Popis: |
A rugged, compact, battery-powered millimeterwave (mm-wave) radar has been developed by using a prototype orbitron maser as the source. The orbitron maser was found suitable for such an application since it is high power, wideband (thus multi-channel) and frequency tunable. The radiation emanating directly from the tube was fairly uniform and the divergence angle (100) was diffraction-limited. The orbitron pulse had a fast risetime (10Ons), short pulsewidth (500ns) and no spurious oscillations. The orbitron output power was 6.7W minimum (possibly ~6.7kW due to the detector saturation and 400kW input power) at the V-band (50-75GHz). The power levels were similar at lower bands and constant up to 10Hz of repetition frequency. An innovative DC-DC converter was used to amplify 24V of battery potential up to 1000 times. The orbitron maser was characterized by simultaneous measurements of the applied voltage, discharge current (thus input-power and plasma-resistance), luminousity and wave signal. A linear scaling law was found for the mm-wave power to increase with the discharge current. Output power with hydrogen was twice to that observed with air or nitrogen working gases. |