Single-feed dual-frequency dual-polarized slotted square microstrip antenna

A novel dual frequency dual-polarized square microstrip patch antenna embedded with a slot is presented. The proposed antenna offers tunability of the frequency ratio between the two frequencies by adjusting the slot dimensions. This configuration also provides a size reduction up to -51 and 35% for the two modes as compared to a square micro strip patch antenna

Circularly Polarized Compact Microstrip Antenna

A compact microstrip antenna with circular polarization radiation is demonstrated.A reducation in the required parameters for achieving CP radiation makes the present antenna design simpler

Dual-band dual-polarized compact microstrip antenna

Experimental studies on a compact dual frequency microstrip antenna are presented. This antenna configuration provides an area reduction of 40% compared to a standard rectangular antenna operating at the same frequency without much degradation of the gain. The antenna structure can be modified to achieve the desired ratio between the two resonant frequencies

A New Compact Dual-Band Dual-Polarized Microstrip Antenna

A new compact dual-band, dual-polarized microstrip antenna is presented. 7'iris antenna resonates at two frequencies with different polarizations: a linearly polarized one for terrestrial communication, and a circularly polarized one for satellite mobile communication. This antenna also provides an area reduction of 70% compared to a standard rectangular patch antenna

Dual-Port Dual-Polarized Microstrip Antenna

Experimental and simulated results for a dual-port dual-polarized microstrip antenna are presented. The antenna excites two orthogonally polarized resonant frequencies providing an isolation of -30 dB between the ports. The patch geometry consists of two circular arcs of different radii with their centers displaced by a distance. This new design offers an area reduction of -70% coinpared to it standard rectangular microstrip antenna with a reduction in gain of 1.7 dB

Dual-frequency dual-polarized slot -coupled compact microstrip antenna for communication system

A new design of' a dual-frequency dual-polarized square microsh'ip antenna fed along the diagonal, embedded with a square slot having three extended stubs for frequency tuning, is introduced. The proposed antenna was fabricated using a standard photolithographic method and the antenna was tested using the HP 3510(:; Vector Network Analyser. The antenna is capable of generating dual resonant frequencies with mutually perpendicular polarizations and broad radiation pattern characteristics. Such dual-frequency designs find wide applications in personal mobile handsets combining GSM and CDS 1800 modes, and applications in which different frequencies are used for emission and reception such as personal satellite communications and cellular network systems.

A Circularly Polarized Corrugated Flanged Feed Horn

Design and development of a circularly polarized and matched H-plane sectorial horn antenna have been reported By proper trimming of the flange parameters any desired polarization can be obtained from the horn

INVESTIGATIONS ON SLOT-LOADED SQUARE MICROSTRIP PATCH ANTENNAS FOR COMPACT DUAL FREQUENCY DUAL POLARIZED OPERATIONS

The thesis is the outcome of the experimental and theoretical investigations carried out on a novel slotted microstrip antenna.The antenna excites two resonance frequencies and provides orthogonal polarization. The radiation characteristics of the antenna are studied in detail. The antenna design is optimized using IE3D electromagnetic simulation tool. The frequency-Difference Time-Domain (FDTD) method is employed for the analysis of the antenna.The antenna can be used for personal and satellite communication applications.

Hopf bifurcation in parallel polarized Nd:YAG laser

Dynamics of Nd:YAG laser with intracavity KTP crystal operating in two parallel polarized modes is investigated analytically and numerically. System equilibrium points were found out and the stability of each of them was checked using Routh–Hurwitz criteria and also by calculating the eigen values of the Jacobian. It is found that the system possesses three equilibrium points for (Ij, Gj), where j = 1, 2. One of these equilibrium points undergoes Hopf bifurcation in output dynamics as the control parameter is increased. The other two remain unstable throughout the entire region of the parameter space. Our numerical analysis of the Hopf bifurcation phenomena is found to be in good agreement with the analytical results. Nature of energy transfer between the two modes is also studied numerically.

An electromagnetically coupled dual-band dual-polarized microstrip antenna for WLAN applications

A new design of a dual-band dual-polarized electromagnetically coupled slot loaded square patch antenna, covering the WLAN 5.2 GHz and 5.8 GHz bands, achieving bandwidth enhancement by using tapered slot structure, is presented here. The proposed antenna covers 5.09–5.47 GHz and 5.7–5.88 GHz bands. Details of the antenna design along with experimental and simulated results are presented and discussed.

Investigations on pathologies in higher spin field theories

The present thesis deals with the studies on certain aspects of pathological higher field theories .It brings to light some new abnormalities and new samples of abnormal theories and also puts forward a novel approach towards the construction of trouble free theories