bajit De

Design and analysis of various Wilkinson Power Divider Networks for L band applications

Different Wilkinson Power Divider Networks using stepped multiple sections of the conventional Wilkinson Divider are presented in this paper. The operating frequency range has been chosen as 1.25 GHz to 1.45 GHz. As, the chosen frequency range lies in the L band, these power dividers can be used as feeding network for antenna arrays operated in the L band. We have fabricated and tested the 2:1, 4:1, 8:1 and 16:1 Wilkinson Power Divider Networks to validate all their simulation results. All these structures have been designed and simulated in CST MWS.

AN INVESTIGATION ON END-FIRE RADIATION FROM LINEARLY POLARIZED MICROSTRIP ANTENNA FOR AIRBORNE SYSTEMS

In airborne systems, where low aerodynamic drag is urgently required, an end-fire antenna is suitable to be used. An effort to develop such an antenna, using planar elements, is described in this paper. Here, a new kind of Microstrip Slotted Antenna with end-fire properties is presented. For investigating the end-fire radiation from microstrip antenna, three antenna elements are proposed during the study — 1) Single Patch Single Feed Microstrip Slotted Antenna, 2) Dual Patch Single Feed Microstrip Slotted Antenna and 3) Dual Patch Dual Feed Microstrip Slotted Antenna. All these proposed antennas are designed and simulated in two different EM tools, which are — CST Microwave Studio (MWS) based on time domain solver and ANSYS HFSS based on frequency domain solver. Thereafter, these antenna prototype models have been fabricated and tested. Good agreement is obtained between the simulated and measured results.

DESIGN AND DEVELOPMENT OF A MULTI-FEED END-FIRED MICROSTRIP ANTENNA FOR TCAS AIRBORNE SYSTEM

Traffic alert and Collision Avoidance System (TCAS) is an airborne system which is designed to provide the service as a last defense equipment for avoiding mid-air collisions between the aircraft. In such airborne systems, where low aerodynamic drag is urgently required, the end-fire antenna is suitable to be used. An effort to develop such an antenna, using microstrip elements, is described in this paper. Here, a Multi-Feed Microstrip Antenna is presented which radiates in the end-fire direction. The proposed antenna is designed in such a way that it can radiate the whole 360◦ surveillance region of the aircraft. To encapsulate the antenna inside an enclosure, an aerodynamically shaped Radome is also designed and presented in this paper. For designing this antenna model and its Radome, CST Microwave Studio is used here as the EM tool. The performance and other antenna characteristics have been explored from the simulation results followed by the antenna fabrication and measurement. Quite good agreement is achieved between the simulated and measured results. Much better performance characteristics make this proposed antenna a good candidate for this application.

Design and development of a unit element microstrip antenna for aircraft collision avoidance system

ABSTRACT Aircraft/traffic alert and collision avoidance system (ACAS/TCAS) is an airborne system which is designed to provide the service as a last defense equipment for avoiding mid-air collisions between the aircraft. In the existing system, four monopole stub-elements are used as ACAS directional antenna and one blade type element is used as ACAS omnidirectional antenna. The existing ACAS antenna has some drawbacks such as low gain, large beamwidth, frequency and beam tuning/scanning issues etc. Antenna issues like unwanted signals reception may create difficulties to identify the possible threats. In this paper, the focus is on the design and development of a unit element microstrip antenna which can be used for ACAS application and to overcome the possible limitations associated with the existing techniques. Two proposed antenna models are presented here, which are single feed and dual feed microstrip dual patch slotted antenna. These are designed and simulated in CST Microwave Studio tool. The performance and other antenna characteristics have been explored from the simulation results followed by the antenna fabrication and measurement. A good reflection coefficient, Voltage Standing Wave Ratio (VSWR), narrow beamwidth, perfect directional radiation pattern, high gain and directivity make this proposed antenna a good candidate for this application.

Design of a dual band rectangular Microstrip Patch Antenna with DGS for wireless applications

In this paper, we have proposed a Slotted Microstrip Patch Antenna with a Defected Ground Structure (DGS). Here, we have integrated the concept of DGS and Slotted Patch Antenna in order to get enhanced bandwidth and gain. The proposed antenna consists of a microstrip fed slotted rectangular patch with E-shaped cut in the ground plane. The performance of this antenna is discussed and analyzed with the variations in patch width and number of slots. The variations in Return Loss (S11), Radiation Pattern and Gain of the designed antenna are analyzed for different case studies. The antenna shows a dual band characteristics having a return loss of below -20 dB at 3.2-3.5 GHz and below -10 dB at 5.6-5.8 GHz, which is suitable for IEEE 802.16 WiMAX and IEEE11p WLAN applications. CST MWS 2015 is used to simulate the antenna structure.

A review : Theoretical analysis of TCAS antenna : Traffic collision avoidance system for aircrafts

This paper describes a theoretical model of TCAS (Traffic Collision Avoidance System) Antenna installed in an Aircraft. The theoretical analysis has been developed to study the overall effect on the aircraft due to the performance of TCAS Antenna. Bearing Angle measurement, Signal transmission and reception technique using TCAS Antenna has been discussed in this article. This paper also contains a new proposed idea of TCAS Antenna which might be more beneficial than the existing system of the aviation field.

RF MEMS TCAS patch antenna

In this paper, a very new proposed model of TCAS (Traffic Collision Avoidance System) Antenna, installed in an Aircraft has been designed using HFSS (High Frequency Structure Simulator) Software. This new proposed antenna is a Slotted Microstrip Patch Antenna that can be used as a TCAS Directional Antenna. A RF MEMS Switch has also been designed using HFSS Software. This RF MEMS Switch is going to be used in TCAS Antenna for signal transmitting and receiving purpose. Ferrite Material Phase Shifters will also be used to steer the radiation pattern of the TCAS Antenna so that it can track a wide range of surveillance area. A mathematical concept has been developed for this Phase Shifter.

RF MEMS Metal to Metal Contact Type Shunt Switch

This article details about the design of a RF MEMS Metal to Metal Contact Type Shunt Switch. This switch has been designed in High Frequency Structure Simulator (HFSS) & all the Radio Frequency characteristics have been studied in this paper. The electromagnetic behaviour of this switch which is obtained from the simulation result is satisfactory. This Switch operates perfectly for microwave frequency band (1-40 GHz) applications.

RF MEMS Capacitive Type Shunt Switch

This article details about the design of a RF MEMS Capacitive Type Shunt Switch. This switch has been designed in High Frequency Structure Simulator (HFSS) & the important Radio Frequency characteristics have been studied in this paper. The electromagnetic behavior of this switch which is obtained from the simulation result is satisfactory. This Switch operates perfectly for microwave frequency band (1-40 GHz) applications.