Journal Article

PUBDB-2020-04936

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Results on FPGA-Based High-Power Tube Amplifier Linearization at DESY

Bellandi, A. (Corresponding author)DESY* ; Ayvazyan, V.DESY* ; Butkowski, L.DESY* ; Cichalewski, W.Extern* ; Dursun, B.DESY* ; Gumus, C.DESY* ; Omet, M. ; Pfeiffer, S.DESY* ; Onken, R.DESY* ; Rybaniec, R. ; Schmidt, C.DESY* ; Vogel, V.DESY* ; Branlard, J.DESY*

2020
IEEE New York, NY

This record in other databases:    

Please use a persistent id in citations: doi:10.1109/TNS.2020.2980929

Abstract: Vacuum-tube amplifiers are the most widespread type of radio frequency (RF) sources used to produce high-power signals needed for beam acceleration in superconducting cavities. At Deutsches Elektronen-Synchrotron (DESY), megawatt-rated klystrons are used to produce millisecond-long RF shots for pulsed operation in particle accelerators. In contrast, inductive output tubes (IOTs) are used to provide a continuous RF signal for continuous-wave (CW) operation. In both cases, the amplifiers suffer from amplitude-dependent nonlinearity between the driving and generated signals. This nonlinearity complicates the setup operations of the low-level RF (LLRF) system and makes it harder to regulate the accelerating field. Therefore, a way to linearize the amplifier is highly valuable. This article covers the design, implementation, and test of a field-programmable gate array (FPGA)-based predistortion linearization unit. The first results on the performance of this component in linearizing the amplifiers of running CW and pulsed superconducting accelerators are presented. Such a component uses programmable interpolating lookup tables (LUT) that are addressed using the squared value of the requested signal amplitude. This component only adds 64-ns latency to the RF control system without relying on any vendor-dependent FPGA component. Other benefits of using programmable interpolating LUT are low usage of FPGA resources and flexibility in terms of the type of amplifier to be corrected. The benefits of using this linearizer for klystrons and IOTs are presented and quantified.

Note: Waiting for fulltext

---

Contributing Institute(s):

1. Strahlkontrollen (MSK)
2. MHFp Fachgruppe 4 (MHFp)
3. HF-Technik Elektronen (MHFe)

Research Program(s):

1. 631 - Accelerator R & D (POF3-631) (POF3-631)

Experiment(s):

1. Facility (machine) XFEL

Appears in the scientific report 2020

---

Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---