Madhur Deo Upadhayay

Dual port ASA for frequency switchable active antenna

This report presents the design of a dual-port dual-band annular slot antenna suitable for use in the feed-back path of an oscillator resulting in an active antenna configuration. The proposed antenna is designed to radiate and transmit equal amounts of power. The return loss of the proposed antenna is higher than that desired for one-port antenna application at the desired dual-band frequencies. The antenna is fabricated on one side of a Neltec substrate (εr=3.2 and thickness = 0.762 mm) and the microstrip feeding line is fabricated on the opposite side of the board. The antenna was designed to operate at WLAN bands centered at 2.4 and 5.2 GHz. The simulated and measured results show fairly good agreement. The measured return losses were found 20.5 dB at 2.4 GHz and 13.9 dB at 5.2GHz while simulated return losses were 9.36 dB at 2.4 GHz and 31.35 dB at 5.2 GHz. The radiation pattern is approximately omnidirectional at both frequencies in H-plane.

Active Integrated Antenna Using BJT With Floating Base

A feedback-oscillator type active antenna using RF BJT with floating base terminal has been demonstrated for the first time. Other than simplifying bias connections, which is important for large arrays and power combining, this has potential for future optical sensing and control circuitry, since the floating base is light-sensitive.

Design and Simulation of a Zinc Oxide Thin Film Bulk Acoustic Resonator Filter for 2.6 GHz Band Applications

ABSTRACT This work presents the design and simulation of a zinc oxide based thin film bulk acoustic resonator (TFBAR) bandpass filter for 2.6 GHz band applications. Third and fifth-order filters in ladder topology are designed and compared. The third-order filter has an insertion loss of 1.62 dB and return loss of 18.97 dB with a bandwidth of 80 MHz whereas the fifth-order filter has insertion loss, return loss, and bandwidth of 2.85 dB, 25.28 dB, and 60 MHz, respectively. With a central frequency of 2.67 GHz, the designed filter has applications in the 2.6 GHz (2500–2690 MHz) band, which has been identified by the International Telecommunication Union as a global frequency band for mobile broadband services.

Study on Design and Simulation of Zinc Oxide Based Film Bulk Acoustic Resonator for RF Filters

Film Bulk Acoustic Resonator (FBAR) technology is one of the enabling technologies which fulfill the two major needs of wireless industry i.e. high operating frequency range and miniaturization of RF components. This paper presents the design and simulation of a FBAR with zinc oxide as the piezoelectric layer. In the present work, FBAR has been designed and simulated for piezoelectric thickness of 0.75 and 1.25 μm. A thickness of 0.75 μm corresponds to a simulated frequency of 3.57 GHz and can be used for WiMAX applications whereas a 1.25 μm thick layer is suitable for GSM applications at 1.94 GHz. The suitability of the structure for RF filter applications has been observed in terms of electromechanical coupling coefficient.

Simulation and Analysis of Actuation Voltage of Electrostatically Actuated RF MEMS Cantilever and Fixed – Fixed Switches with Variable Beam Parameters

Radio Frequency (RF) Microelectromechanical system (MEMS) switches are becoming more and more popular in the electronics industry. The main concern in using RF MEMS switch is its high actuation voltage. Thus the main focus in this paper is to obtain low actuation voltage. This paper presents the simulation and analysis of RF MEMS cantilever beam and Fixed – Fixed beam switches. RF MEMS switches simulated in this paper use electrostatic actuation method. Simulations were done using finite element modeling. Different designs and parameters such as gap between electrodes, beam thickness, beam length, and relative permittivity values of medium between electrodes were chosen for analyzing the deflection of beams for various actuation voltages. Perforations of different dimensions were made on both type of beams and the resulted deflections were studied. The simulation results show that the Cantilever and Fixed – Fixed beams follow approximately similar deflection pattern with Cantilever beam deflecting more for applied actuation voltage in all the studies.

Slotted ground circular antenna for personal communication system (PCS) & broadcasting

This paper presents a broadcasting antenna design operating at 2.4 GHz frequency. The proposed antenna is designed, simulated and fabricated on FR4 substrate of permittivity 4.1 and thickness 1.5 mm. The measured return loss is 17.5 dB at 2.4 GHz whereas the simulated return loss is 36.88 dB. Thus, the fabricated & simulated antenna are in good harmony. Also the cross polarization is less than -20 dB. This antenna can be used to broadcast on several type of wireless systems that we use in our day to day life like Amplitude modulation (AM), Frequency modulation (FM) radio, satellite telephony & Global Positioning System (GPS).

Generation of OAM mode using radially oriented Circular Array

In this paper, we first make a theoretical and numerical analysis of electromagnetic (EM) vertex wave, which carries rotating phase (helical) front and orbital angular momentum (OAM). Subsequently 8 elements rectangular inset feed incrementally phased Circular Array (CA) Antenna is simulated which can generate Orbital Angular Momentum beam at 10 GHz. The simulated results verifies rotating phase with the result from the mathematical analysis.

Frequency switchable active antenna

This paper proposes a novel Active Antenna (AA) has capability of frequency switching. The passive antenna with rectangular slot and frequency splitter is used to design the proposed AA. Two separate networks are designed at two separate frequencies and integrated with three port rectangular slot antenna. PIN Diode switches are used to switch between two networks for achieving frequency switching. The proposed antenna can be used for WLAN applications.

Circular polarized dual port annular slot antenna

This paper presents the design of a dual-port dual-band circular polarized annular slot antenna, suitable to use in the feed-back path of an oscillator resulting in an active antenna configuration. The proposed antenna is designed to radiate and transmit equal amounts of power. The return loss of the proposed antenna is higher than that desired for one-port antenna application at the desired dual-band frequencies. The antenna is fabricated on one side of a Neltec substrate (εr=3.2 and thickness = 0.762 mm) and the microstrip feeding line is fabricated on the opposite side of the board. The antenna was designed to operate at WLAN bands centered at 2.4 and 5.2 GHz. The simulated and measured results show fairly good agreement. The measured return losses were found 10 dB at 2.4 GHz and 14.5 dB at 5.2 GHz while simulated return losses were 8.57 dB at 2.4 GHz and 15.2 dB at 5.2 GHz. The radiation pattern is approximately omnidirectional at both frequencies in H-plane.