European Space Agency

Objectives

A new waveguide interface WR340 ¼ height will extend the portfolio for todays high power S-Band travelling wave tubes (TWTs) from THALES. The interface will have high reliability since no dielectrics inside the interface is used. The interface is common for all radiation cooled and conduction cooled TWTs and is extendable for future developments with higher power levels. The material and technology is used from other frequency bands with long heritage.

The objective of the project is to develop a WR 340 ¼ height waveguide interface for standard high power S-Band travelling wave tubes (TWTs) with one design for conduction cooled as well as for radiation cooled TWTs. A key issue is to avoid any dielectric in the waveguide interface which could cause out gassing and reliability problems for RF power above 250W.


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Challenges

  • Robust low-loss interface with high reliability,
  • Material and technology with heritage from other frequency bands,
  • Improvement of multipaction margin for higher power levels,
  • High temperature range,
  • Low weight.

Benefits

The new waveguide interface WR340 ¼ height is a consequent enhancement of the THALES product portfolio for high power S-Band TWTs. The interface has a high reliability due to no dielectric used inside the interface and an inductive coupling with excellent cooling for the inner conductor. A high multipaction margin was reached and the interface is extendable for future developments with higher power levels. The material and the technology were used from other frequency bands and have a long heritage inside THALES.

Features

The development should replace on standard high power TWTs the coaxial output interfaces like TNC and SC. Both coaxial interfaces have dielectrics inside which could cause out gassing and reliability problems for RF power level above 250W. Following main features has been combined in the new development:

  • Low weight: WR340 ¼ height waveguide interface with top orientation has been used to arrange a weight impact of the complete waveguide below 200g for radiation cooled TWTs and below 230g for conduction cooled TWTs,
  • Material and technology with heritage from other RF bands,
  • Frequency range from 2.16 GHz to 2.67 GHz,
  • No dielectrics inside interface,
  • Inductive coupling for ideal cooling,
  • Same Interface for conduction cooled TWTs and for radiation cooled TWTs,
  • Extendable for future TWTs with higher power levels with excellent multipaction margin.

Specification values for qualification:

Mechanical interfaces
Mass g 1705g CC / 2400g RC
TWT baseplate temp
Qualification  °C  -20°C min / +95°C max
Cold start (accept.)  °C  -30°C
Cold start (qual.)  °C  -35°C
Space Environment  (RC TWT)
Acceptance  °C -180°C min. / +105°C max.
Qualification  °C -180°C min. / +110°C max.
Vibration Levels (qualification)
z- Axis   17.4 grms RC / 22.5 grms CC
x- and y- Axis   12.5 grms RC / 17.4 grms CC
Shock Levels
    200 Hz               140 g
    4000 Hz             4000g
    10000 Hz           4000g

 

Plan

Qualification and Mission Life Test successfully performed

Current status

Completed

Status date

Monday, November 21, 2011 - 13:14