Design and Implementation of Multi-Hormonics RF Wave Generator using Lumped-Element Components

Abstract

Triangular and Sawtooth wave generation at RF frequency is one of the important tasks for the design of buncher circuit in particle accelerators to increase the bunching efficiency. On the basis of Fourier series method different non-sinusoidal signals like triangular, sawtooth etc. are generated with combination of harmonics of sinusoidal signal with different amplitude and phase. These multi harmonic non-sinusoidal waves can be generated using passive RF components like phase-shifter, hybrid-coupler, power combiner/divider etc. This paper deals with lumped element approach for design and implementation of line phase shifters, 3-dB hybrid coupler and power divider/combiner, which have been used for the generation of triangular and saw tooth wave forms at 25 MHz. The ABCD (transfer) matrix formulation is used for the analytical prediction of the performance of these components. Experiments have been carried out to validate the analytical results.

Indexing terms:

• Buncher circuit
• Multi-harmonics RF wave
• Sawtooth waveform
• Lumped element circuits
• ABCD matrix

Additional information

Notes on contributors

K P Ray

K P Ray obtained MTech degree in Microwave Electronics from University of Delhi, South Campus, in 1985 and joined SAMEER (TIFR), Mumbai. He has been working on the design of different types of antenna elements and arrays, high power generation of RF and Microwaves and other microwave components/systems and successfully completed many Government and Industry sponsored projects. Currently, he is heading the RF and Microwave System (RFMS) Division in SAMEER. He received his PhD degree from Electrical Engineering Department, IIT, Bombay, in 1999. His thesis work was on “Broadband, Compact, and Dual Frequency Microstrip Antennas”. He has been a visiting/guest faculty in IIT, Bombay and Bombay University for postgraduate courses. He has published more than 75 research papers in national/international journals and conferences and co-authored a book entitled, “Broadband Microstrip Antennas” for Artech House, USA in 2003. He has been selected a reviewer of IEEE, MTT. He is a senior member of IEEE (USA), a fellow IETE, and life member of Instrument society of India and Engineers of EMI/EMC society of India. He has won merit scholarships, fellowships and awards.

H K Pandey

H K Pandey joined 43rd training batch of Bhabha Atomic Research center (BARC) in 1999 and currently working as a scientific officer with Radioactive Ion Beam (RIB) project at Variable Energy Cyclotron Centre (VECC), Department of Atomic Energy (DAE), Kolkata. Radio Frequency System for RF Accelerators is the area of specialization. Born in 1973 at Ghazipur, UP. Graduated in Electronics & Telecommunication from University of Allahabad in 1997 and MTech from University of Allahabad.

A Chakrabarti

Alok Chakrabarti joined Bhabha Atomic Research Centre, Mumbai as a Physicist in 1979 after completing the 22nd batch of BARC Training School. A post-graduate in physics from Jadavpur University, Kolkata, he is known for his pioneering research on Exotic Nuclei and Radioactive Ion Beam (RIB) facility development in the country. His research interests are decay spectroscopy of exotic nuclei, development of experimental techniques for the study of exotic nuclei, development of experimental techniques for the study of exotic nuclei and physics and technology of Radioactive Ion Beams. Having built the the first heavy-ion Radio Frequency Quadrupole (RFQ) linac accelerator in the country, Dr Chakrabarti’s present responsibility entails the team leadership in the design and development of a RIB facility at Variable Energy Cyclotron Centre, Kolkata.