PHY 693/ESE 593 fall 2024

Syllabus

1. Instructors
Jayant P. Parekh, Binping Xiao1, Wencan Xu2
jayant.parekh@stonybrook.edu| Light Eng. 225
1 binping@bnl.gov
2 wxu@bnl.gov

2. Course Description
The course starts with an essential review of the properties of low and medium power RF waves and components including transmission lines, waveguides and cavities, and then proceeds to highlight the properties and limitations under high power RF conditions. The principal deleterious effects taking place at high power levels are caused by arcing (a high peak power effect) and the ohmic dissipation in the metal walls (a high average power effect). Exceeding the power handling capacity of the RF components can result in expensive repairs. Methods of mitigating or avoiding these expensive repairs are discussed. Important applications of high power rf are discussed in depth. Finally the students are given an extended project on implementing a particle accelerator using the traditional method of placing cylindrical cavities in tandem and using the longitudinal electric field in the TM010 cavity mode to pump RF power into a particle beam and cause the desired acceleration of the charge particles.

Full Course title: High Power RF Engineering
Course catalog # and section: ESE 593
Credit hours: 3
Contact hours: each class 1.5 hours, twice per week.
Semester: Fall semester, once in two years
General education designation(s) (SBC) (senior undergraduate and graduate): Graduate course
Prerequisites: A basic course in microwaves
Office hours: TBD
TA Information: N/A

3. Textbook
None. Class notes and references will be provided by the instructor

4. Course Learning Objectives
Upon completion of the course, students will have
• refreshed their background and learning of low and medium power RF waves and components;
• learnt about the important limitations of using RF components at high power levels, and methods of mitigating the deleterious arcing and ohmic dissipation overheating problems which cause expensive repairs;
• learnt about high-power RF amplifiers and oscillators
• learnt about important application of high power RF; and
• learnt about how high RF particle accelerators are implemented in practice

5. Topics
5.1. ESSENTIAL REVIEW OF LOW AND MEDIUM POWER RF:
• Lorentz force equation, cyclotron motion of charged particles
• Maxwell Equations, electromagnetic wave equation, uniform plane EM waves in dielectrics and conductors, power flow
• Transmission lines (TLs): wave behavior of voltage and current on a TL arising from the distributed circuit nature of TLs, voltage reflection coefficient Г, VSWR S, Smith Chart, impedance matching techniques. Derivation of time-average power flow in the TEM mode in a coaxial TL, and its dependence on the geometry of the TL and the peak or amplitude value of the electric field. High power handling capability of coaxial TLs and the limitations imposed by arcing or dielectric breakdown taking place when the electric field between conductors of a coaxial TL exceeds a threshold value, and also the propagation loss arising from ohmic dissipation. Derivation of the propagation loss in TEM wave propagating in a coaxial TL in dB/m.
• Waveguides (WGs): TE and TM modes, dominant modes in rectangular and circular WGs, electric and magnetic field expressions in the dominant modes, derivation of time-average power flow in the TE10 mode in a rectangular WG and sample calculation of the maximum value of this power in the TE10 mode before arcing occurs, derivation of the attenuation in dB/m of the TE10 mode due to Ohmic dissipation
• RF Cavities: properties of rectangular and circular cavities, resonant frequencies, Q factor, field profiles in cavities, TM010 mode of cylindrical cavity used in accelerators because of the longitudinal rf electric field which imparts the accelerating force to the charged particle beam, equivalent resonant LRC circuit
• Scattering parameters for multi-port RF components and their use in computing reflection and transmission coefficients and power flow in RF circuits components such as isolators, circulators, directional couplers, phase shifters, the Riblet coupler, the magic tee, etc.

5.2. HIGH POWER RF:
High-power RF components (TLs, WGs, cavities, etc.) are dimensionally the same as their low or medium power counterparts.
• Two main problems exist in using RF components at high RF power levels:
  i) High peak power kills hardware through dielectric breakdown (arcing), and
  ii) High average power kills hardware through excessive heating due to ohmic dissipation in the metal walls
  Some mitigation of the arcing problem is achieved by placing gaseous or solid dielectrics with higher dielectric constants, thereby raising the threshold electric field above which arcing takes place.
  Some mitigation of the excessive heating problem is achieved by using a heat sink implemented using cooling methods.
  Exceeding the power handling limitations of RF components can result in expensive repairs.
• High power RF amplifiers: tetrode amplifiers, solid-state amplifiers, traveling wave tube (TWT) amplifiers (popular in high-power RF transmitters, satellite transponders, radars, etc.)
• High power RF generators: klystrons, magnetrons, solid-state oscillators

5.3. APPLICATIONS OF HIGH POWER RF AND HOW THEY WORK:
• The ubiquitous microwave oven
• Broadband jamming
• Electronic warfare
• Pulsed radar
• RF transmitters and receivers
• Food processing industry
• Industrial heating and drying applications
• Plasma generators (used in the production of integrated circuits, solar cells, batteries, fuel cells, flat panel displays, etc.)
• Particle accelerators
• High-power microwave guns or directed-energy weapons

5.4. EXTENDED PROJECT ON USING HIGH POWER RF IN PARTICLE ACCERATORS:
• Cylindrical RF cavities placed in tandem and connected via drift tubes through which a particle beam accelerates
• TM010 mode of cylindrical cavity used in transferring power into the beam via its longitudinal electric field and thereby accelerating the particles
• Students to submit a detailed report on the design of a particle accelerator using high power longitudinal electric field in the cavities

6. Assignments
6.1. Homework Assignments Homework Assignments will be issued once every week. All homework solutions must be submitted on the Blackboard by the midnight of the assigned day. No late submission of homework is accepted except under extenuating circumstances.

6.2. No makeup Exams or Homeworks: There will be no “make-up” exams or homeworks except under absolutely extenuating or exceptional circumstances.

7. Questions on grading
Any questions on grading of homeworks must be brought to the attention of the instructor and resolved within ten days of the return of the homeworks to the students. Late queries will not be entertained.

8. Academic Honesty
Cheating of any kind is considered a serious offence, and will be treated according to the university rules of academic dishonesty, which provide for failure, suspension, and/or dismissal of the students involved. Regarding homework assignments and test preparation, you may freely interact with other students. But when you do the actual homework assignment or exam, you are to work alone and your work is to be yours alone.

9. Student Accessibility Support Center Statement
If you have a physical, psychological, medical, or learning disability that may impact on your course work, please contact the Student Accessibility Support Center, 128 ECC Building, (631) 632-6748, or at sasc@stonybrook.edu. They will determine with you what accommodations are necessary and appropriate. All information and documentation is confidential.

10. Grading
1. Term Exam 25%
2. Homework 25%
3. Final Exam 25%
4. Project 25%

11. Syllabus subject to change
This syllabus is subject to change in terms of course content or any other way as dictated by progress in or needs of the class.

Lectures

08/26/24 Lecture 1 (Parekh): Introduction to PHY 693 & ESE 593 course The simplest harmonic wavefunction, properties of generic uniform plane waves (amplitude, frequency, wavelength), phase and group velocities, wave equation, instantaneous and phasor expressions. Propagation in arbitrary direction

08/28/24 Lecture 2 (Parekh): A uniform plane electromagnetic wave (UPEMW) as two UPWs moving synchronously together and in phase in space and time, one representing the electric field component of the wave and the other representing the magnetic field component of the wave, with the unit vectors iE, iH and iK in the directions of the electric field, magnetic field and propagation of the wave forming a right-handed triad of orthogonal unit vectors. EM wave equations. Instantaneous and time-average Poynting vector

09/04/24 Lecture 3 (Parekh): Maxwell Equations. Derivation of EM wave equation UPEMW propagation in dielectric and conducting media. Skin depth. Power loss in propagation through a highly conductive medium such as a metal UPEMW propagation in a magnetized ferrite medium exhibiting anisotropic propagation behavior, with application to nonreciprocal microwave components

09/09/24 Lecture 4 (Parekh): Transmission line (TL) as a distributed circuit element. Derivation of the TL voltage and current equations by considering an infinitesimal length of TL. Lossless TLs. Voltage and current on a TL satisfy the wave equation and thus behave as waves. Voltage reflection coefficient Г(z) as a useful variable in the theory of TLs. Impedance Z(z) at any point z on TL as a bilinear function of Г(z) at the same point z, and vice versa. Input impedance Zin of a TL in terms of the load impedance and the electrical length of the TL. VSWR.

09/11/24 Lecture 5 + 09/16/24 Lecture 6 + 09/18/24 Lecture 7 (All Parekh): Power flow on TLs. Impedance matching. Quarter-wave transformer. Single short-circuited stub tuner. Smith Chart as an alternative tool for obtaining rapid solution to TL problems, i.e., finding the impedance Z(z) or voltage reflection coefficient Г(z) at any point on TL. Scattering Parameters.

09/23/24 Lecture 8 (Wencan & Binping) + 09/25/24 Lecture 9 (Wencan & Binping): One lecture on theory and introduction to CST Studio Suite, one lecture on simulation with CST Studio Suite. Scattering parameters for multi-port RF components and their use in computing reflection and transmission coefficients and power flow in RF circuits components such as isolators, circulators, directional couplers, phase shifters, the Riblet coupler, the magic tee, etc.

09/30/24 Lecture 10 (Binping) + 10/02/24 Lecture 11 (Binping): High power handling capability of coaxial TLs and the limitations imposed by arcing or dielectric breakdown taking place when the electric field between conductors of a coaxial TL exceeds a threshold value, and also the propagation loss arising from ohmic dissipation. Derivation of the propagation loss in TEM wave propagating in a coaxial TL in dB/m.

10/07/24 Lecture 12 (Binping) + 10/09/24 Lecture 13 (Binping) + 10/16/24 Lecture 14 (Wencan): Waveguides (WGs): TE and TM modes, dominant modes in rectangular and circular WGs, electric and magnetic field expressions in the dominant modes, derivation of time-average power flow in the TE10 mode in a rectangular WG and sample calculation of the maximum value of this power in the TE10 mode before arcing occurs, derivation of the attenuation in dB/m of the TE10 mode due to Ohmic dissipation. Special features of high power RF components Deleterious effects of using microwave components at high-power levels: i) High peak power kills hardware through dielectric breakdown (arcing), and ii) High average power kills hardware through excessive heating due to ohmic dissipation in the metal walls Mitigation methods

10/21/24 Mid Term Exam (Parekh, Binping, Wencan)

10/23/24 Lecture 15 (Binping) + 10/28/24 Lecture 16 (Binping)+ 10/30/24 Lecture 17 (Binping)+ 11/04/24 Lecture 18 (Wencan): RF Cavities: properties of rectangular and circular cavities, resonant frequencies, Q factor, field profiles in cavities, TM010 mode of cylindrical cavity used in accelerators because of the longitudinal rf electric field which imparts the accelerating force to the charged particle beam, equivalent resonant LRC circuit. Design of a linear accelerator using the TM010 mode in cylindrical cavities placed in tandem as well as RHIC. Examples of high power RF components and systems

11/06/24 Lecture 19 + 11/11/24 Lecture 20 (Binping & Wencan): Detailed design and simulation (2D and/or 3D simulation tools) of particle accelerators using the TM010 mode in cavities Take home project

11/13/24 Lecture 21 (Wencan)+ 11/18/24 Lecture 22 (Wencan): High power RF amplifiers: tetrode amplifiers, klystrons, traveling wave tube (TWT) amplifiers (popular in high-power RF transmitters, satellite transponders, radars, etc.)

11/20/24 Lecture 23 (Wencan): Other high power RF amplifiers and generators, solid-state amplifiers, solid-state oscillators, magnetrons

11/25/24 Lecture 24 + 12/02/24 Lecture 25 (Binping & Wencan): Hands on experience of RF components.

12/04/24 Lecture 26 & 12/09/24 Lecture 27 (Parekh): Applications of high-power RF, including microwave ovens, broadband jamming, electronic warfare, pulsed radar, RF transmitters and receivers, food processing industry, industrial heating and drying, etc

Final exam (Parekh, Binping, Wencan)