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Broadband millimeter wave power generation using integrated circuits

Yoke Choy Leong, University of Massachusetts Amherst


Broadband, millimeter-wave signals can be generated by using frequency multipliers that are cascaded by broadband power amplifier at the output. This approach has the potential to generate an electronically tunable signal with adequate output power over a wide range of frequencies. In this work, important issues including device modeling, broadband amplifier design and frequency tripler design are investigated. New equations for modeling the drain current, the gate-source and the gate-drain capacitances for HEMT have been proposed. The parameters of the proposed drain current model can be extracted directly and the parameters of the capacitance models can be estimated directly. This results in a fast and efficient parameter extraction process. The new capacitance models ensure that the nonlinear model is consistent with the common small-signal equivalent circuit model along a resistive load line in the IV plane. Since the common small-signal equivalent circuit model has been successfully used in MMIC designs up to 200 GHz, consistency between the models will ensure that the nonlinear model is valid along the known resistive load line at millimeter-wave frequencies. Good agreement between modeled and experimental measurements has been achieved by using the new model on three different HEMT devices. On the design of the broadband power amplifier, a systematic design procedure has been outlined to ensure sufficient power drive for all stages of amplification across the range of frequency of operation. A full W-band MMIC medium power amplifier has been designed by using this procedure. The fabricated chip delivers between 25 mW and 43 mW of power across 75 GHz to 110 GHz. This is the first MMIC amplifier that could deliver such power across the entire W-band. On the design of the active frequency tripler, a new topology that is based on using three-phase signals has been proposed. It has been theoretically shown that the output of this tripler will have good suppression of unwanted harmonic components. An experimental MMIC tripler shows that better than 18 dB of suppression of the fundamental and second harmonic component has been achieved when the output frequency of the tripler is between 42 GHz and 42.7 GHz.

Subject Area

Electrical engineering

Recommended Citation

Leong, Yoke Choy, "Broadband millimeter wave power generation using integrated circuits" (2000). Doctoral Dissertations Available from Proquest. AAI9988814.