| 摘要 |
An radio frequency (RF)/microwave power amplification circuit is disclosed herein having improved power and frequency characteristics. The RF power circuit is characterized by having the output capacitance of the device resonate with a shunt inductance that is physically closer to the device than provided in conventional RF power circuits. This is realized by mounting a direct current (DC) bypass capacitor directly on the same metalized pad that the device terminal is mounted on. By doing this, the inductance associated with a wire bond connection from the device to the capacitor is eliminated or at least reduced. Also disclosed is a dual cell power circuit that consists of matching the impedance characteristics of the active cells to each other by adjusting the circuit parameters in which the active devices interact with. In addition, an RF power circuit is disclosed that includes a pair of vertical cells in a parallel relationship formed on a thin semiconductor to cause more current flow through a metal layer rather than the lossy substrate. Furthermore, a novel metal-dielectric-metal chip capacitor is disclosed that is fabricated on a refractory metal substrate, which results in a high quality factor (Q) for the capacitor. The capacitor has contacts to both capacitor plates by way of its top metallization surfaces, and access to one of the plates through the bottom, i.e. the mounting surface of the capacitor. Additionally, a high power device is disclosed that encompasses at least some or all of the techniques described above to achieve an amplification that exhibits both high power and high cutoff frequency characteristics. |
