TRANSISTOR-BASED MINIATURE MICROWAVE HEATER

摘要

This paper describes a solid-state amplifier implementation in a small-scale microwave heating. The miniature heater employs an LDMOS-transistor amplifier in an oscillator scheme, in which the heating applicator is incorporated in the positive feedback loop. The paper presents the conceptual design and the experimental results of a 20-W transistor-based microwave heater for biological tests at 2.14 GHz. The applicator contains a test tube of <1-cm{sup}3 volume filled with proteins heated to temperatures up to 40°C (controlled by the transistor's DC bias). This heater is used in a study of the effect of microwave radiation on the time resolved luminescence of green fluorescence protein (GFP). The paper discusses also the availability of high-power microwave transistors and their applicability for future transistor-based microwave heaters.