Source Module Based on Diodes-Multipliers to Extend Signal Generator Capability from 140 GHz to 220GHz

The paper has designed and analyzed a source module based on diodes-multipliers which extended a microwave signal generator capability from 140 to 220GHz. Considering the current level of the component, especially for millimeter amplifier, the source module adopted ×2×3×2 multipler chain. A commercial synthesizer source produces 11.6 - 18.4GHz signal via doubler producing I-2mW signal in 23.2-36.8GHz signal amplified by a 23.2-36.8GHz power synthesizing amplifier producing 300-400mW signal to drive a broadband tripler producing 70-110 GHz signal, and driving 140-220GHz doubler directly. The approach of spatial power-combining was introduced to the 70-110 GHz tripler design, which is fabricate by two mirror-image circuits without dielectric material and each circuit have two devices containing four diodes achieving high efficiency and power handling. It produced more than 25mW output power in 70-110GHz with 300-400mW input power. The 140-220GHz doubler is the last stage of the multiplier chain, also, whose efficiency with 300-400mW input power is the key to ensure the 140-220GHz source module. It was designed with split waveguide blocks which seat a T-type series diodes in the reduced output waveguide comparing with the standard topology which seat the anti-parallel diode in reduced-height input waveguide having high efficiency. The efficiency of the doubler is more than 6% in 140-220 GHz and the peak is 11 %. Finally, the source module can produce more than 2mW output power in 140-220 GHz which is measured by millimeter and submillimeter power meter PM-5.