| 摘要 |
PURPOSE:To reduce the parasitic capacitance of a spiral inductance to nearly 1/3-1/5 of the conventional inductance by removing a ground conductor beneath the spiral inductance and providing a hole at a case placed beneath the inductance. CONSTITUTION:The hole left after the ground conductor beneath the spiral inductance is removed is shown in caption 8, and the hole provided to the case placed beneath the spiral inductance is shown in caption 9. An example of the frequency versus gain characteristic of a microwave band amplifier through the constitution above and an example of the frequency versus gain characteristic of the microwave band amplifier through a conventional constitution are shown in figure. Curve (b) shows the frequency versus gain characteristic of the microwave band amplifier of this constitution, the gain is nearly 20dB at 1.5-2.0GHz, which is well coincident with the calculation value. Curve (c) indicates the example of frequency versus gain characteristic of the microwave band amplifier through the conventional constitution. The change in the frequency characteristic is decreased. |
