Sanjay Devkumar

Circuit modeling of an UWB patch antenna

An ultra wideband (UWB) patch antenna is analyzed in this paper. The design uses FR-4 substrate with dielectric constant of 4.9 and thickness of 1.6 mm. Circuit model of such antenna is developed under AWR microwave office environment. Obtained results from simulating the antenna in CST microwave studio are then compared with the results taken from the Circuit Model.

An Impulse UWB Patch Antenna with Integrated Bandpass Filter

An Ultra wideband patch antenna is tested in this paper for Impulse UWB applications. The UWB patch antenna is integrated with UWB bandpass filter of desired operating frequency range. The design is on FR-4 substrate with dielectric constant of 4.4 and thickness of 1.6 mm. Impulse performance and angle of operation for such antenna are shown.

Lumped element circuit model approximation of an UWB patch antenna

Simplified lumped element circuit model of an UWB patch antenna had been derived. The model was tuned based on the scattering parameter (S11) of the antenna structure obtained from the full electromagnetic simulator CST Microwave Office. The design uses FR-4 substrate with dielectric constant of 4.9 and thickness of 1.6 mm. Circuit model of such antenna is developed under AWR Microwave Office environment. Obtained results from the two simulators are then compared with the measured results.

Circuit Element Modeling Scheme for a Hairpin Resonator by Using EDA Tool

This paper describes how a circuit element modeling scheme was used to analyze and optimize a microstrip open loop resonator. With the discrete optimization, realistic values can be assigned to the designed resonator. The circuit element models of the open loop resonator represent the structure very well with respect to electromagnetic models. Besides that, it provides a fine computation speed of simulation to study the resonator. The understanding and intuition of particular segment of the structure is very helpful and valuable for the designers to make the initial estimation.

Super-heterodyne interferometer for non-contact dielectric measurements on millimeter wave material

This paper describes the use of AD8302 evaluation board from Analog Devices in super-heterodyne millimeter wave interferometer for dielectric measurement. The measurements are performed without direct contact on the millimeter wave material. Signals from the output of two mixers in the interferometer were obtained for phase shifting analysis. They are used as inputs to the evaluation board. The output from the evaluation board was connected to computer for data processing. The voltage values obtained from the board was then converted to phase angle by using the pre-calibrated data and LabViewtrade graphical programming language.

Study of ultra wideband bandpass filter using electromagnetic simulator

An ultrawideband composite microstrip bandpass filter is designed using electromagnetic (EM) structure simulation. The design utilizes embedding individually designed highpass and lowpass filter (LPF) onto each other on a FR-4 board. The stepped-impedance LPF is employed to attenuate the upper stopband where as short-circuited stubs are used to realize the lower stopband. The results are analyzed in terms of the insertion loss, return loss, overall group delay and also the input and output signals. EM structure simulation is done using CST(Microwave Studio). Fabrication and measurements are done to conduct comparative studies between the simulated results and the measured results.

The Effects of Slotline on Directivity and Return Loss Characteristics of a Planar UWB Antenna

The effect of the slotline is tested on an ultra wideband antenna. The antenna consists of a rectangular patch with two steps, a single slot on the patch, and partial ground plane. The design is simulated on FR-4 substrate with dielectric constant of 4.4 and thickness of 1.6 mm. In this work, the effect on the directivity and return loss characteristics by the size and position of the slotline are shown.

Effects of Varied Stub Width on UWB Bandpass Filters with Notched Bands

In this paper, effects of changing the width of stubs in the previously proposed UWB bandpass filters with notched bands are analyzed. The effects of varied stub width were observed from the reflection loss and insertion loss of the filter. The response of the rejection bands due to the varied stub width was also observed. Simulations have been carried out using the CST Microwave Studio software to also demonstrate the group delay.

Using Lowpass and Highpass filters to Form UWB Bandpass Filter

In this paper, a new UWB bandpass filter is proposed. The combination of an open-circuited lowpass filter with a short-circuited highpass filter is used to design a UWB BPF. This paper also explains the new approach in designing a UWB BPF. The performance of this design in terms of its reflection loss, insertion loss and group delay was also compared with the previously designed UWB BPFs. Simulations were carried out using the CST microwave studio software to demonstrate the reflection loss (S11), insertion loss (S21) and group delay of this design.