ESA STUDY CONTRACT REPORT SUBJECT : CONTRACTOR ESA CONTRACT N

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1 ESA STUDY CONTRACT REPORT ESA CONTRACT N SUBJECT : 100W Q/V-BAND TRAVELLING WAVE TUBE ESA CR ( ) No * STAR CODE No of volumes : 1 This is volume No 1 CONTRACTOR Thales Electronic Systems GmbH Executive Summary ABSTRACT : This report describes the feasibility study of a 100W Q/V Band tube. The necessity of such a tube is due to the fact the the Ku and Ka Band is nearly fully occupied and the trend goes to new services and higher data rates. The next available frequency band is the Q-Band whereas today the experience on travelling wave tubes in this frequency band is low. The feasibility study was divided into four phases. In the first two phases, named technology definition and evaluation phase, available technologies were discussed and evaluated. The next phase was to simulate the design of such a travelling wave tube. Each single component (gun, delay line and collector) was considered and simulated on the given physical constraints. In order to verify the design a Breadboard was built up and due to the tiny delay line pre-housed. The Breadboard showed very promising electrical results. The work described in this report was done under ESA contract. Responsibility for the contents resides in the author or organization that prepared it. Names of authors : D. Kupidura NAME OF ESA STUDY MANAGER ESA BUDGET HEADING DIV : DIRECTORATE : All information contained in this document remains the sole and exclusive property of Thales Electronic Systems GmbH and shall not be disclosed to third party by the recipient and shall only be reproduced in whole or in part with the prior written consent of Thales Electronic Systems GmbH or in accordance with the terms of ESA Contract

2 Issue: - Date: Page: 1 of 9 100W Q/V-BAND TRAVELLING WAVE TUBE (ESA CONTRACT ) EXECUTIVE SUMMARY REPORT Thales Electronic Systems GmbH Söflinger Straße Ulm (Germany) Prepared D. Kupidura Date: Project Management E. Wünsche Date: Configuration Management R. Weber Date: Quality Assurance T. Hilble Date: This document has been configured electronically and is valid without handsignature The THALES configuration management department certifies that this document has been approved by this responsible people Date:

3 100W Q/V-BAND TRAVELLING WAVE TUBE Page: 2 of 9 CHANGE RECORDS Issue Date Change- No. Reason for Change First release - In the case of changes this document will be completely reissued Applicable references and documents: [AD01] Contract N [AD02] Technical proposal AO /09/NL/GLC which contains a preliminary specification [AD02] ESA ECSS specifications: Q-ST-70C: Materials, mechanical parts and processes [RD01] Technical report :100W Q/V-Band Travelling Wave Tube. Phase 1 Task 3 : preliminary design report [AD03] 100W Q Band BREADBOARD TEST REPORT

4 100W Q/V-BAND TRAVELLING WAVE TUBE Page: 3 of 9 Table of contents General introduction and task assignment Assignment of the task... 5 Gun... 5 Delay Line... 5 Collector... 5 Housing Solution proposed... 6 Introduction and available designs Target Market Competition Milestones of the program... 9 List of figures Figure 1 Figure 2 Figure 3 Schematic view of a TWT 6 Proposed Work Flow 7 Targeted frequency and power range for today 8 List of abbreviations BB: Breadboard (EBB: Electrical Breadboard) BW: Bandwidth TED: Thales Electron Devices

5 100W Q/V-BAND TRAVELLING WAVE TUBE Page: 4 of 9 General introduction and task assignment In the last years of rapidly on-going development in satellite applications the required output power of Travelling Wave Tubes (TWTs) has steadily increased. At the same time, it is desired to extend the high output power to frequency ranges in Q-Band for the next commercial communication band, inter-satellite communication as well as for scientific purposes. The reason for this trend is on one hand the increasing usage of lower frequency bands and on the other hand the necessity of faster communication between the satellites as the information density grows. Latest discussions with our customers show their substantial interest on a TWT operating in Q-Band with a power capability in range of 60W up to 100W In order to cover this customer need TED propose in close cooperation with the Agency to develop a complete new high-power and high-frequency space TWT having output power in range of 100W and operation frequency in Q-Band. Gun The gun discussed here is linked to the high power requirement by the usage of very high voltage (18kV in margin case) and uses modified standard space ceramic stack gun. This electrical aspect has been verified at test vehicle and TWT level. Moreover the gun has to bee optimized for high beam current densities and shall be verified by means of a dedicated test vehicle (Beam-Tester) and finally at TWT level. Delay line The technology neede here will address higher output power and hence thermal requirments. The mechanical feasibility and thermal dissipation capability shall be demonstrated by usage of dedicated test vehicles (e.g. DC-Tester) and finally verified at BB level. Collector The needed collector here is completely new solution dedicated to be capable of about 18kV high voltage (margin case) and increased thermal dissipation capability. It shall use a new rod material. The high voltage aspect shall be demonstrated at sub-assembly level as well as at Beam-Tester level and finally at BB level. Housing Within the frame of the feasibility study no final housing shall be addressed and the solution proposed is only preliminary one. The major fuction of this part is to support mechanically the TWT and other topics and especially thermal aspect and environmental aspects cannot be addressed here.

6 100W Q/V-BAND TRAVELLING WAVE TUBE Page: 5 of 9 1. Assignment of the task Over the last years of on-going development and improvement of the Travelling Wave Tube (TWT) being a substantial part of the inter-satellite communication a clear direction has been observed and followed: increasing power and operation frequency. While the newest development in available frequency bands and especially Ku and Ka Band is clearly manifested by the running projects 300W Ku and 250W Ka Band another very interesting development pole became to play a role: medium and high power Q-Band space TWT. The interest on the high-power Q-Band space TWT with an output power in range of 100W and instantaneous bandwidth of 2GHz became finally more concrete in terms of Artes 5.1 ESTEC program. As the work aimed here is nothing less than a completely new developement every key part of the TWT shall be addressed here and especially: Gun The gun discussed here is linked to the high power requirement by the usage of very high voltage (in the range of 20kV in margin case). Another important aspect is the usage of very high density cathode for focusabiulity reasons. Delay Line The main technological task here is the thermal and electrical aspect. The mechanical feasibility and thermal dissipation capability shall be demonstrated by usage of dedicated test vehicles (e.g. DC-Tester) and verified at TWT level. Collector The needed collector here can be characterized shortly be the need for high thermal and high voltage capability. The high voltage aspect shall be demonstrated at sub-assembly level as well as at Beam-Tester level and finally at TWT level Housing Within the frame of the feasibility study discussed here there will be no final housing and the housing to be used is only preliminary one. The major fuction of this part is to support mechanically the TWT and other topics and especially thermal aspect and environmental aspects has not been addressed here. Finally an overall picture of the TWT can be presented as:

7 100W Q/V-BAND TRAVELLING WAVE TUBE Page: 6 of 9 Figure 1 Schematic view of a TWT 2. Solution proposed Introduction and available designs The performed internal investigation and patent survey delivers very clear result concerning the aim of space compatible 100W Q-Band TWT: dedicated new development with usage of previously gained experience. This result can be also stressed with respect to already available designs/twts: 40W medium-power space Q-Band TWT: power limited by the design (cathode current, stability for power >50W) 80W EHF high-power ground station TWT: space non-compatible technologies, low efficiency with drawback of relatively high mass 500W 30GHz design: very powerfull but uses space non-compatible materials 20W 60GHz space TWT limited in power via applicable voltages and thermal design not sufficient Hence the completely new and dedicated development is aimed for every key component of TWT: gun, delay line and collector as already indicated.

8 Following work flow shall be applied: Number: W Q/V-BAND TRAVELLING WAVE TUBE Page: 7 of 9 Phase I: Concept and first verification Phase II: Feasibility at sub-assembly level and first design proof Verification of gun design Beam Tester Thermal design verification DC Tester Design (partial) verification Beam Tester Phase III: Power feasibility at TWT level Building of BB Testing of BB Figure 2 Proposed Work Flow

9 3. Target Market Number: W Q/V-BAND TRAVELLING WAVE TUBE Page: 8 of 9 Targeted market is space TWT market for downlink in this new frequency bandwidth of Q- Band; the situation as seen for today can be represented by a following figure: Figure 3 Targeted frequency and power range for today And the idea is to address future application for the new Ka-Band: the discussed here Q- Band

10 100W Q/V-BAND TRAVELLING WAVE TUBE Page: 9 of 9 4. Competition As announced on the IVEC 2014 the L3 Company offers a Q-Band space TWT in the power class of 100W. Actual offer of the L3 company can be represented by: As this product seems directly linked to the ground station application (relatively large mass, low efficiency TWT 8905HP-6) TED strikes for dedicated space TWT having mass in range of 1100g and efficiency >50%. Light, flexible and powerful is TED answer to competitors. 5. Milestones of the program The goal of the development is clearly addressing the market needs. Therefore the feasibility of a 100W Q-Band tube is shown within this project. The next logical step is to develop the bricks for such a high power/ high frequency tube.