The pyrrolophenanthridine class of alkaloids which have been isolated from various species of Amaryllidaceae.In intramolecular radicalcyclization, we used three methods to synthesize pyrrolophenanthridine.

The Amaryllidaceae class of alkaloids have been isolated from various species of Amaryllidaceae. In intramolecular radical cyclization, we used three methods to synthesize Amaryllidaceae.

No / A novel MIMO/diversity Planar Inverted-F antenna (PI FA) is presented for UWB applications. This antenna assembly is formed by two identical PIFAs, a T-shaped decoupling structure which connects the two PIFAs and a finite ground plane. The compact envelope dimension of this antenna is 50 × 90 × 7.5 mm3. Theoretical and experimental characteristics are illustrated for this antenna that fully covers an operating frequency band of 3.1 – 10.6 GHz for UWB applications, at a reflection coefficient and mutual coupling better than −10 dB and −20 dB respectively. An acceptable agreement is also obtained between computed and measured radiation patterns and gains. These characteristics demonstrate that the proposed antenna is an attractive candidate to provide pattern diversity in enhancing the channel capacity while operating in a rich scattering environment.

No / This paper presents a physically compact, frequency tunable antenna design for use in mobile terminals. The full operating bandwidth is between 1750 MHz and 2400 MHz with good impedance match in the entire tuning range to meet the coverage requirements of the DCS, PCS, UMTS and WLAN bands . The antenna bandwidth is is realized by loading the embedded resonant slot of a PIFA, with a varactor diode, with an equivalent capacitance range of 0.5 pF to 2.5 pF.

The main topic of this diploma thesis is a design of the PIFA antenna working in GSM bands. In the beginning there is a brief analysis of planar antennas. The thesis describes PIFA antenna and the techniques for minimization of dimensions of the antenna. Essential part of the thesis is dedicated to multicriterial optimalizaton of the antenna shape. The genetic algorithm programmed in the MATLAB enviroment cooperates with a full-wave solver CST to obrain desired impedance matching of the antenna its radiationt paterns. Also dimensions of the antenna can be minimized using the optimization procedure. Final part of the thesis compares measured data of the optimalized antenna with results obtained in CST Microwave Studio.

Yes / A compact planar inverted F antenna (PIFA) with a tuneable frequency response is presented. Tuning of the resonant frequency is realized by loading a varactor on an embedded slot of the proposed antenna structure without further optimizing other antenna geometry parameters. The antenna exhibits a wide frequency range from 1570 to 2600 MHz with a good impedance matching (S11 ≤ -10dB) covering the GPS, PCS, DCS, UMTS, WLAN and LTE systems. To validate the theoretical model and design concept, the antenna prototype was fabricated and measured. The compact size of the antenna is 15mm × 8mm × 3mm, which makes this antenna a good candidate for mobile handset and wireless communication applications.

The modified aperture coupled MicroStrip Antenna (MSA) and Planar Inverted F Antenna (PIFA) for mobile applications are studied and presented in this dissertation. The designed antennas are improved multi-band and broad-band characteristics by the modification of radiating elements and/or the ground plane. The novel modified aperture coupling annular-ring antenna fed by stripline is the hybrid structure of the aperture coupling feed MSA and the proximity feed MSA. The proximity feed enable to concentrate the field strength toward the direction of the radiating element and the modified aperture layer contributes to provide the maximum coupling to the radiating element. The measurement bandwidths of the Aperture Coupling Proximity Feed Hybrid MSA #1(ACPF-HMSA#1, design #1) and ACPF-HMSA #2 (design #2) are 185MHz (7%) and 105MHz (4.1%), VSWR in less than 2, respectively. Two layers Planar Inverted F Antenna (PIFA) with the modification of the ground and radiating element was studied. The inserted T-shaped or L-shaped ground and inserted a slot and slits on radiating elements help to adjust the resonant frequencies to the target applications. The result of PIFA #3 (design #3) is presented a significant board-band characteristic on the upper band by 910MHz (from 1.45GHz to 2.36GHz) with VSWR less than 2.5. It covers GPS, DCS, PCS, and UMTS bands. Novel internal loop planar inverted F antennas (L-PIFA) with Inserted Concentrated Annular Rings (ICAR) and Inserted Loop Inductors (ILI) are presented as design #4 (ICAR-L-PIFA #4) and design #5 (ILI-L-PIFA #5), respectively. The simple loop structure consists of a meandered line. It increases the capacitance between adjacent lines. The Inserted annular-rings and loop inductors provide inductance values to the main loop antennas. Therefore, the impedance bandwidth of the design #4 is 570MHz (from 1.69GHz to 2.26GHz) with VSWR less than 2.5. And, the impedance bandwidth of the design #5 is 275MHz (from 1.63GHz to 1.905GHz) and 465MHz (from 2.19GHz to 2.655GHz) with VSWR less than 2.5.

In this paper, the design, analysis, and characterization of reconfigurable antennas based on radio frequency micro-electro-mechanical systems (RF MEMS) operating in the United States' public safety (PS) bands are presented. The design methodology of these antennas, which are different from the normal antenna design, is also reported. In this thesis, two electrically small reconfigurable antenna designs have been presented, with two and three modes of operation, and central frequencies of 718 and 4960 MHz and of 857,809 and 4960 MHz, respectively. The maximum frequency tunable ratio achieved in these designs is 7. The recongurability between the modes is achieved by one and three RF MEMS switches in all three designs. These switches enable a change in the length of the current flow path, thereby changing the resonance frequencies. The measurement results for impedance and radiation characteristics of the fabricated antennas prototypes are also presented, and agree reasonably well with the simulations results from An-soft HFSS.

yes / Size constraints and mutual coupling on the performance of a two-element PIFA assembly are investigated for a design frequency of 2.4 GHz. A benchmark antenna assembly, employing a normal metallic ground plane is compared with an EBG modified ground plane. The height of the antenna elements over the EBG is optimised, and an isolation factor of 9.12 dB is achieved for a gap of 2.5 mm. Prototype structures have been constructed and measured for both cases.

Yes / A frequency tunable planar inverted F antenna (PIFA) is presented for use in the following bands: DCS, PCS, and UMTS. Initially, the tuning was achieved by placing a lumped capacitor, with values in the range of 1.5 to 4 pF, along the slot of the radiator. The final tuning circuit uses a varactor diode, and discrete lumped elements are fully integrated with the antenna. The antenna prototype is tunable over from 1850 MHz to 2200 MHz, with an associated volume of 21×13.5×5 mm3, making it suitable for potential integration in a commercial handset or mobile user terminal.