1. The Development of the Microwave Vacuum Electronics at BVERI
Fujiang Liao and Jinjun Feng
Beijing Vacuum Electronics Research Institute
Vacuum Electronics National Lab
July 14th, 2010

2. Outline Introduction Microwave Power Module ( MPM )
The Microwave Integrated Vacuum Electronics
Teraherz Vacuum Electron Devices

3. Introduction
Recent years as the phase array antenna system and wide band-gap semiconductor devices develop, some system engineers doubt if the microwave vacuum electron tubes will be replaced by the wide band gap semiconductor devices? What is the directions of the vacuum electron devices for the future?
We try to answer this question and intro-duce some work we are doing.

4. The directions of Microwave Vacuum Electron Devices
Some directions of microwave vacuum elec- tron device developments should be:
Microwave Power Module ( MPM );
The microwave integrated vacuum electron devices;
Gyrotron
Teraherz Vacuum Electron Devices.

5. Microwave Power Module ( MPM )
MPM consists of solid state amplifier, electric power conditioning and vacuum electron power booster.
MPM will be used in the phase array antenna system to support the military equipment with low cost microwave power devices.
Next figure shows the MPM picture and small size vacuum electron power booster (mini-TWT).
This small size power booster is the core of MPM.

6. Microwave power module
MPM
Solid State Amplifier
Vacuum Power Booster
EPT
Microwave power module

7. the phase array antenna system

8. the phase array antenna system
We are trying to use MPM into the active phase array antenna system to replace the semiconductor T/R module. The key techniques are to reduce the power output and the working voltage of TWT. It needs also to reduce the TWT size.
One task is to make the plane TWTs.

9. Fabrication of slow-wave-structure
Miniaturized TWTs
Fabrication of slow-wave-structure
for mini TWT
Dielectric stud support with metal vane helix slow-wave structure are developing at BVERI by welding and laser cutting with the support of National key laboratory of high power vacuum electronics .

10. A plane TWT
The Meander line is used to as slow wave structure for plane TWT.
PBG material is to use to replace the ceramic substrate to support the
Meander line slow
wave structure.

11. Vacuum Micro Electronics Device
With the field emission array cathode, the mini TWT can be fabricated.
Next picture shows the field emission array cathode with DC current density 10A/cm2 made in BVERI.

12. Vacuum Micro Electronics Device
Field Emission Array Cathode
Put Field Emission Array Cathode into
the Traveling Wave Tube.

13. Microwave Integrated Vacuum Electronics Devices
Microwave integrated vacuum electron device is made with 3D-MCM technique. Mini TWTs, SSA, phase shifters, filters and EPC are all integrate in the ceramic substrate.
Next picture shows the microwave integra-ted vacuum electron device.

14. Microwave Integrated Vacuum Electronics Devices
RF Input
Attenuator
Phase shifter
SSA
gun
Collector
Power out
gun
Collector
EPC

15. Optical Control TWTs
Optical beam and RF input
Picture shows the optical control TWT. Microwave is modulated on the optical beam. Then the optical beam is put on the photoelectron cathode to make the electron emission.
No RF input here
This electron current is microwave modulated. It will make interaction with RF structure of TWT to make signal amplification.

16. Gyrotron
Gyrotron can be worked at Ka band and above. We are doing some research work on the gyrotron at Ka band and W band.
Ka band gyro-TWT made in China

17. Teraherz Vacuum Electron Devices
TH vacuum electron device works at more than 300GHz. The folded waveguide TWT, Meander line or helix TWTs are also developed at 100, 140, 220GHz.

18. Structures using micro-fabrication

19. Conclusion
Professor Carter worked in the vacuum electronics field for more than 40 years and made great contributions in it. We believe that he concern the directions of microwave vacuum electronics.
Microwave vacuum electronics is very important devices for military and civilian application in the next 20 years.
Microwave vacuum electronics will combi- ne with microelectronics, optoelectronics to form some new devices.

20. The End
Thanks!