3.0 and pH 11.0. However, one study showed that the pH effect is not significant while oxidizing orange II dye on Ti/BDD anode at a current density imposed of 200 mA m -2 [37].…”

A Study of a Compact Microstrip-Fed Uwb Antenna With an Open T-Slot

“…In recent years, various slot antennas fed by microstrip-line have been seen in the literatures [1][2][3][4][5]. With different shapes such as crossshaped slot [1], eccentric annular slot [2], triangular slot [3], squareslot [4], E-shaped slot [5], etc., wide bandwidth can be achieved well and also used for wideband and UWB communications.…”

“…With different shapes such as crossshaped slot [1], eccentric annular slot [2], triangular slot [3], squareslot [4], E-shaped slot [5], etc., wide bandwidth can be achieved well and also used for wideband and UWB communications. In addition, a new technique with multiple Z-like slots is proposed in [6], which is an effective method that creates several resonant paths for bandwidth enhancement.…”