High Powered Electro Magnetic (HPEM) Amplifiers to generate smart waveforms for long range in band Radio Frequency effects
Abstract
High power microwave devices are typically based on ‘Free Electron Physics’, whereby a powerful EM wave is formed by synchronous bunching and subsequent deceleration of an electron beam. Fast wave devices, particularly cyclotron resonant masers break the conventional Pf 2 scaling rule where P is the output power and f is the frequency, which implies that for a given technology as the frequency increases by a factor of 10, the power may typically be expected to fall by a factor of 100. Specifically a cyclotron maser introduces a inherent resonance in the electron beam (the cyclotron frequency) that eases the requirement for the microwave circuit to exclusively define the frequency this allows the microwave circuit to be very much larger, and with less detailed structure, than in slow wave devices for any given frequency. This enables typically two orders of magnitude uplift in peak and-or average power due to the reduced load (either in terms of E field or dissipated power density) on the circuit components. In addition, A recent breakthrough, led by research at Strathclyde, has introduced a weak, 3 fold, helical corrugation into a nominally cylindrical waveguide wall to synthesise waveguide modes having high, constant, group velocity with near infinite phase velocity. This has enabled efficient (30%), high power (1.1MW) wideband amplifiers (8.4 10.4 GHz) with high gain (47dB linear, 37dB saturated) and high stability against oscillation. A similar approach is used to develop a dispersive pulse compressor based on the same waveguide structure. This accomplished tuning frequency and length near 10GHz producing power compression factors of 25 are realisable, for chirped pulses.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 14, 2022
- Source ID
- FA95501917011
Entities
People
- Kevin Ronald
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Strathclyde