Dia Ghosh

Rectangular Microstrip Antenna on Slot-Type Defected Ground for Reduced Cross-Polarized Radiation

A simple rectangular microstrip antenna on slot-type defected ground plane is proposed for reduced cross-polarized (XP) radiation and justified theoretically. This will reduce the XP radiation field compared to a conventional microstrip antenna without affecting its copolarized (CP) radiation characteristics.

Physical and Quantitative Analysis of Compact Rectangular Microstrip Antenna with Shorted Non-Radiating Edges for Reduced Cross-Polarized Radiation Using Modifi ed Cavity Model

A straightforward and compact rectangular microstrip antenna with a shorted nonradiating edge was proposed and experimentally investigated for significant suppression of cross-polarized (XP) radiation compared to maximum co-polarized gain, without affecting the co-polarized radiation pattern. The proposed antenna was thoroughly studied using simulation and experimental results. A modified cavity model (MCM) was also demonstrated to understand the behavior of the cross-polarized radiation and the complete resonance behavior for the new structure. The proposed theory helps to germinate a real and clear view of the observed phenomena. The proposed idea was experimentally confirmed with the present structure on three different substrate materials, with different dielectric constants. The new approach presented here provides an insightful visualization-based understanding of cross-polarized suppression with the present structure.

Study on the complex dynamics of a single loop optoelectronic oscillator

The present literature reports a study on the dynamics of a single loop optoelectronic oscillator. It has been observed that with the variation of the delay parameter the system depicts some complex behavior like limit cycle oscillation through Hopf bifurcation, chaotic oscillation.

A Study on the Effect of an External Periodic Signal in a Chaotic Optoelectronic Oscillator

The present literature reports the effect of an external synchronizing signal on the chaotic dynamics of a single Loop optoelectronic Oscillator (SLOEO). We have applied an external periodic signal in a chaotic optoelectronic oscillator (OEO). The OEO can produce chaotic oscillation with small change of feedback loop delay. It has been observed that application of an external periodic signal with suitably chosen amplitude and frequency can destroy the chaotic oscillation and produce single frequency oscillation. The proposed method can be used to suppress the chaotic oscillation in an OEO.

A new dual loop optoelectronic oscillator

This correspondence reports a new dual loop optoelectronic oscillator (DLOEO). The DLOEO consists of an injection locked oscillator instead of an RF band pass filter(BPF). In addition to this an external sync signal is injected to the system and locking phenomena of the synchronized system is observed.

Optical synchronization of microwave signals in an optoelectronic oscillator

A single loop optoelectronic oscillator is synchronized in the optical domain by an external microwave signal. The system equation of such an oscillator has been derived. Normalized output voltage and frequency are calculated and the steady state output voltage as a function of time is studied. Theoretical results are presented in this short communication.

Accurate CAD formulation for resonant frequency of circular sectorial microstrip antenna

The precise operating frequency of the circular sectorial microstrip antenna (CSMA) is the most significant parameter to be determined in order to design such antenna system to achieve the optimum performance. In the present investigation an improved computer aided design (CAD) formula is proposed for accurate determination of the resonant frequency of circular sectorial microstrip antenna. The theoretical results are verified with high frequency structure simulator (HFSS), and earlier reported results and good agreement is exposed.