摘要 |
A planar transformer comprises an insulating or semiconductor substrate 1, such as gallium arsenide, in which the primary and secondary conductor turns of spiral configuration are formed at different levels within a dielectric layer 2,3 applied to the substrate. This configuration enables the primary and secondary conductor turns to be located in closer proximity than known co-planar designs, thereby providing improved magnetic coupling between the conductors. Furthermore, the width of the conductor turns can be increased, thereby providing a further improvement in the magnetic coupling and enabling a reduction in the resistive loss of the conductor turns. <IMAGE> |