Most spatial magnetron development has been done at 35 GHz, 94 GHz, 140 GHz and 210 GHz. Despite many RADAR development activities at 77 GHz, no vacuum electron devices are available at 77 GHz. We have designed the 77 GHz micro magnetron, which can be an excellent source for medical imaging and RADARs. The compact and efficient millimetre wave magnetron enables imaging experiments for the detection of superficial cancers, concealed weapons and drugs, space debris/airborne objects, etc.
We are working on field emitters to achieve a very high current density from a smaller cathode for beam wave interaction in micro magnetrons. We have secured a grant to develop field emitter for magnetron and cross field amplifiers from the swedish innovation agency i.e. Vinnova with PercyRoc AB Uppsala Sweden. During the MSCA project, we secured new grants for future research on amplifier variants of magnetron from the Horizon 2020 I Fast CERN Research and Innovation program under Grant Agreement No. 101004730 and field emitters from the Vinnova Sweden Innovation agency.
Related with micro-magnetron Funding secured Funding Agency
Amplifier Variant of micro-magnetron 200.000 Euro European Union
Cathode of magnetron 150.000 SEK Vinnova Swedish Innovation agency
The slow wave structure of Cross field amplifier and field emitter with setup is shown in Figure 9 and Figure 10 respectively.
We are also working on a novel megawatt-class 750 MHz Cross-Field Amplifier that has improved performance metrics such as gain, efficiency, phase stability, and longevity. The development of the megawatt-class 750 MHz Cross-Field Amplifier involved comprehensive eigenmode simulations, particle-in-cell simulations, fabrication and experimental validation. Figure 9 (Left) shows the fabricated slow-wave structure, designed after optimising geometric parameters to support operation at 750 MHz. The performance of the structure was verified through S-parameter measurements, with S11 data shown in Figure 9 (Right). The result reveals a minimum reflection at 750 MHz with -15.51 dB, confirming proper impedance matching and successful frequency tuning. This low reflection signifies minimal power loss and validates the accuracy of the simulation-guided design.
In parallel, work on advanced field emitters focused on developing compact, high-current-density electron sources for integration into high-power vacuum devices. Figure 10(a) illustrates the electric field distribution of the emitter under a 30 kV potential difference, highlighting uniform field enhancement across the emitter tips, which is essential for stable electron emission. Figure 10(b) presents a 3D-printed field emitter prototype developed at Uppsala University, demonstrating the viability of additive manufacturing for precise, scalable cathode designs. Finally, Figure 10(c) shows the anode-cathode assembly chamber, where experimental testing of the field emitter setup is performed.
Together, these developments strengthen the technological foundation for next-generation high-power microwave amplifiers and compact electron sources, supporting various applications in communication, diagnostics, and defence systems.
