Millimeter-Wave Band Multi-Mirror Open Resonator. E- and H- Polarized Oscillations
This work provides the experimental research results of E- and H-polarized oscillations of the complex multi-mirror open resonator (OR) , one of the mirrors of which is represented by the echelette reflective grating. The essential difference between the spectra of E- and H- polarized oscillations of complex open resonator (COR) is noted. It is evident that within the range of measurements performed for the H-polarization, only one oscillation mode is excited while in the case with the E-polarization there are excited several of such modes. In this case the self-collimation reflection from the echelette grating determines the conditions for excitation of the OR, which condition is the dispersive element forming up the OR spectrum. Some functional capabilities implied by the design of the suggested multi-mirror open resonant system are also discussed. The suggested multi-mirror open resonant system can find wide application in millimeter-wave band electronics for frequency stabilization of the electron-vacuum and solid-state devices.
Millimeter wave band open resonators with additional restriction of resonant space
Electromagnetic characteristics of open resonators with a bounded region beside one of the mirrrs are presented. The unknown previously modes are studied and classified. It is the quasi-fundamental modes, associated modes and echelette-echelette oscillations. This result may be used for the applicaiton in the elaboration of oscillation systems of mm-wave devices.
THE PERFORMANCE OF STEADY DETONATION ENGINES
Propulsion systems driven by steady normal detonations are studied. The practical di‐culties associated with stabilizing a detonation wave are highlighted. The requirement on the freestream total enthalpy is considered in parallel with efiects such as condensation or auto-ignition of the fuel-air mixture and limitations associated with fuel sensitivity to detonation. A criterion for detonation stabilization is formulated and applied to an analytical treatment of a detonation ramjet and a detonation turbojet, which are the respective analogs of the ramjet and the turbojet using detonative combustion. The performance of these engines is evaluated and compared to the ideal ramjet and turbojet models for hydrogen and JP10. A limitation is placed on the maximum total temperature allowed in the combustor, based on material considerations. The results show that steady detonation engines have a small thrust-producing range, due to the requirements for detonation stabilization. Their performance is always lower than that of the conventional ramjet and turbojet because of the total pressure loss across the detonation.